[Federal Register Volume 88, Number 113 (Tuesday, June 13, 2023)]
[Proposed Rules]
[Pages 38632-38736]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-11863]
[[Page 38631]]
Vol. 88
Tuesday,
No. 113
June 13, 2023
Part III
Department of Transportation
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National Highway Traffic Safety Administration
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49 CFR Parts 571 and 596
Federal Motor Vehicle Safety Standards: Automatic Emergency Braking
Systems for Light Vehicles; Proposed Rule
Federal Register / Vol. 88 , No. 113 / Tuesday, June 13, 2023 /
Proposed Rules
[[Page 38632]]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Parts 571 and 596
[Docket No. NHTSA-2023-0021]
RIN 2127-AM37
Federal Motor Vehicle Safety Standards: Automatic Emergency
Braking Systems for Light Vehicles
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This NPRM proposes to adopt a new Federal Motor Vehicle Safety
Standard to require automatic emergency braking (AEB), including
pedestrian AEB (PAEB), systems on light vehicles. An AEB system uses
various sensor technologies and sub-systems that work together to
detect when the vehicle is in a crash imminent situation, to
automatically apply the vehicle brakes if the driver has not done so,
or to apply more braking force to supplement the driver's braking. The
AEB system proposed in this NPRM would detect and react to an imminent
crash with a lead vehicle or pedestrian. This NPRM promotes NHTSA's
goal to equip vehicles with AEB and PAEB, and advances DOT's January
2022 National Roadway Safety Strategy that identified requiring AEB,
including PAEB technologies, on new passenger vehicles as a key
Departmental action to enable safer vehicles. This NPRM also responds
to a mandate under the Bipartisan Infrastructure Law directing the
Department to promulgate a rule to require that all passenger vehicles
be equipped with an AEB system.
DATES: Comments must be received on or before August 14, 2023.
Proposed compliance date: Vehicles manufactured on or after
September 1, four years after the publication date of a final rule,
would be required to meet all requirements. Vehicles manufactured on or
after September 1, three years after the publication date of a final
rule, but before September 1, four years after the publication date of
a final rule, would be required to meet all requirements except that
lower speed PAEB performance test requirements specified in S5(b) would
apply. Small-volume manufacturers, final-stage manufacturers, and
alterers would be provided an additional year (added to those above) to
meet the requirements of the final rule. Early compliance is permitted
but optional.
ADDRESSES: You may submit comments to the docket number identified in
the heading of this document by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the online instructions for submitting
comments.
Mail: Docket Management Facility, M-30, U.S. Department of
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery or Courier: West Building, Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, between 9 a.m. and 5 p.m.
Eastern Time, Monday through Friday, except Federal holidays. To be
sure someone is there to help you, please call 202-366-9332 before
coming.
Fax: 202-493-2251.
Regardless of how you submit your comments, please provide the
docket number of this document.
Instructions: For detailed instructions on submitting comments and
additional information on the rulemaking process, see the Public
Participation heading of the Supplementary Information section of this
document. Note that all comments received will be posted without change
to https://www.regulations.gov, including any personal information
provided.
Privacy Act: In accordance with 5 U.S.C. 553(c), DOT solicits
comments from the public to better inform its decision-making process.
DOT posts these comments, without edit, including any personal
information the commenter provides, to www.regulations.gov, as
described in the system of records notice (DOT/ALL-14 FDMS), which can
be reviewed at www.transportation.gov/privacy. In order to facilitate
comment tracking and response, the agency encourages commenters to
provide their name, or the name of their organization; however,
submission of names is completely optional. Whether or not commenters
identify themselves, all timely comments will be fully considered.
Docket: For access to the docket to read background documents or
comments received, go to www.regulations.gov, or the street address
listed above. To be sure someone is there to help you, please call 202-
366-9332 before coming. Follow the online instructions for accessing
the dockets.
FOR FURTHER INFORMATION CONTACT: For non-legal issues: Markus Price,
Office of Crash Avoidance Standards (telephone: 202-366-1810). For
legal issues: David Jasinski, Office of the Chief Counsel (telephone:
202-366-2992, fax: 202-366-3820). The mailing address for these
officials is: National Highway Traffic Safety Administration, 1200 New
Jersey Avenue SE, Washington, DC 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
II. Safety Problem
A. Overall Rear-End Crash Problem
B. Rear-End Crashes by Vehicle Type
C. Rear-End Crashes by Posted Speed Limit
D. Rear-End Crashes by Light Condition
E. Rear-End Crashes by Atmospheric Conditions
F. Pedestrian Fatalities and Injuries
G. Pedestrian Fatalities and Injuries by Initial Point of Impact
and Vehicle Type
H. Pedestrian Fatalities and Injuries by Posted Speed Limit
Involving Light Vehicles
I. Pedestrian Fatalities and Injuries by Lighting Condition
Involving Light Vehicles
J. Pedestrian Fatalities and Injuries by Age Involving Light
Vehicles
K. AEB Target Population
III. Data on Effectiveness of AEB in Mitigating Harm
IV. NHTSA's Earlier Efforts Related to AEB
A. NHTSA's Foundational AEB Research
1. Forward Collision Warning Research
2. AEB Research To Prevent Rear-End Impacts With a Lead Vehicle
3. AEB Research To Prevent Vehicle Impacts With Pedestrians
4. Bicycle and Motorcycle AEB
B. NHTSA's New Car Assessment Program
1. FCW Tests
2. Lead Vehicle AEB Tests
3. PAEB Test Proposal
C. 2016 Voluntary Commitment
D. Response To Petition for Rulemaking
V. NHTSA's Decision to Require AEB
A. This Proposed Rule Is Needed To Address Urgent Safety
Problems
B. Stakeholder Interest in AEB
1. National Transportation Safety Board Recommendations
2. Consumer Information Programs in the United States
3. Petition for Rulemaking on PAEB Performance in Dark
Conditions
C. Key Findings Underlying This Proposal
1. Impact Speed Is Key to Improving AEB's Mitigation of
Fatalities and Injuries
2. Darkness Performance of PAEB Is Highly Important
3. NHTSA's 2020 Research on Lead Vehicle AEB and PAEB
Performance Show the Practicability of Higher Speed Tests
a. Lead Vehicle AEB Performance Tests
b. PAEB Daytime Performance Tests
c. PAEB Darkness Performance Tests
d. PAEB Darkness Performance Tests With Overhead Lighting
4. This Proposed Standard Complements Other NHTSA Actions
VI. Proposal To Require Automatic Emergency Braking
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A. Lead Vehicle AEB System Requirement
B. Forward Collision Warning Requirement
1. FCW Modalities
2. FCW Auditory Signal Characteristics
3. FCW Visual Signal Characteristics
4. FCW Haptic Signal
C. Lead Vehicle AEB--Performance Test Requirements
1. Stopped Lead Vehicle Scenario Test Speeds
2. Slower-Moving Lead Vehicle Scenario Test Speeds
3. Decelerating Lead Vehicle Scenario Test Speeds
4. Subject Vehicle Brake Application
D. PAEB System Requirement
E. PAEB--FCW Requirement
F. PAEB--Performance Test Requirements
1. PAEB Scenario Descriptions
2. Overlap
3. Vehicle and Pedestrian Surrogate Travel Speeds
4. Crossing Path Scenario Testing Speeds
5. Stationary Scenario Testing Speeds
6. Along Path Scenario Testing Speeds
7. PAEB Darkness Testing
G. Alternatives to No-Contact Performance Test Requirement
H. False Activation Requirement
1. Steel Trench Plate False Activation Scenario
2. Pass-Through False Activation Scenario
3. Potential Alternatives to False Activation Requirements
I. Malfunction Detection Requirement
J. AEB System Disablement
K. AEB System Performance Information
VII. AEB Test Procedures
A. AEB System Initialization
B. Travel Path
C. Subject Vehicle Preparation
D. Subject Vehicle Tolerance Specifications
E. Lead Vehicle Test Set Up and Tolerance
F. Test Completion Criteria for Lead Vehicle AEB Tests
G. PAEB Test Procedures and Tolerance
H. False Positive AEB Test Procedures
I. Environmental Test Conditions
J. Test Track Conditions
K. Subject Vehicle Conditions
VIII. Test Devices
A. Pedestrian Test Mannequins
1. Background
2. Mannequin Appearance
3. Color and Reflectivity
4. Radar Cross Section
5. Other Considerations
B. Vehicle Test Device
1. Description and Development
2. Specifications
3. Alternatives Considered
IX. Proposed Effective Date Schedule
X. Summary of Estimated Effectiveness, Cost, and Benefits
A. Target Population
B. Lead Vehicle AEB System Effectiveness
C. PAEB System Effectiveness
D. Fatalities Avoided and Injuries Mitigated
E. Costs
F. Cost-Effectiveness
G. Comparison of Regulatory Alternatives
XI. Regulatory Notices and Analyses
XII. Public Participation
XIII. Appendices to the Preamble
I. Executive Summary
In 2019, there were 6,272 pedestrian fatalities in motor vehicle
crashes, representing 17 percent of all motor vehicle fatalities.\1\
This represents the continuation of the recent trend of increased
pedestrian deaths on our nation's roadways.\2\ A further 76,000
pedestrians were injured in motor vehicle crashes. In addition, there
were nearly 2.2 million rear-end police-reported crashes involving
light vehicles, which led to 1,798 deaths and 574,000 injuries. Deaths
and injuries in more recent years are even greater. However, the
agency's analysis of the safety problem focuses on the calendar year
2019 because it is the most recent year without the prominent effect of
the COVID-19 pandemic.
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\1\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813079 Pedestrian Traffic Facts 2019 Data, May 2021.
\2\ Id., Table 1 Pedestrian fatalities 2010--4,302, 2019--6,272.
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This NPRM proposes to address this significant safety problem by
proposing a new Federal Motor Vehicle Safety Standard (FMVSS) to
require automatic emergency braking (AEB) systems on light vehicles
that are capable of reducing the frequency and severity of both rear-
end and pedestrian crashes. This proposed action represents a crucial
step forward in implementing DOT's January 2022 National Roadway Safety
Strategy (NRSS) to address the rising numbers of transportation deaths
and serious injuries occurring on this country's streets, roads, and
highways, including actions to protect vulnerable road users, including
pedestrians.\3\
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\3\ https://www.transportation.gov/sites/dot.gov/files/2022-01/USDOT_National_Roadway_Safety_Strategy_0.pdf.
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The Department's Safe System Approach emphasizes that multiple,
complementary safety interventions to prevent crashes are critical to
improving safety and protecting people. Through the NRSS, the
Department is focusing on advancing initiatives that will significantly
enhance roadway safety. These initiatives include infrastructure design
and interventions along with proposed vehicle regulations such as this
one. The Department is advancing support for the implementation of
Complete Streets policies to help transportation agencies across the
United States plan, develop, and operate roads, streets, and networks.
Complete Streets policies prioritize safety, comfort, and connectivity
to destinations for all users, including pedestrians, bicyclists, those
who use wheelchairs and mobility devices, transit riders, micro-
mobility users, shared ride services, motorists, and freight delivery
services. NHTSA is providing technical assistance to States to
encourage the adoption of a safe system approach with emphasis on
partnering with State Departments of Transportation and Emergency
Medical Service agencies to comprehensively address various roadway
issues including those affecting those who walk, bike and roll. NHTSA
awards annual formula grants to the States to conduct lifesaving
highway safety programs and is also assisting States as they conduct
meaningful public engagement to ensure that affected communities are
involved in program planning and implementation.
The crash problem that can be addressed by AEB is substantial.\4\
For example, 60 percent of fatal rear-end crashes and 73 percent of
injury crashes were on roads with posted speed limits of 60 mph or
below. Similarly, most of these crashes occurred in clear, no adverse
atmospheric conditions--72 percent of fatal crashes and 74 percent of
injury crashes. Also, about 51 percent of fatal and 74 percent of rear-
end crashes involving light vehicles resulting in injuries occurred in
daylight conditions. In addition, 65 percent of pedestrian fatalities
and 67 percent of pedestrian injuries were the result of a strike by
the front of a light vehicle. Of those, 77 percent, and about half of
the pedestrian injuries, occur in dark lighting conditions. This NPRM
proposes to adopt a new FMVSS to require AEB systems on light vehicles
that are capable of reducing the frequency and severity of both lead
vehicle and pedestrian collisions.\5\ AEB systems employ sensor
technologies and sub-systems that work together to sense when the
vehicle is in a crash imminent situation, to automatically apply the
vehicle brakes if the driver has not done so, and to apply more braking
force to supplement the driver's braking. Current systems primarily use
radar- and camera-based sensors, while there are also emerging systems
that use lidar and thermal sensors. These systems can reduce both lead
vehicle rear-end (lead vehicle AEB) and pedestrian crashes (PAEB).
Importantly, this proposal would require that systems are able to avoid
pedestrian crashes in darkness testing conditions. AEB systems have
[[Page 38634]]
reached a level of maturity such that they will be able to reduce the
frequency and severity of crashes and are thus ready to be mandated on
all new light vehicles.
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\4\ The Insurance Institute for Highway Safety (IIHS) estimates
a 50 percent reduction in front-to-rear crashes of vehicles with AEB
(IIHS, 2020) and a 25 to 27 percent reduction in pedestrian crashes
for PAEB (IIHS, 2022).
\5\ For the purpose of this NPRM, ``light vehicles'' means
passenger cars, multipurpose passenger vehicles (MPVs), trucks, and
buses with a gross vehicle weight rating of 4,536 kilograms (10,000
pounds) or less.
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This proposal is issued under the authority of the National Traffic
and Motor Vehicle Safety Act of 1966. Under 49 U.S.C. Chapter 301, the
Secretary of Transportation is responsible for prescribing motor
vehicle safety standards that are practicable, meet the need for motor
vehicle safety, and are stated in objective terms. The responsibility
for promulgation of FMVSSs is delegated to NHTSA. This rulemaking
addresses a statutory mandate under the Bipartisan Infrastructure Law
(BIL), codified as the Infrastructure Investment and Jobs Act
(IIJA),\6\ which added 49 U.S.C. 30129, directing the Secretary of
Transportation to promulgate a rule requiring that all passenger motor
vehicles for sale in the United States be equipped with a FCW system
and an AEB system.
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\6\ Public Law 117-58, 24208 (Nov. 15, 2021).
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The decision to mandate AEB builds on decades of research and
development, which began in the 1990s, with initial research programs
to support development of AEB technologies and methods by which system
performance could be assessed. NHTSA began testing AEB systems as part
of New Car Assessment Program (NCAP) in 2010 and reporting on the
respective research and progress surrounding the technologies shortly
thereafter.\7\ These research efforts led to the incorporation of AEB
into incentive programs designed to raise consumer awareness of AEB,
such as NCAP. NHTSA included FCW systems as a ``recommended advanced
technology'' in NCAP in model year 2011, and in November 2015, added
crash imminent braking (CIB) and dynamic brake support (DBS)
technologies to the program with assessments of these technologies to
begin in model year 2018.\8\ Most recently, NHTSA proposed upgrades to
the lead vehicle AEB test in its March 2022 request for comment on
NCAP.\9\ Separate from NCAP, in March 2016, NHTSA and Insurance
Institute for Highway Safety (IIHS) announced a commitment by 20
manufacturers representing more than 99 percent of the U.S. light
vehicle market to equip low-speed AEB as a standard feature on nearly
all new light vehicles not later than September 1, 2022. As part of
this voluntary commitment, manufacturers would include both FCW and a
CIB system that would reduce a vehicle's speed in certain rear-end
crash-imminent test conditions.
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\7\ 77 FR 39561 (Jul. 2, 2012).
\8\ 80 FR 68604 (Nov. 5, 2015).
\9\ 87 FR 13452 (Mar. 9, 2022). See www.regulatinos.gov, docket
number NHTSA-2021-0002.
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NHTSA also conducted research to understand the capabilities of
PAEB systems beginning in 2011. This work began with an assessment of
the most common pedestrian crash scenarios to determine how test
procedures could be designed to address them. As part of this
development, NHTSA also looked closely at a potential pedestrian
mannequin to be used during testing and explored several aspects of the
mannequin, including size and articulation of the arms and legs. This
work resulted in a November 2019 draft research test procedure
providing the methods and specifications for collecting performance
data on PAEB systems for light vehicles.\10\ This procedure was
expanded to cover updated vehicle speed ranges and different ambient
conditions and included in a March 2022 request for comments notice
proposing to include PAEB, higher speed AEB, blind spot warning and
blind spot intervention into NCAP.\11\
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\10\ 84 FR 64405 (Nov. 21, 2019).
\11\ 87 FR 13452 (Mar. 9, 2022).
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While these actions have increased market penetration of AEB
systems, reduced injuries, and saved lives, NHTSA believes that
mandating AEB systems that can address both lead vehicle and pedestrian
crashes is necessary to better address the safety need. NHTSA
incorporated FCW into NCAP beginning in model year 2011 and AEB into
NCAP beginning in model year 2018. This has achieved success, with
approximately 65% of new vehicles meeting the lead vehicle test
procedures included in NCAP.\12\ Similarly, the voluntary commitment
resulted in approximately 90 percent of new light vehicles having an
AEB system.
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\12\ Percentage based on the vehicle manufacturer's model year
2022 projected sales volume reported through the New Car Assessment
Program's annual vehicle information request.
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However, the test speeds and performance specifications in NCAP and
the voluntary commitment would not ensure that the systems perform in a
way that will prevent or mitigate crashes resulting in serious injuries
and fatalities. The vast majority of fatalities, injuries, and property
damage crashes occur at speeds above 40 km/h (25 mph), which are above
those covered by the voluntary commitment.
NCAP and, even more so, other voluntary measures are intended to
supplement rather than substitute for the FMVSS, which remain NHTSA's
core way of ensuring that all motor vehicles are able to achieve an
adequate level of safety performance. Thus, though the NCAP program
provides valuable safety-related information to consumers in a simple
to understand way, the agency believes that gaps in market penetration
will continue to exist for the most highly effective AEB systems. NHTSA
has also observed that, in the case of both electronic stability
control and rear visibility, only approximately 70 percent of vehicles
had these technologies during the time they were part of NCAP. Thus,
while NCAP serves a vital safety purpose, NHTSA also recognizes its
limitations and concludes that only regulation can ensure that all
vehicles are equipped with AEB that meet the proposed performance
requirements.
These considerations are of even greater weight when considering
whether to require a system that can reduce pedestrian crashes.
Pedestrian fatalities are increasing, and NHTSA's testing has
established that PAEB systems will be able to significantly reduce
these deaths.\13\ Manufacturers' responses to adding lead vehicle AEB
and other technologies into NCAP suggests that it would take several
years after PAEB is introduced into NCAP before the market began to see
significant numbers of new vehicles that would be able to meet a
finalized NCAP test. Moreover, as pedestrian safety addresses the
safety of someone other than the vehicle occupant, it is not clear if
past experiences with NCAP are necessarily indicative of how quickly
PAEB systems would reach the levels of lead vehicle AEB, if pedestrian
functionality that would meet NCAP performance levels was offered as a
separate cost to consumers. NHTSA believes that there can be a
significant safety benefit in NCAP providing consumers with information
about new safety technologies before it is prepared to mandate them,
but this is not a requirement.
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\13\ The accompanying PRIA estimates the impacts of the rule.
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A final factor weighing in favor of requiring AEB is that the
technology is a significantly more mature level than what it was at the
time of the voluntary commitment or when it was introduced into NCAP.
NHTSA's most recent testing has shown that higher performance levels
than those in the voluntary commitment or the existing NCAP
requirements are now practicable. Many model year 2019 and 2020
vehicles were able to repeatedly avoid impacting the lead vehicle in
CIB
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tests and the pedestrian test mannequin in PAEB tests, even at higher
test speeds than those prescribed currently in the agency's CIB and
PAEB test procedures.
These results show that AEB systems are capable of reducing the
frequency and severity of both lead vehicle and pedestrian crashes.
Mandating AEB systems would address a clear and, in the case of
pedestrian deaths, growing safety problem. To wait for market-driven
adoption, even to the extent spurred on by NCAP, would lead to deaths
and injuries that could be avoided if the technology were required, and
would be unlikely to result in all vehicles having improved AEB. Thus,
in consideration of the safety problem and NHTSA's recent test results,
and consistent with the Safety Act and BIL, NHTSA has tentatively
concluded that a new Federal motor vehicle safety standard requiring
AEB systems that can address both lead vehicle and pedestrian
collisions on all new light vehicles is necessary to address the
problem of rear-end crashes resulting in property damage, injuries, and
fatalities. The proposed lead vehicle AEB test procedures build on the
existing FCW, CIB, and DBS NCAP procedures, but include higher speed
performance requirements. Collision avoidance is required at speeds up
to 100 km/h (62 mph) when manual braking is applied and up to 80 km/h
(50 mph) when no manual braking is applied during the test. Based on
data from the 2019 and 2020 research programs, NHTSA believes that it
is practicable to require this higher level of system performance.
Performance at these speeds would address the injuries and fatalities
resulting from rear-end crashes. As part of this proposal, NHTSA is
including testing under both daylight and darkness lighting conditions.
In the darkness testing condition, NHTSA is proposing testing with both
lower beam and upper beam headlamps activated. NHTSA believes darkness
testing of PAEB is necessary because more than three-fourths of all
pedestrian fatalities occur in conditions other than daylight.
The proposed standard includes four requirements for AEB systems
for both lead vehicles and pedestrians. First, vehicles would be
required to have an AEB system that provides the driver with a FCW at
any forward speed greater than 10 km/h (6.2 mph). NHTSA is proposing
that the FCW be presented via auditory and visual modalities when a
collision with a lead vehicle or a pedestrian is imminent. Based on
NHTSA's research, this proposal includes specifications for the
auditory and visual warning components. Additional warning modes, such
as haptic, would be allowed.
Second, vehicles would be required to have an AEB system that
applies the brakes automatically at any forward speed greater than 10
km/h (6.2 mph) when a collision with a lead vehicle or a pedestrian is
imminent. This requirement would serve to ensure that AEB systems
operate at all speeds above 10 km/h (6.2 mph), even if these speeds are
above the speeds tested by NHTSA and provide at least some level of AEB
system performance in those rear-end crashes. An AEB system active at
any speed above 10 km/h (6.2 mph) will be able to mitigate collisions
at high speeds through, at a minimum, speed reduction.
Third, the AEB system would be required to prevent the vehicle from
colliding with the lead vehicle or pedestrian test mannequin when
tested according to the proposed standard's test procedures. These
track test procedures have defined parameters that will ensure that AEB
systems prevent crashes in a controlled testing environment. There are
three general test scenarios each for testing vehicles with a lead
vehicle and four scenarios for testing vehicles with a pedestrian test
mannequin. These test scenarios are designed to ensure that AEB systems
are able to perform appropriately in common crash scenarios. In
particular, the agency has proposed that pedestrian tests be done in
both daylight and darkness. The proposed requirements also include two
false positive tests (driving over a steel trench plate and driving
between two parked vehicles) in which the vehicle would not be
permitted to brake in excess of 0.25g in addition to any manual brake
application.
The final proposed requirement is that a vehicle must detect AEB
system malfunctions and notify the driver of any malfunction that
causes the AEB system not to meet the minimum proposed performance
requirements. Malfunctions would include those attributable to sensor
obstruction or saturation, such as accumulated snow or debris, dense
fog, or sunlight glare. The proposal only includes a specification that
the notification be visual.
To ensure test repeatability that reflects how a subject vehicle--
that is the vehicle under test, would respond in the real world, this
proposal includes specifications for the test devices that NHTSA would
use in both the lead vehicle and pedestrian compliance tests, relying
in large part on relevant International Organization for
Standardization standards.
This proposal would require that all of the AEB requirements be
phased in within four years of publication of a final rule. All
vehicles would be required to meet all requirements associated with
lead vehicle AEB and all daylight test requirements for PAEB within
three years. With respect to darkness testing, there are lower maximum
test speed thresholds that would have to be met within three years for
some specified test procedures. All vehicles would have to meet the
minimum performance requirements with higher darkness test speeds four
years after the publication of a final rule. Small-volume
manufacturers, final-stage manufacturers, and alterers would be
provided an additional year of lead time for all requirements.
NHTSA has issued a Preliminary Regulatory Impact Analysis (PRIA)
that analyzes the potential impacts of this proposed rule. The PRIA is
available in the docket for this NPRM. The proposed rule is expected to
substantially decrease the safety problems associated with rear-end and
pedestrian crashes.
NHTSA's assessment of available safety data indicates that between
2016 and 2019, there were an average of 1.12 million rear-impact
crashes involving light vehicles annually. These crashes resulted in an
approximate annual average of 394 fatalities, 142,611 non-fatal
injuries, and an additional 1.69 million damaged vehicles.
Additionally, between 2016 and 2019, there were an average of
approximately 23,000 crashes that could potentially be addressed by
PAEB annually. These crashes resulted in an annual average of 2,642
fatalities and 17,689 non-fatal injuries.
AEB systems meeting the requirements of this proposed rule would
have a dramatic impact on risks associated with rear-end and pedestrian
crashes, even beyond the benefits assumed to occur due to NCAP and
other voluntary industry adoption. In order to determine the benefits
and costs of this rulemaking, NHTSA developed a baseline, which
reflects how the world would look in the absence of regulation. This
baseline includes an assumption that all new light vehicles will have
some AEB system and that approximately 65 percent of these vehicles
will have systems meeting the NCAP test procedures. Thus, the impacts
of this rule are less than the impacts of AEB as a technology, as it
only accounts for marginal improvements over the baseline. Accordingly,
NHTSA projects that this proposed rule would reduce fatalities by 362
(124 rear-end and 238 pedestrian) annually and reduce injuries by
24,321 (21,649 rear-end and 2,672
[[Page 38636]]
pedestrian) annually.\14\ In addition, lead vehicle AEB systems would
likely yield substantial benefits over the lifetime of the vehicle in
property damage avoided. Further, when calculating benefits, the agency
excluded many scenarios where AEB systems are still likely to lead to
safety benefits but where the agency has not conducted sufficient
research to quantify those benefits, including crashes involving
impacts into the rear of heavy vehicles. Further, the agency excluded
calendar years 2020 and 2021 from its analysis of the safety problem,
as those years may be atypical, but did include a sensitivity case in
the RIA, which shows greater benefits.
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\14\ A breakdown of the severity of the injuries that would be
reduced by this proposed rule can be found in Section 4.3 of the
accompanying PRIA.
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With regard to costs NHTSA anticipates that systems can achieve the
proposed requirements through upgraded software, as all vehicles are
assumed to have the necessary hardware. Therefore, the incremental cost
associated with this proposed rule reflects the cost of a software
upgrade that will allow current systems to achieve lead vehicle AEB and
PAEB functionality that meets the requirements specified in this
proposed rule. The incremental cost per vehicle is estimated at $82.15
for each design cycle change of the model.\15\ When accounting for
design cycles and annual sales of new light vehicles, the total annual
cost associated with this proposed rule is approximately $282.16
million in 2020 dollars.
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\15\ The agency includes a higher potential cost value in the
RIA for ``disruptive'' software changes, which could also serve as a
proxy for potential additional costs, including hardware costs.
However, as discussed in the RIA, that value represents a less-
likely higher end assumption, while the value used here represents
the agency's main assumption. Importantly, though, even under the
higher assumption, benefits still greatly exceed costs.
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Table 1 summarizes the finding of the benefit-cost analysis. The
projected benefits of this proposed rule greatly exceed the projected
costs. The lifetime monetized net benefit of this proposed rule is
projected to be between $5.24 and $6.52 billion with a cost per
equivalent life saved of between $500,000 and $620,000, which is far
below the Department's existing value of a statistical life saved,
which is currently calculated as $11.8 million.
Table 1--Lifetime Summary of Benefits and Costs for Passenger Cars and
Light Trucks (Millions 2020$), Discount Rate
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3% Discount rate 7% Discount rate
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Benefits
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Lifetime Monetized.............. $6,802 $5,518
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Costs
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Lifetime Monetized.............. 282.16 282.16
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Net Benefits
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Lifetime Monetized.............. 6,520 5,235
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Table 2--Estimated Quantifiable Benefits
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Benefits
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Fatalities Reduced......................................... 362
Injuries Reduced........................................... 24,321
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Table 3--Estimated Installation Costs
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Costs (2020$)
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System installation per vehicle per $82.15
design cycle.
Total Fleet per year.................... 282.16 M
------------------------------------------------------------------------
Table 4--Estimated Cost Effectiveness
------------------------------------------------------------------------
------------------------------------------------------------------------
Cost per Equivalent Life Saved
------------------------------------------------------------------------
AEB Systems...................... $0.50 to $0.62 million *
------------------------------------------------------------------------
* The range presented is from a 3% to 7% discount rate.
NHTSA seeks comments and suggestions on all aspects of this
proposal and any alternative requirements that would address this
safety problem. NHTSA also requests comments on the proposed lead time
for meeting these requirements, and how the lead time can be structured
to maximize the benefits that can be realized most quickly while
ensuring that the standard is practicable.
Summary of Technical Terms
The following is a brief explanation of terms and technologies used
to describe AEB systems. More detailed information can be found in
Appendix A to this preamble.
Radar-Based Sensors
Many AEB systems employ radar sensors. At its simplest, radar is a
time-of-flight sensor technology that measures the time between when a
radio wave is transmitted and when its reflection is received back at
the radar sensor. This time-of-flight sensor input is used to calculate
the distance between the sensor and the object that caused the
reflection. Multiple or continuous sampling can also provide
information about the reflecting object, such as the speed at which it
is travelling.
Camera Sensors
Cameras are passive sensors in which optical data are recorded and
then processed to allow for object detection and classification.
Cameras are an important part of many automotive AEB systems and are
typically mounted behind the front windshield near the rearview mirror,
sometimes in groups of two or more. Cameras at this location provide a
good view of the road and are protected by the windshield from debris,
grease, dirt, and other contaminants that could obstruct the sensor.
Some systems that use two or more cameras can see stereoscopically,
allowing the processing system to better determine range information
along with detection and classification.
Forward Collision Warning
A forward collision warning (FCW) system uses sensors that detect
objects in front of vehicles and provides an alert to the driver. An
FCW system is able to use the sensors' input to determine the speed of
an object in front of it and the
[[Page 38637]]
distance between the vehicle and the object. If the FCW system
determines that the closing distance and velocity between the vehicle
and the object is such that a collision may be imminent, the system is
designed to induce an immediate forward crash avoidance response by the
vehicle operator. FCW systems may detect impending collisions with any
number of roadway obstacles, including vehicles and pedestrians.
Warning systems in use today provide drivers with a visual display,
such as an illuminated telltale on or near the instrument panel, an
auditory signal, or a haptic signal that provides tactile feedback to
the driver to warn the driver of an impending collision so the driver
may intervene. FCW systems alone do not brake the vehicle.
Electronically Modulated Braking Systems
Automatic actuation of a vehicle's brakes requires more than just
technology to sense when a collision is imminent. In addition to the
sensing system, hardware is needed to apply the brakes without relying
on the driver to depress the brake pedal. The automatic braking system
relies on two foundational braking technologies--electronic stability
control to automatically activate the vehicle brakes and an antilock
braking system to mitigate wheel lockup. Not only do electronic
stability control and antilock braking systems enable AEB operation,
these systems also modulate the braking force so that the vehicle
remains stable while braking during critical driving situations where a
crash with a vehicle or pedestrian is imminent.
AEB Perception and Decision System
The performance of each AEB system depends on the ability of the
system to use sensor data to appropriately detect and classify forward
objects. The AEB system uses this detection and classification to
decide if a collision is imminent and then avoid or mitigate the
potential crash. Manufacturers and suppliers of AEB systems have worked
to address unnecessary AEB activations through techniques such as
sensor fusion, which combines and filters information from multiple
sensors, and advanced predictive models.
Lead Vehicle Automatic Emergency Braking
A lead vehicle AEB system automatically applies the brakes to help
drivers avoid or mitigate the severity of rear-end crashes. Lead
vehicle AEB has two similar functions that NHTSA has referred to as
crash imminent braking and dynamic brake support. Crash imminent
braking (CIB) systems apply automatic braking when forward-looking
sensors indicate a crash is imminent and the driver has not applied the
brakes. Dynamic brake support (DBS) systems use the same sensors to
supplement the driver's application of the brake pedal with additional
braking when sensors determine the driver has applied the brakes, but
the brake application is insufficient to avoid an imminent crash.
This NPRM does not split the terminology of these CIB and DBS
functionalities, but instead considers them both as parts of AEB. When
NHTSA first tested implementation of these systems, NHTSA found that
DBS systems operated with greater automatic braking application than
CIB systems. However, more recent testing has shown that vehicle
manufacturers' CIB systems provide the same level of braking as DBS
systems. Nevertheless, the proposed standard includes performance tests
that would require an AEB system that has both CIB and DBS
functionalities.
Pedestrian Automatic Emergency Braking
PAEB systems function like lead vehicle AEB systems but detect
pedestrians in front of the vehicle. PAEB systems intervene in crash
imminent situations in which the pedestrian is either directly in the
path of a vehicle or entering the path of the vehicle. Current PAEB
systems operate primarily when the vehicle is moving in a straight
line. Sensor performance is defined by sensing depth, field of view,
and resolution. However, performance may be degraded during low light
conditions. This NPRM proposes requiring PAEB system performance in
darkness conditions using the vehicle's headlamps for illumination.
``AEB'' as Used in This NPRM
When this NPRM refers to ``AEB'' generally, unless the context
clearly indicates otherwise, it refers to a system that has: (a) an FCW
component to alert the driver to an impending collision with a forward
obstacle; (b) a CIB component that automatically applies the vehicle's
brakes if the driver does not respond to the FCW; and (c) a DBS
component that automatically supplements the driver's brake application
if the driver applies insufficient manual braking to avoid a crash.
Furthermore, unless the context indicates otherwise, reference to AEB
includes both lead vehicle AEB and PAEB.
Abbreviations Frequently Used in This Document
The following table is provided for the convenience of readers for
illustration purposes only.
Table 5--Abbreviations
----------------------------------------------------------------------------------------------------------------
Abbreviation Full term Notes
----------------------------------------------------------------------------------------------------------------
AEB..................................... Automatic Emergency Braking Applies a vehicle's brakes automatically
to avoid or mitigate an impending
forward crash.
ADAS.................................... Advanced driver assistance
system.
CIB..................................... Crash Imminent Braking..... Applies automatic braking when forward-
looking sensors indicate a crash is
imminent and the driver has not applied
the brakes.
CRSS.................................... Crash Report Sampling A sample of police-reported crashes
System. involving all types of motor vehicles,
pedestrians, and cyclists, ranging from
property-damage-only crashes to those
that result in fatalities.
DBS..................................... Dynamic Brake Support...... Supplements the driver's application of
the brake pedal with additional braking
when sensors determine the driver-
applied braking is insufficient to avoid
an imminent crash.
FARS.................................... Fatality Analysis Reporting A nationwide census providing annual data
System. regarding fatal injuries suffered in
motor vehicle crashes.
FCW..................................... Forward Collision Warning.. An auditory and visual warning provided
to the vehicle operator that is designed
to induce an immediate forward crash
avoidance response by the vehicle
operator.
FMVSS................................... Federal Motor Vehicle
Safety Standard.
[[Page 38638]]
IIHS.................................... Insurance Institute for
Highway Safety.
IIJA.................................... Infrastructure Investment Public Law 117-58 (Nov. 15, 2021).
and Jobs Act.
ISO..................................... International Organization
for Standardization.
Lead Vehicle AEB........................ Lead Vehicle Automatic An AEB system that is capable of avoiding
Emergency Braking. or mitigating collisions with a lead
vehicle.
MAIS.................................... Maximum Abbreviated Injury A means of describing injury severity
Scale. based on an ordinal scale. An MAIS 1
injury is a minor injury and an MAIS 5
injury is a critical injury.
NCAP.................................... New Car Assessment Program.
PAEB.................................... Pedestrian AEB............. Activates when a crash imminent situation
occurs between the equipped vehicle and
a pedestrian in the forward path.
RFC..................................... Request for Comments.......
VTD..................................... Vehicle Test Device........ A test device used to test AEB system
performance.
----------------------------------------------------------------------------------------------------------------
II. Safety Problem
There were 38,824 fatalities in motor vehicle crashes on U.S.
roadways in 2020 and early estimates put the number of fatalities at
42,915 for 2021.\16\ This is the highest number of fatalities since
2005. While the upward trend in fatalities may be related to increases
in risky driving behaviors during the COVID-19 pandemic,\17\ agency
data show an increase of 3,356 fatalities between 2010 and 2019.\18\
Motor vehicle crashes have also trended upwards since 2010, which
corresponds to an increase in fatalities, injuries, and property
damage.
---------------------------------------------------------------------------
\16\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813266, https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813283.
\17\ These behaviors relate to increases in impaired driving,
the non-use of seat belts, and speeding. NHTSA also cited external
studies from telematics providers that suggested increased rates of
cell phone manipulation during driving in the early part of the
pandemic.
\18\ NHTSA's Traffic Safety Facts Annual Report, Table 2,
https://cdan.nhtsa.gov/tsftables/tsfar.htm#. Accessed March 28,
2023.
---------------------------------------------------------------------------
A. Overall Rear-End Crash Problem
This NPRM proposes a new FMVSS to reduce the frequency and severity
of vehicle-to-vehicle rear-end crashes and to reduce the frequency and
severity of vehicle crashes into pedestrians. NHTSA uses data from its
Fatality Analysis Reporting System (FARS) and the Crash Report Sampling
System (CRSS) to account for and understand motor vehicle crashes. As
defined in a NHTSA technical manual relating to data entry for FARS and
CRSS, rear-end crashes are incidents where the first event is defined
as the frontal area of one vehicle striking a vehicle ahead in the same
travel lane. In a rear-end crash, as instructed by the 2020 FARS/CRSS
Coding and Validation Manual, the vehicle ahead is categorized as
intending to head either straight, left or right, and is either
stopped, travelling at a lower speed, or decelerating.\19\
---------------------------------------------------------------------------
\19\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813251 Category II Configuration D. Rear-End.
---------------------------------------------------------------------------
In 2019, rear-end crashes accounted for 32.5 percent of all
crashes, making them the most prevalent type of crash.\20\ Fatal rear-
end crashes increased from 1,692 in 2010 to 2,363 in 2019 and accounted
for 7.1 percent of all fatal crashes in 2019, up from 5.6 percent in
2010. Because data from 2020 and 2021 may not be representative of the
general safety problem due to the COVID-19 pandemic, the following
discussion refers to data from 2010 to 2020 when discussing rear-end
crash safety problem trends, and 2019 data when discussing specific
characteristics of the rear-end crash safety problem. While injury and
property damage-only rear-end crashes from 2010 (476,000 and 1,267,000,
respectively) and 2019 (595,000 and 1,597,000, respectively) are not
directly comparable due to the difference in database structure and
sampling, the data indicate that these numbers have not significantly
changed from 2010-2015 (NASS-GES sampling) and 2016-2019 (CRSS
sampling).
---------------------------------------------------------------------------
\20\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813141 Traffic Safety Facts 2019, Table 29.
\21\ Compiled from NHTSA's Traffic Safety Facts Annual Report,
Table 29 from 2010 to 2020, https://cdan.nhtsa.gov/tsftables/tsfar.htm#. Accessed March 28, 2023.
Table 6--2010-2020 Rear-End Crashes All Vehicle Types by Crash Severity 21
----------------------------------------------------------------------------------------------------------------
Rear-end crash severity
---------------------------------------------------------------
Fatal Injury Property- Total rear-end
First harmful event -------------------------------- damage-only ---------------
----------------
Number Number Number Number
----------------------------------------------------------------------------------------------------------------
2010............................................ 1,692 476,000 1,267,000 1,745,000
2011............................................ 1,808 475,000 1,245,000 1,721,000
2012............................................ 1,836 518,000 1,327,000 1,847,000
2013............................................ 1,815 503,000 1,326,000 1,831,000
2014............................................ 1,971 522,000 1,442,000 1,966,000
2015............................................ 2,225 556,000 1,543,000 2,101,000
2016............................................ 2,372 661,000 1,523,000 2,187,000
2017............................................ 2,473 615,000 1,514,000 2,132,000
2018............................................ 2,459 594,000 1,579,000 2,175,000
2019............................................ 2,363 595,000 1,597,000 2,194,000
2020............................................ 2,428 417,000 1,038,000 1,457,000
----------------------------------------------------------------------------------------------------------------
[[Page 38639]]
Table 7 presents a breakdown of all the crashes in 2019 by the
first harmful event where rear-end crashes represent 7.1 percent of the
fatal crashes, 31.1 percent of injury crashes and 33.2 percent (or the
largest percent) of property damage only crashes.
Table 7--2019 Crashes, by First Harmful Event, Manner of Collision, and Crash Severity 22
----------------------------------------------------------------------------------------------------------------
Crash severity
-----------------------------------------------------------------------------
First harmful event Fatal Injury Property damage only
-----------------------------------------------------------------------------
Number Percent Number Percent Number Percent
----------------------------------------------------------------------------------------------------------------
Collision with Motor Vehicle in
Transport
Angle......................... 6,087 18.2 531,000 27.7 956,000 19.9
Rear-end...................... 2,363 7.1 595,000 31.1 1,597,000 33.2
Sideswipe..................... 917 2.7 138,000 7.2 739,000 15.4
Head On....................... 3,639 10.9 91,000 4.7 86,000 1.8
Other/Unknown................. 150 0.4 8,000 0.4 69,000 1.4
Collision with a Fixed Object
Collision with Object Not Fixed
9,579 28.6 281,000 14.7 657,000 13.7
7,826 23.4 214,000 11.2 648,000 13.5
Non-collision..................... 2,870 8.6 58,000 3.0 54,000 1.1
----------------------------------------------------------------------------------------------------------------
The following paragraphs provide a breakdown of rear-end crashes by
vehicle type, posted speed limit, light conditions and atmospheric
conditions for the year 2019 based on NHTSA's FARS, CRSS and the 2019
Traffic Safety Facts sheets.
---------------------------------------------------------------------------
\22\ NHTSA's Traffic Safety Facts Annual Report, Table 29 for
2019, https://cdan.nhtsa.gov/tsftables/tsfar.htm#. Accessed March
28, 2023.
---------------------------------------------------------------------------
B. Rear-End Crashes by Vehicle Type
In 2019, passenger cars and light trucks were involved in the vast
majority of rear-end crashes. NHTSA's ``Manual on Classification of
Motor Vehicle Traffic Accidents'' provides a standardized method for
crash reporting. It defines passenger cars as ``motor vehicles used
primarily for carrying passengers, including convertibles, sedans, and
station wagons,'' and light trucks as ``trucks of 10,000 pounds gross
vehicle weight rating or less, including pickups, vans, truck-based
station wagons, and utility vehicles.'' \23\ The 2019 data show that
crashes where a passenger car or light truck is a striking vehicle
represent at least 70 percent of fatal rear-end crashes, 95 percent of
crashes resulting in injury, and 96 percent of damage only crashes (See
Table 8).\24\
---------------------------------------------------------------------------
\23\ https://www-fars.nhtsa.dot.gov/help/terms.aspx.
\24\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813141 Traffic Safety Facts 2019.
Table 8--Rear-End Crashes With Impact Location--Front, by Vehicle Type, in 2019 25
----------------------------------------------------------------------------------------------------------------
Property
Vehicle body type, initial impact-front Fatal Injury damage only
----------------------------------------------------------------------------------------------------------------
Passenger Car................................................... 888 329,000 906,000
Light Truck..................................................... 910 245,000 642,000
All Other....................................................... 762 31,000 57,000
----------------------------------------------------------------------------------------------------------------
C. Rear-End Crashes by Posted Speed Limit
When looking at posted speed limit and rear-end crashes, data show
that the majority of the crashes happened in areas where the posted
speed limit was 60 mph (97 km/h) or less. Table 9 shows the rear-end
crash data by posted speed limit and vehicle type from 2019. About 60
percent of fatal crashes were on roads with a speed limit of 60 mph (97
km/h) or lower. That number is 73 percent for injury crashes and 78
percent for property damage-only crashes.
---------------------------------------------------------------------------
\25\ Generated from FARS and CRSS databases (https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/FARS/2019/National/,
https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/CRSS/2019/,
accessed October 17, 2022).
Table 9--2019 Rear-End Crashes Involving Passenger Cars, MPVs, and Light Trucks With Frontal Impact by Posted
Speed Limit 26 27
----------------------------------------------------------------------------------------------------------------
Passenger cars, light trucks, by crash severity
-----------------------------------------------------------------------------
Vehicles by posted speed limit Fatal Injury Property-damage-only
-----------------------------------------------------------------------------
Number Percent Number Percent Number Percent
----------------------------------------------------------------------------------------------------------------
25 mph or less.................... 16 1 28,000 5 103,000 7
30................................ 30 2 24,000 4 78,000 5
35................................ 95 5 91,000 16 267,000 17
40................................ 87 5 66,000 11 175,000 11
45................................ 223 12 129,000 22 373,000 24
[[Page 38640]]
50................................ 99 6 19,000 3 58,000 4
55................................ 401 22 55,000 10 122,000 8
60................................ 133 7 12,000 2 31,000 2
65 and above...................... 684 38 75,000 13 153,000 10
All other......................... 30 2 75,000 13 187,000 12
-----------------------------------------------------------------------------
Total......................... 1,798 100 574,000 100 1,547,000 100
----------------------------------------------------------------------------------------------------------------
D. Rear-End Crashes by Light Condition
Slightly more fatal rear-end crashes (51 percent) occurred during
daylight than during dark-lighted and dark-not-lighted conditions
combined (43 percent) in 2019. However, injury and property damage-only
rear-end crashes were reported to have happened overwhelmingly during
daylight, at 76 percent for injury rear-end crashes and 80 percent for
property-damage-only rear-end crashes. Table 10 presents a summary of
all 2019 rear-end crashes of light vehicles by light conditions, where
the impact location is the front of a light vehicle.
---------------------------------------------------------------------------
\26\ Generated from FARS and CRSS databases (https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/FARS/2019/National/,
https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/CRSS/2019/,
accessed October 17, 2022).
\27\ Total percentages may not equal the sum of individual
components due to independent rounding throughout the Safety Problem
section.
\28\ Generated from FARS and CRSS databases (https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/FARS/2019/National/,
https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/CRSS/2019/,
accessed October 17, 2022).
Table 10--2019 Rear-End Crashes With Light Vehicle Front Impact, by Light Condition 28
----------------------------------------------------------------------------------------------------------------
Crash severity
-----------------------------------------------------------------------------------
Light condition Fatal Injury Property Damage-only
-----------------------------------------------------------------------------------
Percent Number Percent Number Percent Number
----------------------------------------------------------------------------------------------------------------
Daylight.................... 925 51 436,000 76 1,232,000 80
Dark--Not Lighted........... 438 24 28,000 5 59,00060,767 4
Dark--Lighted............... 349 19 86,000 15 192,000 12
All Other................... 86 5 24,000 4 65,000 4
-----------------------------------------------------------------------------------
Total................... 1,798 100 574,000 100 1,547,000 100
----------------------------------------------------------------------------------------------------------------
E. Rear-End Crashes by Atmospheric Conditions
In 2019, the majority of rear-end crashes of light vehicles were
reported to occur during clear skies with no adverse atmospheric
conditions. These conditions were present for 72 percent of all fatal
rear-end crashes, while 14 percent of fatal rear-end crashes were
reported to occur during cloudy conditions. Similar trends are reported
for injury and property damage only crashes. A brief summary of 2019
rear-end crashes of light vehicle with frontal impact by atmospheric
conditions is presented in Table 11.
---------------------------------------------------------------------------
\29\ Generated from FARS and CRSS databases (https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/FARS/2019/National/,
https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/CRSS/2019/,
accessed October 17, 2022).
Table 11--2019 Rear-End Crashes Involving Light Vehicles With Frontal Impact, by Atmospheric Conditions 29
----------------------------------------------------------------------------------------------------------------
Crash severity
-----------------------------------------------------------------------------
Crashes atmospheric conditions Fatal Injury Property damage-only
-----------------------------------------------------------------------------
Percent Number Percent Number Percent Number
----------------------------------------------------------------------------------------------------------------
Clear, No Adverse................. 1,295 72 426,000 74 1,113,000 72
Cloudy............................ 247 14 87,000 15 245,000 16
All Other......................... 256 14 61,000 11 189,000 12
-----------------------------------------------------------------------------
Total......................... 1,798 100 574,000 100 1,547,000 100
----------------------------------------------------------------------------------------------------------------
[[Page 38641]]
F. Pedestrian Fatalities and Injuries
While the number of fatalities from motor vehicle traffic crashes
is increasing, pedestrian fatalities are increasing at a greater rate
than the general trend and becoming a larger percentage of total
fatalities. In 2010, there were 4,302 pedestrian fatalities (13 percent
of all fatalities), which has increased to 6,272 (17 percent of all
fatalities) in 2019. The latest agency estimation data indicate that
there were 7,342 pedestrian fatalities in 2021.\30\ Since data from
2020 and 2021 may not be representative of the general safety problem
due to the COVID-19 pandemic, the following sections refer to data from
2010 to 2020 when discussing pedestrian safety problem trends, and 2019
data when discussing specific characteristics of the pedestrian safety
problem. While the number of pedestrian fatalities is increasing, the
number of pedestrians injured in crashes from 2010 to 2020 has not
changed significantly, with exception of the 2020 pandemic year. In
Table 12, the number and percentage of pedestrian fatalities and
injuries for the 2010 to 2020 period is presented in relationship to
the total number of fatalities and total number of people injured in
all crashes.
---------------------------------------------------------------------------
\30\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813298 Early Estimates of Motor Vehicle Traffic
Fatalities And Fatality Rate by Sub-Categories in 2021, May 2022.
\31\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813079 Pedestrian Traffic Facts 2019 Data, May 2021,
https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813310
Pedestrian Traffic Facts 2020, Data May 2022.
Table 12--2010-2020 Traffic Crash Fatalities and Pedestrian Fatalities, and Injured People and Pedestrians
Injured 31
----------------------------------------------------------------------------------------------------------------
Pedestrian fatalities 1 Pedestrian injured 2
Total -------------------------
Total -------------------------- people
Year fatalities 1 Percent of injured 2 Percent of
Number total Number total
fatalities injured
----------------------------------------------------------------------------------------------------------------
2010............................. 32,999 4,302 13 2,248,000 70,000 3
2011............................. 32,479 4,457 14 2,227,000 69,000 3
2012............................. 33,782 4,818 14 2,369,000 76,000 3
2013............................. 32,893 4,779 15 2,319,000 66,000 3
2014............................. 32,744 4,910 15 2,343,000 65,000 3
2015............................. 35,484 5,494 15 2,455,000 70,000 3
2016............................. 37,806 6,080 16 3,062,000 86,000 3
2017............................. 37,473 6,075 16 2,745,000 71,000 3
2018............................. 36,835 6,374 17 2,710,000 75,000 3
2019............................. 36,355 6,272 17 2,740,000 76,000 3
2020............................. 38,824 6,516 17 2,282,015 55,000 2
----------------------------------------------------------------------------------------------------------------
1 Data source: FARS 2010-2019, 2020 Annual Report (ARF).
2 Data source: NASS GES 2010-2015, CRSS 2016-2019.
The following sections present a breakdown of pedestrian fatalities
and injuries by initial impact point, vehicle type, posted speed limit,
lighting condition, pedestrian age, and light conditions for the year
2019.
G. Pedestrian Fatalities and Injuries by Initial Point of Impact and
Vehicle Type
In 2019, the majority of pedestrian fatalities, 4,638 (74 percent
of all pedestrian fatalities), and injuries, 52,886 (70 percent of all
pedestrian injuries), were in crashes where the initial point of impact
on the vehicle was the front. When the crashes are broken down by
vehicle body type, the majority of pedestrian fatalities and injuries
occur where the initial point of impact was the front of a light
vehicle (4,069 pedestrian fatalities and 50,831 pedestrian injuries)
(see Table 13).32
---------------------------------------------------------------------------
\32\ As described previously, passenger cars and light trucks
are the representative population for vehicles with a GVWR of 4,536
kg (10,000 lbs.) or less.
\33\ NHTSA's Traffic Safety Facts Annual Report, Table 99 for
2019, https://cdan.nhtsa.gov/tsftables/tsfar.htm#Accessed March 28,
2023.
Table 13--2019 Pedestrian Fatalities and Injuries, by Initial Point of Impact Front and Vehicle Body Type 33
----------------------------------------------------------------------------------------------------------------
Crash severity
---------------------------------------------------------------
Vehicle body type, initial impact--front Pedestrian fatalities Pedestrian injuries
---------------------------------------------------------------
Number Percent Number Percent
----------------------------------------------------------------------------------------------------------------
Passenger Car................................... 1,976 43 30,968 59
Light Truck..................................... 2,093 45 19,863 38
All Other....................................... 569 12 2,055 4
---------------------------------------------------------------
Total....................................... 4,638 100 52,886 100
----------------------------------------------------------------------------------------------------------------
H. Pedestrian Fatalities and Injuries by Posted Speed Limit Involving
Light Vehicles
In 2019, the majority of pedestrian fatalities from crashes
involving light vehicles with the initial point of impact as the front
occurred on roads where the posted speed limit was 45 mph or less,
(about 70 percent). There is a near even split between the number of
pedestrian fatalities in 40 mph and lower speed zones and in 45 mph and
above speed zones (50 percent and 47 percent respectively with the
remaining unknown, not reported or lacking). As
[[Page 38642]]
for pedestrian injuries, in a large number of cases, the posted speed
limit is either not reported or unknown (i.e., about 34 percent of the
sampled data). In situations where the posted speed limit is known, 57
percent of the pedestrians were injured when the posted speed limit was
40 mph or below, and 9 percent when the posted speed limit was above 40
mph. Table 14 shows the number of pedestrian fatalities and injuries
for each posted speed limit.
---------------------------------------------------------------------------
\34\ The accompanying PRIA estimates the impacts of the rule
based on the estimated travel speed of the striking vehicle. This
table presents the speed limit of the roads on which pedestrian
crashes occur.
Table 14--2019 Pedestrian Fatalities and Injuries Involving Light Vehicles, by Posted Speed Limit 34
----------------------------------------------------------------------------------------------------------------
Crash severity
---------------------------------------------------------------
Posted speed limit Pedestrians fatalities Pedestrian injuries
---------------------------------------------------------------
Number Percent Number Percent
----------------------------------------------------------------------------------------------------------------
5 mph........................................... 3 0.07 185 0.36
10 mph.......................................... 7 0.17 287 0.56
15 mph.......................................... 10 0.25 865 1.70
20 mph.......................................... 14 0.34 479 0.94
25 mph.......................................... 346 8.50 9,425 18.54
30 mph.......................................... 325 7.99 4,254 8.37
35 mph.......................................... 765 18.80 9,802 19.28
40 mph.......................................... 551 13.54 3,703 7.28
45 mph.......................................... 821 20.18 3,094 6.09
50 mph.......................................... 177 4.35 302 0.59
55 mph.......................................... 463 11.38 546 1.07
60 mph.......................................... 105 2.58 130 0.26
65 mph.......................................... 199 4.89 241 0.47
70 mph.......................................... 103 2.53 105 0.21
75 mph.......................................... 19 0.47 4 0.01
80 mph.......................................... 2 0.05 25 0.05
Not Reported.................................... 118 2.90 15,017 29.54
Unknown......................................... 16 0.39 176 0.35
No Statutory Limit/Non-Trafficway Area.......... 25 0.61 2,191 4.31
---------------------------------------------------------------
Total....................................... 4,069 100 50,831 100
----------------------------------------------------------------------------------------------------------------
I. Pedestrian Fatalities and Injuries by Lighting Condition Involving
Light Vehicles
The majority of pedestrian fatalities where a light vehicle strikes
a pedestrian with the front of the vehicle occurred in dark lighting
conditions, 3,131 (75 percent). There were 20,645 pedestrian injuries
(40 percent) in dark lighting conditions and 27,603 pedestrian injuries
(54 percent) in daylight conditions.
---------------------------------------------------------------------------
\35\ Generated from FARS and CRSS databases (https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/FARS/2019/National/,
https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/CRSS/2019/,
accessed October 17, 2022).
Table 15--2019 Pedestrian Fatalities and Injuries Involving Light Vehicles, by Lighting Condition 35
----------------------------------------------------------------------------------------------------------------
Crash severity
---------------------------------------------------------------
Light condition Pedestrian fatalities Pedestrian injuries
---------------------------------------------------------------
Number Percent Number Percent
----------------------------------------------------------------------------------------------------------------
Daylight........................................ 767 19 27,603 54
Dark-Not Lighted................................ 1,464 36 4,551 9
Dark-Lighted.................................... 1,621 40 15,996 31
Dark-Unknown Light.............................. 46 1 98 0
All Other....................................... 171 4 2,583 5
---------------------------------------------------------------
Total....................................... 4,069 100 50,831 100
----------------------------------------------------------------------------------------------------------------
J. Pedestrian Fatalities and Injuries by Age Involving Light Vehicles
In 2019, 646 fatalities and approximately 106,600 injuries involved
children aged 9 and below. Of these, 68 fatalities and approximately
2,700 injuries involved pedestrians aged 9 and below in crashes with
the front of a light vehicle. As shown in Table 16, the first two age
groups (less than age 5 and 5 to 9) each represent less than 1 percent
of the total pedestrian fatalities in crashes with the front of a light
vehicle. These age groups also represent about 1.5 and 3.8 percent of
the total pedestrian injuries in crashes with the front of a light
vehicle, respectively. In contrast, age groups between age 25 and 69
each represent approximately 7 percent of the total pedestrian
fatalities in crashes with the front of a light vehicle, with the 55 to
59 age group having the highest percentage at 10.9 percent. Pedestrian
injury percentages
[[Page 38643]]
were less consistent, but distributed similarly, to pedestrian
fatalities, with lower percentages reflected in children aged 9 and
below and adults over age 70.
---------------------------------------------------------------------------
\36\ Generated from FARS and CRSS databases (https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/FARS/2019/National/,
https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/CRSS/2019/,
accessed October 17, 2022).
\37\ https://www.census.gov/data/tables/2019/demo/age-and-sex/2019-age-sex-composition.html, Table 12.
Table 16--2019 Pedestrians Fatalities and Injuries in Traffic Crashes Involving Light Vehicles by Initial Point of Impact Front 36 and Age Group 37
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pedestrian fatalities Pedestrians injuries
------------------------------------------------------------
Percent of Percent of
United States Light total total
Age group population Percent of vehicle pedestrian Light vehicle pedestrian
(thousand) population front- fatalities in front-impact injuries in
impact ped. light vehicle ped. injuries light vehicle
fatalities front-impact front-impact
crashes crashes
--------------------------------------------------------------------------------------------------------------------------------------------------------
<5........................................................... 19,736 6.1 37 0.9 770 1.5
5-9.......................................................... 20,212 6.2 31 0.8 1,907 3.8
10-14........................................................ 20,827 6.4 58 1.4 2,830 5.6
15-20........................................................ 20,849 6.4 159 3.9 5,673 11.2
21-24........................................................ 21,254 6.6 173 4.3 3,190 6.3
25-29........................................................ 23,277 7.2 287 7.1 4,394 8.6
30-34........................................................ 21,932 6.8 315 7.7 3,735 7.3
35-39........................................................ 21,443 6.6 316 7.8 3,636 7.2
40-44........................................................ 19,584 6.0 277 6.8 2,812 5.5
45-49........................................................ 20,345 6.3 294 7.2 2,745 5.4
50-54........................................................ 20,355 6.3 350 8.6 3,311 6.5
55-59........................................................ 21,163 6.5 442 10.9 3,678 7.2
60-64........................................................ 20,592 6.3 379 9.3 3,469 6.8
65-69........................................................ 17,356 5.4 303 7.4 2,594 5.1
70-74........................................................ 14,131 4.4 207 5.1 1,724 3.4
75-79........................................................ 9,357 2.9 172 4.2 1,136 2.2
80+.......................................................... 11,943 3.7 252 6.2 1,127 2.2
Unknown...................................................... ............... ........... 17 0.4 2,103 4.1
------------------------------------------------------------------------------------------
Total.................................................... ............... ........... 4,069 100 50,831 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
K. AEB Target Population
AEB technology is not expected to prevent all rear-end crashes or
pedestrian fatalities. In order to determine the portion of the rear-
end and pedestrian fatality population that could be affected by AEB,
NHTSA used the FARS and CRSS databases to derive a target population.
Fatality data were derived from FARS and data on property damage
vehicle crashes and injuries were derived from CRSS. The agency
computed annualized averages for years 2016 to 2019 from fatalities and
injuries.
For lead vehicle AEB, NHTSA first applied filters to ensure the
target population included only rear-end crashes, excluding crashes
other than those resulting from a motor vehicle in transport and only
including crashes where the striking vehicle had frontal damage and the
struck vehicle had rear-end damage. NHTSA conservatively excluded
crashes with more than two vehicles because two-vehicle crashes most
closely mirror the test track testing which includes a single lead
vehicle. NHTSA only included crashes where a light vehicle struck
another light vehicle. The striking vehicle was limited to light
vehicles because this proposal would only apply to light vehicles. The
struck vehicle was limited to light vehicles because the specifications
for the lead vehicle in testing were derived exclusively from light
vehicles. The crash population was further limited to cases where the
subject vehicle was traveling in a straight line and either braked or
did not brake to avoid the crash (excluding instances where the vehicle
attempted to avoid the crash in some other manner). These exclusions
were applied because AEB systems may suppress automatic braking when
the driver attempts to avoid a collision by some other action, such as
turning. Finally, the crash scenarios were limited to those where the
lead vehicle was either stopped, moving, or decelerating along the same
path as the subject vehicle. Other maneuvers, such as crashes in which
the vehicle turned prior to the crash, were excluded because current
sensor systems have a narrow field of view that does not provide
sufficient information to the perception system regarding objects in
the vehicle's turning path.
For PAEB, the target population was also identified based on
reported fatalities (in FARS data) and injuries (in GES and CRSS data).
Each of the estimated target population values were based on a six-year
average (2014 through 2019). NHTSA applied filters such that only
crashes involving a single light vehicle and pedestrians where the
first harmful event was contact with the pedestrian are considered in
the analysis. Further, the impact area was restricted to the front of
the vehicle because the performance proposed in this rule is limited to
forward vehicle movement. Additionally, the vehicle's pre-event
movement (i.e., the vehicle's activity prior to the driver's
realization of the impending crash) was traveling in a straight line
and the pedestrian movement was determined to be either crossing the
vehicle's path or along the vehicle's path to match the track testing
being proposed.
After applying these filters, NHTSA has tentatively concluded that
AEB technology could potentially address up to 3,036 fatalities (394
lead vehicle and 2,642 pedestrian), 160,309 injuries (142,611 lead
vehicle and 17,698 pedestrian), and 1,119,470 property damage only
crashes (only lead vehicle). These crashes represent 15 percent and 14
percent of fatalities and injuries resulting from rear end crashes,
[[Page 38644]]
respectively and 43 percent and 28 percent of fatalities and injuries
from pedestrian crashes. These crashes also represent 8.4 percent of
total roadway fatalities, 5.9 percent of total roadway injuries, and 23
percent of property damage only crashes.
NHTSA has restricted the target population to two-vehicle crashes
although FCW and AEB would likely provide safety benefits in multi-
vehicle crashes even when the first impact would be completely avoided
with FCW and AEB.\38\ NHTSA also limited the target population to light
vehicle to light vehicle crashes because NHTSA does not have data on
how AEB systems would respond to other vehicle types such as heavy
vehicles or motorcycles. NHTSA is currently researching light vehicle
AEB performance in these situations.
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\38\ As discussed in the PRIA for this NPRM, NHTSA decided not
to include multi-vehicle crashes in the target population because it
would be difficult to estimate safety benefits for occupants in the
second and or third vehicles due to limited data.
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III. Data on Effectiveness of AEB in Mitigating Harm
Forward collision warning systems were among the first generation
of advanced driver assistance system technologies designed to help
drivers avoid an impending crash.\39\ In 2008, when NHTSA decided to
include ADAS technologies in the NCAP program, FCW was selected because
the agency believed (1) this technology addressed a major crash
problem; (2) system designs existed that could mitigate this safety
problem; (3) safety benefit projections were assessed; and (4)
performance tests and procedures were available to ensure an acceptable
performance level. At the time, the agency estimated that FCW systems
were 15 percent effective in preventing rear-end crashes. More
recently, in a 2017 study, the Insurance Institute for Highway Safety
(IIHS) found that FCW systems may be more effective than NHTSA's
initial estimates indicated.\40\ IIHS found that FCW systems reduced
rear-end crashes by 27 percent.
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\39\ ADAS technologies use advanced technologies to assist
drivers in avoiding a crash. NCAP currently recommends four kinds of
ADAS technologies to prospective vehicle purchasers--forward
collision warning, lane departure warning, crash imminent braking,
and dynamic brake support (the latter two are considered AEB).
https://www.nhtsa.gov/equipment/driver-assistance-technologies. In a
March 2, 2022 request for comments notice, infra, NHTSA proposed to
add four more ADAS technologies to NCAP.
\40\ Cicchino, J.B. (2017, February), Effectiveness of forward
collision warning and autonomous emergency braking systems in
reducing front-to-rear crash rates, Accident Analysis and
Prevention, 2017 Feb;99(Pt A):142-152. https://doi.org/10.1016/j.aap.2016.11.009.
---------------------------------------------------------------------------
When FCW is coupled with AEB, the system becomes more effective at
reducing rear-end crashes. A limitation of FCW systems is that they are
designed only to warn the driver, but they do not provide automatic
braking of the vehicle. From a functional perspective, research
suggests that active braking systems, such as AEB, provide greater
safety benefits than corresponding warning systems, such as FCW. In a
recent study sponsored by General Motors (GM) to evaluate the real-
world effectiveness of ADAS technologies (including FCW and AEB) on 3.8
million model year 2013-2017 GM vehicles, the University of Michigan's
Transportation Research Institute (UMTRI) found that, for frontal
collisions, camera-based FCW systems produced an estimated 21 percent
reduction in rear-end striking crashes, while the AEB systems studied
(which included a combination of camera-only, radar-only, and fused
camera-radar systems) produced an estimated 46 percent reduction in the
same crash type.\41\ Similarly, in a 2017 study, IIHS found that
vehicles equipped with FCW and AEB showed a 50 percent reduction for
the same crash type.\42\
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\41\ The Agency notes that the FCW effectiveness rate (21%)
observed by UMTRI is similar to that observed by IIHS in its 2019
study (27%). Differences in data samples and vehicle selection may
contribute to the specific numerical differences. Regardless, the
AEB effectiveness rate observed by UMTRI (46%) was significantly
higher than the corresponding FCW effectiveness rate observed in
either the IIHS or UMTRI study.
\42\ Cicchino, J.B. (2017, February), Effectiveness of forward
collision warning and autonomous emergency braking systems in
reducing front-to-rear crash rates, Accident Analysis and
Prevention, 2017 Feb;99(Pt A):142-152, https://doi.org/10.1016/j.aap.2016.11.009.
---------------------------------------------------------------------------
NHTSA has found that current AEB systems often integrate the
functionalities of FCW and AEB into one frontal crash prevention system
to deliver improved real-world safety performance. Consequently, NHTSA
believes that FCW should now be considered a component of lead vehicle
AEB and PAEB, and has, in fact, developed a test in NCAP that assesses
FCW in the same test that evaluates a vehicle's AEB and PAEB
performance.\43\
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\43\ 87 FR 13486 March 9, 2022, proposed update to NCAP's FCW
testing.
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Not only are AEB systems proving effective, data indicate there is
high consumer acceptance of the current systems. In a 2019 subscriber
survey by Consumer Reports, 81 percent of vehicle owners reported that
they were satisfied with AEB technology, 54 percent said that it had
helped them avoid a crash, and 61 percent stated that they trusted the
system to work every time.\44\
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\44\ Consumer Reports, (2019, August 5), Guide to automatic
emergency braking: How AEB can put the brakes on car collisions,
https://www.consumerreports.org/car-safety/automatic-emergency-braking-guide/.
---------------------------------------------------------------------------
However, NHTSA is aware of data and other information indicating
potential opportunities for AEB improvement. The data indicate the
potential of AEB to reduce fatal crashes, especially if AEB systems
performed at higher speeds. While AEB systems on currently available
vehicles are highly effective at lower speed testing, some such systems
do not perform well in tests done at higher speeds.
IV. NHTSA's Earlier Efforts Related to AEB
NHTSA sought to provide the public with valuable vehicle safety
information by actively supporting development and implementation of
AEB technologies through research and development and through NHTSA's
NCAP. NHTSA also sought to incentivize installation of AEB and PAEB on
vehicles by encouraging the voluntary installation of AEB systems by
automakers through a voluntary industry commitment, resulting in
participating automakers committing to installing an AEB system that
met certain performance thresholds on most light duty cars and trucks
by September 1, 2022, and on nearly all light vehicles by September 1,
2025.
A. NHTSA's Foundational AEB Research
NHTSA conducted extensive research on AEB systems to support
development of the technology and eventual deployment in vehicles.
There were three main components to this work. The agency conducted
early research on FCW systems that warn drivers of potential rear-end
crashes with other vehicles. This was followed by research into AEB
systems designed to prevent or mitigate rear-end collisions through
automatic braking. Later, NHTSA evaluated AEB systems designed to
prevent or mitigate collisions with pedestrians in a vehicle's forward
path.
1. Forward Collision Warning Research
NHTSA's earliest research on FCW systems began in the 1990s, at a
time when the systems were under development and evaluation had been
conducted primarily by suppliers and vehicle manufacturers. NHTSA
collaborated with industry stakeholders to identify the specific crash
types that an FCW system could be designed to address, the resulting
minimum functional requirements, and potential
[[Page 38645]]
objective test procedures for evaluation.\45\ In the late 1990s, NHTSA
worked with industry to conduct a field study, the Automotive Collision
Avoidance System Program. NHTSA later contracted with the Volpe
National Transportation Systems Center (Volpe) to conduct analyses of
data recorded during that field study.\46\ From this work, NHTSA
learned about the detection and alert timing and information about
warning signal modality (auditory, visual, etc.) of FCW systems, and
predominant vehicle crash avoidance scenarios where FCW systems could
most effectively play a role in alerting a driver to brake and avoid a
crash. In 2009, NHTSA synthesized this research in the development and
conduct of controlled track test assessments on three vehicles equipped
with FCW.\47\
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\45\ This research was documented in a report, ``Development and
Validation of Functional Definitions and Evaluation Procedures for
Collision Warning/Avoidance Systems,'' Kiefer, R., et al., DOT HS
808 964, August 1999. Additional NHTSA FCW research is described in
Zador, Pub. L., et al., ``Final Report--Automotive Collision
Avoidance System (ACAS) Program,'' DOT HS 809 080, August 2000; and
Ference, J.J., et al., ``Objective Test Scenarios for Integrated
Vehicle-Based Safety Systems,'' Paper No. 07-0183, Proceedings of
the 20th International Conference for the Enhanced Safety of
Vehicles, 2007.
\46\ Najm, W.G., Stearns, M.D., Howarth, H., Koopmann, J., and
Hitz, J., ``Evaluation of an Automotive Rear-End Collision Avoidance
System,'' DOT HS 810 569, April 2006 and Najm, W.G., Stearns, M.D.,
and Yanagisawa, M., ``Pre-Crash Scenario Typology for Crash
Avoidance Research,'' DOT HS 810 767, April 2007.
\47\ Forkenbrock, G., O'Harra, B., ``A Forward Collision Warning
(FCW) Program Evaluation, Paper No. 09-0561, Proceedings of the 21st
International Technical Conference for the Enhanced Safety of
Vehicles, 2009.
---------------------------------------------------------------------------
Because FCW systems are designed only to warn the driver and not to
provide automatic braking for meaningful speed reduction of the
vehicle, NHTSA continued to research AEB systems.\48\
---------------------------------------------------------------------------
\48\ Some FCW systems use haptic brake pulses to alert the
driver of a crash-imminent driving situation, but the pulses are not
intended to slow the vehicle.
---------------------------------------------------------------------------
2. AEB Research To Prevent Rear-End Impacts With a Lead Vehicle
NHTSA's research and test track performance evaluations of AEB
began around 2010. The agency began a thorough examination of the state
of forward-looking advanced braking technologies, analyzing their
performance and identifying areas of concern or uncertainty, to better
understand their safety potential. NHTSA issued a report \49\ and a
request for comments notice seeking feedback on its CIB and DBS
research in July 2012.\50\ Specifically, NHTSA wanted to enhance its
knowledge further and help guide its continued efforts pertaining to
AEB effectiveness, test operation (including how to ensure
repeatability using a target or surrogate vehicle), refinement of
performance criteria, and exploring the need for an approach and
criteria for ``false positive'' tests to minimize the unintended
negative consequences of automatic braking in non-critical driving
situations.
---------------------------------------------------------------------------
\49\ The agency's initial research and analysis of CIB and DBS
systems were documented in a report, ``Forward-Looking Advanced
Braking Technologies: An analysis of current system performance,
effectiveness, and test protocols'' (June 2012). https://www.regulations.gov, NHTSA 2012-0057-0001.
\50\ 77 FR 39561.
---------------------------------------------------------------------------
NHTSA considered feedback it received on the RFC and conducted
additional testing to support further development of the test
procedures. The agency documented its work in two additional reports,
``Automatic Emergency Braking System Research Report'' (August 2014)
\51\ and ``NHTSA's 2014 Automatic Emergency Braking (AEB) Test Track
Evaluations'' (May 2015),\52\ and in accompanying draft CIB and DBS
test procedures.\53\
---------------------------------------------------------------------------
\51\ https://www.regulations.gov, NHTSA 2012-0057-0037.
\52\ DOT HS 812 166.
\53\ https://www.regulations.gov, NHTSA 2012-0057-0038.
---------------------------------------------------------------------------
In the follow-on tests, NHTSA found that CIB and DBS systems
commercially available on several different production vehicles could
be tested successfully to the agency's defined performance measures.
NHTSA developed performance measures to define the performance CIB and
DBS systems should attain to help drivers avoid or at least mitigate
injury risk in rear-end crashes. The agency found that systems meeting
the performance measures have the potential to reduce the number of
rear-end crashes as well as deaths and injuries that result from these
crashes. NHTSA used the research findings to develop NCAP's procedures
for assessing the performance of vehicles with AEB and other crash-
avoidance technologies \54\ and for testing vehicles at higher speeds.
The findings also provided the foundation to upgrade NCAP's current AEB
tests, as discussed in NHTSA's March 9, 2022, request for comments
notice,\55\ and the development of this NPRM.
---------------------------------------------------------------------------
\54\ NCAP recommends forward collision warning, lane departure
warning, crash imminent braking and dynamic brake support (AEB) to
prospective vehicle purchasers and identifies vehicles that meet
NCAP performance test criteria for these technologies.
\55\ 87 FR 13452, March 2, 2022.
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3. AEB Research To Prevent Vehicle Impacts With Pedestrians
NHTSA began research on PAEB systems in 2011.\56\ The agency worked
on a project with Volpe and the Crash Avoidance Metrics Partnership
(CAMP) \57\ to develop preliminary PAEB test methods. The goal of the
project was to develop and validate minimum performance requirements
and objective test procedures for forward-looking PAEB systems intended
to address in-traffic, pedestrian crash scenarios.
---------------------------------------------------------------------------
\56\ At that time, the agency used the term ``pedestrian crash
avoidance and mitigation (PCAM)'' research.
\57\ The participating companies that worked on this project
included representatives from Continental, Delphi Corporation, Ford
Motor Company, General Motors, and Mercedes-Benz.
---------------------------------------------------------------------------
As part of this work, Volpe conducted an analysis of available
crash data and found four common pedestrian pre-crash scenarios. These
are when the vehicle is: 1. Heading in a straight line and a pedestrian
is crossing the road; 2. turning right and a pedestrian is crossing the
road; 3. turning left and a pedestrian is crossing the road; and 4.
heading in a straight line and a pedestrian is walking along or against
traffic. Understanding the pre-crash factors associated with pedestrian
crashes led to the development of the draft research test methods, a
set of test equipment requirements, a preliminary evaluation plan, and
development of a 50th percentile adult male mannequin made from closed-
cell foam. The culmination of this work was documented in a research
report, ``Objective Tests for Forward Looking Pedestrian Crash
Avoidance/Mitigation Systems: Final Report'' (June 2014).\58\
---------------------------------------------------------------------------
\58\ Carpenter, M.G., Moury, M.T., Skvarce, J.R., Struck, M.
Zwicky, T.D., & Kiger, S.M. (2014, June), Objective Tests for
Forward Looking Pedestrian Crash Avoidance/Mitigation Systems: Final
report (Report No. DOT HS 812 040), Washington, DC: National Highway
Traffic Safety Administration.
---------------------------------------------------------------------------
[[Page 38646]]
NHTSA continued to refine the CAMP test procedures in pursuit of
objective and repeatable test procedures using production vehicles
equipped with PAEB systems. In doing so, NHTSA evaluated adult, child,
non-articulating and articulating mannequins, walking and running speed
capabilities, mannequin radar cross section characteristics, and
mannequin position accuracy and control.\59\ The evaluated mannequins
and their characteristics represented the largest portion of the crash
problem. NHTSA also updated its real-world pedestrian crash data
analysis in 2017.\60\
---------------------------------------------------------------------------
\59\ Albrecht, H., ``Objective Test Procedures for Pedestrian
Automatic Emergency Braking Systems,'' SAE Government/Industry
Meeting, January 25-27, 2017.
\60\ Yanagisawa, M., Swanson, E., Azeredo, P., Najm, W.,
``Estimation of Potential Safety Benefits for Pedestrian Crash
Avoidance/Mitigation Systems, DOT HS 812 400, April 2017.
---------------------------------------------------------------------------
In November 2019, NHTSA published a draft research test procedure
that provided the methods and specifications for collecting performance
data on PAEB systems for light vehicles.\61\ The test procedures were
developed to evaluate the PAEB performance in the two most frequent
pre-crash scenarios involving pedestrians: where the pedestrian crosses
the road in front of the vehicle and where the pedestrian walks
alongside the road in the path of the vehicle. NHTSA focused its 2019
draft research test procedures on these two scenarios because a 2017
crash data study suggested they collectively represented 90 percent of
pedestrian fatalities (64 percent and 28 percent, respectively). In
contrast, the study found that the turning right and turning left
scenarios were found to only account for 1 percent and 4 percent of
pedestrian fatalities, respectively. NHTSA further focused the 2019
test procedures on PAEB-addressable crashes. PAEB systems offered at
the time were not offering a wider field of view necessary for
detection and braking in the turning scenarios. These two scenarios
present different challenges due to the relative angles and distances
between subject vehicle and pedestrian and could require additional
hardware resulting in added cost. NHTSA's consideration of including
the turning scenarios is further discussed in the PRIA accompanying
this NPRM. The draft test procedures described in this document rely on
the use of pedestrian mannequins for testing purposes.
---------------------------------------------------------------------------
\61\ https://regulations.dot.gov, Docket No. NHTSA-2019-0102.
---------------------------------------------------------------------------
4. Bicycle and Motorcycle AEB
NHTSA is actively conducting research to characterize the
performance of AEB systems in response to bicycle and motorcycles in
the same scenarios as NHTSA's lead vehicle AEB testing, in both
daylight and darkness conditions. NHTSA tested five vehicles with
bicycle and motorcycle AEB and also tested with a vehicle surrogate as
a control for AEB system performance. In addition to characterizing the
performance of the five vehicles, this testing also allows NHTSA to
refine its test procedures to determine whether any changes would be
needed to test bicycle or motorcycle AEB.
Preliminary results suggest that the lane position of the test
device, the lighting conditions, the positioning of a lead vehicle, and
speed all have a significant effect on the performance of AEB systems
relative to bicycles and motorcycles. However, there is no discernable
pattern across vehicles tested, suggesting that performance is
dependent upon specific test scenario definition. Further, preliminary
testing has raised issues with the design of the bicycle and motorcycle
surrogates and their impact on the vehicles under test. This report is
expected to be completed by the end of 2023. The results from this
research, and other future research, may lead to efforts to define test
procedures, refine the bicycle and motorcycle surrogate devices, and
characterize AEB system performance in response to additional test
devices (scooters, mopeds, wheelchairs, or other assisted walking
devices).
B. NHTSA's New Car Assessment Program
1. FCW Tests
In 2007, based on the research discussed above, NHTSA issued a
notice requesting public comment on including rear-end crash warning/
avoidance systems in NCAP.\62\ The technology under consideration at
the time included forward vehicle sensing with warning or braking. In
2008, based upon feedback and further agency analysis, NHTSA published
a final decision notice announcing its intent to include FCW in NCAP as
a recommended technology and identify for consumers which vehicles have
the technology.
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\62\ 72 FR 3473 (January 25, 2007). NHTSA published a report in
conjunction with this notice titled, ``The New Car Assessment
Program (NCAP); Suggested Approaches for Future Enhancements.''
---------------------------------------------------------------------------
To ensure that NCAP identified only vehicles that had FCW systems
that satisfied a minimum level of performance, NHTSA adopted specific
performance tests and thresholds and time-to-collision-based alert
criteria that a system had to satisfy to be distinguished in NCAP as a
vehicle equipped with the recommended technology. NCAP informs
consumers that a particular vehicle has a recommended technology when
NHTSA has data verifying that the vehicle's system meets the minimum
performance threshold set by NHTSA for acceptable performance. If a
vehicle's system meets the performance threshold using the test method
NHTSA specifies, NHTSA uses a checkmark to indicate on the NCAP website
that the vehicle is equipped with the technology.\63\
---------------------------------------------------------------------------
\63\ The March 2022 request for comments notice discusses, among
other things, NHTSA's plan to develop a future rating system for new
vehicles based on the availability and performance of all of the
NCAP-recommended crash avoidance technologies. That is, instead of a
simple checkmark showing the vehicle has a technology (and it meets
the applicable performance test criteria), vehicles would receive a
rating for each technology based on the systems' performance test
criteria in NHTSA's tests. 87 FR 13452 (March 9, 2022).
---------------------------------------------------------------------------
The performance tests chosen for NCAP consisted of three scenarios
that simulated the most frequent types of light vehicle rear-end
crashes: crashes where a vehicle ahead is either stopped, suddenly
starts braking, or is traveling at a much lower speed in the subject
vehicle travel lane. The scenarios were named ``lead vehicle stopped,''
``lead vehicle decelerating,'' and ``lead vehicle moving,''
respectively.\64\ In each scenario, the time needed for a driver to
perceive an impending rear-end crash, decide the corrective action, and
respond with the appropriate mitigating action is prescribed. If the
FCW system fails to provide an alert within the required time during
testing, the professional test driver applies the brakes or steers away
to avoid a collision.
---------------------------------------------------------------------------
\64\ 73 FR 40016 (July 11, 2008). https://regulations.gov.
Docket No. NHTSA-2006-26555-0118.
---------------------------------------------------------------------------
2. Lead Vehicle AEB Tests
NHTSA incorporated AEB technologies (CIB and DBS) in NCAP as
recommended crash avoidance technologies in 2015,\65\ starting with
model year 2018 vehicles. NHTSA adopted performance tests and
thresholds that a system must meet for the vehicle to be distinguished
in NCAP as a vehicle with the recommended technology. The AEB
performance tests consisted of test scenarios and test speeds that were
derived from crash statistics, field operational tests, and NHTSA
testing experience, including
[[Page 38647]]
experience gained from development of the FCW performance tests already
in NCAP.\66\ In the NCAP recommended crash avoidance technologies
program, vehicles receive credit for meeting the agency's performance
tests for CIB and DBS separately.
---------------------------------------------------------------------------
\65\ 80 FR 68604.
\66\ Id. at 68608.
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For AEB assessment, NCAP uses four test scenarios: lead vehicle
stopped, lead vehicle decelerating, lead vehicle moving, and the steel
trench plate test.\67\ Each test scenario is evaluated separately for
CIB and DBS. The only difference is that, in the DBS tests, manual
braking is applied to the subject vehicle. For the first three test
scenarios, the subject vehicle must demonstrate a specific speed
reduction attributable to AEB intervention. The fourth scenario, the
steel trench plate test, is a false positive test, used to evaluate the
propensity of a vehicle's AEB system to activate inappropriately in a
scenario that would not present a safety risk to the vehicle's
occupants. For each of the scenarios, to receive NHTSA's technology
recommendation through NCAP, the vehicle must meet the minimum
specified performance in at least five out of seven valid test trials.
---------------------------------------------------------------------------
\67\ NHTSA. (2015, October). Crash imminent brake system
performance evaluation for the New Car Assessment Program. https://www.regulations.gov. Docket No. NHTSA-2015-0006-0025.
---------------------------------------------------------------------------
Lead Vehicle Stopped Tests
In the NCAP lead vehicle stopped test scenario, the subject vehicle
encounters a stopped lead vehicle on a straight road. The subject
vehicle travels in a straight line, at a constant speed of 40 km/h (25
mph), approaching a stopped lead vehicle in its path. The subject
vehicle's throttle is released within 500 milliseconds (ms) after the
subject vehicle issues an FCW. In the DBS test, the subject vehicle's
brakes are manually applied at a time-to-collision of 1.1 seconds (at a
nominal headway of 12.2 m (40 ft)). To receive credit for CIB, the
subject vehicle speed reduction attributable to CIB intervention must
be >=15.8 km/h (9.8 mph) before the end of the test. To receive credit
for DBS, the subject vehicle must not contact the lead vehicle.
Lead Vehicle Decelerating Tests
In the lead vehicle decelerating test scenario, the subject vehicle
encounters a lead vehicle slowing with constant deceleration directly
in front of it on a straight road. For this test scenario, the subject
vehicle and lead vehicle are initially both driven at 56.3 km/h (35
mph) with an initial headway of 13.8 m (45.3 ft). The lead vehicle then
decelerates, braking at a constant deceleration of 0.3g in front of the
subject vehicle, after which the subject vehicle throttle is released
within 500 ms after the subject vehicle issues an FCW. In the DBS
testing, the subject vehicle's brakes are applied at a time-to-
collision of 1.4 seconds (at a nominal headway of 9.6 m or 31.5 ft). To
receive credit for passing this test scenario for CIB, the subject
vehicle speed reduction attributable to CIB intervention must be >=16.9
km/h (10.5 mph) before the end of the test. To receive credit for
passing this test for DBS, the subject vehicle must not contact the
lead vehicle.
Lead Vehicle Moving Tests
In the lead vehicle moving test scenario, the subject vehicle
encounters a slower-moving lead vehicle directly in front of it on a
straight road. For this test scenario, two test conditions are
assessed. For the first test condition, the subject vehicle and lead
vehicle are driven at a constant speed of 40 km/h (25 mph) and 16 km/h
(10 mph), respectively. For the second test condition, the subject and
lead vehicle are driven at a constant speed of 72.4 km/h (45 mph) and
32.2 km/h (20 mph), respectively. In both tests, the subject vehicle
throttle is released within 500 ms after the subject vehicle issues an
FCW. In the DBS tests, the subject vehicle's brakes are applied at a
time-to-collision of 1 second (at a nominal headway of 6.7 meters (22
ft)). To receive credit for passing the first CIB test, the subject
vehicle must not contact the lead vehicle during the test. To receive
credit for passing the second CIB test, the subject vehicle speed
reduction attributable to crash imminent braking intervention must be
>=15.8 km/h (9.8 mph) by the end of the test. To receive credit for
either DBS test, the subject vehicle must not contact the lead vehicle.
Steel Trench Plate Tests
In the steel trench plate test scenario, the subject vehicle is
driven towards a steel trench plate (2.4 m x 3.7 m x 25.3 mm or 7.9 ft
x 12.1 ft x 1 in) on a straight road at two different speeds: 40 km/h
(25 mph) in one test and 72.4 km/h (45 mph) in the other. The subject
vehicle throttle is released within 500 ms of the warning. For CIB
tests, if no FCW is issued, the throttle is not released until the test
is completed. For DBS tests, the throttle is released such that it is
completely released within 500 ms of 2.1 seconds time-to-collision (at
a nominal distance of 12.3 m (40.4 ft) or 22.3 m (73.2 ft) from the
trench plate, depending on the test speed). The brake pedal is then
applied at 1.1 s time-to-collision. To pass these tests for CIB, the
subject vehicle must not achieve a peak deceleration equal to or
greater than 0.5 g at any time during its approach to the steel trench
plate. To pass the DBS test, the subject vehicle must not experience a
peak deceleration that exceeds 150 percent of the braking experienced
through manual braking alone for the baseline condition at the same
speed.
3. PAEB Test Proposal
NHTSA conducted research and published several NCAP RFC notices on
the inclusion of PAEB systems. In the 2013 NCAP request for comments
notice, NHTSA noted that PAEB systems capable of addressing both low-
speed front and rear pedestrian impact prevention were already in
production for some vehicle models.\68\ The agency acknowledged that
different technologies were being implemented at the time and different
test procedures were being developed worldwide, although some test
procedure complexities still existed. An additional complexity was the
need for a crash avoidance test dummy that would provide a radar and/or
camera recognition signature that would approximate that of a human and
would be durable enough to withstand any testing impacts. NHTSA
requested comments on methods of addressing and resolving these
complexities.
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\68\ 78 FR 20597 at 20600.
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In 2015, the agency announced its plan for several major NCAP
program enhancements, including NHTSA's intention to implement a new 5-
star rating system to convey vehicle safety information in three major
areas--crashworthiness, crash avoidance, and pedestrian protection.\69\
The agency proposed that PAEB be included in the pedestrian protection
rating, along with rear automatic braking and pedestrian
crashworthiness. At the time, NHTSA noted that the agency was still
refining the pedestrian test scenarios for PAEB systems. Specifically,
three different types of apparatus concepts were identified for
transporting a test mannequin in a test run. These included two
overhead gantry-style designs and one moving sled arrangement.
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\69\ 80 FR 78522 at 78526.
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In November 2019, NHTSA published a Federal Register notice that
sought comment on draft confirmation test procedures for PAEB, among
other technologies (84 FR 64405).\70\ It included the two most fatal
scenario types: Pedestrian crossing path and
[[Page 38648]]
pedestrian along or standing in path. For the crossing path scenario
(S1), the draft included seven specific test procedures (Table 17). The
maximum subject vehicle traveling speed specified was 40 km/h (25 mph)
in all cases.
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\70\ National Highway Traffic Safety Administration (2019,
April), Pedestrian automatic emergency brake system confirmation
test (working draft). Available at: https://www.regulations.gov/document/NHTSA-2019-0102-0005.
[GRAPHIC] [TIFF OMITTED] TP13JN23.009
In the first three scenarios (S1a-b-c), a subject vehicle
approaches an adult test mannequin starting on the right-hand side of
the lane of travel and moving toward the left-hand side. The point on
the vehicle at which the subject vehicle will strike the test mannequin
without automatic braking, or overlap, is 25, 50, and 75 percent from
the passenger side of the subject vehicle, respectively. In the fourth
scenario (S1d), the subject vehicle approaches a crossing child test
mannequin running from behind parked vehicles from the right-hand side
of the travel lane toward the left-hand side with the point of impact
at a 50 percent overlap. In the fifth scenario (S1e), the subject
vehicle approaches an adult test mannequin running from the left side
of the travel lane toward the right with a 50 percent overlap point of
impact.
The sixth and seventh crossing path scenarios (S1f and S1g) are
false positive tests. In the sixth scenario, the subject vehicle
approaches an adult test mannequin, which begins moving from the right-
hand side of the roadway but safely stops short of entering the subject
vehicle's lane of travel. In the seventh scenario, the adult test
mannequin also crosses from the right-hand side of the road toward the
left-hand side, but safely crosses the lane of travel completely. The
false positive scenarios are used to evaluate the propensity of a PAEB
system to inappropriately activate in a non-critical driving scenario
that does not present a safety risk to the subject vehicle occupants or
pedestrian.
NHTSA's research test procedures also consisted of three along path
(S4) test scenarios in which a test mannequin is either standing or
traveling along the vehicle's lane of travel (Table 18). The maximum
subject vehicle traveling speed specified was 40 km/h (25 mph) for all
procedures.
[GRAPHIC] [TIFF OMITTED] TP13JN23.010
In the first scenario the stationary test mannequin is facing away
from the vehicle (S4a) and in the second, it is facing toward the
vehicle (S4b). In third scenario, a subject vehicle encounters an adult
test mannequin walking in front of the vehicle on the nearside of the
road away from the vehicle (S4c). In all three procedures, the
stationary test mannequin is positioned with a 25 percent overlap from
the passenger side of the vehicle.
NHTSA used the test procedures to conduct performance evaluations
of model year 2019 and 2020 vehicles, which were used to support a
March 9, 2022, request for comments notice proposing to include PAEB
tests in NCAP.\71\ In addition to PAEB, the RFC notice proposed
including blind spot detection, blind spot intervention, and lane
keeping support performance tests in NCAP. It further proposed
strengthening the existing performance tests for FCW, AEB (CIB and
DBS), and lane departure warning. It also proposed new rating criteria
and provided a roadmap for future upgrades to the program.
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\71\ 87 FR 13452.
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C. 2016 Voluntary Commitment
On March 17, 2016, NHTSA and the Insurance Institute for Highway
Safety (IIHS) announced a commitment by 20 automakers representing more
than 99 percent of the U.S. light vehicle market to make lower speed
AEB a standard feature on virtually all new light duty cars and trucks
with a gross vehicle weight rating (GVWR) of 3,855 kg (8,500 lbs.) or
less no later than September 1, 2022.\72\ Participating manufacturers
needed to ensure their vehicles had an FCW system that met NHTSA's FCW
NCAP requirements for both the lead vehicle moving and lead vehicle
decelerating performance tests. The
[[Page 38649]]
voluntary commitment does not include meeting NHTSA's FCW NCAP
requirements for the stopped lead vehicle scenario. The voluntary
commitment includes automatic braking system performance (CIB only)
able to achieve a specified average speed reduction over five repeated
trials when assessed in a stationary lead vehicle test conducted at
either 19 or 40 km/h (12 or 25 mph). To satisfy the performance
specifications in the voluntary commitment, the vehicle would need to
achieve a speed reduction of at least 16 km/h (10 mph) in either lead
vehicle stopped test, or a speed reduction of 8 km/h (5 mph) in both
tests. Participating automakers also committed to making the technology
standard on virtually all trucks with a GVWR between 3,856 kg (8,501
lbs.) and 4,536 kg (10,000 lbs.) no later than September 1, 2025.
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\72\ Audi, BMW, FCA US LLC, Ford, General Motors, Honda,
Hyundai, Jaguar Land Rover, Kia, Maserati, Mazda, Mercedes-Benz,
Mitsubishi Motors, Nissan, Porsche, Subaru, Tesla Motors Inc.,
Toyota, Volkswagen, and Volvo Car USA--representing more than 99
percent of the U.S. new light vehicle market.
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D. Response To Petition for Rulemaking
In 2017, NHTSA denied a petition for rulemaking from Consumer
Watchdog, Center for Automotive Safety, and Public Citizen which
requested that NHTSA initiate a rulemaking to require FCW, CIB, and DBS
on all light vehicles.\73\ NHTSA denied the petition after deciding
that NCAP, the voluntary commitment, and the consumer information
programs of various organizations would produce benefits substantially
similar to those that would eventually result from the petitioner's
requested rulemaking. Accordingly, the agency did not find evidence of
a market failure warranting initiation of the requested rulemaking.\74\
NHTSA further stated that the non-regulatory activities being
undertaken at the time would make AEB standard on new light vehicles
faster than could be achieved through a regulatory process and would
thus make AEB standard equipment earlier, with its associated safety
benefits. NHTSA stated that it would monitor vehicle performance in
NCAP and the industry's voluntary commitment, and initiate rulemaking
if the need arose.
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\73\ 82 FR 8391 (January 25, 2017).
\74\ Section 1(b) of E.O. 12866 requires agencies to assess the
failures of private markets to address the problem identified by the
agency.
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V. NHTSA's Decision To Require AEB
A. This Proposed Rule Is Needed To Address Urgent Safety Problems
NHTSA announced its intention to propose an FMVSS for AEB light
vehicles in the Spring 2021 Unified Regulatory Agenda.\75\ In making
the decision to initiate this rulemaking, NHTSA recognized that the
non-regulatory measures leading up to this NPRM had been key to an
increased and more rapid fleet penetration of AEB technology but
decided that rulemaking would best address the rise in motor vehicle
fatalities. In addition, NHTSA found that AEB could perform effectively
at higher speeds than the systems included in the voluntary agreement
and NCAP and that PAEB in darkness has become technologically possible.
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\75\ https://www.reginfo.gov/public/do/eAgendaViewRule?pubId=202104&RIN=2127-AM37.
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NHTSA initiated this rulemaking to reduce the frequency of rear-end
crashes, which is the most prevalent vehicle crash type, and to target
one of the most concerning and urgent traffic safety problems facing
the U.S. today--the rapidly increasing numbers of pedestrian fatalities
and injuries. Rear-end crashes are very common, although most are not
deadly. Nevertheless, approximately 2,000 people die in rear-end
crashes each year, making up 5 to 7 percent of total crash fatalities.
Pedestrian crashes are deadly and have been increasing in recent years.
They tend to happen at night and at higher speeds. About half of fatal
pedestrian crashes happen on roads with a speed limit of 40 mph or
lower and half on roads with a speed limit of 45 mph and higher.
The non-regulatory approaches of the past were instrumental in
developing AEB and encouraging manufacturers to include and consumers
to purchase AEB in most passenger vehicles sold today. With AEB sensors
and other hardware installed in the fleet as a result of NCAP and the
voluntary commitment, regulatory costs to equip new vehicles are
reduced. However, an FMVSS is needed to compel technological
improvement of AEB systems, and to ensure that every vehicle will be
equipped with a proven countermeasure that can drastically reduce the
frequency and severity of rear-end crashes and the safety risks posed
to pedestrians. NHTSA is aware of data and other information indicating
potential opportunities for AEB improvement. A recent IIHS study of
2009-2016 crash data from 23 States suggested that the increasing
effectiveness of AEB technology in certain crash situations is changing
rear-end crash scenarios.\76\ IIHS's study identified rear-end crashes
in which striking vehicles equipped with AEB were over-represented
compared to those without AEB. For instance, IIHS found that striking
vehicles involved in the following rear-end crashes were more likely to
have AEB: (1) where the striking vehicle was turning relative to when
it was moving straight; (2) when the struck vehicle was turning or
changing lanes relative to when it was slowing or stopped; (3) when the
struck vehicle was not a passenger vehicle or was a special use vehicle
relative to a passenger car; (4) on snowy or icy roads; or (5) on roads
with speed limits of 70 mph relative to those with 64 to 72.4 km/h (40
to 45 mph) speed limits. Overall, the study found that 25.3 percent of
crashes where the striking vehicle was equipped with AEB had at least
one of these over-represented characteristics, compared with 15.9
percent of impacts by vehicles that were not equipped with AEB. IIHS
found that in 2016, nearly 300,000 (15 percent) of the police reported
two-vehicle rear-end crashes involved one of the rear-end crashes
mentioned above.
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\76\ Cicchino, J.B. & Zuby, D.S. (2019, August), Characteristics
of rear-end crashes involving passenger vehicles with automatic
emergency braking, Traffic Injury Prevention, 2019, VOL. 20, NO. S1,
S112-S118 https://doi.org/10.1080/15389588.2019.1576172.
---------------------------------------------------------------------------
These results suggest that the metrics used to evaluate the
performance of AEB systems by NHTSA's NCAP, the voluntary industry
commitment, and other consumer information programs have facilitated
the development of AEB systems that reduce the crashes they were
designed to address. However, the results also indicate that AEB
systems have not yet provided their full crash reduction potential.
While they are effective at addressing some of the lower speed rear-end
crashes, they are less effective at fully addressing the safety need.
These data also indicate the potential of AEB to reduce fatal
crashes, especially if test speeds were increased. Accordingly, NHTSA
has issued this NPRM to drive AEB performance to maximize safety
benefits, assess practicability limits, and ensure that AEB technology
is incorporated in all vehicles to the extent possible. This NPRM is
issued to reach farther than NCAP to expand the availability of AEB
technologies to all vehicles--not just to those whose manufacturers
were incentivized to add such systems or whose purchasers were
interested in purchasing them. By ensuring the universal implementation
of AEB, this NPRM would best achieve equity in the safety provided
across vehicles and the safety provided to the communities on whose
roads they operate.
This NPRM would improve the capability of AEB systems beyond that
of the low-speed AEB systems contemplated by the voluntary commitment,
increasing safety benefits. The NPRM also would require PAEB,
[[Page 38650]]
while the voluntary commitment does not address PAEB. Requiring AEB
systems under an FMVSS would ensure that manufacturers design and
produce vehicles that provide at least the minimum level of safety
mandated by the standard or face consequences for not doing so,
including recalling the vehicle and remedying the noncompliance free of
charge. These positive outcomes could not be achieved by a voluntary
commitment alone.
Further, this NPRM responds to Congress's directive that AEB be
required on all passenger vehicles. On November 15, 2021, President
Biden signed the Bipartisan Infrastructure Law, codified as the
Infrastructure Investment and Jobs Act.\77\ Section 24208(a) of BIL
added 49 U.S.C. 30129, directing the Secretary of Transportation to
promulgate a rule to establish minimum performance standards with
respect to crash avoidance technology and to require that all passenger
motor vehicles for sale in the United States be equipped with a forward
collision warning system and an automatic emergency braking system.\78\
The FCW and AEB system is required to alert the driver if the vehicle
is closing its distance too quickly to a vehicle ahead or to an object
in the path of travel ahead and a collision is imminent, and to
automatically apply the brakes if the driver fails to do so.
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\77\ Public Law 117-58, 24208 (Nov. 15, 2021).
\78\ Section 24208 also directs DOT to require a lane departure
warning and lane-keeping assist system that warns the driver to
maintain the lane of travel; and corrects the course of travel if
the driver fails to do so.
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BIL requires that ``all passenger motor vehicles'' be equipped with
AEB and FCW. This NPRM would require AEB and FCW on all passenger cars
and multipurpose passenger vehicles, trucks, and buses with a GVWR of
10,000 lbs. or less. NHTSA believes that the scope of this NPRM
includes all vehicles required be equipped with AEB by section 24208 of
the IIJA.
BIL further requires that an FCW system alert the driver if there
is a ``vehicle ahead or an object in the path of travel'' if a
collision is imminent. Accordingly, NHTSA has defined an AEB system as
one that detects an imminent collision with a vehicle or with an
object. NHTSA does not read this provision as mandating a particular
level of performance regarding the detection of vehicles and objects.
More specifically, NHTSA does not interpret this provision to require
passenger vehicles to detect and respond to imminent collisions with
all vehicles or all objects in all scenarios. Such a requirement would
be unreasonable given the wide array of harmless objects that drivers
could encounter on the roadway that do not present safety risks. NHTSA
also does not interpret section 24208 to mandate AEB performance to
avoid any specific objects or to mandate PAEB.
Instead, NHTSA interprets section 24208 as broadly requiring AEB
capable of detecting and responding to vehicles and objects while
leaving to NHTSA the discretion to promulgate specific performance
requirements. Following this interpretation, NHTSA's proposal, if
implemented, would require light vehicles to be equipped with FCW and
automatic emergency braking, and the proposal defines AEB as a system
that detects an imminent collision with vehicles, objects, and road
users in or near the path of a vehicle and automatically controls the
vehicle's service brakes to avoid or mitigate the collision.
NHTSA has authority and discretion to promulgate requirements that
go beyond those contemplated under Section 24208. Pursuant to its
authority at 49 U.S.C. 30111, NHTSA is proposing that all light
passenger vehicles be required to have PAEB.
B. Stakeholder Interest in AEB
1. National Transportation Safety Board Recommendations
This NPRM is responsive to several National Transportation Safety
Board (NTSB) recommendations. In May 2015, the NTSB issued a special
investigation report, ``The Use of Forward Collision Avoidance Systems
to Prevent and Mitigate Rear-End Crashes.'' \79\ The report detailed
nine crash investigations involving passenger or commercial vehicles
striking the rear of another vehicle, and concluded that collision
warning systems, particularly when paired with active braking, could
significantly reduce the frequency and severity of rear-end crashes. As
a result, the NTSB issued several safety recommendations to NHTSA,
including the following:
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\79\ https://www.ntsb.gov/safety/safety-studies/Documents/SIR1501.pdf.
---------------------------------------------------------------------------
H-15-04: Develop and apply testing protocols to assess the
performance of forward collision avoidance systems in passenger
vehicles at various velocities, including high speed and high velocity-
differential.
In September 2018, the NTSB issued another special investigation
report, ``Pedestrian Safety.'' \80\ This report examined the past 10
years of pedestrian crash data, described NTSB pedestrian safety
investigations, and summarized issues raised in a public forum. As a
result, the NTSB issued several safety recommendations to NHTSA,
including the following:
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\80\ https://www.ntsb.gov/safety/safety-studies/Documents/SIR1803.pdf.
---------------------------------------------------------------------------
H-18-41: Develop performance test criteria for vehicle
designs that reduce injuries to pedestrians.
H-18-42: Develop performance test criteria for
manufacturers to use in evaluating the extent to which automated
pedestrian safety systems in light vehicles will prevent or mitigate
pedestrian injury.
2. Consumer Information Programs in the United States
In the United States, in addition to NHTSA's NCAP, the Insurance
Institute for Highway Safety also tests AEB systems in vehicles for the
purpose of informing consumers about their performance. Both programs
test AEB systems in response to a stationary lead vehicle test device,
but IIHS only performs tests to assess crash imminent braking system
performance, while NCAP AEB evaluations also test DBS responses and
assess system performance for both slower-moving and decelerating lead
vehicle scenarios. NCAP also tests for false positive AEB activation by
having subject vehicles drive over a steel trench plate. NCAP provides
pass/fail results based on speed reduction and crash avoidance in DBS
tests attributed to AEB, while IIHS awards points based only on speed
reduction.\81\ Both programs are considering upgrades to their AEB
performance tests. On March 9, 2022, NHTSA issued a request for
comments notice proposing increased test speeds in its DBS and CIB test
protocols. On May 5, 2022, IIHS announced its intention to test six
vehicles equipped with AEB at higher speeds, up to 72.4 km/h (45 mph),
to better align with reported crashes.\82\
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\81\ The March 9, 2022, request for comments notice also asks
for public comment on NHTSA's plan to develop a future rating system
for new vehicles based on the availability and performance of all
the NCAP-recommended crash avoidance technologies. 87 FR 13452.
\82\ https://www.iihs.org/news/detail/iihs-eyes-higher-speed-test-for-automatic-emergency-braking.
---------------------------------------------------------------------------
IIHS further conducts PAEB tests in two scenarios like those
proposed in the NPRM. In the first scenario, an articulated test
mannequin crosses the subject vehicle's path; this condition is tested
with both the articulated child surrogate (Perpendicular Child) and the
articulated adult surrogate (Perpendicular Adult). In the second
scenario, an adult test mannequin without articulation is standing in a
[[Page 38651]]
vehicle's path, offset 25 percent from center (Parallel Adult). Both
test scenarios are conducted during daylight conditions. Points are
awarded in the IIHS test based on vehicle speed reduction.
Other consumer information groups have also invested effort into
supplying customers with information regarding AEB. Since 2016,
Consumer Reports has been awarding ``bonus'' points to its overall
score for vehicles that come equipped with AEB and FCW as standard
features across all trim levels of a model.\83\
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\83\ https://www.consumerreports.org/car-safety/where-automakers-stand-on-automatic-emergency-braking-pledge/.
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3. Petition for Rulemaking on PAEB Performance in Dark Conditions
On March 22, 2022, IIHS and the Highway Loss Data Institute
petitioned NHTSA to require, through rulemaking, that passenger
vehicles be equipped with AEB that responds to pedestrians in all light
conditions. The petitioners stated that research from IIHS estimates
that PAEB systems reduce pedestrian crash risk by an estimated 32 to 33
percent in daylight or dark conditions with street lighting but does
not reduce pedestrian crash risk in the dark without street lighting.
The petitioners stated that over a third of pedestrian deaths occur in
dark, unlit conditions, and that requiring PAEB systems that function
in those conditions will lead to a greater reduction in fatalities than
only requiring those systems that function in daylight.
When NHTSA received the petition from IIHS, the agency had already
announced in the Fall 2021 Unified Agenda of Regulatory and
Deregulatory Actions \84\ that it had initiated rulemaking on PAEB. The
agency announced that it would issue a proposal to require and/or
standardize performance for light vehicle AEB, including PAEB. NHTSA's
Agenda entry further announced that this rulemaking would set
performance requirements for AEB systems and would specify a test
procedure under which compliance with those requirements would be
measured. Given this context, NHTSA denied the petition as moot because
NHTSA had already commenced rulemaking on the requested action and was,
and remains, deeply immersed in developing the rule. Although NHTSA has
denied the petition, NHTSA has considered its points as suggestions for
this rulemaking. A copy of the petition has been placed in the docket
for this rulemaking.
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\84\ https://www.reginfo.gov/public/do/eAgendaMain; See RIN
2127-AM37, titled, ``Light Vehicle Automatic Emergency Braking (AEB)
with Pedestrian AEB.''
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C. Key Findings Underlying This Proposal
1. Impact Speed Is Key To Improving AEB's Mitigation of Fatalities and
Injuries
As described in the section II of this NPRM, 79 percent of
property-damage-only crashes, 73 percent of injuries, and 60 percent of
fatalities in rear-end crashes involving light vehicles occur on roads
where the posted speed limit is 60 mph (97 km/h) or less. However, the
majority of those crashes are skewed towards the higher end of that
range. Only 3 percent of fatalities, 9 percent of injuries, and 12
percent of property-damage-only crashes occur at posted speeds below 30
mph (48 km/h). NHTSA believes that most of the safety need exists at
speeds greater than 30 mph (48 km/h). In light of these data, this NPRM
seeks to address a safety need at a speed well above that found in the
voluntary commitment, which has a maximum test speed of 40 km/h (25
mph). The data show that speeds higher than those proposed in the 2022
NCAP request for comments notice \85\ (with a maximum testing speed of
80 km/h (50 mph)) are also required to address the safety need.\86\ In
fact, the data demonstrate the safety need for AEB systems to activate
at as high a speed as can practicably be achieved.
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\85\ 87 FR 13452.
\86\ In 2019, 67 percent of fatalities within the target
population occur where the posted speeds are above 50 mph, and 29
percent of the fatalities occur at posted speeds of 55 mph and 60
mph.
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2. Darkness Performance of PAEB Is Highly Important
Out of the 4,069 pedestrian fatalities in 2019 resulting from being
struck by the front of a light vehicle, about 77 percent occurred in
dark conditions and about 50 percent of all pedestrian fatalities
occurred at posted speeds of 40 mph (64 km/h) or less. Forty percent of
all pedestrian injuries, regardless of how a pedestrian is struck,
occur in dark conditions and 57 percent of them occur at posted speeds
of 40 mph (64 km/h) or less. Based on these data, the agency
tentatively concludes that performance testing under various lighting
conditions and at higher speeds is necessary.
During 2020 agency research testing using model year 2019 and 2020
vehicles, observed AEB performance was not consistent for some of the
proposed lighting conditions and speeds. During PAEB testing, 5 out of
11 vehicles avoided collision in at least one test at speeds up to 60
km/h (37.3 mph) in daylight when an adult pedestrian test mannequin
crossed the path of the vehicle from the right; absent PAEB
intervention, the front middle section of the vehicle would have hit
the test mannequin. For the same scenario, 5 vehicles out of 11 avoided
impact with the test mannequin in at least one test at speeds up to 40
km/h (25 mph) when testing using the vehicle's lower beam headlamps in
dark conditions. Only 1 of 11 vehicles could consistently avoid impact
in every test trial in each of the daylight and dark lower beam
headlamp conditions at these speeds.
For tests involving a stationary pedestrian test mannequin situated
toward the right side of the road, but within the path of the vehicle,
3 vehicles out of 11 consistently avoided impact at speeds up to 50 km/
h (31.1 mph) in daylight conditions, and one avoided impact in five out
of six tests at 60 km/h (37 mph). In dark conditions, using only the
lower beam headlamps, one vehicle avoided collision at all speeds up to
50 km/h (31.1 mph) and in four out of five tests at 55 km/h (34.2 mph).
However, other tested vehicles contacted the test mannequin at all
speeds above 16 km/h (10 mph) in the same darkness condition.
NHTSA has tentatively concluded that the performance achieved by
the better performing vehicles in dark lighting conditions can be
achieved by all vehicles given an adequate phase-in period. This is
consistent with recent testing performed by IIHS, which found that
existing systems can perform in darkness conditions regardless of their
IIHS headlamp ratings.\87\ The agency tentatively concludes that AEB
system performance is improving, and the latest AEB systems are already
able to perform much better than previous systems. Concurrent with the
development of this proposed rule, NHTSA performed PAEB testing on
model year 2021 and 2022 vehicles using the proposed performance
requirements and test procedures. The results of this testing are
detailed in the PAEB report docketed with this proposed rule.
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\87\ IIHS dark light press release: https://www.iihs.org/news/detail/pedestrian-crash-avoidance-systems-cut-crashes--but-not-in-the-dark.
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3. NHTSA's 2020 Research on Lead Vehicle AEB and PAEB Performance Show
the Practicability of Higher Speed Tests
In 2020, NHTSA conducted lead vehicle AEB and PAEB performance
tests on 11 model year 2019 and 2020 vehicles from 10 vehicle
manufacturers.
[[Page 38652]]
This work was done to support the agency's March 9, 2022 request for
comments notice proposing to upgrade NCAP, as well as to assist in the
development of this NPRM.
a. Lead Vehicle AEB Performance Tests
To evaluate lead vehicle AEB performance at higher speeds, the
agency performed CIB tests in accordance with NCAP's CIB test
procedures,\88\ but repeated the lead vehicle stopped and lead vehicle
decelerating test scenarios using an expanded set of input conditions
to assess how specific test procedures changes, such as increasing
speed or deceleration magnitude, would affect the vehicle's CIB
performance. NHTSA placed test reports detailing the results in the
docket of the March 9, 2022, NCAP request for comments notice on the
proposed updates.\89\
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\88\ www.regulations.gov. NHTSA Docket No. NHTSA-2015-0006-0025.
\89\ www.regulations.gov. NHTSA Docket No. NHTSA-2021-0002-0002.
``Final MY2019/MY2020 Research Reports for Pedestrian Automatic
Emergency Braking, High-Speed Crash Imminent Braking, Blind Spot
Warning, and Blind Spot Intervention Testing.'' There are 11 test
reports w/the following title for each vehicle name: ``Crash
Imminent Braking System Research Test.''
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For the NCAP CIB lead vehicle stopped test scenario, NHTSA
conducted tests at incremental vehicle speeds from 40 to 72.4 km/h (25
to 45 mph). The results showed that the tested vehicle CIB systems
exceeded the performance established in consumer programs, such as
model year 2022 NCAP and IIHS. Three vehicles were able to demonstrate
no contact with the lead vehicle at speeds up to 72.4 km/h (45 mph),
and the remaining eight vehicles had an average speed reduction of 37.7
km/h (23.4 mph) when tested at this speed.\90\ One vehicle avoided
contact in all tests and at speeds up to 72.4 km/h (45 mph), for a
total of 27 out of 27 tests without contact.
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\90\ Two vehicles were able to avoid contact in five out of five
tests conducted at 72.4 km/h (45 mph). The third vehicle avoided
contact in one out of five tests conducted at 72.4 km/h (45 mph).
---------------------------------------------------------------------------
NHTSA also conducted CIB lead vehicle decelerating tests as a part
of NHTSA's 2020 research study. When the test conditions were modified
such that the lead vehicle decelerated at 0.5g, rather than 0.3g as
specified in NHTSA's CIB NCAP test procedure, eight vehicles
demonstrated the ability to avoid contact with the lead vehicle in at
least one test and three vehicles avoided contact in all tests despite
having less time to avoid the crash. Similarly, when the speed of the
subject vehicle and lead vehicle was increased to 72.4 km/h (45 mph),
nine vehicles demonstrated the ability to avoid contact with the lead
vehicle in at least one test while four vehicles avoided contact in all
tests. One vehicle was able to avoid contact in all lead vehicle
decelerating tests, including both increased speeds and increased lead
vehicle deceleration.
Although NHTSA did not perform higher speed evaluations for the
slower-moving lead vehicle test scenario as part of its CIB study,
NHTSA believes that it is reasonable and appropriate for this NPRM to
propose raising the subject vehicle speed above that specified
currently in NCAP's test to ensure improved AEB performance. NHTSA also
did not conduct DBS testing in its characterization study to evaluate
AEB system performance capabilities. However, the CIB and DBS test
procedures proposed in this NPRM use the same test scenarios.
Differences exist only with respect to the use of subject vehicle
manual brake application and maximum test speeds. NHTSA constructed its
2020 research program using CIB to demonstrate the practicability of
testing at higher speeds with a no-contact requirement. In past
testing, DBS performance has typically been as good as if not better
than CIB.
Concurrent with the development of this proposed rule, NHTSA
performed lead vehicle AEB testing on model year 2021 and 2022 vehicles
using the proposed performance requirements and test procedures. The
results of that testing provide additional support to the tentative
conclusion that the test conditions, parameters, and procedures are
practical to conduct and that the proposed requirements are practical
for manufacturers to achieve. The results of this testing are detailed
in the lead vehicle AEB report docketed with this proposed rule. The 12
model year 2021 and 2022 vehicles were selected to provide a balance of
anticipated market penetration (using 2021 sales data) and a mix of
vehicle types, including internal combustion engine vehicles and
electric vehicles. Tests enabled the agency to refine the test
procedures and validate test execution within the proposed tolerances.
b. PAEB Daytime Performance Tests
NHTSA selected the same 11 model year 2019 and 2020 vehicles used
in the CIB testing to assess the performance of current PAEB systems.
NHTSA issued test reports detailing the results in support of the March
9, 2022, NCAP request for comments notice.\91\
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\91\ See Docket No. NHTSA-2021-0002-0002. There are embedded
reports titled, ``PEDESTRIAN AUTOMATIC EMERGENCY BRAKING SYSTEM
RESEARCH TEST'' for each of the 11 vehicle make/models.
---------------------------------------------------------------------------
As shown in Table 19, NHTSA used its 2019 draft PAEB research test
procedures, but increased the subject vehicle speed for specific test
conditions.\92\ Additionally, NHTSA used articulating test mannequins,
as used in Euro NCAP, instead of the posable mannequins specified in
the draft test procedure.\93\
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\92\ 84 FR 64405 (Nov. 21, 2019). www.regulations.gov, NHTSA
Docket No. NHTSA-2019-0102-0005. Note, in this document, the PAEB
test procedures were called ``Pedestrian Automatic Emergency Brake
System Confirmation Tests.'' NHTSA increased test speeds for the
S1b, S1d, S1e, S4a, and S4c from NHTSA's draft test procedure.
\93\ https://cdn.euroncap.com/media/41769/euro-ncap-pedestrian-testing-protocol-v85.201811091256001913.pdf.
Table 19--Matrix of the Daytime PAEB NHTSA 2020 Research Tests
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crossing path
Along path
--------------------------------------------------------------------------------------------------------------------------------------------------------
Test Mann............................... Adult Child Adult Adult
Adult
---------------------------------------------------------------------------------------------------------------
Motion.................................. Walking
Running
Walking
Fixed Walking
---------------------------------------------------------------------------------------------------------------
Direction............................... Right Right, Left Right Right Facing Facing Away from
Obstructed Away Vehicle Vehicle
---------------------------------------------------------------------------------------------------------------
Test Mann. Speed........................ 5 km/h 5 km/h 8 km/h 5 km/h 5 km/h 0 km/h 0 km/h 5 km/h
[[Page 38653]]
Table 19--Matrix of the Daytime PAEB NHTSA 2020 Research Tests--Continued
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crossing path
Along path
--------------------------------------------------------------------------------------------------------------------------------------------------------
Overlap................................. 25% 50% 75% 50% 50% Stops Crosses/ 25% 25% 25%
Before Clears
Vehicle Vehicle
Path Path
--------------------------------------------------------------------------------------------------------------------------------------------------------
Scenario S1a S1b S1c S1d S1e S1f S1g S4a S4b S4c
--------------------------------------------------------------------------------------------------------------------------------------------------------
Subject Vehicle Speed (km/h)............ 16 16 16 16 40 40 40 16 16 16
40 20 40 20 50 ......... ......... 40 40 40
......... 30 ......... 30 60 ......... ......... 50 ......... 50
......... 40 ......... 40 ......... ......... ......... 60 ......... 60
......... 50 ......... 50 ......... ......... ......... 70 ......... 70
......... 60 ......... 60 ......... ......... ......... 80 ......... 80
--------------------------------------------------------------------------------------------------------------------------------------------------------
The maximum test speeds for the crossing path and along path
scenarios were 60 km/h (37.5 mph) and 80 km/h (50 mph), respectively.
These maximum speeds were consistent with Euro NCAP's AEB Vulnerable
Road User Protection protocol published at the time of testing.\94\
---------------------------------------------------------------------------
\94\ European New Car Assessment Programme (Euro NCAP). (2019,
July). TEST PROTOCOL--AEB VRU systems 3.0.2.
---------------------------------------------------------------------------
The results demonstrated that several vehicles avoided contact with
the test mannequin in nearly all tests conducted, including at speeds
up to 60 km/h (37.5 mph) in the 50 percent overlap test (S1b). The most
challenging crossing path test condition was the running child from
behind parked vehicle condition (S1d); however, one vehicle was able to
detect and avoid contact with the test mannequin at all subject vehicle
speeds up to 60 km/h (37.5 mph). Similarly, in the crossing adult
pedestrian running from the left side test condition (S1e), the testing
demonstrated that at least one vehicle did not collide with the test
mannequin in all tests conducted at speeds up to 60 km/h (37.5
mph).\95\ The walking test mannequin stopping prior to entering the
travel lane test condition (S1f) was the most challenging for vehicles
to predict and not unnecessarily activate PAEB. The other false
positive test, where a crossing adult test mannequin walks from the
nearside and clears the vehicle's path (S1g), resulted in fewer
instances of automatic braking.
---------------------------------------------------------------------------
\95\ At the 60 km/h (37.5 mph) test speed, the vehicle achieved
no contact in four out of five tests conducted.
---------------------------------------------------------------------------
In the test with the stationary pedestrian facing away from the
subject vehicle (S4a), NHTSA's research testing showed that several
vehicles were able to repeatedly avoid impacting the test mannequin at
speeds of 50 km/h (31 mph) and 60 km/h (37.5 mph). However, vehicles
were not able to avoid impact at the highest test speed of 80 km/h (50
mph). In the scenario where the subject vehicle encounters an adult
pedestrian walking away from the vehicle (S4c), two vehicles were able
to avoid contact with the test mannequin in tests at speeds up to 65
km/h (40.3 mph) during each test performed at that speed.
c. PAEB Darkness Performance Tests
NHTSA conducted additional PAEB tests under dark lighting
conditions using vehicle lower and upper beam headlamps. The tests used
the same test scenarios and conditions as NHTSA's 2019 draft research
test procedures and the same 11 vehicles tested for CIB and daylight
PAEB performance. Tests were conducted first with the test mannequin
illuminated only by the vehicle's lower beam headlamps and then by the
upper beam headlamps. The area where the test mannequin was located was
not provided any additional light source.
Table 20--Matrix of the Dark Lighting PAEB NHTSA 2020 Research Tests *
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Crossing path
Along path
----------------------------------------------------------------------------------------------------------------
Test Mann....................... Adult Child Adult Adult Adult
-------------------------------------------------------------------------------
Motion.......................... Walking Running Fixed Walking
-------------------------------------------------------------------------------
Direction....................... Right Right, Left Facing Away Away from
Obstructed Vehicle
-------------------------------------------------------------------------------
Test Mann. Speed................ 5 km/h 5 km/h 8 km/h 0 km/h 5 km/h
-------------------------------------------------------------------------------
Overlap......................... 50% 50% 50% 25% 25%
----------------------------------------------------------------------------------------------------------------
Scenario S1b S1d S1e S4a S4c
----------------------------------------------------------------------------------------------------------------
Subject Vehicle Speed (km/h).... 16 16 40 16 16
20 20 50 40 40
30 30 60 50 50
40 40 .............. 60 60
50 50 .............. 70 70
60 60 .............. 80 80
----------------------------------------------------------------------------------------------------------------
* Tests were separately conducted with the vehicle lower and upper beam headlamps activated.
[[Page 38654]]
NHTSA's testing showed that tests conducted with upper beam
headlamps generally resulted in greater braking and less contact with
the test mannequin than identical tests conducted with lower beam
headlamps in the S1b test condition. The maximum speed at which at
least one vehicle avoided contact in all trials with the test mannequin
was 60 km/h (37.3 mph) for the upper beam condition, compared to 50 km/
h (31.1 mph) for the lower beam condition.
NHTSA observed that many of the model year 2019 and 2020 vehicles
experienced difficulties or inconsistent performance in the crossing
child pedestrian running from behind parked vehicles scenario (S1d).
Many vehicle contacts with the test mannequin did not include any AEB
system activation. Additionally, many of the tests in the crossing
adult pedestrian running from the left side test condition (S1e) were
not conducted due to the lack of PAEB activation at lower speeds. For
example, in the lower beam tests at 40 km/h (25 mph), 8 of the 11
vehicles could not avoid test mannequin contact. Vehicle performance in
the upper beam headlamp tests were only marginally better for this test
condition.
In the along path research tests (S4a), one vehicle was able to
avoid test mannequin contact for all vehicle test speeds up to 60 km/h
(37.5 mph) using the upper beam headlamps and at speeds up to 55 km/h
(34.2 mph) using the lower beam headlamps. However, many other vehicles
were not tested above 40 km/h (25 mph) due to contact with the test
mannequin.
Likewise, in the scenario in which the subject vehicle encounters
an adult pedestrian standing facing away from the vehicle (S4c), many
vehicles were not tested above 40 km/h (25 mph) due to repeated contact
with the test mannequin. In the lower beam headlamp tests, two vehicles
were able to avoid contact with the test mannequin in tests at speeds
up to 60 km/h (37.5 mph), and one was able to do so during each test
performed. In the upper beam headlamp tests, one vehicle was able to
avoid contact with the test mannequin during each test performed at all
tested speeds up to 50 km/h (31.1 mph).
d. PAEB Darkness Performance Tests With Overhead Lighting
To study potential performance differences attributable to the use
of overhead lights during dark conditions, NHTSA performed several of
the PAEB test scenarios at two test speeds, 16 km/h (10 mph) and 40 km/
h (25 mph), using two model year 2020 vehicles.\96\ This study was
performed using the vehicles' lower beams under dark conditions with
overhead lights. In this testing, the agency observed only slightly
better PAEB performance in dark lighting conditions with overhead
lights than in dark lighting conditions without overhead lights.
---------------------------------------------------------------------------
\96\ Specifically, NHTSA performed overhead lighting tests using
scenarios S1b, S1d, and S1e and S4a and S4c.
---------------------------------------------------------------------------
4. This Proposed Standard Complements Other NHTSA Actions
This NPRM is part of NHTSA's multi-pronged approach to enhance
vehicle performance against pedestrian injury and counter the rising
numbers of pedestrian fatalities and injuries. This proposal would
require the installation of PAEB technologies that warn about and
respond to an imminent collision with a pedestrian at higher speeds
than PAEB systems on the market today.
This proposal would complement a rulemaking proposal under
development that would require that passenger vehicle hoods mitigate
the risk of serious or fatal child and adult head injury in pedestrian
crashes.\97\ When new vehicles are equipped with PAEB, fewer
pedestrians will be struck. For impacts that cannot be avoided due to
high closing speed of the vehicle, the automatic braking provided by
PAEB will lower the vehicle's speed at impact. Lowering the speed of
pedestrian impact and strengthening pedestrian protection provided by
vehicle hoods would be complementary actions, resulting in
complementary benefits of the two proposed rules. Furthermore, NHTSA
has announced plans to propose a crashworthiness pedestrian protection
testing program in NCAP. This pedestrian protection program would
incorporate three crashworthiness tests (i.e., head-to-hood, upper leg-
to-hood leading edge, and lower leg-to-bumper).\98\
---------------------------------------------------------------------------
\97\ Unified Agenda of Regulatory and Deregulatory Actions,
Regulation Identifier Number (RIN) 2127-AK98, ``Pedestrian Safety
Global Technical Regulation.''
\98\ 87 FR 13452, March 9, 2022.
---------------------------------------------------------------------------
On February 22, 2022, NHTSA published a final rule amending NHTSA's
lighting standard to allow adaptive driving beam headlamps.\99\ These
headlighting systems incorporate an advanced type of headlamp beam
switching that can provide a variable upper beam sculpted so that it
provides more light on the roadway ahead without creating glare for the
drivers of oncoming or preceding vehicles. Adaptive driving beam
headlighting systems also have the potential to provide safety benefits
in preventing collisions with pedestrians.
---------------------------------------------------------------------------
\99\ RIN 2127-AL83.
---------------------------------------------------------------------------
VI. Proposal To Require Automatic Emergency Braking
This NPRM proposes a new FMVSS to require AEB systems on light
vehicles that are capable of reducing the frequency and severity both
rear-end and pedestrian crashes. Having considered the actions of
industry, including those in response to nonregulatory incentives,
NHTSA has concluded that this rulemaking is necessary to require that
all new light vehicles are equipped with AEB systems and to set
specific performance requirements for AEB systems. NHTSA incorporated
FCW into NCAP beginning in model year 2011 and AEB into NCAP beginning
in model year 2018. This has achieved success, with approximately 65
percent of new vehicles meeting the lead vehicle test procedures
included in NCAP.\100\ Similarly, the voluntary commitment resulted in
approximately 90 percent of new light vehicles having an AEB
system.\101\
---------------------------------------------------------------------------
\100\ Percentage based on the vehicle manufacturer's model year
2022 projected sales volume reported through the New Car Assessment
Program's annual vehicle information request.
\101\ Id.
---------------------------------------------------------------------------
However, NHTSA has tentatively concluded that these actions have
insufficiently addressed the safety problem associated with rear-end
and pedestrian crashes for three primary reasons. First, the test
speeds and performance specifications in NCAP and the voluntary
commitment would not ensure that the systems perform in a way that will
prevent or mitigate crashes resulting in serious injuries and
fatalities. The vast majority of fatalities, injuries, and property
damage crashes occur at speeds above 40 km/h (25 mph), which are above
those covered by the voluntary commitment.
Second, NCAP and, even more so, other voluntary measures are
intended to supplement rather than substitute for the FMVSS, which
remain NHTSA's core way of ensuring that all motor vehicles are able to
achieve an adequate level of safety performance. Thus, though the NCAP
program provides valuable safety-related information to consumers in a
simple to understand way, the agency believes that gaps in market
penetration will continue to exist for the most highly effective AEB
systems. Moreover, as pedestrian safety addresses the safety of someone
other than the vehicle occupant, it is not clear if past experiences
with NCAP are necessarily indicative of how quickly PAEB systems would
reach the levels of
[[Page 38655]]
lead vehicle AEB, if pedestrian functionality that would meet NCAP
performance levels was offered as a separate cost to consumers. NHTSA
believes that there can be a significant safety benefit in NCAP
providing consumers with information about new safety technologies
before it is prepared to mandate them, but this is not a requirement.
A final factor weighing in favor of requiring AEB is that the
technology is a significantly more mature level than what it was at the
time of the voluntary commitment or when it was introduced into NCAP.
NHTSA's most recent testing has shown that higher performance levels
than those in the voluntary commitment or the existing NCAP
requirements are now practicable. Many model year 2019 and 2020
vehicles were able to repeatedly avoid impacting the lead vehicle in
CIB tests and the pedestrian test mannequin in PAEB tests, even at
higher test speeds than those prescribed currently in the agency's CIB
and draft PAEB test procedures.
This proposed rule includes three basic lead vehicle AEB test
scenarios--stopped, slower-moving, and decelerating lead vehicle. Each
lead vehicle AEB scenario has performance requirements at specific
speeds or ranges of speeds. Each scenario also includes performance
requirements with and without manual braking. NHTSA's general approach
in developing performance requirements was to consider the state of AEB
technology and its ability to address crashes. Key parameters were
identified that are important in differentiating between AEB systems
that are effective at preventing crashes, and AEB systems that only
engage in narrow and very controlled conditions, with the latter being
potentially less effective at reducing fatalities and injuries. For
example, a system that only automatically applies the brakes where the
posted speed limit is 25 mph or less would be effective at preventing
property damage rear-end crashes, but would prevent very few fatalities
and injuries. Likewise, PAEB systems that are unable to prevent crashes
in low-light ambient conditions would fail to reduce a large portion of
pedestrian fatalities. Considering the ability of current AEB
technology to safely prevent crashes, and using information from
vehicle testing, NHTSA is proposing requirements, including test
scenarios and parameters, that are either within the capability of at
least one recent production vehicle or for which there is a practical
engineering basis for the prescribed capability in current AEB systems.
The proposal requires a vehicle to provide a FCW and have an
emergency braking system that automatically applies the brakes when a
collision with the rear of another vehicle or a pedestrian is imminent
at speeds above 10 km/h (6.2 mph). Furthermore, proposed AEB
performance requirements will ensure that an AEB system is able to
completely avoid collision with the rear of another vehicle or a
pedestrian. Specifically, the proposal includes a set of performance
requirements for vehicle-level track testing that will realistically
evaluate vehicles at normal driving speeds and introduce test devices
for which vehicles must automatically brake in a way that avoids any
impact with the objects. The requirements include lead vehicle AEB test
scenarios, where the test object that must be avoided is the lead
vehicle test device, and PAEB test scenarios, where the object that
must be avoided is a pedestrian test mannequin. In all tests that
include a test device, the observable and objective criterion for
passing is avoiding contact with the object. The agency is proposing
additional system requirements for false activation and provisions for
indicating AEB malfunction to the vehicle operator.
A. Lead Vehicle AEB System Requirement
The agency is proposing that vehicles be required to have a forward
collision warning system and an automatic emergency braking system that
are able to function continuously to apply the service brakes
automatically when a collision with a vehicle or object is imminent.
The system must operate when the vehicle is traveling at any forward
speed greater than 10 km/h (6.2 mph). This is a general system
equipment requirement with no associated performance test. No specific
speed reduction or crash avoidance would be required. However, this
requirement is included to ensure that AEB systems are able to function
at all times, including at speeds above those NHTSA is proposing as
part of the performance test requirements.
This requirement complements the performance requirements in
several ways. While the track testing described below provides a
representation of real-world crash events, no amount of track testing
can fully duplicate the real world. This requirement ensures that the
AEB's perception system identifies and automatically detects a vehicle,
warns the driver, and applies braking when a collision is imminent.
This requirement also ensures that AEB systems continue to function in
environments that are not as controlled as the test track environment.
For example, unlike during track testing, other vehicles, pedestrians,
bicyclists, and buildings may be present within the view of the
sensors. Finally, track test equipment limitations and safety
considerations limit the ability to test at high speeds. However,
crashes still occur at higher travel speeds. The automatic braking
requirement ensures that AEB systems continue to provide safety
benefits at speeds above those for which a track-testing requirement is
currently not practicable, either because of performance capabilities
or track test limitations. Where a performance standard is not
practical or does not sufficiently meet the need for safety, NHTSA may
specify an equipment requirement as part of an FMVSS.\102\
---------------------------------------------------------------------------
\102\ See 72 FR 17235, 17299 (Apr. 6, 2007) (discussing the
understeer requirement in FMVSS No. 126); Chrysler Corp. v. DOT, 515
F.2d 1053 (6th Cir. 1975) (holding that NHTSA's specification of
dimensional requirements for rectangular headlamps constitutes an
objective performance standard under the Safety Act).
---------------------------------------------------------------------------
Enforcement of such a performance requirement can be based on
evidence obtained by engineering investigation that might include a
post-crash investigation and/or system design investigation. For
instance, if a crash occurs in which the vehicle under examination has
collided with a lead vehicle, NHTSA could investigate the details
surrounding the crash to determine if a warning was provided and the
automatic emergency braking system applied the service brakes
automatically. In appropriate cases in the context of an enforcement
proceeding, NHTSA could also use its information-gathering authority to
obtain information from a manufacturer describing the basis on which it
certified that its FCW and AEB systems meet this proposed requirement.
B. Forward Collision Warning Requirement
NHTSA is proposing that AEB-equipped vehicles must have forward
collision warning functionality that provides a warning to the vehicle
operator if a forward collision with a lead vehicle is imminent. The
proposal defines FCW as an auditory and visual warning provided to the
vehicle operator that is designed to elicit an immediate crash
avoidance response by the vehicle operator. The system must operate
when the vehicle is traveling at any forward speed greater than 10 km/h
(6.2 mph).
[[Page 38656]]
While some vehicles are equipped with alerts that precede the FCW
and research has examined their use, NHTSA's proposal is not specifying
an advisory or preliminary alert that would precede the FCW. Lerner,
Kotwal, Lyons, and Gardner-Bonneau (1996) differentiated between an
imminent alert, which ``requires an immediate corrective action,'' and
a cautionary alert, which ``alerts the operator to a situation which
requires immediate attention and may require a corrective action.''
\103\ A 2004 NHTSA report titled ``Safety Vehicles using adaptive
Interface Technology (Task 9): A Literature Review of Safety Warning
Countermeasures,'' examined the question of whether to include a
cautionary alert level in an FCW system. Although the two FCW
algorithms in the Automotive Collision Avoidance System Field
Operational Test algorithms included a cautionary phase, the Collision
Avoidance Metrics Partnership (1999) program recommended that only
single (imminent) stage warnings be used.
---------------------------------------------------------------------------
\103\ Lerner, Kotwal, Lyons, and Gardner-Bonneau (1996).
Preliminary Human Factors Guidelines for Crash Avoidance Warning
Devices. DOT HS 808 342. National Highway Traffic Safety
Administration.
---------------------------------------------------------------------------
Unlike the FCW required as part of the track testing, NHTSA is not
specifically requiring that FCW presentation occur prior to the onset
of braking in instances that are not tested on the track. This is to
provide manufacturers with the flexibility to design systems that are
most appropriate for the complexities of various crash situations, some
of which may provide very little time for a driver to take action to
avoid a crash. A requirement that FCW occur prior to automatic braking
could suppress the automatic braking function in some actual driving
scenarios, such as a lead vehicle cutting immediately in front of an
AEB-equipped vehicle, where immediate automatic braking should not wait
for a driver warning.
1. FCW Modalities
Since approximately 1994, NHTSA has completed research and
published related reports for more than 35 research efforts related to
crash avoidance warnings or forward collision warnings. These research
efforts, along with other published research and existing ISO standards
(15623 and 22839) and SAE International (SAE) documents (J3029 and
J2400), provide a basis for the proposed requirements.\104\
---------------------------------------------------------------------------
\104\ ISO 15623--Forward vehicle collision warning systems--
Performance requirements and test procedures; ISO 22839--Forward
vehicle collision mitigation systems--Operation, performance, and
verification requirements (applies to light and heavy vehicles); SAE
J3029: Forward Collision Warning and Mitigation Vehicle Test
Procedure and Minimum Performance Requirements--Truck and Bus (2015-
10; WIP currently); SAE J2400 2003-08 (Information report). Human
Factors in Forward Collision Warning Systems: Operating
Characteristics and User Interface Requirements.
---------------------------------------------------------------------------
NHTSA NCAP and Euro NCAP information relating to FCW was also
considered. Since model year 2011, the agency has included FCW as a
recommended technology in NCAP and identifies to consumers which light
vehicles have FCW systems that meet NCAP's performance tests. NHTSA's
March 2022 request for comments notice on proposed changes to NCAP
sought comment on which FCW modalities or modality combinations should
be necessary to receive NHTSA's NCAP recommendation.\105\ Commenters
generally supported the use of a multimodal FCW strategy. The Alliance
for Automotive Innovation and Intel both advocated allowing credit for
any effective FCW signal type. Multiple commenters supported allowing
NCAP credit for FCW having either auditory or haptic signals. BMW,
Stellantis, and General Motors supported use of FCW auditory or haptic
signals in addition to a visual signal. NTSB and Advocates for Highway
and Auto Safety recommended that NHTSA conduct research examining the
human-machine interface and examine the effectiveness of haptic warning
signals presented in different locations (e.g., seat belt, seat pan,
brake pulse). Dynamic Research, Inc. advocated allowing NCAP credit for
implementation of a FCW haptic brake pulse, while ZF supported use of a
haptic signal presented via the seat belt. Bosch warned that use of a
haptic signal presented via the steering wheel for lane keeping or
blind spot warning and FCW should be avoided as it may confuse the
driver. The Alliance for Automotive Innovation raised the potential
benefits of standardizing the warning characteristics to improve
effectiveness as individuals move from vehicle to vehicle.
---------------------------------------------------------------------------
\105\ 87 FR 13452 (Mar. 9, 2022).
---------------------------------------------------------------------------
All current U.S. vehicle models appear to provide auditory and
visual FCW signals, while only a few manufacturers also provide a
haptic signal (e.g., seat pan vibration or a brake pulse). Visual FCW
signals in current models consist of either a symbol or word (e.g.,
``BRAKE!''), presented on the instrument panel or head-up display, and
most are red.
For this NPRM, NHTSA proposes that the FCW be presented to the
vehicle operator via at least two sensory modalities, auditory and
visual. Use of a multimodal warning ensures that most drivers will
perceive the warning as soon as its presented, allowing the most time
for the driver to take evasive action to avoid a crash. As a vehicle
operator who is not looking toward the location of a visual warning at
the time it is presented may not see it, NHTSA's proposal views the
auditory warning signal as the primary modality and the visual signal
as a secondary, confirmatory indication that explains to the driver
what the warning was intended to communicate (i.e., a forward crash-
imminent situation). However, because hearing-impaired drivers may not
perceive an FCW auditory signal, a visual signal would be important for
presenting the FCW to hearing-impaired individuals.
A multimodal FCW strategy is consistent with the recommendations of
multiple U.S. and international organizations including ISO, SAE
International, and Euro NCAP. ISO recommends a multimodal approach in
both ISO 15623, ``Forward vehicle collision warning systems--
Performance requirements and test procedures,'' and ISO 22839,
``Forward vehicle collision mitigation systems--Operation, performance,
and verification requirements'' (which applies to light and heavy
vehicles). SAE addresses the topic of a multimodal FCW strategy in both
information report J2400 2003-08, ``Human Factors in Forward Collision
Warning Systems: Operating Characteristics and User Interface
Requirements,'' and J3029, ``Forward Collision Warning and Mitigation
Vehicle Test Procedure and Minimum Performance Requirements--Truck and
Bus (2015-10; Work in Progress currently).'' Most of these
recommendations specify an FCW consisting of auditory and visual
signals, while ISO 15623 specifies that an FCW include a visual warning
as well as an auditory or haptic signal.
2. FCW Auditory Signal Characteristics
The proposed FCW auditory signal would be the primary means used to
direct the vehicle operator's attention to the forward roadway and
should be designed to be conspicuous to quickly capture the driver's
attention, convey a high level of urgency, and be discriminable from
other auditory signals presented within the vehicle.\106\ Some
specifications from NHTSA's ``Human Factors Design Guidance For Driver-
Vehicle Interfaces'' are proposed
[[Page 38657]]
as forward collision warning specifications to meet these
criteria.\107\ As the FCW auditory signal would be the primary warning
mode, this signal would not be permitted to be disabled.
---------------------------------------------------------------------------
\106\ DOT HS 810 697, Crash Warning System Interfaces: Human
Factors Insights and Lessons Learned--Final Report
\107\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
---------------------------------------------------------------------------
To be conspicuous and quickly capture the driver's attention, the
FCW auditory signal must ensure that the driver will readily detect the
warning under typical driving conditions (e.g., ambient noise). The
auditory signal must be clearly perceptible and quickly focus the
driver's attention on the forward roadway. To ensure that the FCW
auditory signal is conspicuous to the vehicle operator, any in-vehicle
system or device that produces sound that may conflict with the FCW
presentation would be required to be muted, or substantially reduced in
volume, during the presentation of the FCW.\108\ In order for the
warning to be detectable, a minimum intensity of 15-30 dB above the
masked threshold (MT) should be used.109 110 111 112 Because
sound levels inside a vehicle can vary based on any number of different
factors, such as vehicle speed and pavement condition, NHTSA is not
proposing a specific sound level at this time, but requests comments on
suitable and reasonable approaches for ensuring that the FCW auditory
signal can be detected by drivers under typical driving conditions.
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\108\ DOT HS 810 697, Crash Warning System Interfaces: Human
Factors Insights and Lessons Learned--Final Report.
\109\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration. ``The amplitude of auditory signals is in the range
of 10-30 dB above the masked threshold (MT), with a recommended
minimum level of 15 dB above the MT (e.g., [1, 2, 3]).
Alternatively, the signal is at least 15 dB above the ambient noise
[3].''
\110\ Campbell, J.L., Richman, J.B., Carney, C., and Lee, J.D.
(2002). In-vehicle display icons and other information elements.
Task F: Final in-vehicle symbol guidelines (FHWA-RD-03-065).
Washington, DC: Federal Highway Administration.
\111\ International Organization for Standardization (ISO).
(2005). Road vehicles--Ergonomic aspects of in-vehicle presentation
for transport information and control systems--Warning systems (ISO/
TR 16532). Geneva, Switzerland: International Organization of
Standards.
\112\ MIL-STD-1472F. (1998). Human engineering. Washington, DC:
Department of Defense.
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For communicating urgency and ensuring comprehension of auditory
messages, fundamental frequency, the lowest frequency in a periodic
signal, is a key design parameter.\113\ Research has shown that
auditory warning signals with a high fundamental frequency of at least
800 Hz more effectively communicate urgency.114 115 Greater
perceived urgency of a warning is associated with faster reaction
times, which would mean a quicker crash avoidance response by the
driver.116 117 118 Therefore, NHTSA proposes that the FCW
auditory signal's fundamental frequency must be at least 800 Hz.\119\
Additional proposed FCW auditory signal requirements that support
communication of the urgency of the situation include a duty
cycle,\120\ or percentage of time sound is present, of 0.25-0.95, and
faster auditory signals with a tempo in the range of 6-12 pulses per
second to be perceived as urgent and elicit rapid driver response.\121\
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\113\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
\114\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
\115\ Guilluame, A., Drake, C., Rivenez, M., Pellieux, L., &
Chastres, V. (2002). Perception of urgency and alarm design.
Proceedings of the 8th International Conference on Auditory Display.
\116\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
\117\ Campbell, J.L., Richman, J.B., Carney, C., & Lee, J.D.
(2004). In-vehicle display icons and other information elements,
Volume I: Guidelines (Report No. FHWA-RD-03-065). Washington, DC:
Federal Highway Administration. Available at www.fhwa.dot.gov/publications/research/safety/03065/index.cfm.
\118\ Suied, C., Susini, P., & McAdams, S. (2008). Evaluating
warning sound urgency with reaction times. Journal of Experimental
Psychology: Applied, 14(3), 201-212.
\119\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
\120\ Duty cycle, or percentage of time sound is present, is
equal to the total pulse duration divided by the sum of the total
pulse duration and the sum of the inter-pulse intervals.
\121\ Gonzalez, C., Lewis, B.A., Roberts, D.M., Pratt, S.M., &
Baldwin, C.L. (2012). Perceived urgency and annoyance of auditory
alerts in a driving context. Proceedings of the Human Factors and
Ergonomics Society Annual Meeting, 56(1), 1684-1687.
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The FCW auditory signal needs to be easily discriminable from other
auditory signals in the vehicle. Therefore, vehicles equipped with more
than one crash warning type should use FCW auditory signals that are
distinguishable from other warnings.\122\ This proposed requirement is
consistent with ISO 15623.\123\ Standardization of FCW auditory signals
would likely be beneficial in ensuring driver comprehension of the
warning condition across vehicle makes and models. NHTSA invites
comments on the feasibility of specifying a common FCW auditory signal.
While this proposal contains no specific requirements ensuring that the
FCW auditory signal is distinguishable from other auditory warnings in
the vehicles, NHTSA believes that industry is likely to consider this
in their vehicle designs as part of their due diligence and safety
assurance.
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\122\ DOT HS 810 697, Crash Warning System Interfaces: Human
Factors Insights and Lessons Learned--Final Report
\123\ ISO 15623--Forward vehicle collision warning systems--
Performance requirements and test procedures.
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3. FCW Visual Signal Characteristics
Current FCWs in the U.S. vehicle fleet use a mix of symbols and
words as a visual forward collision warning. Use of a common FCW symbol
across makes and models would help to improve consumer understanding of
the meaning of FCWs and encourage more appropriate driver responses in
forward crash-imminent situations.
ISO 7000, ``Graphical symbols for use on equipment--Registered
symbols,'' \124\ and the SAE J2400 (2003-08) \125\ information report,
``Human Factors in Forward Collision Warning Systems: Operating
Characteristics and User Interface Requirements,'' contain recommended
FCW symbols shown in Figure 1. These symbols are similar as they both
communicate a forward impact, while the ISO symbol portrays the forward
impact as being specifically with another vehicle.
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\124\ ISO 7000--Graphical symbols for use on equipment--
Registered symbols.
\125\ SAE J2400 (info. report, not RP or standard), 2003-08.
Human Factors in Forward Collision Warning Systems: Operating
Characteristics and User Interface Requirements.
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[[Page 38658]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.011
Because the symbol in SAE J2400 relates the idea of a frontal crash
without depicting a particular forward object, this symbol could
visually represent and apply to both the lead vehicle and pedestrian
scenarios. Therefore, NHTSA finds the SAE J2400 symbol to be most
applicable to the FCW requirements in this proposal. NHTSA proposes
that FCW visual signals using a symbol must use the SAE J2400 (2003-08)
symbol.
Some other vehicle models employ a word-based visual warning, such
as ``STOP!'' or ``BRAKE!'' SAE J2400 also includes a word-based visual
warning recommendation consisting of the word, ``WARNING.'' A well-
designed warning should instruct people about what to do or what not to
do to avoid a hazard. The potential benefit of a word-based warning for
FCW is that it can communicate to the driver an instruction about what
to do to avoid or mitigate the crash, thereby expediting the driver's
initiation of an appropriate crash avoidance response. However,
Consumer Reports noted in its online ``Guide to forward collision
warning'' that for some models, visual warning word use was found to be
confusing to some drivers surveyed.\126\ Respondents reported a common
complaint that ``their vehicle would issue a visual ``BRAKE'' alert on
the dash, but it wouldn't bring the car to a stop . . .'' This
confusion as to whether the word is meant to communicate what the
driver should do or what the vehicle is doing may stem from drivers
assuming that any information presented within the instrument panel
area is communicating something relating to the vehicle's condition or
state, as symbols presented in that location generally do. Presenting a
word-based warning in a higher location away from the instrument panel,
as recommended by SAE J2400, may be interpreted more accurately by
drivers as well as increase the likelihood of FCW visual warning
perception by drivers.\127\ NHTSA requests comments on this issue and
any available objective research data that relates to the effectiveness
of word-based FCW visual signals in instrument panel versus head-up
display locations. NHTSA also requests comments regarding whether
permitting word-based warnings that are customizable in terms of
language settings is necessary to ensure warning comprehension by all
drivers.
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\126\ ``Guide to forward collision warning: How FCW helps
drivers avoid accidents.'' Consumer Reports. https://www.consumerreports.org/car-safety/forward-collision-warning-guide/.
Accessed April 2022.
\127\ SAE J2400 2003-08 (Information report). Human Factors in
Forward Collision Warning Systems: Operating Characteristics and
User Interface Requirements.
---------------------------------------------------------------------------
One plausible benefit of a word-based visual warning is that some
word choices that instruct the driver to initiate a particular action,
such as ``STOP!,'' would be fully applicable to both lead vehicle and
pedestrian scenarios, whereas a symbol containing an image of a lead
vehicle would not be directly applicable to a forward pedestrian
imminent crash scenario. As the response desired from the driver, to
apply the brakes, is the same for both lead vehicle and forward
pedestrian scenarios, the content of the visual warning need not be
specific to the type of forward obstacle, but needs simply to
communicate the idea of an impending forward crash. NHTSA requests
comments and any available research data regarding the use and
effectiveness of obstacle-specific symbols and word-based visual
warnings and the relative effectiveness of word-based visual warnings
compared to symbols.
While many current vehicle models present a visual FCW signal
within the instrument panel, drawing a driver's eyes downward away from
the roadway to the instrument panel during a forward crash-imminent
situation is likely to have a negative impact on the effectiveness of
the driver's response to the FCW. Research indicates that a visual FCW
signal presented in the instrument panel can slow driver response.\128\
The research findings support the SAE J2400 recommendation advising
against the use of instrument panel based visual FCWs.\129\ SAE J2400
(2003-08) states:
---------------------------------------------------------------------------
\128\ ``Evaluation of Forward Collision Warning System Visual
Alert Candidates and SAE J2400,'' SAE Paper No. 2009-01-0547,
https://trid.trb.org/view/1430473.
\129\ SAE J2400 2003-08 (Information report). Human Factors in
Forward Collision Warning Systems: Operating Characteristics and
User Interface Requirements.
Visual warnings shall be located within a 10-degree cone of the
driver's line of sight. Qualitatively, this generally implies a top-of-
dashboard or head-up display location. A conventional dashboard
location shall not be used for the visual warning. The rationale for
this is based on the possibility that an instrument panel-based visual
warning may distract the driver from the hazard ahead.
This FCW visual signal location guidance is also consistent with
ISO 15623, which states that the FCW visual signal shall be presented
in the ``main glance direction.'' Current vehicles equipped with head-
up displays have the ability to present a FCW visual signal within the
driver's forward field of view. Furthermore, some GM vehicles not
equipped with head up displays currently have the ability to present a
FCW visual signal reflected onto the windshield in the driver's forward
line-of-sight. Despite the FCW visual signal being considered secondary
to the auditory signal, NHTSA agrees that the effectiveness of a FCW
visual signal would be maximized for both hearing and hearing-impaired
drivers if the signal is presented at a location within the driver's
forward field of view above the instrument panel. To ensure maximum
conspicuity of the FCW visual signal (be it word-based or a symbol),
NHTSA proposes that it be presented within a 10-degree cone of the
driver's line of sight. The line of sight
[[Page 38659]]
would be based on the forward-looking eye midpoint (Mf) as
described in FMVSS No. 111, ``Rear visibility,'' S14.1.5.
The FCW visual signal would be required to be red, as is generally
used to communicate a dangerous condition and as recommended by ISO
15623 and SAE J2400 (2003-08). Because the FCW visual signal is
intended to be confirmatory for the majority of drivers, the symbol
would be required to be steady burning.
4. FCW Haptic Signal
The agency considered also specifying a complementary haptic FCW
signal as part of the proposed FCW specifications. Currently, only a
portion of U.S. vehicles equipped with forward collision warning
include a haptic warning component. For example, General Motors
vehicles equipped with the haptic warning feature can present either a
haptic seat pulse (vibration) or auditory warning based on a driver-
selectable setting. Some other vehicle manufacturers, such as
Stellantis and Audi, use a brake pulse, or brief deceleration of the
vehicle, as part of the FCW. Some Hyundai/Kia models incorporate a
haptic steering wheel vibration into the FCW. As haptic steering wheel
signals are used by many lane keeping features of current vehicles to
encourage drivers to steer the vehicle back toward the center of the
lane, providing a haptic FCW signal via the steering wheel may result
in driver confusion and be less effective in eliciting a timely and
beneficial driver response.
ISO 15623 allows a haptic signal as an alternative to an auditory
signal.\130\ It permits a haptic brake pulse warning with a duration of
less than 1 second when the driver is not already applying the brakes.
ISO 15623 also allows actuation of a seat belt pretensioner as a haptic
FCW signal.
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\130\ ISO 15623--Forward vehicle collision warning systems--
Performance requirements and test procedures.
---------------------------------------------------------------------------
Some research has shown that haptic FCW signals can improve crash
avoidance response. NHTSA research on ``Driver-Vehicle Interfaces for
Advanced Crash Warning Systems'' found that a haptic signal delivered
via the seat belt pretensioner would be beneficial in eliciting an
effective crash avoidance response from the vehicle operator. The
research showed for FCWs issued at 2.1-s time-to-collision (TTC) that
seat belt pretensioner-based FCW signals elicited the most effective
crash avoidance performance.\131\ Haptic FCW signals led to faster
driver response times than did auditory tonal signals. FCW modality had
a significant effect on participant reaction times and on the speed
reductions resulting from participants' avoidance maneuvers (regardless
of whether a collision ultimately occurred). Brake pulsing or seat belt
tensioning were found to be effective for returning distracted drivers'
attention to the forward roadway and eliciting desirable vehicle
control responses; seat vibration similar to a virtual rumble strip
(vibrating the front of the seat) was not found to return driver
attention rapidly and reliably to the forward roadway within the Crash
Warning Interface Metrics research. Similarly, research by Aust (2014)
found that ``combining sound with seat belt jerks or a brake pulse
leads to significantly faster response times than combining the sound
with a visual warning'' and stated, ``these results suggest that future
FCWs should include a haptic modality to improve driver performance.''
\132\ Aust (2014) also found use of a haptic seat belt FCW signal to be
slightly more effective (100 ms faster driver response) than a haptic
brake pulse in one of two scenarios (response times were equal in a
second scenario). Despite these promising research results associated
with use of a seat belt based FCW haptic component, NHTSA was unable to
identify any current U.S. vehicle models equipped with a haptic seat
belt FCW component.
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\131\ Lerner, N., Singer, J., Huey, R., Brown, T., Marshall, D.,
Chrysler, S., . . . & Chiang, D.P. (2015, November). Driver-vehicle
interfaces for advanced crash warning systems: Research on
evaluation methods and warning signals. (Report No. DOT HS 812 208).
Washington, DC: National Highway Traffic Safety Administration.
\132\ Aust, M. (2014) Effects of Haptic Versus Visual Modalities
When Combined With Sound in Forward Collision Warnings. Driving
Simulation Conference 2014, Paper number 36. Paris, France,
September 4-5, 2014.
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Other studies found FCW haptic brake pulses effective at getting a
driver's attention and that drivers are more likely to detect a brake
pulse if it produces a sensation of ``jerk'' or ``self-motion.''
133 134 Kolke reported reaction times shortened by one-third
(approximately 0.3 s, non-signi[filig]cant) when a brake pulse was
added to an audio-visual warning.\135\ One usability drawback is that
drivers tend to report that vehicle brake pulses are too disruptive,
which can lead to unfavorable annoyance.\136\
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\133\ Lee, J.D., McGehee, D.V., Brown, T.L., & Nakamoto, J.
(2012). Driver sensitivity to brake pulse duration and magnitude.
Ergonomics, 50(6), 828-836.
\134\ Brown, S.B., Lee, S.E., Perez, M.A., Doerzaph, Z.R.,
Neale, V.L., & Dingus, T.A. (2005). Effects of haptic brake pulse
warnings on driver behavior during an intersection approach.
Proceedings of the Human Factors and Ergonomics Society 49th Annual
Meeting, 1892-1896.
\135\ Kolke, Gauss, and Silvestro (2012). Accident reduction
through emergency braking systems in passenger cars. Presentation at
the 8th ADAC/BASt-Symposium ``Driving Safely in Europe.'' October 5,
2012, Workshop B.
\136\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
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Presentation of a FCW haptic signal via the driver's seat pan has
also been investigated. NHTSA's ``Human factors design guidance for
driver-vehicle interfaces'' contains best practice information for
implementation of haptic displays, including ``Generating a Detectable
Signal in a Vibrotactile Seat.'' \137\ In a large-scale field test of
FCW and LDW systems on model year 2013 Chevrolet and Cadillac vehicles,
the University of Michigan Transportation Research Institute and GM
found that GM's Safety Alert Seat, which provides haptic seat vibration
pulses, increases driver acceptance of both FCW and LDW systems
compared to auditory signals.\138\
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\137\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
\138\ Flannagan, C., LeBlanc, D., Bogard, S., Nobukawa, K.,
Narayanaswamy, P., Leslie, A., Kiefer, R., Marchione, M., Beck, C.,
and Lobes, K. (2016, February), Large-scale field test of forward
collision alert and lane departure warning systems (Report No. DOT
HS 812 247), Washington, DC: National Highway Traffic Safety
Administration.
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NHTSA's March 2022 request for comments notice on the NCAP sought
comment on which FCW modalities or modality combinations should receive
credit and asked specific questions regarding haptic signals and
whether certain types should be excluded from consideration (e.g.,
because they may be such a nuisance to drivers that they are more
likely to disable the FCW or AEB system). A preliminary review of
comments on that notice found multiple comments highlighting a need for
more research relating to FCW signals. The National Transportation
Safety Board highlighted the need for additional information regarding
haptic signals presented in different locations, stating ``[w]ithout
examining the efficacy of different means of providing haptic alerts
and defining appropriate, research-supported implementations, a prudent
approach would give credit only for audible unimodal alerts or for bi-
modal alerts that include audible alerts.'' Rivian stated ``[t]he
agency should award credit to systems that provide both audible and
haptic alerts
[[Page 38660]]
and provide the option to turn either of them OFF based on driver
preference. These audible or haptic alerts should be in sync with
providing a visual alert of an impending collision. The agency should
recommend the decibel level and the haptic feedback location and type
as a baseline and based on research on reducing nuisance to the
driver.'' As the agency is actively reviewing comments, NHTSA is not
proposing to require a complementary FCW haptic signal component at
this time.
Given the lack of consensus within available research as to the
best location for a FCW haptic signal (seat belt, seat pan, steering
wheel, or brake pulse), NHTSA is not at this time proposing to require
a haptic FCW component, but invites comment on whether requiring FCW to
contain a haptic component presented via any location may increase FCW
effectiveness or whether a FCW haptic signal presented in only one
specific, standardized location should be allowed.
While the FCW auditory signal is envisioned as being the primary
means of warning the driver, providing a haptic FCW signal that would
complement or supplant the auditory warning signal would likely improve
FCW perception for hearing-impaired drivers. Some drivers also may
prefer an alternative modality to auditory warnings (e.g., due to
annoyance caused by the auditory warning). However, the degree of
additional benefit that may be accrued by requiring a haptic FCW signal
in addition to a well-designed auditory and visual FCW that meets the
specifications proposed is not known.
A haptic FCW signal, to be effective, would necessarily require the
driver to be in physical contact with the vehicle component through
which the haptic signal is presented in order to perceive the warning.
For example, if the driver is not wearing a seat belt, a haptic FCW
signal presented via the seat belt would not be effectively received. A
seat pan based haptic FCW signal would be unlikely to have such a non-
contact issue. Providing a haptic FCW signal would increase the
likelihood of FCW perception by hearing-impaired drivers and could also
be used to provide an alternative modality to drivers who do not prefer
auditory warnings. NHTSA is interested in research data documenting the
comparison of a compliant auditory-visual FCW to that same FCW with an
added haptic component. NHTSA also welcomes any objective data
documenting the relative effectiveness of different haptic signal
presentation locations for FCW use.
C. Lead Vehicle AEB--Performance Test Requirements
In addition to the requirement that vehicles must provide a forward
crash warning and automatically control the brakes to reduce the
vehicle's speed, the agency is proposing performance test requirements
that involve a no collision criterion under specific testing scenarios.
NHTSA is proposing lead vehicle AEB performance tests requiring a
vehicle to automatically brake or supplement insufficient manual
braking as a means of avoiding contact with the lead vehicle under
three specific test scenarios--stopped lead vehicle, slower-moving lead
vehicle, and decelerating lead vehicle.
The scenarios are implemented using track tests and are based on
those used in NCAP and NHTSA's research testing to evaluate AEB
systems.\139\ The proposed performance criterion for all AEB tests
involving a lead vehicle is full collision avoidance, meaning the
subject vehicle must not contact the lead vehicle. NHTSA chose the
performance criterion of collision avoidance because it maximizes the
safety benefits of the rule as compared to a metric that might permit a
reduced speed collision. NHTSA has tentatively concluded that a no-
contact criterion for the performance test requirements is practicable
to achieve, consistent with the need for safety, and may be necessary
to ensure test repeatability.\140\
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\139\ 87 FR 13452 (Mar. 9, 2022).
\140\ Requiring vehicles to avoid contact during testing
addresses practical considerations as well. These practical
considerations are discussed in section VI.G of this NPRM, in which
NHTSA seeks comment on alternatives to the no-contact requirement.
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The lead vehicle AEB tests include parameters necessary to fully
define the initial test conditions in each scenario. Key test
parameters for the lead vehicle AEB tests include the travel speed of
both the subject vehicle and lead vehicle, the initial headway between
the subject vehicle and the lead vehicle, the deceleration of the lead
vehicle, and any manual brake application made to the subject vehicle.
Some of these key parameters are chosen from a range of values.\141\
The use of a range of potential values allows the agency to ensure that
AEB system performance remains consistent, as test parameters vary
within the bounds of the range. During testing, some AEB systems
performed better at high speeds and did not perform well at lower
speeds.\142\ The key proposed test parameters and the combinations in
which they will be used are summarized in Table 21. The sections that
follow provide more detail about the selection of these test
parameters.
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\141\ In instances where an FMVSS includes a range of values for
testing and/or performance requirements, 49 CFR 571.4 states, ``The
word any, used in connection with a range of values or set of items
in the requirements, conditions, and procedures of the standards or
regulations in this chapter, means generally the totality of the
items or values, any one of which may be selected by the
Administration for testing, except where clearly specified
otherwise.''
\142\ https://www.regulations.gov/document/NHTSA-2021-0002-0002.
Table 21--Lead Vehicle AEB Collision Avoidance--Key Test Parameters
----------------------------------------------------------------------------------------------------------------
Speed (km/h) Lead Vehicle
--------------------------------- Headway \1\ Deceleration Manual brake
Subject vehicle Lead vehicle (m) (g) application
----------------------------------------------------------------------------------------------------------------
Stopped Lead Vehicle........ Any 10-80...... 0 ............... ............... No.
Any 70-100..... 0 ............... ............... Yes.
Slower-Moving Lead Vehicle.. Any 40-80...... 20 ............... ............... No.
Any 70-100..... 20 ............... ............... Yes.
Decelerating Lead Vehicle... 50............. 50 Any 12-40...... Any 0.3-0.5.... No.
50............. 50 Any 12-40...... Any 0.3-0.5.... Yes.
80............. 80 Any 12-40...... Any 0.3-0.5.... No.
80............. 80 Any 12-40...... Any 0.3-0.5.... Yes.
----------------------------------------------------------------------------------------------------------------
\1\ Where headway is not noted, headway is not a key parameter. The initial headway for these scenarios is based
on the travel speeds and is defined within the detailed test conditions.
[[Page 38661]]
The stopped lead vehicle scenario consists of the vehicle traveling
straight ahead, at a constant speed, approaching a stopped lead vehicle
in its path. The vehicle must be able to avoid contact with the stopped
lead vehicle. The slower-moving lead vehicle scenario involves the
subject vehicle traveling straight ahead at constant speed, approaching
a lead vehicle traveling at a slower speed in the subject vehicle path.
The decelerating lead vehicle scenario is meant to assess the AEB
performance when the subject vehicle and lead vehicle initially are
travelling at the same constant speed in a straight path and the lead
vehicle begins to decelerate.
The agency proposes testing under two conditions. In one condition,
NHTSA would test without any manual brake application. This would
simulate a scenario where a driver does not intervene at all in
response to the FCW or impending collision. In the other condition,
NHTSA would test with manual brake application that would not be
sufficient to avoid the crash. Not only does the second condition
ensure that the AEB will supplement the manual braking when needed, it
also provides a way by which to ensure that an application of
insufficient manual braking does not suppress automatic braking in
circumstances where it is initiated before the manual brake application
is used.
The proposed speed ranges were selected based on the speeds at
which rear-end crashes tend to happen, while considering two primary
factors. The first factor is the practical ability of AEB technology to
consistently operate and avoid contact with a lead vehicle. NHTSA's
2020 research testing at 72.4 km/h suggested that the selected speed
ranges for the various scenarios are within the capabilities of at
least some MY 2020 AEB-equipped production vehicles. Where a speed
range is proposed, it is meant to ensure AEB system robustness. As an
example, during the agency's AEB research testing, two vehicles
performed better at higher speeds (48 km/h or 30 mph) than at lower
speeds (40 km/h or 25 mph) in the lead vehicle stopped tests, which
suggests that the performance degradation at lower speeds was not due
to the vehicles' brake capabilities.\143\
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\143\ https://www.regulations.gov/document/NHTSA-2021-0002-0002.
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The second factor is the practical limits of safely conducting
track tests of AEB systems. Based on the available data, a majority of
fatalities and injuries from rear-end crashes occur at posted speeds up
to 60 mph (97 km/h). Due to the tendency of fatalities and injuries to
increase as the vehicle travel speed increases, this proposal would
allow for AEB system testing at the highest speeds at which NHTSA can
safely and repeatably conduct tests. If the system does not intervene
as required and the subject vehicle collides with the lead vehicle test
device, it should do so in a manner that will not injure any vehicle
occupants while also limiting damage to the subject vehicle and test
equipment.
The proposed speed ranges were informed based on the results from
the 2020 NHTSA research. When discussing the research as it relates to
this notice, the tested vehicles were assigned an identifier as shown
in Table 22. Additional detail can be found in the Preliminary
Regulatory Impact Assessment for this rulemaking.\144\
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\144\ The Preliminary Regulatory Impact Analysis can be found in
the docket of this notice.
Table 22--NHTSA R&D AEB Tested Vehicles and Assigned Identifier
------------------------------------------------------------------------
Identifier Vehicle
------------------------------------------------------------------------
V1................................ 2020 Nissan Altima.
V2................................ 2020 Volvo S60 T6 AWD Momentum.
V3................................ 2020 Honda Odyssey EX-L.
V4................................ 2020 Toyota Corolla LE.
V5................................ 2020 Ford F-150 4X4 SuperCrew.
V6................................ 2020 Subaru Outback Premium/LDD.
V7................................ 2020 Audi Q5 45 TFSI quattro.
V8................................ 2020 Hyundai Palisade SEL FWD.
V9................................ 2019 Audi A6 3.0 T quattro.
V10............................... 2020 Land Rover Range Rover Sport
HSE.
V11............................... 2020 Mercedes-Benz GLC 300 4Matic
SUV.
------------------------------------------------------------------------
Agency CIB testing in the stopped lead vehicle scenario at 72.4 km/
h (45 mph)--8 km/h (5 mph) lower than the proposed speeds--of 11 MY
2019/2020 vehicles found two vehicles avoided contact with a stopped
lead vehicle in five consecutive tests (See Figure 2).\145\ NHTSA's
evaluation of model year 2021 and 2022 includes tests performed at the
proposed speeds. The results of this testing are detailed in the lead
vehicle AEB report docketed with this proposed rule.
---------------------------------------------------------------------------
\145\ National Highway Traffic Safety Administration (2022,
March), ``Final MY2019/MY2020 Research Reports for Pedestrian
Automatic Emergency Braking, High-Speed Crash Imminent Braking,
Blind Spot Warning, and Blind Spot Intervention Testing,'' https://www.regulations.gov, Docket No. NHTSA-2021-0002-0002.
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BILLING CODE 4910-59-P
[[Page 38662]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.012
At this time, the agency has tentatively concluded that the maximum
practicable test speed is 100 km/h (62 mph) and the maximum speed
differential between the subject vehicle and the lead vehicle is 80 km/
h (50 mph). The proposed test speed ranges reflect this conclusion.
1. Stopped Lead Vehicle Scenario Test Speeds
The two different speed ranges proposed for the AEB stopped lead
vehicle tests are dependent on whether the brakes were applied manually
in the subject vehicle during the test. For tests with no manual brake
application, the test speed is chosen from any speed between 10 km/h (6
mph) and 80 km/h (50 mph). For tests with manual brake application, the
test speed is chosen from any speed between 70 km/h (44 mph) and 100
km/h (62 mph).
For the stopped lead vehicle scenario, the proposed lower bound of
the speed range is 70 km/h (44 mph) when testing with manual brake
application and the lower bound of the speed range for the condition of
no manual brake application is specified is 10 km/h (6 mph). This
presents an overlap in test speeds where manual braking and automatic
braking might occur. The overlap of the speed ranges is intended
evaluate AEB system robustness by ensuring that automatic braking still
occurs if manual braking is insufficient to avoid the crash scenario.
NHTSA believes that by testing at the higher end of the proposed speed
range manufacturers will extend this functionality to the entire speed
range and the testing burden can be reduced.
To assure that AEB system functionality with and without manual
brake application exists, the speed ranges when testing with and
without manual brake application overlap between 70 km/h (44 mph) and
80 km/h (50 mph). Because AEB systems must activate with or without
manual brake application at all speeds above 10 km/h (6 mph),
evaluating the subject vehicle braking performance with and without
manual brake application from 70 km/h (44 mph) to 80 km/h (50 mph)
provides a basis for comparison and a way to ensure that performance of
the AEB system with manual brake application does not affect the
ability of the subject vehicle to avoid colliding with the lead
vehicle. These are the same criteria as proposed for AEB system
performance without manual brake application.
The upper bound when testing with no manual brake application is 80
km/h (50 mph) since this is the highest practicable test speed
differential.\146\ Similarly, the 100 km/h (62 mph) upper bound for the
manual brake application scenario is the highest practicable test speed
and testing speed differential.\147\ Testing with the subject vehicle
speed of 80 km/h (50 mph) is consistent with NHTSA's NCAP request for
comments notice and Euro NCAP test speeds.\148\
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\146\ See Travel Speed introduction section for further details.
\147\ Under the proposed scenario the subject vehicle traveling
at 100 km/h (62 mph) under constant average deceleration of 0.4 g
would impact the lead vehicle in similar manner to the vehicle
traveling at 80 km/h (50 mph) with no manual brake application.
\148\ See NHTSA's NCAP Request for Comments notice (87 FR 13452
(Mar. 9, 2022) at 13485, 13487) and Euro NCAP test speeds (Euro NCAP
TEST PROTOCOL--AEB VRU systems 3.0.2, July 2019).
---------------------------------------------------------------------------
2. Slower-Moving Lead Vehicle Scenario Test Speeds
In the slower-moving lead vehicle scenario, the proposed subject
vehicle test speed is any speed between 40 km/h (24.9 mph) and 80 km/h
(50.0 mph). Given that the lead vehicle speed is always 20 km/h (12.4
mph) during the proposed lead vehicle moving test, this translates to a
relative speed range of 20 km/h (12.4 mph) to 60 km/h (37.3 mph).
Because the stopped lead vehicle test is almost always more stringent
than the slower-moving lead vehicle test (both in
[[Page 38663]]
terms of the AEB sensing/recognition and braking timing) NHTSA
tentatively concludes that AEB performance at relative speeds below 20
km/h (12.4 mph) is adequately evaluated by the proposed stopped lead
vehicle performance requirement, and it would be duplicative to test
both scenarios at low speeds.
The second proposed subject vehicle speed range for tests performed
with manual brake application is any speed between 70 km/h (43.5 mph)
and 100 km/h (62.1 mph) (the same as for the stopped lead vehicle
scenario).\149\ Given that the lead vehicle speed is always 20 km/h
(12.4 mph) during the proposed lead vehicle moving test, this
translates to a relative speed range of 50 km/h (31.1 mph) to 80 km/h
(49.7 mph).
---------------------------------------------------------------------------
\149\ See previous sections from Travel Speed for speed range
reasoning not mentioned here.
---------------------------------------------------------------------------
NHTSA's 2020 CIB research testing showed that all 11 tested
vehicles did not collide with the lead vehicle when the vehicle speed
was 40 km/h (24.9 mph), and lead vehicle speed was 16 km/h (9.9 mph).
Furthermore, 10 of the 11 tested vehicles did not collide with the lead
vehicle when the subject vehicle speed was 72.4 km/h (45.0 mph) and the
lead vehicle speed was 32.2 km/h (20.0 mph) on all test runs (See
Figures 3 and 4).\150\ Based on these data, NHTSA proposes one
consistent 20 km/h (12.4 mph) speed for the slower-moving lead vehicle
in this test scenario. These speed combinations also align with those
specified in the March 9, 2022, NCAP RFC for the lead vehicle moving
scenario, which have been shown to be practicable.\151\
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\150\ 87 FR 13452 (Mar. 9, 2022) and National Highway Traffic
Safety Administration (2022, March), Final MY2019/MY2020 Research
Reports for Pedestrian Automatic Emergency Braking, High-Speed Crash
Imminent Braking, Blind Spot Warning, and Blind Spot Intervention
Testing, https://www.regulations.gov, Docket No. NHTSA-2021-0002-
0002.
\151\ 87 FR 13452 (Mar. 9, 2022).
[GRAPHIC] [TIFF OMITTED] TP13JN23.013
[[Page 38664]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.014
3. Decelerating Lead Vehicle Scenario Test Speeds
The initial speed conditions for the decelerating lead vehicle
scenario are not as critical to the outcome of the test as other
parameters. Because the subject and lead vehicle speeds are initially
the same, the main parameters for a successful test outcome are the
headway and lead vehicle deceleration. Thus, NHTSA proposes to use two
discrete test speeds rather than a speed chosen from a range for both
the subject and lead vehicles in the decelerating lead vehicle test
scenario, and to use ranges for the headway and deceleration
parameters. This NPRM proposes that both the subject vehicle and lead
vehicle travel at the same speed of either 50 km/h (31.1 mph) or 80 km/
h (49.7 mph) in tests both with and without manual brake
application.\152\
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\152\ The agency is proposing two discrete speeds, instead of
one, for the Decelerating Lead Vehicles scenarios to ensure system
robustness.
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NHTSA's 2020 CIB research testing was performed with the subject
vehicle and lead vehicle traveling at 56.3 km/h (35.0 mph) with a lead
vehicle deceleration of 0.3g and 0.5g and a headway of 13.8 m (45.0 ft)
(See Figure 5) as well as with the subject vehicle and lead vehicle
traveling at 72.4 km/h (45.0 mph) and a deceleration of 0.3g. When
testing at 56.3 km/h (35.0 mph) with 0.3 g deceleration of the lead
vehicle, 7 out of 11 vehicles avoided contact with the lead vehicle in
all tests. Using the same test speeds but 0.5 g deceleration of the
lead vehicle, 3 out of 11 vehicles avoided contact in all test runs.
For the testing performed with the vehicle and lead vehicle travelling
at 72.4 km/h (45.0 mph) and a deceleration of 0.3 g with the same
headway of 13.8 m (45.0 ft), 4 out of 11 vehicles avoided contact with
the lead vehicle.
[[Page 38665]]
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[GRAPHIC] [TIFF OMITTED] TP13JN23.016
[[Page 38666]]
BILLING CODE 4910-59-C
Headway and lead vehicle deceleration are the main parameters for
the dynamics of the decelerating lead vehicle test because both subject
and lead vehicles start the test at the same speed. At the start of the
test, the proposed headway specifications include any distance between
12 m (39.4 ft) and 40 m (131.2 ft).\153\ Based on the initial headway
and lead vehicle deceleration, the most stringent headway and
deceleration combination is the shortest headway (12 m (39.4 ft)) and
the greatest deceleration (0.5g). Based on the 2020 research test
results, which used a 13.8 m (45.3 ft.) headway for the decelerating
lead vehicle test scenario, NHTSA has tentatively concluded based on
the 2020 research test results that the proposed 12 m (39.4 ft) headway
is practicable and is currently performing additional testing at this
headway.\154\
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\153\ The bounds of the headway range are consistent with the
headways in the April 2021 European New Car Assessment Programme
(Euro NCAP), Test Protocol--AEB Car-to-Car systems, Version 3.0.3
for the same scenario.
\154\ 87 FR 13452 (Mar. 9, 2022).
---------------------------------------------------------------------------
NHTSA proposes testing at any deceleration of the lead vehicle from
0.3g to 0.5g during the conduct of the decelerating lead vehicle tests.
Based on previous agency research, when drivers need to apply the
brakes in a non-emergency situation, they do so by decelerating up to
approximately 0.306g, while drivers encountering an unexpected obstacle
apply the brakes at 0.48g.\155\ NHTSA's past research analysis of event
data recorder data also showed that drivers applied the brakes at 0.383
g in rear-end crash scenarios.\156\ Based upon this research, NHTSA has
tentatively concluded that deceleration between 0.3g and 0.5g is
representative of manual, on-the-road, service brake application.
---------------------------------------------------------------------------
\155\ Gregory M. Fitch, Myra Blanco, Justin F. Morgan, Jeanne C.
Rice, Amy Wharton, Walter W. Wierwille, and Richard J. Hanowski
(2010, April) Human Performance Evaluation of Light Vehicle Brake
Assist Systems: Final Report (Report No. DOT HS 811 251) Washington,
DC: National Highway Traffic Safety Administration, p. 13 and p.
101.
\156\ Automatic Emergency Braking System (AEB) Research Report,
NHTSA, August 2014, pg. 47. https://www.regulations.gov/document/NHTSA-2012-0057-0037.
---------------------------------------------------------------------------
From NHTSA's 2020 research testing, of the 11 vehicles tested with
subject vehicle and lead vehicle speeds of 56.3 km/h (35.0 mph), a
headway of 13.8 m (45 ft) and a lead vehicle deceleration of 0.5g, 3
vehicles avoided contact on every test run and 2 vehicles avoided
contact on four out of five tests. When tested with a subject vehicle
and lead vehicle speed of 56.3 km/h (35.0 mph) and a 0.3g lead vehicle
deceleration, 7 out of 11 vehicles avoided contact with the lead
vehicle in every test, and 3 of the other 4 vehicles avoided contact
with the lead vehicle in five or six out of seven tests. The fourth
vehicle could not avoid contact with the lead vehicle in the tests, but
the AEB system provided an average speed reduction of 31 km/h (19.3
mph) over seven tests. When tested with a subject vehicle and lead
vehicle speed of 72.4 km/h (45.0 mph) and a 0.3 g deceleration of the
lead vehicle, 4 out of 11 vehicles avoided contact in every test and 2
other vehicles avoided contact in all but one test. Three of the
remaining vehicles avoided contact in one or two tests, while the two
others could not avoid contact but both demonstrated an average 21 km/h
(13 mph) speed reduction.
From these results NHTSA has tentatively concluded that current AEB
systems will be able to avoid a collision using a 12.0 m (39.3 ft)
headway, 0.5g lead vehicle deceleration, and 50.0 km/h (31.1 mph) and
80.0 km/h (49.7 mph) subject vehicle speeds. Further, the agency
believes that some of the other tested AEB systems have hardware
capable of full crash avoidance, but the perception software is not
tuned for the higher lead vehicle deceleration (0.5g).
4. Subject Vehicle Brake Application
The manual brake application tests two potential functions within
the AEB system. The first function is directly linked to driver
engagement. Normally, in a potential rear-end collision event, an FCW
will be provided before the onset of automatic braking. In situations
where it is practical for the vehicle to warn prior to automatic
activation of the brakes, an inattentive driver may re-engage in the
driving task and apply the brakes. However, in these circumstances,
research suggests that a driver's brake application typically does not
take advantage of the full capacity of the foundation braking system,
and a crash may still occur. The AEB system, on the other hand, can use
forward-looking sensor input, coupled with brake pressure information,
to determine that additional braking is needed to avoid a crash. The
proposed test conditions replicate this situation so that the AEB
system must provide the additional braking needed to avoid contact with
the lead vehicle.
The second function of the tests is to ensure that the brake
application by the driver in a crash imminent situation does not
suppress the vehicle's automatic brake application. In other words, the
brake pedal cannot be used as a means of overriding the AEB system.
NHTSA recognizes that in some on-road scenarios, high-level emergency
braking may not be the appropriate vehicle response. If deemed
necessary to override an emergency braking event, a means to do so can
be provided.
All lead vehicle scenarios include a test condition for which a
manual brake application is used. This is functionally similar to
NHTSA's NCAP DBS test. When manual brake application is part of the
test parameters, the service brake on the subject vehicle is applied in
such a manner that the subject vehicle decelerates with an average
magnitude of 0.4g (absent automatic braking) starting at 1.0 second
after onset of the FCW.
A deceleration of up to 0.5g is expected from a driver during an
emergency crash imminent brake application. However, research has shown
that female and older drivers tend not to apply the same force to the
brake pedal as young male drivers, thus resulting in lower
deceleration.\157\ Based on this information, for the manual brake
application tests, the brake pedal will be applied with a displacement,
force, or some combination thereof, to sufficiently decelerate the
subject vehicle an average of 0.4g. This is consistent with the manual
brake applications defined in NHTSA's NCAP test procedures for DBS
performance assessment and NHTSA's past research analysis of event data
recorder data from rear-end crashes.158 159
---------------------------------------------------------------------------
\157\ Gregory M. Fitch, Myra Blanco, Justin F. Morgan, Jeanne C.
Rice, Amy Wharton, Walter W. Wierwille, and Richard J. Hanowski
(2010, April) Human Performance Evaluation of Light Vehicle Brake
Assist Systems: Final Report (Report No. DOT HS 811 251) Washington,
DC: National Highway Traffic Safety Administration, pp. 104-108.
\158\ Automatic Emergency Braking System (AEB) Research Report,
NHTSA, August 2014, pg. 47. https://www.regulations.gov/document/NHTSA-2012-0057-0037.
\159\ National Highway Traffic Safety Administration (2014,
August), Dynamic Brake Support Performance Evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
---------------------------------------------------------------------------
The brake will be applied 1.0 second after the vehicle has provided
an FCW. This 1.0 second delay is based on the time it takes a driver to
react when presented with an obstacle. Previous NHTSA research has
shown that on average, it takes drivers 1.04 seconds to begin applying
the brake when presented with an unexpected obstacle and 0.8 seconds
when presented with an anticipated obstacle.\160\
---------------------------------------------------------------------------
\160\ Gregory M. Fitch, Myra Blanco, Justin F. Morgan, Jeanne C.
Rice, Amy Wharton, Walter W. Wierwille, and Richard J. Hanowski
(2010, April) Human Performance Evaluation of Light Vehicle Brake
Assist Systems: Final Report (Report No. DOT HS 811 251) Washington,
DC: National Highway Traffic Safety Administration, p. 101.
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[[Page 38667]]
D. PAEB System Requirement
NHTSA is proposing that AEB systems also be able to provide a
warning to the driver and automatically intervene to avoid or mitigate
collisions with pedestrians in the vehicle's forward path. Similar to
the lead vehicle AEB proposal, the performance requirements for PAEB
are to provide an FCW and automatically apply the service brakes at all
forward speeds attainable by the vehicle above 10 km/h (6 mph) in
response to an imminent collision with a pedestrian.\161\ The proposal
would require that the vehicle completely avoid a collision with a
pedestrian test mannequin during specific test track scenarios. NHTSA
is not proposing FCW and AEB systems to be active below 10 km/h (6
mph), because it has tentatively concluded that AEB systems do not
offer consistent performance at such low speeds.\162\ A lower bound of
10 km/h (6 mph), which is 6 km/h (3.7 mph) less than that stipulated in
NHTSA's 2019 draft PAEB research test procedure, is also consistent
with the lower bound for testing under the Euro NCAP rating program and
the proposed lower bound for PAEB testing under the agency's NCAP.\163\
Not requiring PAEB to be active below 10 km/h (6 mph) should not be
construed to preclude making the AEB system active, if possible, at
speeds below 10 km/h (6 mph). In fact, the agency anticipates that
manufacturers will make the system available at the lowest practicable
speed (the manual for 6 of the 11 tested vehicles shows PAEB available
at speeds below 10 km/h).
---------------------------------------------------------------------------
\161\ The FCW and brake application need not be sequential.
\162\ A review of 11 model year 2019/2020 vehicle owner's
manuals found that PAEB activation ranged from 4.8 km/h (3 mph) to
11.3 km/h (7 mph) with the average being 7.7 km/h (4.8 mph).
\163\ European New Car Assessment Program (Euro NCAP) (2019,
July), Test Protocol--AEB Car- to-Car systems, Version 3.0.2; 87 FR
13452 (Mar. 9, 2022); and www.regulations.gov, NHTSA Docket No.
NHTSA-2019-0102-0005.
---------------------------------------------------------------------------
Automatic braking must be able to decelerate the vehicle when a
collision with a pedestrian is imminent in the absence of any driver
brake input. Unlike for lead vehicle AEB, the proposed requirements for
PAEB do not require that the AEB system supplement the driver's brake
input. The reason is that the agency has tentatively concluded that,
due to the sudden succession of events in a potential collision between
a vehicle and a pedestrian, particularly for the pedestrian crossing
path scenarios, a driver is unlikely to have enough time to react to
the crash imminent event, and the vehicle will brake automatically
without driver input. While this proposal would not specifically
require PAEB to supplement driver brake input, it anticipates that AEB
system designs will include this feature.
E. PAEB--FCW Requirement
NHTSA is proposing that the same FCW specifications outlined for
the lead vehicle AEB condition be applied to the PAEB condition. The
FCW system must operate at any forward speed greater than 10 km/h (6.2
mph). The proposed FCW modalities and related characteristics of
auditory and visual components are the same for lead vehicle AEB and
PAEB conditions. NHTSA is proposing that the auditory mode have a high
fundamental frequency of at least 800 Hz, a duty cycle of 0.25-0.95,
and tempo in the range of 6-12 pulses per second; the visual mode would
be located according to SAE 2400 AUG2003 paragraph 4.1.14 and must
include the crash icon in the bottom right of paragraph 4.1.16.\164\
Line of sight as referenced in 4.1.14 would be determined based on the
forward-looking eye midpoint (Mf) as described in FMVSS No.
111 S14.1.5.
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\164\ SAE 2400 AUG2003, Human Factors in Forward Collision
Warning Systems: Operating Characteristics and User Interface
Requirements.
---------------------------------------------------------------------------
Some current vehicle models display a pedestrian symbol during
activation of the FCW for PAEB scenarios. However, NHTSA is now aware
of research or data indicating that displaying a visual symbol that
corresponds to the type of forward obstacle (i.e., vehicle or
pedestrian) affects the driver's response. Providing consistency across
FCWs provided for lead vehicle AEB and PAEB imminent crash scenarios
should maximize the likelihood that drivers will associate the FCW with
a forward crash of any sort. As such, the agency is not proposing
different symbols for the visual FCW modality based on the type of
forward obstacle to which the AEB is responding.
When evaluating existing PAEB systems through NHTSA's 2020 research
testing, the agency found that during certain test scenarios, FCW did
not occur prior to the onset of automatic braking.\165\ NHTSA
tentatively concludes that, due to the dynamics of some pedestrian
crashes that result in a quick succession of events, it is impractical
to require that the warning and automatic braking be sequential, as it
could potentially hinder the reaction time of AEB systems. The agency
anticipates that FCW may occur at any time during the automatic braking
event. When it occurs after onset of automatic braking, the FCW would
serve to inform the driver that automatic braking is ongoing, rather
than solicit a driver response.
---------------------------------------------------------------------------
\165\ As an example, when testing the Obstructed Running Child,
Crossing Path from the Right Scenario (see following paragraphs for
scenario description) with a MY 2020 Subaru Outback traveling at 16
km/h the onset of the alert was 0.92s (FCW on time history plot) and
service brake application was at 0.91 s (PAEB on time history plot)
essentially at the same time. ``Final Report of Pedestrian Automatic
Emergency Braking System Research Testing of a 2020 Subaru Outback
Premium/LDD,'' https://www.regulations.gov/document/NHTSA-2021-0002-0002, See: Figure D66. Time History for PAEB Run 180, S1d, Daytime,
16 km/h.
---------------------------------------------------------------------------
F. PAEB--Performance Test Requirements
NHTSA is proposing that AEB-equipped vehicles avoid a collision by
applying the brakes automatically and alerting the vehicle operator
when a collision with a pedestrian is imminent under specified test-
track scenarios. Similar to the lead vehicle AEB performance test
requirements, NHTSA has tentatively concluded that a no-contact
requirement is necessary for PAEB testing in order to maximize safety.
Even low-speed vehicle impacts with pedestrians can result in
fatalities and serious injuries. NHTSA has tentatively concluded that a
no-contact criterion for the performance test requirements is
practicable to achieve, consistent with the need for safety, and may be
necessary to ensure test repeatability.\166\
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\166\ Requiring vehicles to avoid contact during testing
addresses practical considerations as well. These practical
considerations are discussed in section VI.G of this NPRM, in which
NHTSA seeks comment on alternatives to the no-contact requirement.
---------------------------------------------------------------------------
The test scenarios proposed for PAEB evaluation involve track tests
and are based on previous research completed by the agency to evaluate
existing PAEB systems and on knowledge and experience from developing
the related NCAP test procedures.\167\ The proposed speed ranges and
other key parameters detailed in the following sections are based on
the observed capabilities of PAEB systems, limitations of the
pedestrian test mannequins, and the safety problem.\168\
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\167\ See Research section of this notice, 87 FR 13452 (Mar. 9,
2022) at 13472 and 13473, and https://www.regulations.gov/document/NHTSA-2021-0002-0002.
\168\ See Safety Problem section of this notice.
---------------------------------------------------------------------------
Manual brake application by the driver is not a parameter of the
proposed test scenarios for PAEB. However, NHTSA anticipates that,
because AEB systems will be tested under the proposed requirements with
manual brake activation for lead vehicle, that functionality will exist
for
[[Page 38668]]
PAEB.\169\ The absence of manual brake application in NHTSA's proposed
test parameters should not be construed to mean that AEB systems should
not function when a manually applied brake input is present.
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\169\ Since supplementing brake application is a functionality
that must already exist for the lead vehicle AEB based on this NPRM,
NHTSA anticipates the same capability will be provided when the
subject vehicle encounters an emergency braking situation involving
a pedestrian and manual braking is applied.
---------------------------------------------------------------------------
The proposed series of on-track tests fall into three groups of
scenarios based on the pedestrian test mannequin actions. The first
group of scenarios involves the test mannequin crossing the path of the
vehicle. In each of the first group of scenarios, the test mannequin
travels perpendicular to the vehicle's path. In the second group, the
test mannequin is stationary within the path of the vehicle. In the
third group, the test mannequin is moving along the travel path of the
vehicle. In all scenarios, the test is set up such that the subject
vehicle would collide with the test mannequin if it did not
automatically brake. The key test parameters for the PAEB test
scenarios include the type of test mannequin, the initial location of
the test mannequin, the direction of travel of the test mannequin, the
point on the subject vehicle that would impact the test mannequin (the
overlap), the vehicle speed, the speed of the test mannequin, the
ambient light condition, and the headlamp beam used during darkness
These key test parameters and the combinations in which they will
be used are summarized in Table 23. The sections that follow provide
more detail about how and why these key test parameters where selected.
Table 23--PAEB Collision Avoidance Key Test Parameters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Speed (km/h)
Pedestrian surrogate reference Overlap ----------------------------------------- Lighting condition
location (%) Subject vehicle Pedestrian
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crossing Path....................... Right................................. 25 Any 10-60................. 5 Daylight.
Right................................. 50 Any 10-60 Daylight.
Right................................. 50 Any 10-60 \1\ Lower Beams.
Right................................. 50 Any 10-60 Upper Beams.
Right \2\............................. 50 Any 10-50................. \3\ 5 Daylight.
Left.................................. 50 Any 10-60................. \4\ 8 Daylight.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stationary Along Path............... Right................................. 25 Any 10-55................. 0 Daylight.
Any 10-55 \1\............. Lower Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Any 10-55 Upper Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Moving Along Path................... Right................................. 25 Any 10-65................. 5 Daylight.
Any 10-65 \1\............. Lower Beams.
Any 10-65 \1\ Upper Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Final speed range requirements after an additional one-year phase-in.
\2\ Obstructed, running child.
\3\ Running child.
\4\ Running adult.
There are certain test conditions in Table 23 where the test speed
would be implemented one additional year after the initial proposed
phase-in. Based on the performance of existing PAEB systems during the
agency's dark lower-beam and dark upper-beam pedestrian tests, NHTSA
proposes a reduced speed range for the first three years after the
proposed requirements are to take effect. As discussed further in this
notice, NHTSA has tentatively concluded that this approach would afford
adequate lead time for vehicle manufacturers and suppliers to adjust
their PAEB system designs for higher speed ranges in these scenarios.
Table 24 summarizes the scenarios to which these changes apply. The
agency proposes that four years after the date of publication of the
final rule, the performance testing requirements follow all the key
parameters in Table 23. A more detailed discussion on the phase-in
appears further below in this section. Concurrent with the development
of this proposal, NHTSA conducted testing of model year 2021 and model
year 2022 vehicles using the proposed performance test requirements.
The details of these tests and results are docketed with this proposed
rule.
Table 24--PAEB Collision Avoidance Key Test Parameters, Reduced Speed Ranges
--------------------------------------------------------------------------------------------------------------------------------------------------------
Speed (km/h)
Pedestrian surrogate reference Overlap ----------------------------------------
location (%) Test Lighting condition
Vehicle mannequin
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crossing Path....................... Right................................ 50 Any 10-40................ 5 Lower Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stationary Along Path............... Right................................ 25 Any 10-50................ 0 Lower Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Moving Along Path................... Right................................ 25 Any 10-60................ 5 Lower Beams.
Any 10-60................ Upper Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 38669]]
In all PAEB collision avoidance scenarios (see Table 23 and Table 24)
the vehicle must avoid a collision with the pedestrian through use of
the vehicle's AEB system without manual brake input.
NHTSA evaluated various scenarios when developing the draft NCAP
test procedures for PAEB.\170\ During this evaluation, four scenarios
were found to account for 98 percent of functional years lost (i.e.,
the years of life lost due to fatal injury and the years of functional
capacity lost due to nonfatal injury) and the direct economic cost of
all vehicle-pedestrian crashes, but they only accounted for 46 percent
of all national pedestrian cases from NHTSA's General Estimate Systems
database.\171\ These scenarios were subject vehicle traveling straight
ahead and pedestrian crossing the road, subject vehicle traveling
straight ahead and pedestrian walking along/against traffic, subject
vehicle turning right and pedestrian crossing the road, and subject
vehicle turning left and pedestrian crossing the road.
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\170\ Mikio Yanagisawa, Elizabeth Swanson, and Wassim G. Najm
(2014, April) Target Crashes and Safety Benefits Estimation
Methodology for Pedestrian Crash Avoidance/Mitigation Systems
(Report No. DOT HS 811 998) Washington, DC: National Highway Traffic
Safety Administration, p. xi.
\171\ T. Miller, J. Viner, S. Rossman, N. Pindus, W. Gellert, J.
Douglass, A. Dillingham, and G. Blomquist, ``The Costs of Highway
Crashes''. FHWA-RD-91-055, October 1991.
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Further NHTSA research found that, on average, the subject vehicle
traveling straight ahead and pedestrian crossing the road and subject
vehicle traveling straight ahead and pedestrian walking along/against
traffic accounted for approximately 52 percent of vehicle-pedestrian
crashes and 90 percent of fatal vehicle-pedestrian crashes with a light
vehicle striking a pedestrian as the first event.\172\ Based on this
research, the following scenarios are proposed because they would have
the highest impact on the safety problem.
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\172\ Mikio Yanagisawa, Elizabeth D. Swanson, Philip Azeredo,
and Wassim Najm (2017, April) Estimation of potential safety
benefits for pedestrian crash avoidance/mitigation systems (Report
No. DOT HS 812 400) Washington, DC: National Highway Traffic Safety
Administration, p xiii.
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1. PAEB Scenario Descriptions
Pedestrian Crossing Path From the Right
The crossing path from the right scenarios consist of the subject
vehicle traveling straight ahead at a constant speed towards the adult
pedestrian test mannequin, which enters its travel path from the right
side of the vehicle.\173\ The subject vehicle must be able to avoid
contact with the pedestrian test mannequin crossing its path.
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\173\ Travel Path is the path projected onto the road surface by
a point located at the intersection of the subject vehicle's
frontmost vertical plane and longitudinal vertical center plane as
the subject vehicle travels.
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A basic setup for the pedestrian crossing the path of the vehicle
from the right scenarios with 25 percent and 50 percent overlap is
shown in Figure 7.
BILLING CODE 4910-59-P
[[Page 38670]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.017
In this scenario, an obstructed child pedestrian moves in the
vehicle's travel path. The child pedestrian is simulated by a child
pedestrian surrogate that appears from the right of the travel path.
The pedestrian surrogate crosses the subject vehicle's travel path from
in front of two stopped vehicle test devices. The VTDs are parked to
the right of the subject vehicle's travel path, in the adjacent lane,
at 1.0 m (3 ft) from the side of the subject vehicle. The VTDs are
parked one after the other and are facing in the same direction as the
subject vehicle.\174\ The basic setup for the obstructed running child
pedestrian scenario is shown in Figure 8. The subject vehicle must
avoid collision with the child pedestrian surrogate without manual
brake input.
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\174\ See the Proposed Test Procedure section of this NPRM for
further details.
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[[Page 38671]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.018
In this scenario, a simulated running adult pedestrian (the
pedestrian surrogate) crosses into the path of the vehicle traveling
straight ahead at a constant speed. The pedestrian surrogate enters the
path from the left side of the vehicle. No contact between the subject
vehicle and pedestrian surrogate is allowed. For testing, the subject
vehicle travels at a constant speed when it encounters the pedestrian
surrogate crossing from the left side. Figure 9 shows the basic setup
for this scenario.
[[Page 38672]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.019
In this scenario the pedestrian surrogate, with its back to the
subject vehicle, is stationary in the travel path of the subject
vehicle at a 25 percent overlap. The subject vehicle travels at a
constant speed and encounters the stationary pedestrian surrogate
positioned in the subject vehicle's path. The subject vehicle must
completely avoid a collision with the pedestrian surrogate. Figure 10
shows the basic setup for the pedestrian stationary in the path of the
subject vehicle.
[[Page 38673]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.020
In this scenario, a moving pedestrian is traveling along the
vehicle's path. The vehicle must avoid collision with the pedestrian
surrogate. Figure 11 shows the basic setup for this scenario.
[[Page 38674]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.021
2. Overlap
The overlap is the location on the subject vehicle where the
vehicle would collide with the pedestrian surrogate. Overlap is defined
as the percent of the vehicle's width that the pedestrian would
traverse prior to impact if the vehicle's speed and pedestrian's speed
remain constant. Overlap is based on overall vehicle width, as shown in
Figure 12, and is the intended point of impact with the pedestrian
mannequin in the absence of vehicle braking. Two overlaps are proposed
for testing, a 25 percent overlap and a 50 percent overlap. The minimum
overlap is 25 percent to allow for the test mannequin to be fully in
the path of the vehicle. The overlap determines the available time for
the AEB system to detect and react when a collision with the test
mannequin is imminent--a 50 percent overlap allows for more time than a
25 percent overlap.\175\
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\175\ As an example, for the timing, for a road width of 3 m (10
ft), a subject vehicle width of 2 m (7 ft) and the constant
pedestrian speed of 5 km/h (3 mph), the time it takes the pedestrian
to travel from the edge of the road to the 25% overlap is 0.72 s and
the time it takes the pedestrian to travel to the 50% overlap is
1.08 s.
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[[Page 38675]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.022
BILLING CODE 4910-59-C
For the scenarios involving a pedestrian crossing from the right,
two overlap conditions are proposed: A more challenging test condition
of 25 percent overlap and a 50 percent overlap to ensure system
robustness. The 25 percent overlap tests are performed only under
daylight conditions, while the 50 percent overlap tests are performed
in all lighting conditions. For the crossing path scenarios, as
described in the testing section of this notice, the pedestrian
surrogate continues to travel along its path either until collision
occurs or it clears the subject vehicle's path. NHTSA also considered a
75 percent overlap, and this condition was included in the testing
performed in 2020. As expected, due to the increase in time range
afforded by a larger overlap, the AEB performance observed when testing
at 75 percent overlap was substantially similar to the AEB performance
achieved when testing at 50 percent overlap.\176\ NHTSA believes that a
75 percent overlap need not be included in the proposed requirements
because the minimum performance is sufficiently addressed by testing at
the 25 percent and 50 percent overlap.
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\176\ For the 75% overlap condition the agency only performed
daylight testing. In general, when testing in the daylight
condition, AEB performance was similar, or better, when testing at
the 75% overlap versus testing at 50% and 25% overlaps.
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Based on the no contact criterion and braking performance observed
during its 2020 research testing of 11 vehicles, NHTSA is proposing to
test PAEB performance with the dark upper beam and dark lower beam
conditions at 50 percent overlap only. NHTSA has tentatively concluded
that, due to the reduced timing and AEB system reaction time observed
during the 25 percent overlap tests, testing at 25 percent overlap for
the dark upper beam and lower beam is not currently practicable. NHTSA
is also proposing to use only 50 percent overlap in the obstructed
child running from the right and the running adult from the left
scenarios due to the same reduced reaction time.
NHTSA considered requiring testing at 25 percent overlap for all
crossing path scenarios. However, this would have required reducing the
subject vehicle speed to allow more reaction time for the AEB system to
avoid the pedestrian surrogate at the proposed speeds. NHTSA lacks
information as to practicable maximum test speed for this condition.
The proposal to test only at 50 percent overlap for certain scenarios
allows for testing at higher speeds, which is more representative of
the safety problem, while effectively encompassing tests at 25 percent
overlap and lower speeds.\177\ Further, if an AEB system is able to
avoid collision in daylight at 25 percent overlap, poor performance for
other crossing path scenarios would not be linked to the vehicle's
braking performance, but rather would likely be linked to the detection
and processing part of the AEB system.
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\177\ For the pedestrian test mannequin to reach the 50 percent
overlap, it must pass through the 25 percent overlap location. As an
example, for a road width of 3 m (10 ft), a vehicle width of 2 m (7
ft), a pedestrian speed of 5 km/h (3 mph), a 0.7 g average
deceleration and a AEB system which reacts when the pedestrian test
mannequin reaches the edge of the road, testing with the subject
vehicle speed of 27 km/h (17 mph) for the crossing path from the
right scenario at 50 percent overlap is equivalent to testing at 18
km/h (11 mph) at 25 percent overlap.
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The 25 percent overlap for the stationary and along path scenarios
emulate a pedestrian standing stationary or walking on the roadway in
the path of the subject vehicle. In along path scenarios in the real
world, the pedestrian is positioned towards the edge of the roadway in
the path of the subject vehicle. Positioning the pedestrian surrogate
at 25 percent overlap assures that the surrogate test target is fully
in the path of the vehicle. NHTSA has tentatively concluded that a 25
percent overlap for the along path scenarios also represents a more
stringent condition than 50 percent overlap for the AEB system, as it
ensures that the system has an adequate operational field of view and
is able to identify pedestrians that are not at the center of the
travel path.
3. Vehicle and Pedestrian Surrogate Travel Speeds
The proposed subject vehicle and pedestrian surrogate travel speed
ranges for the PAEB test scenarios were informed by results from
NHTSA's 2020 research study and results from a NHTSA research program
examining four vehicles under dark lighting conditions for PAEB
performance.178 179
[[Page 38676]]
As in the case for lead vehicle AEB, the proposed speed ranges for PAEB
testing consider two primary factors--the ability of AEB systems to
consistently operate and avoid contact with the surrogate pedestrian
and the practical limits for testing safely.\180\
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\178\ 87 FR 13452 (Mar. 9, 2022).
\179\ See 87 FR 13452 (Mar. 9, 2022) Tables 4, 5 and 6 for the
complete test matrix. The other 4 vehicles tested for PAEB
functionality under dark lighting conditions were only tested at 16
km/h and 40 km/h.
\180\ Where possible and practicable, the proposed speed ranges
align with the latest NCAP proposed upgrade (87 FR 13452 (Mar. 9,
2022)). In instances where system performance for existing PAEB was
lower, or a safety need exists, the top speeds of the ranges were
adjusted accordingly.
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All proposed speed ranges for the PAEB tests have a lower bound of
10 km/h (6 mph). The upper bound is set at the highest speed NHTSA has
tentatively determined is practicable. The 10 km/h (6 mph) lower bound
for the speed range was based on the agency's tentative conclusion that
PAEB systems may not offer consistent performance at speeds below 16
km/h (10 mph) and corroborated by NHTSA's 2020 testing. The lower bound
of 10 km/h (6 mph) is 6 km/h (4 mph) less than that specified in the
2019 NHTSA draft PAEB research test procedure and is consistent with
the lower bound established for testing under Euro NCAP's rating
program and the lower bound proposed for NCAP testing.\181\ The agency
has tentatively concluded that testing at speeds below 10 km/h is not
practicable at this time and testing at speeds above 10 km/h
sufficiently addresses performance of AEB systems at low speeds.
Concurrent with the development of this proposed rule, NHTSA performed
PAEB testing on model year 2021 and 2022 vehicles using the proposed
performance requirements and test procedures. The results of that
testing provide additional support to the tentative conclusion that the
test conditions, parameters, and procedures are practical to conduct
and that the proposed requirements are practical for manufacturers to
achieve. The results of this testing are detailed in the PAEB report
docketed with the proposed rule.
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\181\ https://www.euroncap.com/en/for-engineers/protocols/vulnerable-road-user-vru-protection/, 87 FR 13452 (Mar. 9, 2022) and
https://www.regulations.gov/document/NHTSA-2019-0102-0005.
Table 25--User Manual PAEB Range of Functionality by Tested Vehicle
----------------------------------------------------------------------------------------------------------------
Speed
Vehicle ---------------------------------------------------------------
Low (km/h) Low (mph) High (km/h) High (mph)
----------------------------------------------------------------------------------------------------------------
V1.............................................. 9.6 6 59.2 37
V2.............................................. 4.8 3 80 50
V3.............................................. 4.8 3 99.2 62
V4.............................................. 11.2 7 80 50
V5.............................................. 4.8 3 120 75
V6.............................................. 11.2 7 160 100
V7.............................................. 9.6 6 80 50
V8.............................................. 8 5 72 45
V9.............................................. 9.6 6 80 50
V10............................................. 4.8 3 59.2 37
V11............................................. 6.4 4 68.8 43
----------------------------------------------------------------------------------------------------------------
About half of all pedestrian fatalities and injuries occur in areas
where the posted speed limit is 40 mph or lower.\182\ In order to
mitigate as much of the safety problem as possible, the agency is
proposing the highest practicable speeds for the upper bound of the
subject vehicle speed ranges. However, the testing speed may also be
limited by the ability to test safely and repeatably. The pedestrian
surrogates NHTSA plans to use for testing have a maximum impact speed
of 60 km/h (37.5 mph). Therefore, similar to the lead vehicle, the
highest subject vehicle test speed is determined by the speed
differential, which is equivalent to the maximum impact speed. The
maximum test speeds for crossing pedestrian and stationary adult
scenarios are 60 km/h (37.5 mph), and 65 km/h (40.4 mph) for the
pedestrian surrogate moving away from vehicle at 5 km/h (3.1 mph)
scenario, which corresponds to a 60 km/h (37.5 mph) speed
differential). The 65 km/h (37.5 mph) proposed subject vehicle speed is
consistent with NCAP's request for comments notice but is 5 km/h (3.1
mph) greater than the Euro NCAP test speed.\183\
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\182\ See Safety Problem section of this notice.
\183\ Euro NCAP test speeds, https://www.euroncap.com/en/for-engineers/protocols/vulnerable-road-user-vru-protection/, 87 FR
13470 (Mar. 9, 2022).
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When testing at higher speeds and dark lower and dark upper beam
lighting conditions, PAEB performance was not consistent across the
tested fleet. The test results, however, showed that for the majority
of test conditions, at least one of the AEB systems for the MY 2019 and
2020 test vehicles could perform at the proposed speed ranges. NHTSA
believes that this aggregate performance of available production AEB
systems is not indicative of shortcomings in the overall capability of
AEB technology, but is due to differences in how manufacturers have
developed perception and decision-making algorithms for specific
scenarios absent an FMVSS. To afford time to manufacturers to adjust
the performance of their AEB systems to the proposed requirements, we
are proposing an extended phase-in period for some test conditions.
NHTSA observed a similar trend with the deployment of AEB
technology approximately four years ago, when performance was
inconsistent in NHTSA's NCAP program for the lead vehicle AEB
scenarios. AEB systems failed to meet all of the NCAP performance
levels at that time, but AEB performance quickly improved as
manufacturers updated and improved software.
The proposed walking and running speeds of the pedestrian
surrogates are based on the action of the pedestrian in the test
scenario. For walking adult scenarios and the running child scenario,
the pedestrian surrogate speed is 5 km/h (3 mph), and for the running
adult condition, the pedestrian surrogate speed is 8 km/h (5 mph).
Research performed by Directorate-General for Research and Innovation
and published in 2014 identified these speeds as most appropriate for
PAEB
[[Page 38677]]
testing.\184\ The proposed pedestrian surrogate speeds and the
stationary pedestrian surrogate condition are also consistent with
previous NHTSA research, 2019 draft NHTSA PAEB test procedures, and
Euro NCAP.\185\
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\184\ https://cordis.europa.eu/docs/results/285/285106/final1-aspecss-publishable-final-report-2014-10-14-final.pdf at pg. 19.
\185\ 87 FR 13452 (Mar. 9, 2022), Euro NCAP test speeds, https://www.euroncap.com/en/for-engineers/protocols/vulnerable-road-user-vru-protection/.
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4. Crossing Path Scenario Testing Speeds
Two speed ranges are proposed for the crossing path test
conditions--a range of 10 km/h (6 mph) to 60 km/h (37 mph) for all
adult pedestrian scenarios in the walking and running conditions
(pedestrian surrogate moving at 5 km/h (3 mph) and 8 km/h (5 mph),
respectively), and a range of 10 km/h (6 mph) to 50 km/h (31 mph) for
the running child (pedestrian surrogate moving at 5 km/h (3 mph))
obstructed view scenario.
The proposed speed ranges for PAEB are based on the results from
the 2020 NHTSA research. When discussing the research as it relates to
this notice, the tested vehicles were assigned an identifier as shown
in Table 22. From the vehicles tested, V3 did not have PAEB
capabilities in most tests and is not further discussed. Testing
performed for the 25 percent overlap daylight condition at 16 km/h (10
mph) and 40 km/h (25 mph) (pedestrian surrogate speed 5 km/h (3 mph))
showed that four of the tested vehicles avoided a collision with the
pedestrian surrogate in all tests conducted and six vehicles avoided
collision with the pedestrian surrogate in all tests when tested at 40
km/h (25 mph) (See Table 26).
[GRAPHIC] [TIFF OMITTED] TP13JN23.023
Figure 13 shows the automatic speed reduction from the testing
performed at the 25 percent overlap. As an example, if the subject
vehicle traveling at 40 km/h (25 mph) would approach a stopped object,
it would need to reduce its speed by 40 km/h (25 mph) to avoid
collision with the object. However, since the pedestrian surrogate
continues its movement even after reaching the overlap, the subject
vehicle does not need to come to a stop to avoid contact with the
pedestrian surrogate (for an example, see V9 at 40 km/h (25 mph) in
Figure 13). Different marker shapes are used based on the tested speed
and shading of the markers to differentiate between the trials where
the subject vehicle collided with the pedestrian surrogate and the
successful trials with no contact. As shown in the figures, a
successful no contact trial is represented by a shaded (filled) shape,
while the trials with contact are shown as shapes with no shade (no
fill). The only exception are the trials at 16 km/h (10 mph), where the
``x'' represents the no contact trials and the ``-'' represents the
trials with contact.
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\186\ https://www.regulations.gov/document/NHTSA-2021-0002-0002.
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[[Page 38678]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.024
Even though testing was not performed at 60 km/h (37 mph) for the
crossing path from the right and 25 percent overlap condition, based on
the safety need and the consistency of the results observed at 40 km/h
(25 mph) for the 25 percent overlap, NHTSA has tentatively concluded
that the proposed performance testing requirements are practicable. The
agency is currently performing testing at the proposed speed ranges,
including the 60 km/h (37 mph) speed, to corroborate this conclusion.
NHTSA is proposing a range for the tested speeds from a low 10 km/h (6
mph) starting point to ensure system performance at all speeds, as
opposed to only testing at the highest practicable speeds. As an
example, the owner's manual of V5 shows the PAEB system working from 5
km/h (3 mph) up to 120 km/h (75 mph), but when tested, V5 failed to
avoid collision on all trials at 16 km/h (10 mph). These proposed
subject vehicle speed ranges are also consistent with Euro NCAP vehicle
speed ranges and the pedestrian surrogate speeds are consistent with
both NCAP's latest request for comments notice and Euro NCAP pedestrian
testing speeds.\188\
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\187\ Id.
\188\ EuroNCAP test speeds, https://www.euroncap.com/en/for-engineers/protocols/vulnerable-road-user-vru-protection/, 87 FR
13470 (Mar. 9, 2022).
---------------------------------------------------------------------------
The crossing path from the right at 50 percent overlap test
scenarios with an adult pedestrian surrogate in the daylight condition
was performed at a range of speeds from 16 km/h (10 mph) up to 60 km/h
(37 mph) in NHTSA's 2020 research study. From the 10 relevant vehicles,
3 avoided collision in all tests up to 50 km/h (31 mph) and one avoided
collision in all but one test up to 60 km/h (37 mph) (See Table 27).
[[Page 38679]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.025
Figure 14 shows the speed reduction at various tested speeds. For
clarity, not all tested speeds are shown. The testing speeds shown
represent the current PAEB research test procedures test speeds (16 km/
h (10 mph) and 40 km/h (25 mph)) and three other speeds relevant to the
proposed testing requirements. The three vehicles that avoided impact
on all tests up to 50 km/h (31 mph) were also able to significantly
reduce their speeds when tested at 60 km/h (37 mph). This suggests that
a slight tuning of the AEB systems would allow those systems to avoid
collision at 60 km/h (37 mph).
[GRAPHIC] [TIFF OMITTED] TP13JN23.026
In the agency's crossing path from the right with 50 percent
overlap during dark lighting condition using the vehicle's upper beam
headlamps, one vehicle avoided collision in all but one test when
tested at speeds up to 60 km/h (37 mph), and another vehicle avoided
collision on all tests at speeds above 20 km/h (12 mph) and on most
tests at 16 km/h (10 mph). A total of four vehicles avoided collision
either on all or some of the tests at 60 km/h (37 mph) and on
[[Page 38680]]
all tests at 50 km/h (31 mph). Table 28 shows a summary of the tests
with no contact versus the total number of tests conducted at each test
speed.
[GRAPHIC] [TIFF OMITTED] TP13JN23.027
The four vehicles that avoided contact with the test mannequin on
all or some of the tests at 60 km/h (37 mph) also achieved a speed
reduction of 30 km/h (19 mph) or more before collision in the tests
where contact was observed (See Figure 15), which suggests that the
systems can be adjusted with minimal hardware to the achieve consistent
collision avoidance at 60 km/h (37 mph).
[[Page 38681]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.028
When testing the crossing path scenario from the right with 50
percent overlap at night using the lower beam headlamps, performance
was generally worse than when testing with the upper beam headlamps or
during the daylight condition. Only two vehicles were tested at 50 km/h
(31 mph), one of which avoided contact in two out of four tests and the
other made contact in every test.\189\ V4 had no contact in four out of
five tests at 40 km/h (25 mph) and V6 avoided collision in all tests at
the same speed. From the 10 vehicles tested, 5 had at least one test
that resulted in collision avoidance at 40 km/h (25 mph). A summary of
the no contact tests and the total number of tests per vehicle at each
speed is presented in Table 29.
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\189\ In general, based on the testing matrix a vehicle was
tested at a higher speed only after it had a majority of no contact
tests at the previous tested speed. Conversely, testing at a 5 km/h
lower speed was performed only if the vehicle had a least one no
contact test at the higher speed.
[GRAPHIC] [TIFF OMITTED] TP13JN23.029
[[Page 38682]]
Of the two vehicles tested at 50 km/h (31 mph), V6 only had tests
that resulted in contact but was able to achieve a speed reduction of
33 km/h (21 mph) in two tests and 23 km/h (14 mph) in the other. While
V4 was able to avoid contact in two tests, it only showed a speed
reduction of 13 km/h (8 mph) in the tests with contact. The five
vehicles that had at least one no contact run at 40 km/h (25 mph) also
achieved a speed reduction of 25 km/h (16 mph) or more (except for one
test for V9) on the tests which resulted in contact with the test
mannequin. Speed reduction by vehicle and tested speed for this
scenario is presented in Figure 16. The observed performance of AEB
systems when tested under the dark lower beam condition led the agency
to tentatively conclude that requiring PAEB at speeds up to 60 km/h (37
mph) is not practicable at this time, but achievable with an adequate
phase-in. Therefore, for this scenario, as well as other dark testing
scenarios (see Table 25), in order to afford manufacturers sufficient
time to adjust the performance of the AEB systems to the proposed test
requirements, the higher testing speeds are proposed to be implemented
four years (instead of three years) after the date of publication of
the final rule. Based on the results of NHTSA's testing, a 10 to 40 km/
h (6 to 25 mph) range is currently practicable (See Figure 16). Tests
conducted on model year 2021 and 2022 vehicles (available in the docket
of this proposed rule) and based on current data from NHTSA's 2020
research testing, NHTSA expects improved performance across all speeds.
[GRAPHIC] [TIFF OMITTED] TP13JN23.030
Testing for the obstructed running child (child pedestrian
surrogate travelling at a speed of 5 km/h (3 mph)) scenario with a 50
percent overlap for the daylight condition found one vehicle that
avoided collision in all tests up to 50 km/h (31 mph) and in four out
of five tests from 60 km/h (37 mph). Another vehicle avoided collision
in all but one test up to 40 km/h (25 mph) and had two tests without
contact at 50 km/h (31 mph). Table 30 shows the ratio of no contact
tests to total test by vehicle and tested speed.
[[Page 38683]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.031
Only V4 was tested at 60 km/h (37 mph), and V4 avoided contact with
the child mannequin in four out of five tests and achieved a speed
reduction of more than 50 km/h (31 mph) in the test with contact. Of
the two vehicles tested at 50 km/h (31 mph), V4 avoided collision in
all cases. V2 avoided collision in two tests and achieved more than a
25 km/h (15.5 mph) speed reduction in two tests and a 19 km/h (12 mph)
speed reduction in a third. Figure 17 shows the speed reduction at the
test speed for all vehicles tested. Based on the observed performance
during testing, the agency has tentatively concluded that requiring
performance at speeds up to 50 km/h (31 mph) is practicable in daylight
conditions with an adequate phase-in. Concurrent with the development
of this proposed rule, NHTSA performed PAEB testing on model year 2021
and 2022 vehicles using the proposed performance requirements and test
procedures. The results of that testing provide additional support to
the tentative conclusion that the test conditions, parameters, and
procedures are practical to conduct and that the proposed requirements
are practical for manufacturers to achieve. The results of this testing
are detailed in the PAEB report docketed with this proposed rule.
[[Page 38684]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.032
NHTSA's testing of the running adult pedestrian scenario
(pedestrian surrogate travelling at 8 km/h (5 mph)) from the left was
performed at speeds from 40 km/h (25 mph) to 60 km/h (37 mph) with a 50
percent overlap during daylight.\190\ The results showed that five
vehicles made no contact with the pedestrian surrogate in at least one
test conducted at 60 km/h (37 mph) and all had no contact tests at 50
km/h (31 mph). One of the five vehicles, V2, avoided contact with the
test mannequin in all tests at 60 km/h (37 mph). A summary of the tests
is shown in Table 31.
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\190\ Only V5 and V11 were tested at 35 km/h (22 mph) due to
poor performance at 40 km/h per the test matrix.
[GRAPHIC] [TIFF OMITTED] TP13JN23.033
[[Page 38685]]
For the 60 km/h (37 mph) tests, the vehicles that did not avoid
contact still exhibited significant speed reduction. In the one
instance where V1 collided with the test mannequin, it still achieved a
speed reduction of 42 km/h (26 mph). V4, V6 and V7 all achieved a speed
reduction of more than 35 km/h (22 mph) in all instances with contact
when tested at 60 km/h (37.5 mph). In general, except for V5 and two
tests (V9 at 40 km/h (25 mph) and V7 at 55 km/h (34 mph)) all vehicles
achieved significant speed reduction over all tested speeds. Figure 18
shows the speed reduction at the test speed for all vehicles tested.
The observed performance of five vehicles avoiding contact with an
adult surrogate running from the left in tests conducted at 60 km/h (37
mph) leads the agency to tentatively conclude that requiring
performance at speeds up to 60 km/h (37 mph) is practicable in daylight
conditions three years after the publication of a final rule.
[GRAPHIC] [TIFF OMITTED] TP13JN23.034
5. Stationary Scenario Testing Speeds
NHTSA is proposing a range of subject vehicle travel speeds from 10
km/h (6 mph) to 55 km/h (34 mph) for the stationary pedestrian along
path scenario.
NHTSA's 2020 research testing of this scenario during daylight
conditions found one vehicle, V1, that avoided collision with the test
mannequin on all tests but one at 60 km/h (37.5 mph), and two other
vehicles, V4 and V6, that avoided collision with the test mannequin
when tested at speeds up to 55 km/h (34 mph). For all the tests up to
55 km/h (34 mph), V4 avoided collision in all tests and V6 had only one
collision at 55 km/h (34 mph). Four other vehicles had some no contact
runs at 40 km/h (25 mph) and 9 of the 10 vehicles had no contact on all
tests at 16 km/h (10 mph). Table 32 shows a brief overview of test
results.
[[Page 38686]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.035
The three vehicles tested at 60 km/h (37 mph), vehicles V1, V4, and
V6, had considerable speed reduction on the tests where they collided
with the test mannequin. Where V1 collided with the test mannequin, it
achieved a speed reduction of 37 km/h (23 mph). Where V6 collided with
the test mannequin, it showed very consistent results and had a speed
reduction between 52 km/h (32 mph) and 55 km/h (34 mph) on all three
tests at 60 km/h (37.5 mph). Similarly, V4 had a speed reduction when
tested at 60 km/h (37.5 mph) of between 40 km/h (25 mph) and 45 km/h
(28 mph). The consistent speed reduction results at 60 km/h (37.5 mph)
reinforce the agency's opinion that minimal tunning is required for
existing systems to perform at the proposed requirements. Figure 19
shows the speed reduction at the test speed for all vehicles tested.
[[Page 38687]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.036
NHTSA upper beam testing using the stationary pedestrian along path
scenario under dark lighting conditions resulted in one vehicle, V4,
being able to avoid collision in all tests at speeds up to and
including 55 km/h (34 mph). The vehicle achieved an average speed
reduction of 48 km/h (30 mph) in three other tests conducted at 60 km/h
(37 mph). Two other vehicles avoided collision in all tests at 40 km/h
(25 mph) (See Table 33).
[GRAPHIC] [TIFF OMITTED] TP13JN23.037
When tested at 60 km/h, V4 and V11 collided with the test
mannequin, but were still able to achieve significant speed reduction.
V4 had very consistent speed reductions ranging from 46 km/h (28.6 mph)
to 52 km/h (32.3 mph), and V11 achieved a speed reduction of 29 km/h
(18 mph) and 32 km/h (19.9 mph). When tested at 55 km/h (34 mph), V11
achieved a speed reduction of 25 km/h (15.5 mph) or more in two tests
and did not have a large speed reduction on the other test. At 50 km/h
(31.1 mph), V11 achieved speed reductions of more than 30 km/h (18.6
mph) when it contacted
[[Page 38688]]
the test mannequin. The other vehicles, where they did not avoid
contact at 40 km/h (25 mph), had a significant number of tests without
large speed reductions when they contacted the test mannequin. However,
V9 at 40 km/h (25 mph) showed an average speed reduction of 23.5 km/h
(14.6 mph) in the tests where it contacted the test mannequin. Figure
20 shows the speed reduction at the test speed for all vehicles tested.
[GRAPHIC] [TIFF OMITTED] TP13JN23.038
Based on the results of the testing, NHTSA has tentatively
concluded that requiring testing up to 55 km/h (34.2 mph) is feasible
give the three-year phase-in period after the publication of the final
rule. At the speeds where some of the tested vehicles made contact, V4,
with similar hardware, was able to avoid collision. The agency
anticipates that the other vehicles will be able to avoid contact at
the proposed testing speed ranges through tunning of their systems to
the requirements. Concurrent with the development of this proposed
rule, NHTSA performed PAEB testing on model year 2021 and 2022 vehicles
using the proposed performance requirements and test procedures. The
results of that testing provide additional support to the tentative
conclusion that the test conditions, parameters, and procedures are
practical to conduct and that the proposed requirements are practical
for manufacturers to achieve. The results of this testing are detailed
in the PAEB report docketed with this proposed rule.
The same vehicle that avoided collision in all tests up to 55 km/h
(34 mph) under dark conditions with upper beams (V4) also avoided
collision during all lower beam testing under dark conditions in tests
up to and including those performed at 50 km/h (31 mph) and during four
out of five tests at 55 km/h (34 mph). The other tested vehicles
contacted the test mannequin at speeds on all or most tests when tested
at speeds above 16 km/h (10 mph). A brief overview of the results for
the dark lower beam testing for the stationary along path scenario is
presented in Figure 21 and Table 34.
[[Page 38689]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.039
V4 had significant and consistent speed reduction of between 45 km/
h (28 mph) and 52 km/h (32 mph) when tested at 60 km/h (37 mph). V4
also reduced its speed by more than 30 km/h (19 mph) in the one
instance it contacted the test mannequin when tested at 55 km/h (34
mph). All other vehicles showed poor results at speeds above 16 km/h
(10 mph). Three vehicles had no meaningful AEB activation on all tests,
including 16 km/h (10 mph). V9 was the only vehicle that was able to
avoid collision on two tests at 40 km/h (25 mph) and had significant
speed reduction on the other tests at this speed. Figure 21 shows the
speed reduction at the test speed for all vehicles tested.
[GRAPHIC] [TIFF OMITTED] TP13JN23.040
Given that V4, using commonly found hardware in AEB systems, was
able to avoid contact on every test up to 50 km/h (31.1 mph), avoided
contact on most tests at 55 km/h (34 mph), and achieved significantly
reduced speed on all other
[[Page 38690]]
higher speed tests (including 65 km/h (60 mph)), the agency has
tentatively concluded that a no contact requirement for speed ranges up
to 55 km/h (34 mph) is feasible. The proposed 50 km/h (31 mph) upper
bound of the range 3 years after final rule publication and 55 km/h (34
mph) 4 years after publication of the final rule is necessary due to
pedestrian crashes and fatalities predominantly happening at night and
at higher speeds (see safety section and PRIA). Concurrent with the
development of this proposed rule, NHTSA performed PAEB testing on
model year 2021 and 2022 vehicles using the proposed performance
requirements and test procedures. The results of that testing provide
additional support to this tentative conclusion. The results of this
testing are detailed in the PAEB report docketed with this proposed
rule.
6. Along Path Scenario Testing Speeds
The proposed travel speed range for the pedestrian test mannequin
moving (walking at 5 km/h (3 mph)) along the vehicle's path is from 10
km/h (6 mph) to 65 km/h (40 mph). NHTSA's 2020 PAEB research testing
identified three vehicles that avoided contact with the test mannequin
during all tests performed at 65 km/h (40 mph) (V1 was only tested once
at 65 km/h (40 mph) where it avoided collision with the test
mannequin). Of these three vehicles, V6 avoided collision on all tests
and tested speeds up to 65 km/h (40 mph), V1 avoided collision on all
but one test up to 65 km/h (40 mph), and V9 avoided collision on all or
most of the tests up to 65 km/h (40 mph) and avoided collision on 2 out
of 5 tests at 70 km/h (44 mph). Another vehicle that performed well,
V4, avoided collision on all tests up to 60 km/h (37.5 mph). Table 35
provides a breakdown of tests based on the collision avoidance outcome.
[GRAPHIC] [TIFF OMITTED] TP13JN23.041
V4 had a significant speed reduction of more than 40 km/h on all
tests when tested at 65 km/h (40 mph). On the test at 50 km/h (31.1
mph), where V1 collided with the target, it still achieved a speed
reduction of more than 30 km/h (18.6 mph). Speed reduction for this
scenario by relevant tested speeds is shown in Figure 22. Based on the
results from the 2020 testing, NHTSA has tentatively concluded that an
upper speed bound of 65 km/h (40 mph) is practicable three years after
the publication of the final rule.
[[Page 38691]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.042
Testing for the dark upper beam along path pedestrian test
mannequin moving scenario produced better performance than when testing
for the dark upper beam stationary scenario. In the along path moving
scenario, the test mannequin moves away from the subject vehicle at a
constant speed and continues moving even as the subject vehicle
decelerates during the AEB event. This has the potential to allow for
more time and distance to avoid collision. In the agency's research
testing, one vehicle, V11, avoided collision on all tests at speeds up
to 50 km/h (31.1 mph), had four out of five test runs at 55 km/h (34
mph) with no contact, and avoided collision once at 60 km/h (37 mph).
V4 avoided collision on all tests up to 40 km/h (25 mph), collided once
out of five tests at 50 km/h (31.1 mph), once out of five tests at 60
km/h (37 mph), and had one out of four no collision tests at 65 km/h
(40 mph). Another vehicle, V9, avoided collision on all tests at 50 km/
h (31.1 mph) and avoided collision on a majority of tests at the other
tested speeds except at 65 km/h (40 mph). A total of five vehicles
avoided collision on at least some of the tests at speeds up to 50 km/h
(31.1 mph). Table 36 presents a summary of the test results.
[[Page 38692]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.043
Figure 23 shows the speed reduction achieved by each vehicle by
tested speed. For example, when V11 contacted the test mannequin, it
achieved significant speed reduction. Another vehicle achieving
significant speed reduction in the tests where it contacted the test
mannequin across all tested speeds was V4. This vehicle was the only
one to avoid collision at 65 km/h (40 mph), and even though it only
avoided collision in one test, it achieved a speed reduction of more
than 50 km/h (31.1 mph) in all others. The other vehicles did not
provide consistent results during testing, with a wide range of speed
reduction values. Because no vehicle was able to avoid collision on all
tests at the higher speeds, the agency is proposing that the upper
bound for the speed range for this scenario be 60 km/h (37 mph) three
years after publication of the final rule and 65 km/h (40 mph) four
years after publication of the final rule. Concurrent with the
development of this proposed rule, NHTSA performed PAEB testing on
model year 2021 and 2022 vehicles using the proposed performance
requirements and test procedures. The results of that testing provide
additional support to this tentative conclusion. The results of this
testing are detailed in the PAEB report docketed with this proposed
rule.
[[Page 38693]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.044
Similar to the stationary scenarios, the results from lower beam
testing in dark lighting conditions for the along path moving test
condition were less consistent than for the other lighting conditions.
The tested vehicles were able to avoid contact with the test mannequin
at higher speeds than in the stationary along path scenario. Two
vehicles were able to avoid contact with the test mannequin in at least
one test during tests performed at 60 km/h (37 mph). One vehicle, V4,
avoided contact with the test mannequin in all tests at 60 km/h (37
mph) and had two out of five no contact tests at 50 km/h (31.1 mph).
The other vehicle, V9, had one no contact test out of four at 60 km/h
(37.5 mph) and a majority of no contact tests at all lower tested
speeds. The results of the tests are presented in Table 37.
[GRAPHIC] [TIFF OMITTED] TP13JN23.045
[[Page 38694]]
For the along path moving scenario dark lower beam testing, V4 had
significant speed reduction when tested at 65 km/h (40 mph) in two test
runs but failed to activate in a meaningful manner in one test. When
tested at 60 km/h (37 mph), V9 had two tests with a speed reduction of
at least 30 km/h (18.6 mph) and one test with no meaningful speed
reduction. The results from the other tested speeds for V4 and V9 show
that their AEB systems performed in a similar manner to their
performance for the upper speeds already discussed. In general, the
other tested vehicles performed poorly at all speeds except 16 km/h (10
mph) and did not show consistent speed reduction. Figure 24 shows the
speed reduction at the test speed for all vehicles tested.
[GRAPHIC] [TIFF OMITTED] TP13JN23.046
Two vehicles avoided contacting the surrogate in at least one test
at 60 km/h (37 mph). NHTSA has tentatively concluded that this can be
achieved across the fleet three years after the publication of a final
rule. While no vehicle was able to avoid collision at a test speed of
65 km/h (40 mph), based on the fact that V4 and V9 (equipped with AEB
systems with hardware in common) were able to avoid collision in at
least one test at 60 km/h (37 mph), the agency tentatively concludes
that four years after the publication of the final rule, vehicles will
be able to achieve no contact at 65 km/h (40 mph). The need for testing
at higher speeds in dark lighting conditions is dictated by the safety
need, since as previously discussed, pedestrian fatalities
predominantly occur during dark conditions and at higher speeds.
Concurrent with the development of this proposed rule, NHTSA performed
PAEB testing on model year 2021 and 2022 vehicles using the proposed
performance requirements and test procedures. The results of that
testing provide additional support to this tentative conclusion. The
results of this testing are detailed in the PAEB report docketed with
this proposed rule.
7. PAEB Darkness Testing
During agency testing, PAEB system performance was not consistent
for some of the proposed lighting conditions and speeds. However, the
agency has tentatively concluded that testing in dark lighting
conditions is necessary, and vehicles can be designed and produced to
avoid collisions in all dark lighting test conditions given an adequate
phase-in period. This is consistent with recent IIHS tests finding that
existing systems can perform in the dark-lighted conditions regardless
of their IIHS headlamp ratings.191 192 NHTSA tentatively
concludes that PAEB system performance is improving, and the latest
PAEB systems are already able to perform much better under the proposed
lighting conditions than previous iterations of the systems.\193\
Concurrent with the development of this proposed rule, NHTSA performed
PAEB testing on model year 2021 and 2022 vehicles using the proposed
[[Page 38695]]
performance requirements and test procedures. The results of that
testing provide additional support to the tentative conclusion that the
test conditions, parameters, and procedures are practical to conduct
and that the proposed requirements are practical for manufacturers to
achieve. The results of this testing are detailed in the PAEB report
docketed with this proposed rule.
---------------------------------------------------------------------------
\191\ IIHS dark light press release: https://www.iihs.org/news/detail/pedestrian-crash-avoidance-systems-cut-crashes--but-not-in-the-dark.
\192\ Id.
\193\ ``The better-performing systems are too new to be included
in our study of real-world crashes . . . This may indicate that some
manufacturers are already improving the darkness performance of
their pedestrian AEB systems.'' Id.
---------------------------------------------------------------------------
When tested, the observed crash avoidance performance of the tested
PAEB systems was best for the daylight and upper beam conditions. Table
38 shows the maximum speeds at which the test vehicles did not collide
with the test mannequin either on all trials or at least one trial.
Based on the previously detailed results of the 2020 testing, the
agency tentatively concludes that three years after final rule
publication, consistent performance is possible for the darkness
testing conditions through further tuning of existing AEB systems
without major hardware upgrades. The additional year of phase-in for
higher speed darkness performance requirements would allow time for
systems that currently do not perform consistently to be adjusted or
tuned to the proposed requirements. NHTSA has also concluded that the
crossing path running child from the right scenario and the running
adult from the left scenario with dark lower beam or upper beam are not
a practicable requirement at this time.
Table 38--PAEB: Highest Speed at Which a Vehicle Avoided Contact on at Least One Trial Versus All Trials
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Crossing path--right, 50 percent overlap Stationary Along-path
Lighting condition --------------------------------------------------------------------------------------------------------------------------------------------------------------
At least one trial All trials At least one trial All trials At least one trial All trials
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Daylight......................... 60 km/h.................. 60 km/h.................. 60 km/h.................. 55 km/h................. 70 km/h................. 65 km/h.
Dark, Upper Beam................. 60 km/h.................. 60 km/h.................. 55 km/h.................. 55 km/h................. 65 km/h................. 50 km/h.
Dark, Lower Beam................. 50 km/h.................. 40 km/h.................. 55 km/h.................. 50 km/h................. 60 km/h................. 60 km/h.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
G. Alternatives to No-Contact Performance Test Requirement
NHTSA is considering two alternatives to a no-contact requirement
for both the lead vehicle and pedestrian performance test requirements.
The first alternative would be to permit low speed contact in
NHTSA's on-track testing. Under this alternative, the subject vehicle
would meet the requirements of the standard if it applied the brakes
automatically in a way that reduced the impact speed either by a
defined amount or to a maximum collision speed. The speed at which the
collision would be allowed to occur would be low enough that the crash
would be highly unlikely to be fatal or to result in serious injury.
NHTSA seeks comment on the appropriateness of such a requirement,
any factors to consider surrounding such a performance level, and what
the appropriate reduction in speed or maximum impact speed should be.
NHTSA has considered this alternative separately for the lead vehicle
requirement and the pedestrian requirement and came to the same
tentative conclusion to propose a no contact performance requirement
for on-track testing in each case. However, NHTSA seeks comment on this
level of performance separately for the lead vehicle and pedestrian
requirements because the safety implications of low-speed impacts are
different for each of these two crash types.
NHTSA also seeks comment on the potential consequences on testing
if vehicle contact were allowed. NHTSA has extensive experience with
performing AEB evaluations and has observed that it is possible for
even relatively low-speed collisions with the lead vehicle test device
or pedestrian test mannequin to potentially damage the subject vehicle.
For instance, if a test vehicle were to strike the lead vehicle test
device, even at a low speed, sensors on the vehicle could become
misaligned, and subsequent tests might not be representative of the
vehicle condition at time of first sale. For instance, cameras or radar
devices could become misaligned. Additionally, striking the vehicle
test device or pedestrian test mannequin might prematurely degrade the
appearance of the device and modify its specifications, including in
ways that are not immediately observable. For example, damage to the
test device might affect the radar cross section that requires a long
verification procedure to discover. NHTSA is concerned that any
performance test requirement that allows for vehicle contact could
result in expensive or time-consuming interruptions to repair the
subject vehicle or test device to ensure repeatable testing. NHTSA
seeks comment on this concern.
The second alternative the agency is considering is a no contact
requirement that permits the vehicle to use multiple runs to achieve
the performance test requirements. For example, NHTSA's CIB and DBS
NCAP test performance criteria currently specify that the speed
reduction requirements for each test scenario must be met in at least 5
out of 7 tests runs. This approach would provide a vehicle more
opportunities to achieve the required performance and the agency more
statistical power in characterizing the performance of the vehicle. The
agency seeks comment on the number of repeated tests for a given test
condition and on potential procedures for repeated tests. The agency
also seeks comment on the merits of permitting a vehicle that fails to
activate its AEB system in a test to be permitted additional repeat
tests, including a repeat test process similar to that in the recent
revisions to UN ECE Regulation No. 151.\194\ Finally, the agency seeks
comment on whether there should be additional tests performed in the
event no failure occurs on an initial test for each series.
---------------------------------------------------------------------------
\194\ Section 6.10.1 of UN ECE Regulation No. 151 provides
robustness criteria that specifies that each test condition is
performed two times. If vehicle does not meet the required
performance criteria in one of the two test runs, a third test may
be conducted. A test scenario is considered passed if the required
performance is met in two test runs. However, the total number of
failed test runs cannot exceed 10 percent for the lead vehicle and
pedestrian tests.
---------------------------------------------------------------------------
In the request for comments on upgrades to NCAP, NHTSA sought
comment on an approach that permitted repeated trials for collision
avoidance requirements if an impact occurred with a minimum speed
reduction of at least 50 percent.\195\ This approach would not permit
repeated trials if an impact occurred above certain speeds during the
test series conducted for a given test scenario/condition. NHTSA seeks
comment on the implications if NHTSA were to require a partial speed
reduction, such as 50 percent, in
[[Page 38696]]
combination with an alternate approach for multiple trials. For
example, if a collision occurs and the relative impact speed is less
than 50 percent of the initial speed, the test is repeated. If a
collision occurs again, the subject vehicle would be noncompliant.
Alternatively, even if the subject vehicle avoids a collision, NHTSA
could test again. The number of repeated tests needed to meet the
performance test requirement would be established by NHTSA. If the
agency were to consider such an approach, what should be the required
speed reduction (e.g., 50 percent, 75 percent, etc.) and how many tests
must follow without a collision?
---------------------------------------------------------------------------
\195\ 87 FR 13452 March 9, 2022.
---------------------------------------------------------------------------
H. False Activation Requirement
NHTSA is also proposing to include two scenarios in which braking
is not warranted. These tests are sometimes referred to as ``false-
positive'' tests. AEB systems need to be able to differentiate between
a real threat and a non-threat to avoid false activations. NHTSA is
concerned that false activation events may introduce hard braking
situations when such actions are not warranted, potentially causing
rear-end crashes. The proposed false activation tests establish only a
baseline for system functionality. They are by no means comprehensive,
nor sufficient to eliminate susceptibility to false activations.
Rather, the proposed tests are a means to establish minimum
performance. NHTSA expects that vehicle manufacturers will design AEB
systems to thoroughly address the potential for false activations.\196\
Vehicles that have excessive false positive activations may pose an
unreasonable risk to safety and may be considered to have a safety-
related defect. Previous implementations of other technologies have
shown that manufacturers have a strong incentive to mitigate false
positives and are successful even in the absence of specific
requirements.
---------------------------------------------------------------------------
\196\ From the NCAP request for comments notice ``Specifically,
the Alliance stated that vehicle manufacturers will optimize their
systems to minimize false positive activations for consumer
acceptance purposes, and thus such tests will not be necessary.
Similarly, Honda stated that vehicle manufacturers must already
account for false positives when considering marketability and
HMI.'' 87 FR 13452 (Mar. 9, 2022) at 13460.
---------------------------------------------------------------------------
The two proposed false activation scenarios are the steel trench
plate and the vehicle pass-through test scenarios. Both of these tests
will include acceleration pedal release and testing both with and
without manual braking, similar to testing with a stopped lead vehicle.
NHTSA is proposing that, during each test trial, the subject vehicle
accelerator pedal will be released either when a forward collision
warning is given or at a headway that corresponds to a time-to-
collision of 2.1 seconds, whichever occurs earlier. For tests where
manual braking occurs, the brake is applied at a headway that
corresponds to a time-to-collision of 1.1 seconds.
1. Steel Trench Plate False Activation Scenario
The steel trench plate test was introduced in the NHTSA NCAP test
procedures to assess whether a false positive condition could be
identified and consistently utilized.\197\ In the steel trench plate
test, a steel plate commonly used in road construction is placed on the
surface of a test track. The steel plate presents no imminent danger,
and the subject vehicle can safely travel over the plate without harm.
---------------------------------------------------------------------------
\197\ CIB Non-Threatening Driving Scenarios (DOT HS 811 795);
NHTSA CIB--Crash Imminent Braking test procedure- https://www.regulations.gov/document/NHTSA-2015-0006-0025, https://www.regulations.gov/document/NHTSA-2015-0006-0176.
---------------------------------------------------------------------------
In the steel trench plate false activation scenario, a subject
vehicle traveling at 80 km/h (50 mph) encounters a secured 2.4 m (7.9
ft) wide by 3.7 m (12.1 ft) long steel by 25 mm (1 in) thick ASTM A36
steel plate placed flat in the subject vehicle's lane of travel, and
centered in the travel path, with its short side toward the vehicle
(long side transverse to the path of the vehicle). The AEB system must
not engage the brakes to create a peak deceleration of more than 0.25g
additional deceleration than any manual brake application generates (if
used). The basic setup for the steel trench plate false positive test
is shown in Figure 25.
[GRAPHIC] [TIFF OMITTED] TP13JN23.048
2. Pass-Through False Activation Scenario
The pass-through test, as the name suggests, simulates the subject
vehicle encountering two vehicles outside of the subject vehicle's path
that do not present a threat to the subject vehicle. The test is
similar to the UNECE R131 and UNECE R152 false reaction tests.\198\ In
the pass-through scenario, two VTDs are positioned in the adjacent
lanes to the left and right of the subject vehicle's travel path, while
the lane in which the subject vehicle is traveling is free of
obstacles.
---------------------------------------------------------------------------
\198\ U.N. Regulation No. 131 (Feb. 27, 2020), available at
https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2015/R131r1e.pdf; U.N. Regulation No. 152, E/ECE/TRANS/505/Rev.3/Add.151/
Amend.1 (Nov. 4, 2020), available at https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2020/R152am1e.pdf.
---------------------------------------------------------------------------
The two stopped VTDs are positioned parallel to each other and 4.5
m (14.8 ft) apart in the two adjacent lanes to that of the subject
vehicle (one to the left and one to the right with a 4.5 m (14.8 ft)
gap between them). The 4.5 m (14.8 ft) gap represents a typical travel
lane of about 3.6 m (11.8 ft) plus a reasonable distance at which a
vehicle would be stationary within the adjacent travel lanes.\199\
Similar to the steel trench plate false activation scenario, the AEB
must not engage the brakes to create a peak deceleration of more than
0.25g beyond any manual braking. In Figure 26, a basic setup for the
test is shown.
---------------------------------------------------------------------------
\199\ Federal Highway Administration (Oct. 15, 2014), Range of
lane widths for travel lanes and ramps, https://safety.fhwa.dot.gov/geometric/pubs/mitigationstrategies/chapter3/3_lanewidth.cfm.
---------------------------------------------------------------------------
[[Page 38697]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.049
3. Potential Alternatives to False Activation Requirements
As alternatives to these two false activation tests, NHTSA is
considering removing the false activation tests completely, requiring a
robust documentation process or specifying a data storage requirement.
First, NHTSA seeks comment on the anticipated impacts on safety and the
certification burden if the agency were to finalize a rule that did not
contain one or both of the proposed false positive tests.
Alternatively, NHTSA is considering requiring that manufacturers
maintain documentation demonstrating that robust process standards are
followed specific to the consideration and suppression of false
application of AEB in the real world. Other industries where safety-
critical software-controlled equipment failures may be life-threatening
(e.g., aviation \200\ and medical devices) \201\ are regulated via
process controls ensuring that good software development engineering
practices are followed. This approach recognizes that system tests are
limited in their ability to evaluate complex and constantly changing
software-driven control systems. Software development lifecycle
practices that include risk management, configuration management, and
quality assurance processes are used in various safety-critical
industries. ISO 26262, ``Road vehicles--Functional safety,'' ISO 21448,
``Safety of the Intended Functionality (SOTIF),'' and related
standards, are examples of an approach for overseeing software
development practices. Process standards could be a robust approach to
the regulation of false positives because false activation of braking
is a complex engineering problem with multiple factors and conditions
that must be considered in the real world. The agency seeks public
comment on all aspects of requiring manufacturers to document that they
have followed process standards in the consideration of the real-world
false activation performance of the AEB system.
---------------------------------------------------------------------------
\200\ 14 CFR 33.201 (a) The engine must be designed using a
design quality process acceptable to the FAA, that ensures the
design features of the engine minimize the occurrence of failures,
malfunctions, defects, and maintenance errors that could result in
an IFSD, loss of thrust control, or other power loss.
\201\ 21 CFR 820.30(a)(1) Each manufacturer of any class III or
class II device, and the class I devices listed in paragraph (a)(2)
of this section, shall establish and maintain procedures to control
the design of the device in order to ensure that specified design
requirements are met.
---------------------------------------------------------------------------
Finally, NHTSA is considering requiring targeted data recording and
storage of significant AEB activations. These data could then be used
by manufacturers to improve system performance, or by the agency to
review if a particular alleged false activation was part of a safety
defect investigation. NHTSA is considering a requirement that an AEB
event that results in a speed reduction of greater than 20 km/h (12
mph) activate the recording and storage of the following key
information: date, time, engine hours (i.e., the time as measured in
hours and minutes during which an engine is operated), AEB activation
speed, AEB exit speed (i.e., vehicle speed at which the AEB is
completely released), AEB exit reason (e.g., driver override with
throttle or brake, or system decision), location, and camera image
data. This information could be used by investigators to analyze the
source of the activation and determine if there was a false activation.
Such data would need to be accessible by the agency and potentially by
the vehicle operator for a full and transparent analysis. The agency
seeks comment on all aspects of this data collection approach as an
alternative to false activation testing, including whether this list of
potential elements is incomplete, overinclusive, or impractical.
I. Malfunction Detection Requirement
NHTSA is proposing that AEB systems must continuously detect system
malfunctions. If an AEB system detects a malfunction that prevents it
from performing its required safety function, the vehicle would provide
the vehicle operator with a warning. The warning would be required to
remain active as long as the malfunction exists while the vehicle's
starting system is on. NHTSA would consider a malfunction to include
any condition in which the AEB system fails to meet the proposed
performance requirements. NHTSA is proposing that the driver must be
warned in all instances of component or system failures, sensor
obstructions, environmental limitations (like heavy precipitation), or
other situations that would prevent a vehicle from meeting the proposed
AEB performance requirements. While NHTSA is not proposing the
specifics of the telltale, NHTSA anticipates that the characteristics
of the alert will be documented in the vehicle owner's manual and
provide sufficient information to the vehicle operator to identify it
as an AEB malfunction.
NHTSA is considering requirements pertaining to specific failures
and including an accompanying test procedure. For instance, NHTSA could
develop or use available tests that specify examples of how an AEB
system might be placed in a malfunctioning state, such as disconnecting
sensor wires, removing fuses, misaligning or covering sensors.
NHTSA is considering minimum requirements for the malfunction
indication to standardize the means by which the malfunction is
communicated to the vehicle operator. Malfunctions of
[[Page 38698]]
an AEB system are somewhat different than other malfunctions NHTSA has
considered in the past. While some malfunctions may be similar to other
malfunctions NHTSA has considered in FMVSSs because they require repair
(loose wires, broken sensors, etc.), others are likely to resolve
without any intervention, such as low visibility due to environmental
conditions or blockages due to build-up of snow, ice, or loose debris.
NHTSA is considering requiring that the malfunction indicator
convey the actions that a driver should take when an AEB malfunction is
detected. NHTSA seeks comment on the potential advantages of specifying
test procedures that would describe how the agency would test a
malfunction indicator and on the level of detail that this regulation
should require for a malfunction indicator. Additionally, NHTSA is
considering requiring more details for the indicator itself, such as a
standardized appearance (e.g., color, size, shape, illuminance). NHTSA
seeks comment on the need and potential safety benefits of requiring a
standardized appearance for the malfunction indicator and what
standardized characteristics would achieve the best safety outcomes.
NHTSA seeks comment on the use of an amber FCW warning indicator visual
icon as the malfunction indicator.
NHTSA anticipates driving situations in which AEB activation may
not increase safety and in some rare cases may increase risk. For
instance, an AEB system in which sensors have been compromised because
of misalignment, frayed wiring, or other partial failure, could provide
the perception system with incomplete information that is then
misinterpreted and causes a dangerous vehicle maneuver to result. In
other instances, such as when a light vehicle is towing a trailer with
no independent brakes, or brakes that do not include stability control
functions, emergency braking may cause jack-knifing, or other dangerous
outcomes. NHTSA is considering restricting the automatic deactivation
of the AEB system generally and providing a list of situations in which
the vehicle is permitted to automatically deactivate the AEB or
otherwise restrict braking authority granted to the AEB system.
In addition to these, NHTSA is considering allowing the AEB system
to be placed in a nonfunctioning mode whenever the vehicle is placed in
4-wheel drive low or when ESC is turned off, and whenever equipment
such as a snowplow is attached to the vehicle that might interfere with
the AEB system's sensors or perception system. The malfunction
indication requirements would apply in any such instance. NHTSA seeks
comment on the permissibility of automatic deactivation of the AEB
system and under which situations the regulation should explicitly
permit automatic deactivation of the AEB system.
J. AEB System Disablement
This proposed rule would not permit manual AEB system disablement
at any speed above the proposed 10 km/h (6 mph) minimum speed threshold
above which the AEB system must operate. NHTSA seeks comment on whether
manual deactivation for an AEB system should be allowed at speeds above
10 km/h (6 mph), similar to what is allowed for ESC systems in FMVSS
No. 126.\202\ NHTSA seeks comment on the appropriate performance
requirements if the standard were to permit the installation of a
manually operated deactivation switch. Such requirements might include
limitations such that the default position of the switch be ``AEB ON''
with each cycle of the starting system, or the deactivation
functionality could be limited to specific speeds.
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\202\ 49 CFR 571.126 S5.4.
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K. AEB System Performance Information
This proposed rule has no requirements that the vehicle
manufacturer provide information to vehicle operators about how the AEB
system works. NHTSA is considering a requirement that manufacturers
provide information describing the conditions under which the AEB
system can avoid collisions, warning drivers that the AEB system is an
emergency system and not designed for typical braking situations, and
specifying the conditions under which the AEB system is not likely to
prevent a collision. NHTSA seeks comment on the potential safety
impacts of requiring such information be provided to vehicle operators
and any costs associated with such an information requirement.
VII. AEB Test Procedures
To determine compliance with the proposed requirements, NHTSA
proposes to test AEB systems on a test track using specified procedures
and conditions. To establish the appropriate test procedures and
conditions, the agency considered several factors, including the
expected real-world conditions under which AEB systems need to operate
to effectively reduce crash risk, the procedures and conditions that
provide a high degree of test repeatability and reproducibility, the
procedures and conditions needed for safe testing, procedures and
conditions that are within the practical operating range of AEB
systems, the consistency between FMVSS and NCAP test procedures and
conditions, and harmonization with test procedures and conditions in
international AEB regulations and other test programs such as NCAP.
NHTSA's 2014 draft CIB and DBS research test procedures are the
original basis for the proposed AEB-Lead Vehicle test procedures
included in this NPRM.203 204 Similarly, NHTSA's 2019 draft
research test procedure for PAEB systems is the original basis for the
PAEB test procedures in this NPRM.\205\ Those documents reflect the
agency's experience researching automatic braking systems at the NHTSA
Vehicle Research and Test Center. They also are the main source of
NHTSA's current NCAP test procedures for AEB-equipped vehicles.
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\203\ National Highway Traffic Safety Administration (2014,
August), Crash imminent brake system performance evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
\204\ National Highway Traffic Safety Administration (2014,
August), Dynamic Brake Support Performance Evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
\205\ National Highway Traffic Safety Administration (2019,
April), Pedestrian automatic emergency brake system confirmation
test (working draft). Available at: https://www.regulations.gov/document/NHTSA-2019-0102-0005.
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To the extent possible, the proposed test conditions (such as
environmental conditions, vehicle set-up, etc.) are the same in all
tests unless otherwise specified. This provides for simplified,
consistent test procedures and conditions.
A. AEB System Initialization
NHTSA is proposing that AEB systems will be initialized before each
series of performance tests to ensure the AEB system is in a ready
state for each test trial. The electronic components of an AEB system,
including sensors and processing modules, may require a brief interval
following each starting system cycle to reset to their default
operating state. It also may be necessary for an AEB-equipped vehicle
to be driven at a minimum speed for a period of time prior to testing
so that the electronic systems can self-calibrate to a default or
baseline condition, and/or for the AEB system to become active. The
proposed initialization procedure specifies that, once the test vehicle
starting system is cycled on, it will remain on for at least one minute
and the vehicle is driven at a forward speed of at least 10 km/h (6
mph) before any performance trials
[[Page 38699]]
commence. This procedure also ensures that no additional driver actions
are needed for the AEB system to be in a fully active state.
B. Travel Path
To maximize test repeatability, the travel path in each of the
proposed test scenarios is straight rather than curved. A straight path
simplifies vehicle motion and eliminates the more complex vehicle
control needed for curve-following and which is likely to be less
repeatable. NHTSA's draft research test procedures also specify
straight-line vehicle tests, and other AEB test programs including
NHTSA's NCAP employ a straight travel path.
The intended travel path is the target path for a given test
scenario. For the proposed AEB tests as conducted by NHTSA for NCAP,
the travel path has been programmed into a robotic steering controller,
and a global positioning system (GPS) has been used to follow the
intended path. The proposed text does not limit the method for steering
the subject vehicle and as such any method including a human driver
could be used by the agency during compliance testing. Regardless of
the steering method, the positional tolerance would be maintained for a
valid test. The travel path is identified by the projection onto the
road surface of the frontmost point of the subject vehicle that is
located on its longitudinal, vertical center plane. The subject
vehicle's actual travel path is recorded and compared to the intended
path. For test repeatability, the subject vehicle's actual travel path
is measured during each test run and will not deviate more than a
specified distance from the intended path.
NHTSA is proposing that the intended subject vehicle travel path be
coincident with the center of a test lane whenever there are two edge
lines marking a lane on the test track surface. If there is only one
lane line (either a single or double line) marked on the test track,
the vehicle path will be parallel to it and offset by 1.8 m (6 ft) to
one side (measured from the inside edge of the line). Modern vehicles
equipped with AEB often are equipped with other advanced driver
assistance systems, such as lane-centering technology, which detects
lane lines and which might be triggered if the travel path diverges
substantially from the center of a marked test lane, potentially
leading to unrepeatable results. These specifications reflect the
agency's NCAP tests for AEB.206 207
208
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\206\ National Highway Traffic Safety Administration (2014,
August), Crash imminent brake system performance evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
\207\ National Highway Traffic Safety Administration (2014,
August), Dynamic Brake Support Performance Evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
\208\ National Highway Traffic Safety Administration (2013,
February), Lane departure warning system confirmation test and lane
keeping support performance documentation. See https://www.regulations.gov, Docket No. NHTSA-2006-26555-0135.
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C. Subject Vehicle Preparation
NHTSA is proposing that there be no specific limitations on how a
subject vehicle may be driven prior to the start of a test trial. As
long as the specified initialization procedure is executed, a subject
vehicle may be driven under any conditions including any speed and
direction, and on any road surface, for any elapsed time prior to
reaching the point where a test trial begins. This is because the
manner in which a subject vehicle is operated prior to a crash imminent
situation should not compromise or otherwise affect the functionality
of the AEB system. Also, ancillary subject vehicle operation on and
around a test track will vary depending on exigencies of testing such
as test lane location. For example, a subject vehicle may need to be
driven across an unmarked section of pavement, be maneuvered using
unspecified steering, braking, and accelerator inputs, and/or be driven
in reverse in order to reach the start position for a test trial.
D. Subject Vehicle Tolerance Specifications
NHTSA is proposing that the subject vehicle speed would be
maintained within a tolerance range of 1.6 km/h (1.0 mph) of the chosen test speed between the beginning of a test
and the onset of the forward collision warning. For test repeatability,
subject vehicle speed would be as consistent as possible from run to
run. Subject vehicle speed determines the time-to-collision, which is a
critical variable in AEB tests. In NHTSA's experience, subject vehicle
speed can be reliably controlled within the 1.6 km/h
(1.0 mph) tolerance range, and speed variation within that
range yields consistent test results. A smaller speed tolerance is
unnecessary for repeatability and burdensome as it may result in a
higher test rejection rate without any greater assurance of accuracy of
the AEB system's test track performance. This speed tolerance also is
the same as that specified in the agency's NCAP tests for AEB systems.
NHTSA is proposing that, during each test trial, the subject
vehicle accelerator pedal will be released when a forward collision
warning is given or when the AEB system first engages, whichever is
sooner. Input to the accelerator pedal after AEB has engaged will
potentially interfere with the system and may override the automatic
braking. Therefore, it is necessary to fully release the subject
vehicle's accelerator pedal. The proposed procedure states that the
accelerator pedal is released at any rate and is fully released within
500 milliseconds. This ensures consistent release of the accelerator to
eliminate any interference with AEB engagement and improve test
repeatability. This procedure also better reflects real-world
conditions because a driver's first reaction to a forward collision
warning is likely to be accelerator release.\209\ This manner of
accelerator pedal control is the same as specified in the agency's NCAP
test procedures for AEB systems.
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\209\ Campbell, J.L., Brown. J.L., Graving, J.S., Richard, C.M.,
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December).
Human factors design guidance for driver-vehicle interfaces (Report
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety
Administration.
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The accelerator pedal release can be omitted from tests of vehicles
with cruise control actively engaged because there is no driver input
to the accelerator pedal in that case. The AEB performance requirements
in this proposal are the same for vehicles with and without cruise
control engaged, and AEB systems must provide an equivalent level of
crash avoidance or mitigation whether or not cruise control is active.
NHTSA is proposing that the subject vehicle yaw rate does not
exceed 1.0 deg/s prior to onset of when the subject vehicle
forward collision warning is given or the subject vehicle AEB system
first engages, whichever is sooner. The agency proposes to adopt this
tolerance for test repeatability. A 1.0 deg/s yaw rate
tolerance, which is the most stringent value among the yaw rate limits
specified in the agency's NCAP test procedures for AEB.
NHTSA is proposing that the travel path of the subject vehicle does
not deviate more than 0.3 m (1.0 ft) laterally from the centerline of
the lead vehicle. For consistent test conduct, it is necessary to
maintain close alignment between the subject vehicle path and the lead
vehicle path. Significant misalignment of the travel paths may change
detection characteristics such as range and relative direction,
potentially resulting in test-to-test inconsistency. Therefore, the
agency proposes to use the tolerance requirement of 0.3 m (1.0 ft) for
the subject vehicle's lateral position, which is more stringent than
[[Page 38700]]
the lateral tolerance used in NHTSA's NCAP test procedures for AEB, but
less stringent than the lateral tolerance specified in NHTSA's NCAP
test procedures for PAEB. This tolerance is consistent with the SAE
International recommended practice for AEB. In this proposal, the same
lateral tolerance 0.3 m (1.0 ft) would be used for both lead vehicle
AEB and PAEB.
E. Lead Vehicle Test Set Up and Tolerance
NHTSA is proposing that the speed of the lead vehicle would be
maintained within a tolerance of 1.6 km/h (1.0
mph) during slower-moving tests and during decelerating lead vehicle
tests until the lead vehicle initiates its deceleration. Like the
subject vehicle speed, the speed of the lead vehicle (i.e., the target
vehicle) is a key parameter that directly influences TTC and other test
outcomes. Results from a series of tests with run-to-run speed
variations outside this tolerance range may be inconsistent. Therefore,
for lead vehicle speed, the agency is proposing to use the same
tolerance of 1.6 km/h (1.0 mph) specified for
the subject vehicle speed, which also reflects the tolerance value used
for NHTSA's NCAP AEB tests.
NHTSA is proposing that the lead vehicle would not diverge
laterally more than 0.3 m (1.0 ft) from the intended travel path. This
tolerance applies to both the slower-moving and decelerating lead
vehicle test scenarios (for the stopped lead vehicle scenario, the lead
vehicle is stationary and is centered on the projected subject vehicle
travel path). If the lead vehicle's lateral position deviates
significantly from the intended travel path, its alignment within the
field of view of the forward sensors of the subject vehicle will be
off-center, which can contribute to test series variability. The 0.3 m (1.0 ft.) tolerance for the lead vehicle's
lateral position is the same tolerance specified for the subject
vehicle's lateral position, which is consistent with the tolerance used
in the SAE recommended practice for AEB testing.\210\
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\210\ SAE International (2017), Automatic Emergency Braking
(AEB) System Performance Testing (SAE J3087).
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Controlled lead vehicle deceleration is essential for repeatable
decelerating lead vehicle AEB testing because the reaction of the
subject vehicle depends largely on the position and motion of the lead
vehicle. NHTSA is proposing that the lead vehicle will achieve the
specified deceleration within 1.5 seconds of the onset of lead vehicle
braking. Over this time period, the overall deceleration will be lower
than the target, but will rise over time, allowing for easier test
completion. This lead-in time also makes it easier for the test to be
performed while not making the test harder to pass. The lead vehicle
will maintain this deceleration until 250 milliseconds prior to the
vehicle coming to rest. Over these 250 milliseconds the vehicle
dynamics do not reflect the overall dynamics of the test, and any
acceleration data recorded is dismissed. This deceleration profile is
consistent with NHTSA's NCAP test procedures and SAE's industry
recommended practice for AEB systems.\211\
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\211\ SAE International (2017), Automatic Emergency Braking
(AEB) System Performance Testing (SAE J3087).
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F. Test Completion Criteria for Lead Vehicle AEB Tests
For lead vehicle tests, NHTSA is proposing test-completion criteria
to clearly establish the point at which a test trial has concluded. For
all lead vehicle scenarios, each test run is considered complete
immediately when the subject vehicle makes contact with the lead
vehicle. In the case of stopped or decelerating lead vehicle tests,
each test run also would be considered complete when the subject
vehicle comes to a complete stop without impact. For slower-moving lead
vehicle tests, the test is complete when the subject vehicle's speed is
less than the lead vehicle speed. These test completion criteria are
important in identifying a pass-fail outcome for AEB-equipped light
vehicles. These criteria also are needed to limit consideration of
vehicle motion or behavior after there is no longer a foreseeable
collision with the lead vehicle.
G. PAEB Test Procedures and Tolerance
For PAEB testing, NHTSA proposes using the same general procedures
described above, as applicable, including procedures for subject
vehicle speed, yaw rate, travel path, lateral tolerance, subject
vehicle accelerator pedal release.
Overlap refers to the test mannequin's potential impact point
measured horizontally across the front end of the subject vehicle. It
identifies the point on the subject vehicle that would contact a test
mannequin that is within the subject vehicle travel path if the subject
vehicle were to maintain its speed without braking. NHTSA proposes
using an overlap value of either 50 percent, the midpoint of the
subject vehicle's frontal surface, or 25 percent indicating the point
that is one-quarter of the subject vehicle width from the right side of
the subject vehicle. NHTSA is proposing a 0.15 m (0.5 ft) overlap
tolerance, which provides a high degree of test repeatability while
also allowing a spacing tolerance for the pedestrian test mannequin
position.
NHTSA is proposing different test scenarios in which the pedestrian
test mannequin enters the path of the subject vehicle, including
entering from the right side and left side of the subject vehicle's
lane. For a pedestrian test mannequin initially positioned on the right
side, NHTSA proposes an origination point that is 4.0 0.1 m
(13.1 0.3 ft) from the subject vehicle's intended travel
path. For a pedestrian test mannequin initially positioned on the left
side, NHTSA proposes an origination point that is 6.0 0.1 m
(19.7 0.3 ft) from the intended travel path. These initial
pedestrian test mannequin positions are somewhat longer than those
specified in NHTSA's 2019 draft test procedures for PAEB, which specify
a right-side test mannequin offset of 3.5 m (11.5 ft) and left-side
test mannequin offset of 5.5 m (18.0 ft).\212\ NHTSA is proposing the
larger test mannequin offsets because the agency has found that the
test mannequin sways and oscillates in an inconsistent manner when it
is just starting to move, and the extra distance will provide time for
it to stabilize before entering the subject vehicle's travel path.
This, in turn, will enhance repeatability and accuracy of the test.
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\212\ National Highway Traffic Safety Administration (2019,
April), Pedestrian automatic emergency brake system confirmation
test (working draft). Available at: https://www.regulations.gov/document/NHTSA-2019-0102-0005.
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For test scenarios with a moving pedestrian test mannequin, NHTSA
proposes to specify the maximum distance for the pedestrian test
mannequin to reach its intended speed. NHTSA is proposing 1.5 m (4.9
ft) as the maximum distance which will be used for both crossing path
test scenarios and along path test scenarios. Although it is generally
desirable for the test mannequin to attain its final speed as quickly
as possible to efficiently execute tests, the agency has found that
acceleration that is too sudden often results in inconsistent, jerky
test mannequin motions that may compromise repeatability. NHTSA
therefore is proposing distances that are similar to the requirements
in NHTSA's 2019 draft research test procedures for a PAEB system.
NHTSA is proposing that the simulated walking speed of the
pedestrian test mannequin be maintained within 0.4 km/h (0.2 mph)
[[Page 38701]]
during PAEB tests. In NHTSA's 2020 PAEB research experience in
conducting hundreds of tests, this amount of test mannequin speed
tolerance is consistently achievable and provides a high level of run-
to-run repeatability and consistent test results.
NHTSA is proposing clear test completion criteria to establish a
point when a PAEB test may be considered fully concluded. In all PAEB
test scenarios, a test is immediately complete if the subject vehicle
makes contact with the pedestrian test mannequin. In test scenarios
with the pedestrian test mannequin either crossing or stationary within
the subject vehicle path, a test is complete when the subject vehicle
comes to a complete stop without contacting the pedestrian test
mannequin. In scenarios where the pedestrian mannequin moves along the
forward path of the subject vehicle, the test is complete when the
subject vehicle slows to below the pedestrian test mannequin speed.
These test completion criteria are important for identifying a pass-
fail outcome for PAEB-equipped light vehicles. These criteria also are
needed to limit consideration of vehicle motion or behavior after there
is no longer a risk of collision with a pedestrian test mannequin.
NHTSA is proposing that, when conducting PAEB tests with two VTDs,
their left sides are aligned on the same plane, and they are positioned
1.0 0.1 m (3.3 0.3 ft) from the subject
vehicle's right side when coincident with the intended travel path. The
VTD positioning is consistent with NHTSA's 2019 draft research test
procedures for PAEB systems for the scenario where an obscured child
test mannequin runs into traffic from behind two parked vehicles. These
test specifications are repeatable and provide for consistent test
results.
H. False Positive AEB Test Procedures
For the steel trench plate test, the starting point, L0,
is measured between the subject vehicle's front plane and the leading
edge (closest to the subject vehicle) of the steel trench plate. For
the pass-through scenario, the starting point is measured between the
front plane of the subject vehicle and the vertical plane that contains
the rearmost point of the vehicle test devices.
NHTSA is proposing criteria to clearly establish when a false-
activation test trial may be considered fully concluded. For steel
trench plate tests, a test trial is complete when the subject vehicle
either comes to a stop or passes the leading edge of the steel trench
plate. For the pass-through test, a test trial is complete when the
subject vehicle either comes to a stop or passes between the vehicle
test devices. These criteria provide a definitive, observable pass-fail
basis for false-activation test outcomes in each of the two scenarios.
I. Environmental Test Conditions
NHTSA proposes testing AEB systems in daylight and in darkness to
ensure performance in a wide range of ambient light conditions.
For daylight testing, the proposed ambient illumination at the test
site is not less than 2,000 lux.\213\ This minimum level approximates a
typical roadway light level on an overcast day.\214\ The acceptable
range also includes any higher illumination level including levels
associated with bright sunlight on a clear day.
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\213\ This illumination threshold is the same as that adopted in
SAE J3087 ``Automatic Emergency Braking (AEB) System Performance
Testing.''
\214\ During an overcast day (no sun), when the solar altitude
is around 6 degrees, the light intensity on a horizontal surface is
around 2,000 lux. Illuminating Engineering Society of North America.
1979. ``Recommended Practice of Daylighting.''
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To ensure test repeatability, the agency further proposes that
testing is not performed while the intended travel path is such that
the heading angle of the vehicle is less than 25 degrees with respect
to the sun \215\ and while the solar elevation angle is less than 15
degrees. The intensity of low-angle sunlight aligned directly into the
sensing element of a camera or other optical AEB sensor can saturate or
``wash out'' the sensor and lead to unrepeatable test results. Also,
low-angle sunlight may create long shadows around a test vehicle, which
could potentially compromise test repeatability.
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\215\ The horizontal angle between the sun and a vertical plane
containing the centerline of the subject vehicle would be not less
than 25 degrees for a valid test.
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For the proposed PAEB testing in darkness, the ambient illumination
at the test site must be no greater than 0.2 lux. This value
approximates roadway lighting in dark conditions without direct
overhead lighting with moonlight and low levels of indirect light from
other sources, such as reflected light from buildings and signage. An
illumination level of 0.2 lux also is the same level specified in the
test procedures for the recently issued final rule for adaptive driving
beams.\216\ This darkness level accounts for the effect ambient light
has on AEB performance, particularly for camera-based systems. This
ensures robust performance of all AEB systems, regardless of what types
of sensors they may use.
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\216\ 87 FR 9916.
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NHTSA proposes that the ambient temperature in the test area be
between 0 Celsius (32 [deg]F) and 40 Celsius (104 [deg]F) during AEB
testing. This ambient temperature range matches the range specified in
NHTSA's safety standard for brake system performance.\217\ These
temperatures represent a wide range of conditions that AEB-equipped
vehicles will encounter. While AEB controls and sensors can operate at
lower temperatures, the limiting factor in this case is the braking
performance. The reduced surface friction possible in below-freezing
temperatures may result in unrepeatable test conditions and may
adversely affect subject vehicle braking performance.
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\217\ FMVSS No. 135--Light vehicle brake systems.
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NHTSA is proposing that the maximum wind speed during AEB
compliance testing be no greater than 10 m/s (22 mph) for lead vehicle
avoidance tests and 6.7 m/s (15 mph) for pedestrian avoidance tests.
These are the same maximum wind speeds specified for AEB tests in the
agency's AEB NCAP procedures and PAEB draft research test
procedure.218 219 Excessive wind during testing could
disturb the test devices in various ways. For example, high wind speeds
could affect the ability of the VTD to maintain consistent speed and/or
lateral position. The pedestrian mannequin could bend or sway
unpredictably in excessively windy conditions. Test equipment that
needs to remain stable also could be affected by wind. To ensure test
repeatability, the agency has tentatively decided to adopt these wind
speed specifications to minimize wind effects during testing.
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\218\ National Highway Traffic Safety Administration (2014,
August), Crash imminent brake system performance evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
\219\ National Highway Traffic Safety Administration (2019,
April), Pedestrian automatic emergency brake system confirmation
test (working draft). Available at: https://www.regulations.gov/document/NHTSA-2019-0102-0005.
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NHTSA is proposing that AEB compliance tests not be conducted
during periods of precipitation, including rain, snow, sleet, or hail.
The presence of precipitation could influence the outcome of the tests.
Wet, icy, or snow-covered pavement has lower friction, which may affect
the outcome of the test. More importantly, in those conditions compared
to dry conditions, it is more difficult to reproduce a friction level
with good precision. Therefore, the agency is proposing to adopt the
precipitation specification specified in the agency's NCAP test
procedures for AEB systems.
NHTSA is proposing that AEB performance tests be conducted when
visibility at the test site is unaffected by
[[Page 38702]]
fog, smoke, ash, or airborne particulate matter. AEB systems may use
cameras to detect other vehicles and pedestrians. Reduced visibility
due to the presence of fog or other substances is difficult to
reproduce in a manner that produces repeatable test results. A current
industry standard specifies that the horizontal visibility at ground
level must be greater than 1 km (0.62 miles), and AEB test procedures
in the European NCAP use that requirement.220 221 NHTSA
believes a minimum visibility range is unnecessary to ensure test
repeatability. Therefore, the agency is proposing a limitation on the
presence of conditions that would obstruct visibility, including fog or
smoke during AEB testing, but is not proposing a minimum visibility
range. NHTSA seeks comment on whether to adopt a minimum level of
visibility.
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\220\ SAE International (2017), Automatic Emergency Braking
(AEB) System Performance Testing (SAE J3087).
\221\ European New Car Assessment Program (Euro NCAP) (2019,
July), Test Protocol--AEB Car-to-Car systems, Version 3.0.2.
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J. Test Track Conditions
NHTSA is proposing that the test track surface have a peak friction
coefficient of 1.02 when measured using an ASTM F2493 standard
reference test tire, in accordance with ASTM E1337-19 at a speed of
64.4 km/h (40 mph), without water delivery.\222\ Surface friction is a
critical factor in brake system performance testing, including AEB. The
presence of moisture will significantly change the measured performance
of a braking system. A dry surface is more consistent and provides for
greater test repeatability. The proposed peak friction coefficient is
the same value that NHTSA selected for an update of a NHTSA FMVSS
related to surface friction for brake performance testing.\223\
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\222\ ASTM E1337-19, Standard Test Method for Determining
Longitudinal Peak Braking Coefficient (PBC) of Paved Surfaces Using
Standard Reference Test Tire.
\223\ 87 FR 34800 (June 8, 2022), Final rule, Standard Reference
Test Tire.
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NHTSA is proposing that the test surface have a consistent slope
between 0 and 1 percent. The slope of a road surface can affect the
performance of an AEB-equipped vehicle.\224\ It also influences the
dynamics and layout involved in the proposed AEB test scenarios for
both lead vehicle AEB and PAEB. Therefore, NHTSA proposes to limit the
slope of the test surface by adopting the slope requirement specified
for AEB tests in the agency's lead vehicle AEB NCAP procedures and PAEB
draft research test procedure.225 226
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\224\ Kim, H. et al., Autonomous Emergency Braking Considering
Road Slope and Friction Coefficient, International Journal of
Automotive Technology, 19, 1013-1022 (2018).
\225\ National Highway Traffic Safety Administration (2014,
August), Crash imminent brake system performance evaluation (working
draft). Available at: https://www.regulations.gov/document/NHTSA-2012-0057-0038.
\226\ National Highway Traffic Safety Administration (2019,
April), Pedestrian automatic emergency brake system confirmation
test (working draft). Available at: https://www.regulations.gov/document/NHTSA-2019-0102-0005.
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NHTSA proposes that the lead vehicle and pedestrian test mannequin
be unobstructed from the subject vehicle's view during compliance tests
except where specified. Furthermore, each compliance test would be
conducted without any vehicles, obstructions, or stationary objects
within one lane width of either side of the subject vehicle's path
unless specified as part of the test procedure. This test condition is
the same as that specified in the agency's research test procedures for
AEB systems. The presence of unnecessary objects near the path of the
subject vehicle could interfere with detection of a lead vehicle or
test mannequin and have an unintentional effect on the field of view of
the AEB system, which may compromise test repeatability.
K. Subject Vehicle Conditions
NHTSA is proposing that the subject vehicle be loaded with not more
than 277 kg (611 lb.), which includes the sum of any vehicle occupants
and any test equipment and instrumentation. The agency proposes this
lightly loaded vehicle specification because the primary goal of the
AEB testing is to measure the sensing and perception capability of a
vehicle, which is relatively insensitive to the level of the vehicle
load. In addition, braking tests with fully loaded vehicles are already
required and conducted under exiting FMVSS, such as FMVSS No. 135,
Light Vehicle Brake Systems, to measure the maximum brake capacity of a
vehicle.
To maximize test repeatability, NHTSA is proposing that subject
vehicle brakes be burnished prior to AEB performance testing according
to the specifications of either S7.1 of FMVSS No. 135, which applies to
passenger vehicles with GVWR of 3,500 kilograms or less, or according
to the specifications of S7.4 of FMVSS No. 105, which applies to
passenger vehicles with GVWR greater than 3,500 kilograms. AEB
capability relies upon the function of the service brakes on a vehicle.
Thus, it is reasonable and logical that the same pre-test conditioning
procedures that apply to service brake performance evaluations should
also apply to AEB system performance evaluations.
To maximize test repeatability, NHTSA is proposing that the subject
vehicle service brakes be maintained at an average temperature between
65 [deg]C (149 [deg]F) and 100 [deg]C (212 [deg]F). The brake
temperature is evaluated using either the front or rear brakes,
depending on which has a higher temperature. This temperature range is
the same as the range specified in NHTSA's safety standard for light
vehicle brake systems \227\ and is important for consistent brake
performance and test repeatability. Foundation brakes that are too cool
or too hot may perform with less consistency, such that stopping
distance may be unrepeatable. Hot or cold brakes also may fade or
experience stiction or other effects that exacerbate inconsistent brake
performance.
---------------------------------------------------------------------------
\227\ FMVSS No. 135--Light vehicle brake systems.
---------------------------------------------------------------------------
User adjustable settings, such as regenerative braking settings and
FCW settings, would be tested in any setting state. Furthermore,
adaptive and traditional cruise control may be used in any selectable
setting during testing. The agency would test vehicles with any cruise
control or adaptive cruise control setting to make sure that these
systems do not disrupt the ability for the AEB system to stop the
vehicle in crash imminent situations. However, for vehicles that have
an ESC off switch, NHTSA will keep ESC engaged for the duration of the
test.
VIII. Test Devices
A. Pedestrian Test Mannequins
NHTSA is proposing specifications for two pedestrian test devices
to be used for compliance testing for the new PAEB requirements. These
specifications would be referenced within the PAEB test procedures and
NHTSA would use test devices meeting these specifications when it
performs compliance testing. The two pedestrian test devices would each
consist of a test mannequin and a motion apparatus (carrier system)
that positions the test mannequin during a test. NHTSA is proposing
specifications for a pedestrian test mannequin representing a 50th
percentile adult male and a pedestrian test mannequin representing a 6-
to 7-year-old child. NHTSA would use these pedestrian test mannequins
to ensure that light vehicles are equipped with PAEB systems that
detect pedestrians and automatically provide emergency braking to avoid
pedestrian test mannequin contact in the tests specified in this
proposal. NHTSA is proposing to
[[Page 38703]]
incorporate by reference specifications from three ISO standards.
1. Background
Since the introduction of PAEB, vehicle manufacturers and other
entities have been engaged in testing and evaluating the technology.
Because testing cannot be performed with live pedestrians, test
mannequins have been developed to facilitate a safe and practical way
to perform these evaluations objectively. However, to ensure the PAEB
systems operate as intended, the test mannequins must be representative
of pedestrians from the perspective of the vehicle sensors. That is,
sensors used to detect the test mannequins must operate as if they were
detecting actual pedestrians in the real world, which in turn allows
the PAEB system to interpret and respond to the sensor data in a
realistic manner. This representativeness ensures that PAEB system test
results translate to real-world safety benefits.
There have been several efforts by different organizations to
develop common specifications for PAEB testing, including an ISO
Standard, ISO 19206-2:2018, ``Road vehicles--Test devices for target
vehicles, vulnerable road users and other objects, for assessment of
active safety functions--Part 2: Requirements for pedestrian targets,''
and an SAE Recommended Practice, SAE International Standard J3116,
``Active Safety Pedestrian Test Mannequin Recommendation.'' ISO 19206-
4:2020, ``Road vehicles--test devices for target vehicles, vulnerable
road users and other objects, for assessment of active safety
functions--Part 4: Requirements for bicyclists targets,'' has color and
infrared reflectivity specifications. Additionally, Euro NCAP specifies
use of test mannequins that conform to the specifications in its
``Articulated Pedestrian Target Specification Document,'' \228\ which
sets specifications for size, color, motion patterns, and detectability
by vehicle sensors.
---------------------------------------------------------------------------
\228\ European Automobile Manufacturers' Association (ACEA),
February 2016, ``Articulated Pedestrian Target Specification
Document,'' Version 1.0, available at https://www.acea.auto/publication/articulated-pedestrian-target-acea-specifications/.
---------------------------------------------------------------------------
In November 2019, NHTSA published a Federal Register notice that
sought comment on NHTSA's draft research test procedure for PAEB
testing (84 FR 64405). The draft test procedures provided methods and
specifications for performing PAEB systems performance
evaluations.\229\ During the development of these test procedures,
NHTSA used the 4activePS pedestrian static mannequin that was developed
by 4Active Systems.\230\ The 4activePS pedestrian static mannequin was
developed specifically for testing PAEB systems and conforms to the
specifications in ISO 19206-2:2018. NHTSA continues to test with test
mannequins developed by 4Active Systems. However, NHTSA has
transitioned to performing tests using the 4activePA, which has
articulated legs.
---------------------------------------------------------------------------
\229\ National Highway Traffic Safety Administration (2019,
April), Pedestrian automatic emergency brake system confirmation
test (working draft). Available at: https://www.regulations.gov/document/NHTSA-2019-0102-0005.
\230\ Id. at 8, citing 4activeSystems GmbH. (n.a.). 4activePS
pedestrian static (web page). Traboch, Austria: Author. Available at
www.4activesystems.at/en/products/dummies/4activeps.html.
---------------------------------------------------------------------------
The change from using static mannequins to mannequins equipped with
articulated, moving legs is in response to information that
demonstrates that articulated mannequins may be more representative of
actual pedestrians. In response to NHTSA's 2015 NCAP request for
comments notice, the agency received comments asking that NHTSA use
articulated mannequins to test PAEB systems. The commenters reasoned
that the articulated mannequins better represent actual pedestrians. In
response to these comments, NHTSA proposed, in its 2022 NCAP RFC, the
use of articulated mannequins.\231\ In adopting this approach, NHTSA
noted that using articulating mannequins would harmonize with other
major consumer information-focused entities that use articulating
mannequins, such as Euro NCAP and IIHS.\232\
---------------------------------------------------------------------------
\231\ 87 FR 13452, March 9, 2022, supra.
\232\ Id.
---------------------------------------------------------------------------
For the test scenarios involving a moving pedestrian, NHTSA is
proposing that the legs of the pedestrian test mannequin would
articulate to emulate a walking motion.\233\ A test mannequin that has
leg articulation when in motion more realistically represents an actual
walking or running pedestrian. For test scenarios involving a
stationary pedestrian, NHTSA is proposing that the legs of the
pedestrian test mannequin remain at rest (i.e., emulate a standing
posture).
---------------------------------------------------------------------------
\233\ The velocity of the articulated legs could be detected by
an AEB system because some sensing technologies, such as radar,
``may be able to measure and detect the relative velocities of
moving legs.'' Since the articulated legs of the current test
mannequin move at a constant pace during a test, identifying proper
leg velocities for a range of speeds would be needed in developing
the next generation test mannequin. European Automobile
Manufacturers' Association (ACEA), February 2016, ``Articulated
Pedestrian Target Specification Document,'' Version 1.0. https://www.acea.auto/publication/articulated-pedestrian-target-acea-specifications/.
---------------------------------------------------------------------------
In developing the specifications for the pedestrian test mannequins
that will be used in NHTSA compliance testing, NHTSA first considered
what characteristics these devices need to have. Not only does a test
mannequin need to be able to facilitate accurate, repeatable, and
reproducible tests when used for compliance testing, but it must also
ensure that performance during the PAEB tests will be representative of
performance in the real world. This means that a PAEB system should
detect and classify the test mannequin similarly to real pedestrians.
It is NHTSA's understanding that PAEB systems currently on the
market may use a combination of camera and radar-based systems, and
that Automated Driving Systems may also use lidar systems. NHTSA is
proposing specifications for the pedestrian test mannequin based on
these technologies. These specifications include those for visual
characteristics, such as the color and physical dimensions. They also
include specifications for infrared reflectivity, radar cross section,
and articulation (the latter two affect how radar-based systems will
perceive the pedestrian test mannequin radar signature).
Additionally, NHTSA has considered the need for the test mannequins
to allow for safe and non-destructive testing. In the course of testing
PAEB systems, the subject vehicle may impact the test mannequin. In the
event contact is made, it is important that the test mannequin has
characteristics that do not pose safety risks to those conducting the
tests. From a practical standpoint, it is also important for test
mannequins to be durable so they can be used repeatedly, yet strikable
in a way that minimizes the risk of damage to the subject vehicle
should contact be made with the test mannequin, even at a high relative
velocity.
NHTSA's proposed specifications incorporate by reference existing
industry standards that represent the culmination of many years of
coordination and research. NHTSA not only believes these specifications
are sufficient to ensure that test results are objective and translate
to real-world safety benefits, but also that there are currently
available test mannequins that meet these specifications and possess
characteristics that allow for safe and non-destructive testing.
2. Mannequin Appearance
The pedestrian test mannequin specification includes basic body
proportions that, from any angle,
[[Page 38704]]
represent either a 50th percentile adult male or a 6 to 7-year-old
child. The pedestrian test mannequins' specifications include a head,
torso, two arms, and two articulating legs. The pedestrian test
mannequin appears clothed in a black long-sleeved shirt and blue long
pants. The black shirt and blue pants are selected to challenge a
camera system, as the minimal contrast between the shirt and pants is
challenging for a camera system to detect.
The physical dimensions of the pedestrian test mannequins are
intended to be consistent with live pedestrians. NHTSA is proposing
that the pedestrian test mannequins have the dimensions specified in
ISO 19206-2:2018, which would be incorporated by reference into
proposed 49 CFR part 561.
Evaluation of crash data indicates that the pedestrian injury and
fatality safety problem is one that predominately affects adults, with
adults aged 21 or older comprising 93 percent of all pedestrian
fatalities.\234\ However, to address child pedestrian safety, NHTSA is
proposing requirements for a scenario representing a child running into
the street from an obstructed location, such as from behind a parked
car. Children are among the most vulnerable road users, especially in
the absence of adult supervision. Due to the small size of children,
they can be obstructed from view until they are already in the travel
path of a vehicle. This situation can be challenging for drivers and
represents an area in which PAEB can also offer safety benefits.
---------------------------------------------------------------------------
\234\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813079 Pedestrian Traffic Facts 2019 Data, May 2021.
---------------------------------------------------------------------------
Both the ISO Standard and SAE Recommended Practice J3116 set forth
specifications for an adult and child test mannequin. The ISO Standard
specifies a 50th percentile adult male test mannequin and a 6 to 7-
year-old child test mannequin. The SAE recommendation specifies an
adult test mannequin based on the average adult pedestrian involved in
fatal pedestrian crashes, and a 6-year-old child test mannequin. The
specific dimensions for the test mannequins differ slightly between the
two recommended practices, but NHTSA has tentatively concluded that
this difference is immaterial as it relates to this NPRM. As an
example, one of the biggest differences in dimensions is the height of
the adult test mannequin, where the ISO document specifies a height for
the adult test mannequin of 1800 mm (70.9 in) with shoes and the SAE
specifies a height of 1715 mm (67.5 in) without shoes (the SAE
recommended practice provides no recommendation for shoe height, or for
a test mannequin with shoes).\235\ In considering the appropriate
dimensions for the test mannequins used for AEB testing, NHTSA found
most persuasive ISO 19206-2:2018, particularly due to the wide adoption
of the specification and commercial availability of test mannequins
based on the specification.\236\ Furthermore, NHTSA uses the test
mannequins recommended in the ISO standard for all PAEB tests. NHTSA
has no information on how a different recommendation for the test
mannequin, such as the SAE recommended practice, would affect
correlation between results and test repeatability. However, NHTSA
requests comments on whether it would be more appropriate to use the
SAE Recommended Practice specifications because they are more
representative of the average pedestrian fatality.
---------------------------------------------------------------------------
\235\ A mannequin wearing shoes is representative of a person
crossing the road. If considering a 30 mm (1.2 in) height for shoes
the differences in height between the two recommended practices is
55 mm (2.2 in).
\236\ NHTSA is not aware of any commercially available test
mannequins conforming to SAE J3116.
---------------------------------------------------------------------------
For the remaining proposed PAEB scenarios, NHTSA is proposing to
use only the adult test mannequin. For these scenarios, NHTSA is
proposing specifications that are largely from ISO 19206-2:2018.
However, for color and infrared reflectivity, including skin color,
NHTSA is proposing specifications from ISO 19206-4:2020, ``Road
vehicles--test devices for target vehicles, vulnerable road users and
other objects, for assessment of active safety functions--Part 4:
Requirements for bicyclists targets.''
NHTSA believes that it is important for PAEB performance
requirements to ensure real world safety benefits across a broad
spectrum of real-world pedestrian crash scenarios. While NHTSA
understands that, for practical reasons the performance requirements
cannot address every pedestrian crash scenario, NHTSA also seeks to
understand better whether the specifications for the adult test
mannequin in the ISO standards are reasonably sufficient to address the
crash risks for pedestrians of other sizes, such as small adult women.
NHTSA seeks comment on whether use of the 50th percentile adult male
test mannequin ensures PAEB systems would react to small adult females
and other pedestrians other than mid-size adult males.
NHTSA has considered whether a small adult female mannequin is
necessary. However, NHTSA is unaware of any standards providing
specifications for a 5th percentile adult female test mannequin, or of
any consumer information programs testing with such a device. Instead,
NHTSA seeks comment on whether the child test mannequin also should be
specified for use in all PAEB scenarios. Such an approach could better
ensure that PAEB systems are able to perceive and respond to a larger
range of pedestrians in the real world than if only the 50th percentile
adult male test mannequin was prescribed. However, as NHTSA has not
performed testing with the child test mannequin in all of the test
scenarios, the agency requests comment on whether such a requirement is
feasible or appropriate.
In summary, NHTSA is proposing to incorporate by reference the
dimensions and posture specifications found in ISO 19206-2:2018 for a
test mannequin representing a 50th percentile adult male and a 6- to 7-
year-old child. NHTSA considers these specifications to be an
appropriate representation for the test mannequins. Specifically, NHTSA
is proposing to incorporate by reference the complete set of dimensions
for the adult and child test mannequins found in Annex A, Table A.1 of
ISO 19206-2:2018. NHTSA is also proposing to incorporate by reference
Figures A.1 and A.2, which illustrate reference dimensions for the
adult and child test mannequins.
3. Color and Reflectivity
Specifications for test mannequin skin color are not found in ISO
19206-2:2018. Further, while the standard provides specifications for
reflectivity, it does not include procedures for measuring it. For
these reasons, NHTSA is proposing to incorporate by reference the
bicyclist mannequin specifications for color and reflectivity found in
ISO 19206-4:2018, ``Road vehicles--test devices for target vehicles,
vulnerable road users and other objects, for assessment of active
safety functions--Part 4: Requirements for bicyclists targets.''
Although this standard provides requirements for bicyclist test
devices, NHTSA proposes to reference these specifications for color and
reflectivity for the prescribed adult and child test mannequins because
the specifications appear workable for use with the ISO Standard for
pedestrian test devices. NHTSA is specifying that the test mannequins
be of a color that matches a specified range of skin colors
representative of very dark to very light complexions, with features
that
[[Page 38705]]
represent hair, facial skin, hands, a long-sleeve black shirt, blue
long pants, and black shoes.
NHTSA believes that the specifications in ISO 19206-4:2020 for
color and infrared reflectivity for a bicyclist mannequin can be used
for PAEB testing and should be incorporated by reference to fill in
gaps in ISO 19206-2:2018 for those specifications. Not only would these
specifications provide needed specifications for these features, but
they also allow NHTSA to harmonize with specifications for test
mannequins in use by Euro NCAP.
4. Radar Cross Section
Some PAEB systems use radar sensors to detect the presence of
pedestrians. Accordingly, NHTSA is proposing that the pedestrian test
mannequins have radar reflectivity characteristics that are
representative of real pedestrians. Specifically, NHTSA is proposing
that the radar cross section of the pedestrian test mannequin, when
measured in accordance with procedures specified in ISO 19206-2:2018,
Annex C, fall within the upper and lower boundaries shown in Annex B,
Section B.3, Figure B.6.
5. Other Considerations
In addition to the characteristics specified in this proposal,
NHTSA considered whether the test mannequins should have thermal
characteristics. NHTSA believes there is a potential that thermal
sensing technologies may be used in active safety systems in the
future. While NHTSA does not want to dissuade manufacturers from
developing or implementing such technology, the agency is not aware of
any vehicle manufacturers currently using such technology for the
detection of pedestrians as part of a PAEB system. NHTSA has also not
conducted research on what specifications would be needed to ensure
that a test mannequin has thermal characteristics that are
representative of real-world pedestrians. Accordingly, NHTSA has not
included thermal specifications for the pedestrian test mannequins in
the draft regulatory text.
NHTSA also considered whether it was necessary to propose
specifications for the motion of the pedestrian test mannequin carrier
system. The carrier system is needed to control the speed (where
applicable) and position of the pedestrian test device. Specifically,
this equipment is needed to achieve the necessary closed-loop test
scenario choreography between the subject vehicle and pedestrian test
mannequin (e.g., lateral overlap relative to the front of the subject
vehicle and desired baseline contact points). ISO 19206-2:2018 provides
recommended specifications in section 7. These specifications are
designed to ensure that the carrier system is capable of positioning
the pedestrian test mannequin relative to the target within the
specific tolerances required by the different test procedures. Careful
positioning is necessary because the relative position and speed of the
subject vehicle and pedestrian test mannequin need to be consistent in
order to achieve repeatable and reproducible test results.
However, ISO 19206-2:2018 also includes specifications intended to
ensure that the carrier system minimally affects how the pedestrian
test mannequin is perceived by the subject vehicle. Tentatively, NHTSA
has concluded that including specifications for the pedestrian test
mannequin carrier system itself is not necessary. This is primarily
because no specific reflective or radar characteristics of the carrier
system are needed to ensure objective and representative PAEB testing.
Moreover, the characteristics of the carrier system should be
irrelevant for conducting the test, as the carrier system ought not
bear on the results of the test. To the extent that the carrier system
is detected by a PAEB-equipped vehicle during compliance testing, NHTSA
believes that such detection would not adversely affect the test
result. Accordingly, NHTSA intends to use a carrier system for
compliance testing that has minimal radar cross-section and minimal
optical features based on test environment.
B. Vehicle Test Device
1. Description and Development
To ensure repeatable and reproducible testing that reflects how a
subject vehicle would be expected to respond to an actual vehicle in
the real world, this proposal includes broad specifications for a
vehicle test device to be used as a lead vehicle, pass through vehicle,
or obstructing vehicle during testing. NHTSA is proposing that the
vehicle test device be based on certain specifications defined in ISO
19206-3:2021, ``Road vehicles--Test devices for target vehicles,
vulnerable road users and other objects, for assessment of active
safety functions--Part 3: Requirements for passenger vehicle 3D
targets.'' \237\ The vehicle test device is a tool that NHTSA proposes
to use to facilitate the agency's compliance tests to measure the
performance of AEB systems required by the proposed FMVSS. This NPRM
describes the vehicle test device that NHTSA would use.
---------------------------------------------------------------------------
\237\ https://www.iso.org/standard/70133.html. May 2021.
---------------------------------------------------------------------------
The surrogate vehicle NHTSA currently uses in its research testing
is the Global Vehicle Target (GVT). The GVT is a full-sized harmonized
surrogate vehicle developed to test crash avoidance systems while
addressing the limitations of earlier generation surrogate vehicles. To
obtain input from the public and from industry stakeholders, NHTSA
participated in a series of five public workshops and three radar
tuning meetings between August 2015 and December 2016. These workshops
and meetings provided representatives from the automotive industry with
an opportunity to inspect, measure, and assess the realism of prototype
surrogates during the various stages of development. Workshop and
meeting participants were permitted to take measurements and collect
data with their own test equipment, which they could then use to
provide specific recommendations about how the surrogate vehicle's
appearance, to any sensor, could be improved to increase realism.
After feedback from automotive vehicle manufacturers and suppliers
was incorporated into an earlier design of the GVT, a series of high-
resolution radar scans were performed by the Michigan Tech Research
Institute (MTRI) under NHTSA contract. These measurements provided an
independent assessment of how the radar characteristics of the GVT
compared to those from four real passenger cars.\238\ This study found
that the GVT has generally less radar scatter than the real vehicles to
which it was compared. However, MTRI found that ``even though the [GVT]
may more often reflect a greater amount of energy than the [real]
vehicles, it is not exceeding the maximum energy of the returns from
the vehicles. Thus, a sensor intended for the purpose of detecting
vehicles should perform well with the [GVT].'' \239\
---------------------------------------------------------------------------
\238\ The comparison passenger cars used were a 2008 Hyundai
Accent, a 2004 Toyota Camry, a 2016 Ford Fiesta hatchback, and a
2013 Subaru Impreza.
\239\ Buller, W., Hart, B., Aden, S., and Wilson, B. (2017, May)
``Comparison of RADAR Returns from Vehicles and Guided Soft Target
(GST),'' Michigan Technological University, Michigan Tech Research
Institute. Docket NHTSA-2015-0002-0007 (www.regulations.gov).
---------------------------------------------------------------------------
NHTSA also performed tests to determine the practicality of using
the GVT for test-track performance evaluations by examining how
difficult it was to reassemble the GVT after it was struck in a test.
Using a randomized matrix designed to minimize the effect
[[Page 38706]]
of learning, these tests were performed with teams of three or five
members familiar with the GVT reassembly process.\240\ NHTSA found that
reassembly of the GVT on the robotic platform takes approximately 10
minutes to complete; however, additional time is often required to re-
initialize the robotic platform GPS afterwards.\241\
---------------------------------------------------------------------------
\240\ Snyder, Andrew C. et al., ``A Test Track Comparison of the
Global Vehicle Target (GVT) and NHTSA's Strikeable Surrogate Vehicle
(SSV),'' July 2019 https://rosap.ntl.bts.gov/view/dot/41936.
\241\ Id.
---------------------------------------------------------------------------
Finally, NHTSA conducted its own crash imminent braking tests to
compare the speed reduction achieved by three passenger cars as they
approached the GVT, compared to the Strikable Surrogate Vehicle (SSV),
the surrogate vehicle NHTSA currently uses for its NCAP AEB tests.
These tests found that any difference that might exist between the GVT
and the SSV were small enough to not appreciably influence the outcome
of vehicle testing.\242\
---------------------------------------------------------------------------
\242\ Id.
---------------------------------------------------------------------------
When used during lead vehicle AEB testing, the GVT is secured to
the top of a low-profile robotic platform. The robotic platform is
essentially flat and is movable and programmable. The vehicle test
device's movement can be accurately and repeatably defined and
choreographed with the subject vehicle and testing lane through the use
of data from the robotic platform's on-board inertial measurement unit,
GPS, and closed-loop control facilitated by communication with the
subject vehicle's instrumentation. The shallow design of the robotic
platform allows the tested vehicle to drive over it. The GVT is secured
to the top of the robotic platform using hook-and-loop fastener
attachment points, which allow the pieces of the GVT to easily and
safely break away without significant harm to the vehicle being tested
if struck.
The internal frame of the GVT is constructed primarily of vinyl-
covered foam segments held together with hook-and-loop fasteners. The
GVT's exterior is comprised of multiple vinyl ``skin'' sections
designed to provide the dimensional, optical, and radar characteristics
of a real vehicle that can be recognized as such by camera and radar
sensors.\243\ If the subject vehicle impacts the GVT at low speed, the
GVT is typically pushed off and away from the robotic platform without
breaking apart. At higher impact speeds, the GVT breaks apart as the
subject vehicle essentially drives through it.
---------------------------------------------------------------------------
\243\ Id.
---------------------------------------------------------------------------
2. Specifications
The most recent widely accepted iteration of vehicle test device
specifications is contained in ISO 19206-3:2021. Using data collected
by measuring the fixed-angle/variable-range radar cross section for
several real vehicles, ISO developed generic ``acceptability
corridors,'' which are essentially boundaries that the vehicle test
device's radar cross section must fit within to be deemed
representative of a real vehicle.\244\ All vehicles that ISO tested
have radar cross section measurements that fit within the boundaries
set forth in the ISO standard.
---------------------------------------------------------------------------
\244\ The vehicles tested to develop the ISO standard are: 2016
BMW M235i, 2006 Acura RL, 2019 Tesla Model 3, 2017 Nissan Versa,
2018 Toyota Corolla, and 2019 Ford Fiesta.
---------------------------------------------------------------------------
This proposal would incorporate by reference ISO 19206-3:2021 into
NHTSA's regulations and specify that the vehicle test device meets
several specifications in ISO 19206-3:2021, in addition to other
specifications identified by NHTSA. Because the GVT was considered
during the development of ISO 19206-3:2021, the GVT would meet the
standard's specifications. However, should the design of the GVT change
or a new vehicle test device be developed, reference to the more
general specifications of ISO 19206-3:2021 should ensure that NHTSA is
able to test with such other vehicle test devices, and should also
ensure that such vehicle test devices have properties needed by an AEB
system to identify it as a motor vehicle.
The vehicle test device's physical dimensions are proposed to be
consistent with those of the subcompact and compact car vehicle class.
The specific range of dimensions in this proposal for individual
surfaces of the vehicle test device are incorporated from ISO 19206-
3:2021, Annex A, Table A.4. These include specifications for the test
device's width and the placement of the license plate, lights, and
reflectors relevant to the rear-end of the vehicle test device.
The vehicle test device is proposed to have features printed on its
surface to represent features that are identifiable on the rear of a
typical passenger vehicle, such as tail lamps, reflex reflectors,
windows, and the rear license plate. The proposed color ranges for the
various surface features, including tires, windows, and reflex
reflectors, are incorporated from ISO 19206-3:2021, Annex B, Tables B.2
and B.3. Table B.2 specifies the colors of the tires, windows, and
reflectors, which reflect the colors observed the in the real world.
The color of the exterior of the vehicle is specified to be a range
representing the color white, which provides a high color contrast to
the other identifiable features. White is also a common color for motor
vehicles.\245\ The proposed reflectivity ranges for the various
features on the vehicle test device are incorporated from ISO 19206-
3:2021, Annex B, Table B.1. Table B.3 specifies the recommended
minimum, mean, and maximum color range for the white body, specifically
the outer cover.
---------------------------------------------------------------------------
\245\ Globally, white was the most popular color for light
vehicles in 2021. https://gmauthority.com/blog/2022/02/white-was-
the-most-popular-car-color-again-in-2021/
#:~:text=According%20to%20PPG%2C%2035%20percent,by%20silver%20at%2011
%20percent.
---------------------------------------------------------------------------
Because many AEB systems rely on radar sensors in some capacity to
identify the presence of other vehicles, the vehicle test device must
have a radar cross section that would be recognized as a real vehicle
by an AEB system. In particular, the vehicle test device must have a
radar cross section consistent with a real vehicle when approached from
the rear over a range of distances.
NHTSA is proposing that the radar cross section of the vehicle test
device fall within an ``acceptability corridor'' when measured using an
automotive-grade radar sensor. This acceptability corridor would be
defined by the upper and lower boundaries specified by ISO 19206-
3:2021, Annex C, Equations C.1 and C.2, using the radar cross section
boundary parameters defined in ISO 19206-3:2021, Annex C, Table C.3 for
a fixed viewing angle of 180 degrees. NHTSA is aware that, unlike some
predecessor specification documents, such as Euro NCAP Technical
Bulletin 025 from May 2018, the ISO standard does not specify that the
radar cross section measurements be verified using a specific model of
radar. Rather, the ISO standard specifies that the radar sensor used
have certain specifications and operational characteristics. NHTSA's
proposal similarly does not specify that the vehicle test device's
initial radar cross section be measured with a specific model or brand
of radar. NHTSA only proposes that the radar sensor used to validate
the radar cross section operate within the 76-81 GHz bandwidth, have a
horizontal field of view of at least 10 degrees, a vertical field of
view of at least 5 degrees, and a range greater than 100 m (328 ft).
Additionally, NHTSA's proposal does not specify that the VTD's radar
cross section during in-the-field verifications be performed to
objectively assess whether the radar cross section still falls within
the acceptability corridor. NHTSA seeks comment about whether
[[Page 38707]]
use of the optional field verification procedure provided in ISO 19206-
3:2021, Annex E, section E.3 should be used.
Because the test procedures proposed in this rule only involve
rear-end approaches by the subject vehicle, NHTSA is at this time only
proposing to establish specifications applicable for the rear-end of
the vehicle test device. NHTSA seeks comment on whether the
specifications for the vehicle test device should include sides of the
vehicle, as well as the rear-end. If NHTSA were to include, in a final
rule, specifications for sides of a vehicle test device, NHTSA
anticipates that those specifications would also be incorporated from
ISO 19206-3:2021.
3. Alternatives Considered
One alternative test device that NHTSA considered for use in its
lead vehicle AEB evaluations was the agency's self-developed Strikable
Surrogate Vehicle device, which NHTSA currently uses in its NCAP
testing of AEB performance. NHTSA adopted the use of the SSV as part of
its 2015 NCAP upgrade, under which the agency began testing AEB
performance.\246\ The SSV resembles the rear section of a 2011 Ford
Fiesta hatchback. The SSV is constructed primarily from a rigid carbon
fiber mesh, which allows it to maintain a consistent shape over time
(unless damaged during testing). To maximize visual realism, the SSV
shell is wrapped with a vinyl material that simulates paint on the body
panels and rear bumper, and a tinted glass rear window. The SSV is also
equipped with a simulated United States specification rear license
plate. The taillights, rear bumper reflectors, and third brake light
installed on the SSV are actual original equipment from a production
vehicle. NHTSA testing shows that AEB systems will recognize the SSV
and will respond in a way that is comparable to how they would to an
actual vehicle.\247\
---------------------------------------------------------------------------
\246\ 80 FR 68604.
\247\ www.regulations.gov. NHTSA Docket Nos. NHTSA-2012-0057-
0032, NHTSA-2012-0057-0034, and NHTSA-2012-0057-0039.
---------------------------------------------------------------------------
While the SSV and GVT are both recognized as real vehicles by AEB
systems from the rear approach aspect, the SSV has several
disadvantages compared to the GVT. The foremost disadvantage of the SSV
is how easily it can be irreparably damaged when struck by a subject
vehicle during testing, particularly at high relative velocities. While
NHTSA has tried to address this issue by attaching a foam bumper to the
rear of the SSV to reduce the peak forces resulting from an impact by
the subject vehicle, the SSV can still easily be damaged to a point
where it can no longer be used if the relative impact speed is
sufficiently high (i.e., >40 km/h (25 mph), which is much lower than
the maximum relative impact speed of 80 km/h (50 mph) potentially
encountered during the AEB tests performed at the maximum relative
speeds proposed in this notice). Also, unlike the GVT, which has its
movement controlled by precise programming and closed loop control, the
SSV moves along a visible monorail secured to the test surface, which
may be visible to a camera-based AEB system.
In addition to the vehicle test device specifications, NHTSA seeks
comment on specifying a set of real vehicles to be used as vehicle test
devices in AEB testing. UN ECE Regulation No. 152 specifies that the
lead vehicle be either a regular high-volume passenger sedan or a
``soft target'' meeting the specifications of ISO 19206-1:2018.\248\ UN
ECE regulation does not require the use of real vehicles as targets,
but rather offers them as an alternative to manufacturers to homologate
their systems, at their choice. Although NHTSA has tentatively
concluded that the specification in UN ECE Regulation No. 152 of any
high-volume passenger sedan is not sufficiently specific for an FMVSS,
NHTSA seeks comment on whether it should create a list of vehicles from
which NHTSA could choose a lead vehicle for testing. Unlike the UN ECE
regulation, which provides flexibility to manufacturers, inclusion of a
list of vehicles would provide flexibility to the agency in the
assessment of the performance of AEB systems. Such a list would be in
addition to the vehicle test device proposed in this document, to
provide assurance of vehicle performance with a wider array of lead
vehicles. For example, the list could include the highest selling
vehicle models in 2020.
---------------------------------------------------------------------------
\248\ U.N. Regulation No. 152, E/ECE/TRANS/505/Rev.3/Add.151/
Amend.1 (Nov. 4, 2020), available at https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2020/R152am1e.pdf.
---------------------------------------------------------------------------
Using actual vehicles has various challenges, including the
potential for risk to individuals conducting the tests and damage to
the vehicles involved, and assuring a safe testing environment that
could encounter high energy collisions between real vehicles in cases
of poor AEB system performance or AEB or test equipment malfunctions.
NHTSA seeks comment on the utility and feasibility of test laboratories
safely conducting AEB tests with real vehicles, such as through
removing humans from test vehicles and automating scenario execution,
and how laboratories would adjust testing costs to factor in the risk
of damaged vehicles.
Beyond the practical safety limits and cost of testing described
above, managing a list of relevant lead vehicles would require the
standard to be updated periodically to keep pace with the vehicle fleet
and to ensure that lead vehicles are available years after a final
rule. NHTSA seeks comments on the merits and potential need for testing
using real vehicles, in addition to using a vehicle test device, as
well as challenges, limitations, and incremental costs of such.
IX. Proposed Effective Date Schedule
NHTSA is proposing that, within four years after publication of a
final rule, all requirements for AEB would be applicable. Most
requirements would have to be met within three years of the date of
publication of the final rule. Small-volume manufacturers, final-stage
manufacturers, and alterers would be provided an additional year (added
to those above) to meet the requirements of the final rule.
NHTSA anticipates that nearly all vehicles subject to this proposal
would already have the hardware capable of meeting the proposed
requirements by the effective date of a final rule. An AEB system
requires sensing, perception, warning hardware, and electronically
modulated braking subsystems. The perception subsystem is comprised of
computer software that analyzes information provided by the sensors and
computational hardware to process the code. NHTSA anticipates that
manufacturers will need time to build code that analyses the frontal
view of the vehicle in a way that achieves the requirements of this
proposed rule.
NHTSA has found that some manufacturers have already built systems
that are capable of meeting some of the scenarios that are proposed.
Therefore, for all lead vehicle AEB, PAEB daylight, PAEB darkness with
upper beam headlamps, and most PAEB darkness with lower beam headlamps
activated, NHTSA proposes a three-year lead time for manufacturers to
build the needed software capabilities. NHTSA proposes a four-year lead
time for the remaining higher speed PAEB scenarios. NHTSA expects
manufacturers to create any new code needed to meet the second stage
lead time requirements as well as to modify existing vehicle equipment
such as headlamps to support the functionality of PAEB in darkness.
[[Page 38708]]
NHTSA is concerned about the potential costs and practicability
burdens imposed on manufacturers. Given that darkness pedestrian
avoidance technology is new, the agency believes that more time should
be afforded to manufacturers to refine PAEB systems to meet the crash
avoidance requirements for the higher end of the speed range in
darkness conditions, compared to lead vehicle avoidance or lower speed
pedestrian avoidance. The agency is also aware that implementing new
technology outside of the normal vehicle redesign cycle can increase
costs of implementation.
With these considerations, NHTSA is proposing a split compliance
schedule. For requirements other than those proposed for the darkness
pedestrian avoidance requirements at higher speeds, NHTSA proposes an
effective date of the first September 1st that is at least three years
from the date of publication of a final rule. The proposed schedule
then requires full compliance for all vehicles manufactured on or after
the first September 1st four years after publication of a final rule.
X. Summary of Estimated Effectiveness, Cost, and Benefits
NHTSA's assessment of available safety data indicates that between
2016 and 2019, light vehicles averaged 1.12 million rear-impact crashes
annually. These crashes resulted in an annual average of 394
fatalities, 142,611 non-fatal injuries, and an additional 1.69 million
damaged vehicles. Additionally, between 2016 and 2019, an average of
approximately 23 thousand crashes annually could potentially have been
addressed by PAEB. These crashes resulted in an annual average of 2,642
pedestrian fatalities and 17,689 non-fatal injuries.
A. Target Population
The target population for the lead vehicle AEB analysis includes
two-vehicle, rear-end light vehicle crashes and their resulting
occupant fatalities and non-fatal injuries. FARS is used to obtain the
target population for fatalities and CRSS is used to obtain the target
population for property damage only crashes and occupant injuries. The
target population includes two-vehicle light-vehicle to light-vehicle
crashes in which the manner of collision is a rear-end crash and the
first harmful event was a collision with a motor vehicle in transport.
Further refinement includes limiting the analysis to crashes where the
striking vehicle was traveling straight ahead prior to the collision at
a speed less than 90 mph (145 km/h) and the struck vehicle was either
stopped, moving, or decelerating.
Table 39--Light Vehicle to Light Vehicle Target Population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Injuries
Light vehicle to light vehicle target Crashes PDOs ------------------------------------------------------------------- Fatalities
population MAIS1 MAIS2 MAIS3 MAIS4 MAIS5 MAIS 1-5
--------------------------------------------------------------------------------------------------------------------------------------------------------
All Conditions................................ 1,119,470 1,692,678 130,736 9,364 1,942 256 57 142,611 394
--------------------------------------------------------------------------------------------------------------------------------------------------------
The target population for the PAEB analysis considered only light
vehicle crashes that included a single vehicle and pedestrian in which
the first injury-causing event was contact with a pedestrian. The area
of initial impact was limited to the front of the vehicle, specified as
clock points 11, 12, and 1, and the vehicle's pre-event movement was
traveling in a straight line. These crashes were then categorized as
either the pedestrian crossing the vehicle path or along the vehicle
path. The crashes are inclusive of all light, road surface, and weather
conditions to capture potential crashes, fatalities, and injuries in
real world conditions. Data elements listed as ``unknown'' were
proportionally allocated, as needed.
Table 40--Target Population of Pedestrian Fatalities and Non-Fatal Injuries
--------------------------------------------------------------------------------------------------------------------------------------------------------
Injuries
Light vehicle to pedestrian target population ------------------------------------------------------------------------------ Fatalities
MAIS 1 MAIS 2 MAIS 3 MAIS 4 MAIS 5 MAIS 1-5
--------------------------------------------------------------------------------------------------------------------------------------------------------
All Scenarios................................................ 13,894 3,335 1,541 300 75 19,511 2,508
Crossing Path................................................ 12,637 3,087 1,442 284 71 17,522 2,083
Along Path................................................... 1,257 248 98 16 4 1,622 425
--------------------------------------------------------------------------------------------------------------------------------------------------------
B. Lead Vehicle AEB System Effectiveness
Lead vehicle AEB system effectiveness was determined based on the
expected injury risk reduction applied to current crashes resulting in
injuries or fatalities. The target population was split into three
groups corresponding to the three lead vehicle test scenarios (lead
vehicles stopped, moving, and decelerating). The crashes in these
scenarios were further categorized into two sub-groups: Those in which
the striking vehicle driver did not apply the brakes prior to impact
and those where the striking vehicle driver applied the brakes as an
avoidance maneuver. The baseline for the system effectiveness analysis
assumed that the striking vehicle in the control group is not equipped
with FCW or any AEB functionality. For the treatment group, NHTSA
predicted the crash outcomes if the striking vehicle were equipped with
an AEB system meeting the proposed performance requirements.
For crashes where the striking vehicle's operator did not apply the
brakes, the initial event treatment section has two stages. The first
stage covers when FCW activates, and the second stage covers how the
driver reacts to the FCW warning. Depending on whether the striking
vehicle driver is predicted to react to the warning or not, the second
stage models how the vehicle intervenes. If the striking vehicle driver
reacts to the FCW and applies the brakes, the vehicle was modeled to
provide supplemental braking. If the striking vehicle driver was
predicted to not apply the brakes, the vehicle was modeled to apply the
brakes automatically.
Similarly, for cases where the striking vehicle driver applied the
brakes according to the crash database, the initial treatment section
has two stages. The first stage models the driver's reaction to FCW and
the second stage
[[Page 38709]]
models supplemental braking (there are no conditions for which the
driver is modeled not to apply the brakes in this situation because
NHTSA does not anticipate that an FCW will decrease the probability of
a driver applying the brakes). For cases where the driver applied the
brakes, it was assumed that, in response to a forward collision
warning, the driver would apply the brakes sooner compared to the crash
database and that the resulting deceleration would be greater as a
result of supplemental braking.
Although NHTSA evaluated the crash data assuming the striking
vehicles were not equipped with any AEB functionality, NHTSA does
anticipate that lead vehicle AEB systems will have substantial
voluntary market penetration, though at lower performance level than
the proposed requirements in this NPRM. Therefore, the baseline (what
the world would look like in the absence of the proposed regulation)
takes into account voluntary installation of AEB. The baseline is
incorporated by evaluating injury risk based on the expected difference
in vehicle performance between a baseline vehicle and a vehicle meeting
the proposed requirements. System effectiveness is estimated based on
the calculated difference of the vehicle striking speed between the
baseline and proposed rule and the difference in injury risk for each
group and sub-group described above.
C. PAEB System Effectiveness
To estimate PAEB system effectiveness, the target populations for
along path and crossing path were further grouped by vehicle travel
speed.
NHTSA assumes that a PAEB system meeting the proposed requirements
would recognize a pedestrian standing or moving along the same
longitudinal path as the vehicle and be able to identify the speed
differential between the two. NHTSA also estimates that the PAEB
system's capabilities include reaching a stop 55 centimeters in front
of the pedestrian. Thus, in the absence of external mitigating factors
(the impacts of these factors are included later in the analyses),
NHTSA estimates that PAEB would prevent all fatalities along path
scenarios when activated within the operational speed range up to 45
mph (73 km/h).
For pedestrian crossing path crashes, NHTSA first estimated the
distribution of collision by the location along the front of the
vehicle at which the pedestrians were struck. This step establishes the
time in which the pedestrian is within the path of the vehicle for a
crossing path situation. This timing is important for NHTSA to model
the PAEB system's ability to avoid or mitigate the crash (very short
times do not provide much time for the PAEB system to react and thus
the reduction in speed before the impact is low). After this, the
effectiveness of a PAEB system that meets the proposed requirements is
established for each travel speed.
To account for external physical factors impeding PAEB-braking
system effectiveness, NHTSA adjusted the estimated fatalities prevented
and non-fatal injuries that would be mitigated by PAEB downward by 10
percent. This assumption represents limitations associated with factors
such as tire traction and pedestrian visibility due to inclement
weather, contaminants on the roadway, changes in vehicle balance
affecting traction, and poor tire and road maintenance.
D. Fatalities Avoided and Injuries Mitigated
Table 41 presents the safety benefits associated with the proposed
rule. As a result of the proposed rule, NHTSA estimates that a total of
362 fatalities would be prevented, and 24,321 non-fatal (MAIS 1-5)
injuries would be mitigated over the course of one vehicle model year's
lifetime.
Table 41--Summary of Safety Benefits: Fatalities Prevented and Non-Fatal Injuries Mitigated
----------------------------------------------------------------------------------------------------------------
Category Lead vehicle AEB PAEB Total
----------------------------------------------------------------------------------------------------------------
Non-fatal Injuries (MAIS 1-5)............................... 21,649 2,672 24,321
Fatalities.................................................. 124 238 362
----------------------------------------------------------------------------------------------------------------
The agency considers these estimates to be conservative because
some benefits of the proposed rule may not be quantified. The target
population does not include multiple-vehicle rear-end crashes. AEB is
also likely to be effective at reducing some rear-end crashes where the
struck vehicle is something other than a light vehicle, such as a heavy
vehicle or motorcycle. Additionally, these estimates are influenced by
voluntary adoption of AEB. If voluntary performance levels are lower
than the agency estimates, the benefits of the rule will be higher than
estimated.
E. Costs
The analysis makes use of annual sales data between calendar year
2011-2020 to estimate the number of vehicles subject to the proposed
rule. Table 42 presents the annual sales of new light vehicles for 2011
through 2020. Over the ten-year period, an average of 15.7 million
light vehicles were sold annually, of which approximately 40 percent
were cars and 60 percent were light trucks.
Table 42--Annual Sales of New Light Vehicles
[Thousands]
----------------------------------------------------------------------------------------------------------------
Total light
Year Cars Light trucks vehicle sales
----------------------------------------------------------------------------------------------------------------
2011........................................................ 6,093 6,449 12,542
2012........................................................ 7,245 6,975 14,220
2013........................................................ 7,586 7,693 15,279
2014........................................................ 7,708 8,484 16,192
2015........................................................ 7,529 9,578 17,107
2016........................................................ 6,883 10,296 17,179
2017........................................................ 6,089 10,738 16,827
2018........................................................ 5,310 11,609 16,919
2019........................................................ 4,720 11,911 16,630
[[Page 38710]]
2020........................................................ 3,402 10,712 14,114
---------------------------------------------------
Annual Average.......................................... 6,257 9,445 15,701
(% of total LV sales)................................... (39.8) (60.2) (100)
----------------------------------------------------------------------------------------------------------------
Because common hardware is used across lead vehicle AEB and PAEB
systems, specific system functionality can be achieved through upgraded
software. Therefore, the incremental cost associated with this proposed
rule reflects the cost of a software upgrade that would allow current
systems to achieve lead vehicle AEB and PAEB functionality that meets
the requirements specified in the proposed rule. The incremental cost
per vehicle is estimated at $82.15 for each design cycle change of the
model. When accounting for design cycles and annual sales of new light
vehicles, the total annual cost associated with the proposed rule is
approximately $282.16 million in 2020 dollars.
Table 43--Total Annual Cost
----------------------------------------------------------------------------------------------------------------
Number of Per vehicle cost
Category vehicles -------------------------------- Total annual cost
(thousands) Design cycle Annual (millions)
----------------------------------------------------------------------------------------------------------------
Cars......................................... 6,257 $82.15 $27.38 $171.32
Light Trucks................................. 9,445 11.74 110.84
------------------------------------------------------------------
Total.................................... 15,701 .............. .............. 282.16
----------------------------------------------------------------------------------------------------------------
Note: Values may not sum due to rounding.
F. Cost-Effectiveness
This proposed rule is highly cost effective. Based on cost-
effectiveness and benefit-cost analyses, it is expected that society
would be better off as a result of this proposed rule. When discounted
at three and seven percent, the cost per equivalent life saved under
the proposed rule ranges from $0.50 to $0.62 million. Because the cost
per equivalent life saved is less than the comprehensive economic cost
of a fatality, the proposed rule is considered to be cost-
effective.\249\ Furthermore, when discounted at three and seven
percent, the net benefits associated with the proposed rule are
estimated at approximately $6.52 and $5.24 billion, respectively.
Positive net benefits indicate that the proposed rule generates a net
benefit to society.
---------------------------------------------------------------------------
\249\ The PRIA presents the Value of a Statistical Life as $11.6
million based on the ``Revised Departmental Guidance, Treatment of
Value of Preventing Fatalities and Injuries in Preparing Economic
Analyses'', March 2021.
Table 44--Summary of Costs and Benefits
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benefits Cost per equivalent life Net benefits (millions)
----------------------------------------------------------------------------------- saved (millions) ---------------------------
Monetized benefits Total cost ----------------------------
(millions) (millions)
Equivalent fatalities ---------------------------- 3% 7% 3% 7%
3% 7%
--------------------------------------------------------------------------------------------------------------------------------------------------------
675................................................... $6,802 $5,518 $282.16 $0.50 $0.62 $6,520 $5,235
--------------------------------------------------------------------------------------------------------------------------------------------------------
G. Comparison of Regulatory Alternatives
To explore fully other possible rulemaking options, the agency
examined a variety of combinations of performance requirements, with
greater and lesser stringency than the preferred alternative. NHTSA
evaluated regulatory alternatives for this rulemaking. These regulatory
options were: (1) Requiring light vehicles to meet the proposed lead
vehicle AEB requirements only (no requirements for PAEB), (2) PAEB
systems requirements only during daylight conditions (no change to the
lead vehicle AEB requirements in the proposed rule), and (3) adding
PAEB requirements in turning scenarios in addition to the requirements
proposed in this NPRM (no change to the lead vehicle AEB requirements
in the proposed rule). The last option, adding PAEB requirements in
turning scenarios, is the only option that is expected to require new
hardware in addition to software to cover a wider field of view when
the vehicle is turning. The added sensors contributed to the higher
projected cost per vehicle and the low anticipated benefits from adding
these scenarios contributed to the higher estimated cost per equivalent
life saved shown in Table 45. When comparing cost-effectiveness and
benefit-cost measures across regulatory options, the proposed rule is
the most cost-effective option and also offers the highest net
benefits.
[[Page 38711]]
Table 45--Summary of Regulatory Alternatives
----------------------------------------------------------------------------------------------------------------
Cost per equivalent life Net benefits (millions)
saved (millions) -------------------------
Regulatory options Relative to preferred option --------------------------
3% 7% 3% 7%
----------------------------------------------------------------------------------------------------------------
Option #1: Lead Vehicle AEB Less Stringent.............. $0.88 $1.09 $3,650 $2,910
Requirements.
Option #2: Daylight only PAEB. Less Stringent.............. 0.71 0.87 4,594 3,674
Option #3: Proposed Rule...... Preferred Option............ 0.50 0.62 6,520 5,235
Option #4: Add turning More Stringent.............. 3.13 3.86 5,447 4,062
scenarios for PAEB.
----------------------------------------------------------------------------------------------------------------
XI. Regulatory Notices and Analyses
Executive Orders 12866, 13563, and 14094 and DOT Regulatory Policies
and Procedures
The agency has considered the impact of this rulemaking action
under Executive Order (E.O.) 12866, E.O. 13563, E.O. 14094, and the
Department of Transportation's regulatory procedures. This rulemaking
is considered ``(3)(f)(1) significant'' and was reviewed by the Office
of Management and Budget under E.O. 12866, ``Regulatory Planning and
Review,'' as amended by E.O. 14094, ``Modernizing Regulatory Review.''
It is expected to have an annual effect on the economy of $200 million
or more. NHTSA has prepared a preliminary regulatory impact analysis
that assesses the cost and benefits of this proposed rule, which has
been included in the docket listed at the beginning of this NPRM. The
benefits, costs, and other impacts of this NPRM are summarized in the
prior section of this NPRM.
Regulatory Flexibility Act
The Regulatory Flexibility Act of 1980, as amended, requires
agencies to evaluate the potential effects of their proposed and final
rules on small businesses, small organizations, and small governmental
jurisdictions. I certify that this NPRM would not have a significant
economic impact on a substantial number of small entities.
The PRIA discusses the economic impact of the proposed rule on
small vehicle manufacturers, of which NHTSA is aware of 12. NHTSA
believes that this proposed rule would not have a significant economic
impact on these manufacturers. Much of the work developing and
manufacturing AEB system components would be conducted by suppliers.
Although the final certification would be made by the manufacturer,
this proposal would allow one additional year for small-volume
manufacturers to comply with any requirement. This approach is similar
to the approach we have taken in other rulemakings in recognition of
manufacturing differences between larger and smaller manufacturers.
This NPRM proposes a phased compliance schedule to attain lead vehicle
AEB and PAEB safety benefits as soon as practicable, while providing
more time to develop technology improvements, such as those needed to
meet darkness PAEB requirements. As the countermeasures are developed,
AEB suppliers would likely supply larger vehicle manufacturers first,
before small manufacturers. This NPRM recognizes this and proposes to
provide smaller manufacturers flexibility, so they have time to obtain
the equipment and work with the suppliers after the demands of the
larger manufacturers are met.
This proposal may also affect final stage manufacturers, many of
whom would be small businesses. However, it is NHTSA's understanding
that final stage manufacturers rarely make modifications to a vehicle's
braking system and instead rely upon the pass-through certification
provided by a first-stage manufacturers. As with small-volume
manufacturers, final stage manufacturers would be provided with one
additional year to comply with any requirement.
Additional information concerning the potential impacts of this
proposal on small business is presented in the PRIA accompanying this
proposal.
National Environmental Policy Act
The National Environmental Policy Act of 1969 (NEPA) \250\ requires
Federal agencies to analyze the environmental impacts of proposed major
Federal actions significantly affecting the quality of the human
environment, as well as the impacts of alternatives to the proposed
action.\251\ The Council on Environmental Quality (CEQ) directs federal
agencies to prepare an environmental assessment for a proposed action
``that is not likely to have significant effects or when the
significance of the effects is unknown.'' \252\ When a Federal agency
prepares an environmental assessment, CEQ's NEPA implementing
regulations require it to (1) ``[b]riefly provide sufficient evidence
and analysis for determining whether to prepare an environmental impact
statement or a finding of no significant impact;'' and (2) ``[b]riefly
discuss the purpose and need for the proposed action, alternatives . .
., and the environmental impacts of the proposed action and
alternatives, and include a listing of agencies and persons
consulted.'' \253\
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\250\ 42 U.S.C. 4321-4347.
\251\ 42 U.S.C. 4332(2)(C).
\252\ 40 CFR 1501.5(a).
\253\ 40 CFR 1501.5(c).
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This section serves as NHTSA's Draft Environmental Assessment (EA).
In this Draft EA, NHTSA outlines the purpose and need for the proposed
rulemaking, a reasonable range of alternative actions the agency could
adopt through rulemaking, and the projected environmental impacts of
these alternatives.
Purpose and Need
This NPRM sets forth the purpose of and need for this action. In
this NPRM, NHTSA proposes to adopt a new FMVSS to require AEB systems
on light vehicles that are capable of reducing the frequency and
severity of both lead vehicle rear-end (lead vehicle AEB) and
pedestrian crashes (PAEB). As explained earlier in this preamble, the
AEB system improves safety by using various sensor technologies and
sub-systems that work together to detect when the vehicle is in a crash
imminent situation, to automatically apply the vehicle brakes if the
driver has not done so, or to apply more braking force to supplement
the driver's braking, thereby detecting and reacting to an imminent
crash with a lead vehicle or pedestrian. This NPRM promotes NHTSA's
goal to reduce the frequency and severity of crashes described in the
summary of the crash problem discussed earlier in the NPRM, and
advances DOT's January 2022 National Roadway Safety Strategy that
identified requiring AEB, including PAEB technologies, on new passenger
vehicles as a key Departmental action to enable safer vehicles. This
NPRM also responds to a mandate under the Bipartisan Infrastructure Law
(BIL)
[[Page 38712]]
directing the Department to promulgate such a rule.
Alternatives
NHTSA has considered four regulatory alternatives for the proposed
action and a ``no action alternative.'' Under the no action
alternative, NHTSA would not issue a final rule requiring that vehicles
be equipped with systems that meet minimum specified performance
requirements, and manufacturers would continue to add AEB systems
voluntarily. However, since the BIL directs NHTSA to promulgate a rule
that would require that all passenger vehicles be equipped with an AEB
system, the no action alternative is not a permissible option.
Alternative 1 considers requirements specific to lead vehicle AEB only.
Alternative 2 includes the lead vehicle AEB requirements in Alternative
1 and a requirement in which PAEB is only required to function in
daylight conditions. Alternative 3, the preferred alternative,
considers requirements for lead vehicle AEBs and PAEB requirements in
both daylight and darkness conditions. Alternative 4 considers a more-
stringent requirement in which PAEB would be required to provide
pedestrian protections in turning scenarios (no change to the lead
vehicle AEB requirements in the proposed rule).
NHTSA has also considered the International Organization for
Standardization (ISO) standards, SAE International standards, the
Economic Commission for Europe (ECE) standards, test procedures used by
NHTSA's New Car Assessment Program (NCAP) and Euro NCAP, and more which
are described above in this preamble and accompanying appendixes. In
the proposed rule, NHTSA incorporates aspects of the test procedures
and standards mentioned here, but departs from them in numerous and
significant ways.
Environmental Impacts of the Proposed Action and Alternatives
This proposed rule is anticipated to result in the employment of
sensor technologies and sub-systems on light vehicles that work
together to sense when a vehicle is in a crash imminent situation, to
automatically apply the vehicle brakes if the driver has not done so,
and to apply more braking force to supplement the driver's braking.
This proposed rule is also anticipated to improve safety by mitigating
the amount of fatalities, non-fatal injuries, and property damage that
would result from crashes that could potentially be prevented or
mitigated because of AEB. As a result, the primary environmental
impacts \254\ that could potentially result from this rulemaking are
associated with: greenhouse gas emissions and air quality,
socioeconomics, public health and safety, solid waste/property damage/
congestion, and hazardous materials. Consistent with CEQ regulations
and guidance, this EA discusses impacts in proportion to their
potential significance. The effects of the proposed rulemaking that
were analyzed further are summarized below.
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\254\ NHTSA anticipates that the proposed action and
alternatives would have negligible or no impact on the following
resources and impact categories, and therefore has not analyzed them
further: topography, geology, soils, water resources (including
wetlands and floodplains), biological resources, resources protected
under the Endangered Species Act, historical and archeological
resources, farmland resources, environmental justice, and Section
4(f) properties.
---------------------------------------------------------------------------
Greenhouse Gas Emissions and Air Quality
NHTSA has previously recognized that additional weight required by
FMVSS could potentially negatively impact the amount of fuel consumed
by a vehicle, and accordingly result in greenhouse gas emissions or air
quality impacts from criteria pollutant emissions. Atmospheric
greenhouse gases (GHGs) affect Earth's surface temperature by absorbing
solar radiation that would otherwise be reflected back into space.
Carbon dioxide (CO2) is the most significant greenhouse gas
resulting from human activity. Motor vehicles emit CO2 as
well as other GHGs, including methane and nitrous oxides, in addition
to criteria pollutant emissions that negatively affect public health
and welfare.
Additional weight added to a vehicle, like added hardware from
safety systems, can cause an increase in vehicle fuel consumption and
emissions. An AEB system requires the following hardware: sensing,
perception, warning hardware, and electronically modulated braking
subsystems. As discussed in the preamble and the PRIA, NHTSA
anticipates that under the no-action alternative and Alternatives 1-3,
nearly all vehicles subject to the proposal would already have all of
the hardware capable of meeting the proposed requirements by the
effective date of a final rule. For all alternatives, NHTSA assumes
that manufacturers will need time to build code that analyses the
frontal view of the vehicle (i.e., manufacturers would need to upgrade
the software for the perception subsystem) in a way that achieves the
requirements of this proposed rule, but no additional hardware would
need to be added. Alternative 4 does include an assumption that two
cameras will be added; however, based on weight assumptions included in
studies cited in the PRIA, that weight impact would be minimal, at
approximately 1570 grams, or 3.46 pounds. NHTSA has previously
estimated that a 3-4-pound increase in vehicle weight is projected to
reduce fuel economy by 0.01 mpg.\255\ Accordingly, while Alternatives
1-3 would not have any fuel economy penalty because no hardware would
be added, Alternative 4 would potentially have a negligible fuel
economy penalty.
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\255\ Final Regulatory Impact Analysis, Corporate Average Fuel
Economy for MYs 2012-2016 Passenger Cars and Light Trucks, Table IV-
5 (March 2010).
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Pursuant to the Clean Air Act (CAA), the U.S. Environmental
Protection Agency (EPA) has established a set of National Ambient Air
Quality Standards (NAAQS) for the following ``criteria'' pollutants:
carbon monoxide (CO), nitrogen dioxide (NO2), ozone, particulate matter
(PM) less than 10 micrometers in diameter (PM10), PM less
than 2.5 micrometers in diameter (PM2.5), sulfur dioxide
(SO2), and lead (Pb). The NAAQS include ``primary''
standards and ``secondary'' standards. Primary standards are intended
to protect public health with an adequate margin of safety. Secondary
standards are set at levels designed to protect public welfare by
accounting for the effects of air pollution on vegetation, soil,
materials, visibility, and other aspects of the general welfare. Under
the General Conformity Rule of the CAA,\256\ EPA requires a conformity
determination when a Federal action would result in total direct and
indirect emissions of a criteria pollutant or precursor originating in
nonattainment or maintenance areas equaling or exceeding the emissions
thresholds specified in 40 CFR 93.153(b)(1) and (2). However, the
General Conformity Rule does not require a conformity determination for
Federal actions that are ``rulemaking and policy development and
issuance,'' such as this action.\257\ Therefore, NHTSA has determined
it is not required to perform a conformity analysis for this action.
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\256\ Section 176(c) of the CAA, codified at 42 U.S.C. 7506(c);
To implement CAA Section 176(c), EPA issued the General Conformity
Rule (40 CFR part 51, subpart W and part 93, subpart B).
\257\ 40 CFR 93.153(c)(2)(iii).
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Socioeconomics
The socioeconomic impacts of the proposed rulemaking would be
primarily felt by vehicle manufacturers, light vehicle drivers,
passengers, and pedestrians on the road that would
[[Page 38713]]
otherwise be killed or injured in light vehicle crashes. NHTSA
conducted a detailed assessment of the economic costs and benefits of
establishing the new rule in its PRIA. The main economic benefits come
primarily from the reduction in fatalities and non-fatal injuries
(safety benefits). Reductions in the severity of motor vehicle crashes
would be anticipated to have corresponding reductions in costs for
medical care, emergency services, insurance administrative costs,
workplace costs, and legal costs due to the fatalities and injuries
avoided. Other socioeconomic factors discussed in the PRIA that would
affect these parties include software costs and property damage
savings. Overall, Alternative 1 is anticipated to have societal net
benefits of $2.91 to $3.65 billion, Alternative 2 is anticipated to
have societal net benefits of $3.67 to $4.59 billion, Alternative 3
(the preferred alternative) is anticipated to have societal net
benefits of $5.24 to $6.52 billion, and Alternative 4 is anticipated to
have societal net benefits of $4.06 to $5.45 billion. The PRIA
discusses this information in further detail.
Public Health and Safety
The affected environment for public health and safety includes
roads, highways and other driving locations used by all light vehicle
drivers, other drivers, passengers in light vehicles and other motor
vehicles, and pedestrians or other individuals who could be injured or
killed in crashes involving the vehicles regulated by the proposed
action. In the PRIA, the agency determined the impacts on public health
and safety by estimating the reduction in fatalities and injuries
resulting from the decreased crash severity due to the use of AEB
systems under the four action alternatives. Under Alternative 1, it is
expected that the addition of a less stringent requirement that only
specifies requirements for lead vehicle AEB would result each year in
260 to 320 equivalent lives saved. Under Alternative 2, it is expected
that the less-stringent requirement, in which PAEB is only required to
function in daylight conditions, would result each year in 323 to 398
equivalent lives saved. Under Alternative 3 (the preferred
alternative), it is expected that the regulatory option would result
each year in 454 to 559 equivalent lives saved. Finally, under
Alternative 4, it is expected that the addition of more stringent
requirements in which PAEB would be required to provide pedestrian
protections in turning scenarios would result each year in 490 to 604
equivalent lives saved. The PRIA discusses this information in further
detail.
Solid Waste/Property Damage/Congestion
Vehicle crashes can generate solid wastes and release hazardous
materials into the environment. The chassis and engines, as well as
associated fluids and components of automobiles and the contents of the
vehicles, can all be deemed waste and/or hazardous materials. Solid
waste can also include damage to the roadway infrastructure, including
road surface, barriers, bridges, and signage. Hazardous materials are
substances that may pose a threat to public safety or the environment
because of their physical, chemical, or radioactive properties when
they are released into the environment, in this case as a result of a
crash.
NHTSA's proposed rulemaking is projected to reduce the amount and
severity of light vehicle crashes, and therefore may reduce the
quantity of solid waste, hazardous materials, and other property damage
generated by light vehicle crashes in the United States. The addition
of an AEB system may also result in reduced damage to the vehicles and
property, as well as reduced travel delay costs due to congestion. This
is especially the case in ``property damage only'' crashes, where no
individuals are injured or killed in the crash, but there may be damage
to the vehicle or whatever is impacted by it. NHTSA estimates that
based off data from 2016-2019 alone, an average of 1.12 million rear-
impact crashes involving light vehicles occurred annually. These
crashes resulted in an annual average of 394 fatalities, 142,611 non-
fatal injuries, and approximately 1.69 million property damage only
vehicles (PDOV).
Less solid waste translates into cost and environmental savings
from reductions in the following areas: (1) transport of waste
material, (2) energy required for recycling efforts, and (3) landfill
or incinerator fees. Less waste will result in beneficial environmental
effects through less GHG emissions used in the transport of it to a
landfill, less energy used to recycle the waste, less emissions through
the incineration of waste, and less point source pollution at the scene
of the crash that would result in increased emissions levels or
increased toxins leaking from the crashed vehicles into the surrounding
environment.
The addition of an AEB system may also result in reduced post-crash
environmental effects from congestion. As discussed in the PRIA,
NHTSA's monetized benefits are calculated by multiplying the number of
non-fatal injuries and fatalities mitigated by their corresponding
``comprehensive costs.'' The comprehensive costs include economic costs
that are external to the value of a statistical life (VSL) costs, such
as emergency management services or legal costs, and congestion costs.
NHTSA has recognized that motor vehicle crashes result in congestion
that has both socioeconomic and environmental effects. These
environmental effects include ``wasted fuel, increased greenhouse gas
production, and increased pollution as engines idle while drivers are
caught in traffic jams and slowdowns.'' \258\ NHTSA's monetized
benefits therefore do include a quantified measure of congestion
avoidance. NHTSA did not calculate congestion effects specifically for
each regulatory alternative, however, because comprehensive costs are a
discrete cost applied to non-fatal injuries and fatalities at the same
rate, we can conclude that there are increasing benefits associated
with fewer crashes, and specifically decreased congestion, as the
monetized benefits increase across regulatory alternatives. To the
extent that any regulatory option for AEB results in fewer crashes and
accordingly higher monetized benefits, there would be fewer congestion-
related environmental effects.
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\258\ Blincoe, L.J., Miller, T.R., Zaloshnja, E., & Lawrence,
B.A. (2015, May). The economic and societal impact of motor vehicle
crashes, 2010. (Revised) (Report No. DOT HS 812 013). Washington,
DC: National Highway Traffic Safety Administration.
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NHTSA has tentatively concluded that under the agency's proposal,
the economic benefits resulting from improved safety outcomes, property
damage savings, fuel savings, and GHG reductions would not only limit
the negative environmental impacts caused by additional solid waste/
property damage due to crashes but also would limit such effects.
Similarly, while the potential degree of hazardous materials spills
prevented due to the reduction of crash severity and crash avoidance
expected from the rulemaking has not specifically been analyzed in the
PRIA or NPRM, the addition of the AEB system is projected to reduce the
amount and severity of light vehicle crashes and may improve the
environmental effects with respect to hazardous material spills. While
the PRIA does not specifically quantify these impact categories, in
general NHTSA believes the benefits would increase relative to the
crashes avoided and would be relative across the different
alternatives. The PRIA
[[Page 38714]]
discusses information related to quantified costs and benefits of
crashes, and in particular property damage due to crashes, for each
regulatory alternative in further detail.
Cumulative Impacts
In addition to direct and indirect effects, CEQ regulations require
agencies to consider cumulative impacts of major Federal actions. CEQ
regulations define cumulative impacts as the impact ``on the
environment that result from the incremental [impact] of the action
when added to . . . other past, present, and reasonably foreseeable
future actions regardless of what agency (Federal or non-Federal) or
person undertakes such other actions.'' \259\ NHTSA notes that the
public health and safety, solid waste/property damage/congestion, air
quality and greenhouse gas emissions, socioeconomic, and hazardous
material benefits identified in this EA were based on calculations
described in the PRIA, in addition to other NHTSA actions and studies
on motor vehicle safety. That methodology required the agency to adjust
historical figures to reflect vehicle safety rulemakings that have
recently become effective. As a result, many of the calculations in
this EA already reflect the incremental impact of this action when
added to other past actions.
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\259\ 40 CFR 1508.1(g)(3).
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NHTSA's and other parties' past actions that improve the safety of
light vehicles, as well as future actions taken by the agency or other
parties that improve the safety of light vehicles, could further reduce
the severity or number of crashes involving light vehicles. Any such
cumulative improvement in the safety of light vehicles would have an
additional effect in reducing injuries and fatalities and could reduce
the quantity of solid and hazardous materials generated by crashes.
With regard to vehicle fuel use that leads to criteria air pollutant
and GHG emissions, Federal or State actions, like NHTSA's Corporate
Average Fuel Economy standards for light duty vehicles or EPA's
greenhouse gas and criteria pollutant emissions standards for light
duty vehicles, may result in additional emissions reductions by light
vehicles in the future.
Agencies and Persons Consulted
This preamble describes the various materials, persons, and
agencies consulted in the development of the proposal.
Finding of No Significant Impact
Although this rule is anticipated to result in increased FMVSS
requirements for light vehicle manufacturers, AEB systems have already
largely been introduced by manufacturers voluntarily. The addition of
regulatory requirements (depending on the regulatory alternative) to
standardize the AEB systems in all vehicle models is anticipated to
result in no or negligible fuel economy and emissions penalties (i.e.,
only Alternative 4 would potentially require additional hardware, but
the added weight is negligible), increasing socioeconomic and public
safety benefits as the alternatives get more stringent, and an increase
in benefits from the reduction in solid waste, property damage, and
congestion (including associated traffic level impacts like reduction
in energy consumption and tailpipe pollutant emissions) from fewer
vehicle crashes across the regulatory alternatives.
Based on the information in this Draft EA and assuming no
additional information or changed circumstances, NHTSA expects to issue
a Finding of No Significant Impact (FONSI).\260\ NHTSA has tentatively
concluded that none of the impacts anticipated to result from the
proposed action and alternatives under consideration will have a
significant effect on the human environment. Such a finding will be
made only after careful review of all public comments received. A Final
EA and a FONSI, if appropriate, will be issued as part of the final
rule.
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\260\ 40 CFR 1501.6(a).
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Executive Order 13132 (Federalism)
NHTSA has examined this NPRM pursuant to Executive Order 13132 (64
FR 43255, August 10, 1999) and concludes that no additional
consultation with States, local governments, or their representatives
is mandated beyond the rulemaking process. The agency has concluded
that the rulemaking will not have sufficient federalism implications to
warrant consultation with State and local officials or the preparation
of a federalism summary impact statement. The NPRM will not have
``substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.''
NHTSA rules can preempt in two ways. First, the National Traffic
and Motor Vehicle Safety Act contains an express preemption provision:
When a motor vehicle safety standard is in effect under this chapter, a
State or a political subdivision of a State may prescribe or continue
in effect a standard applicable to the same aspect of performance of a
motor vehicle or motor vehicle equipment only if the standard is
identical to the standard prescribed under this chapter. 49 U.S.C.
30103(b)(1). It is this statutory command by Congress that preempts any
non-identical State legislative and administrative law addressing the
same aspect of performance.
The express preemption provision described above is subject to a
savings clause under which compliance with a motor vehicle safety
standard prescribed under this chapter does not exempt a person from
liability at common law. 49 U.S.C. 30103(e). Pursuant to this
provision, State common law tort causes of action against motor vehicle
manufacturers that might otherwise be preempted by the express
preemption provision are generally preserved.
However, the Supreme Court has recognized the possibility, in some
instances, of implied preemption of such State common law tort causes
of action by virtue of NHTSA's rules, even if not expressly preempted.
This second way that NHTSA rules can preempt is dependent upon there
being an actual conflict between an FMVSS and the higher standard that
would effectively be imposed on motor vehicle manufacturers if someone
obtained a State common law tort judgment against the manufacturer,
notwithstanding the manufacturer's compliance with the NHTSA standard.
Because most NHTSA standards established by an FMVSS are minimum
standards, a State common law tort cause of action that seeks to impose
a higher standard on motor vehicle manufacturers will generally not be
preempted. However, if and when such a conflict does exist--for
example, when the standard at issue is both a minimum and a maximum
standard--the State common law tort cause of action is impliedly
preempted. See Geier v. American Honda Motor Co., 529 U.S. 861 (2000).
Pursuant to Executive Order 13132 and 12988, NHTSA has considered
whether this proposed rule could or should preempt State common law
causes of action. The agency's ability to announce its conclusion
regarding the preemptive effect of one of its rules reduces the
likelihood that preemption will be an issue in any subsequent tort
litigation. To this end, the agency has examined the nature (i.e., the
language and structure of the regulatory text) and objectives of this
proposed rule and finds that this rule, like many NHTSA
[[Page 38715]]
rules, would prescribe only a minimum safety standard. As such, NHTSA
does not intend this NPRM to preempt state tort law that would
effectively impose a higher standard on motor vehicle manufacturers
rule. Establishment of a higher standard by means of State tort law
will not conflict with the minimum standard adopted here. Without any
conflict, there could not be any implied preemption of a State common
law tort cause of action.
Civil Justice Reform
With respect to the review of the promulgation of a new regulation,
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
4729, February 7, 1996) requires that Executive agencies make every
reasonable effort to ensure that the regulation: (1) Clearly specifies
the preemptive effect; (2) clearly specifies the effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct, while promoting simplification and burden reduction;
(4) clearly specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
Pursuant to this Order, NHTSA notes as follows. The preemptive
effect of this rulemaking is discussed above. NHTSA notes further that
there is no requirement that individuals submit a petition for
reconsideration or pursue other administrative proceeding before they
may file suit in court.
Paperwork Reduction Act (PRA)
Under the PRA of 1995, a person is not required to respond to a
collection of information by a Federal agency unless the collection
displays a valid OMB control number. There are no ``collections of
information'' (as defined at 5 CFR 1320.3(c)) in this NPRM.
National Technology Transfer and Advancement Act
Under the National Technology Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104-113), all Federal agencies and departments shall
use technical standards that are developed or adopted by voluntary
consensus standards bodies, using such technical standards as a means
to carry out policy objectives or activities determined by the agencies
and departments. Voluntary consensus standards are technical standards
(e.g., materials specifications, test methods, sampling procedures, and
business practices) that are developed or adopted by voluntary
consensus standards bodies, such as the International Organization for
Standardization and SAE International. The NTTAA directs us to provide
Congress, through OMB, explanations when we decide not to use available
and applicable voluntary consensus standards.
NHTSA is proposing to incorporate by reference ISO and ASTM
standards into this proposed rule. NHTSA considered several ISO
standards and has proposed to use ISO 19206-3:2021 to specify the
vehicle test device and a combination of ISO 19206-2:2018 and ISO
19206-4:2020 to specify the test mannequins. NHTSA is incorporating by
reference ASTM E1337-19, which is already incorporated by reference
into many FMVSSs, to measure the peak braking coefficient of the
testing surface.
NHTSA considered SAE International Recommended Practice J3087,
``Automatic emergency braking (AEB) system performance testing,'' which
define the conditions for testing AEB and FCW systems. This standard
defines test conditions, test targets, test scenarios, and measurement
methods, but does not provide performance criteria. There is
considerable overlap in the test setup and conditions between this
proposed rule and the SAE standard including the basic scenarios of
lead vehicle stopped, slower moving, and decelerating. This SAE
recommended practice is substantially similar to the existing NCAP test
procedures and this proposal.
NHTSA also considered SAE International Standard J3116, ``Active
Safety Pedestrian Test Mannequin Recommendation,'' which provides
recommendations for the characteristics of a surrogate that could be
used in testing of active pedestrian safety systems. NHTSA proposed to
incorporate the ISO standard because the ISO Standard specifications
are more widely adopted than the SAE Recommended Practice. However,
NHTSA requests comments on whether it would be more appropriate to use
the SAE Recommended Practice specifications because they are more
representative of the average pedestrian fatality.
In Appendix B of this preamble, NHTSA describes several
international test procedures and regulations the agency considered for
use in this NPRM. This proposed rule has substantial technical overlap
with UNECE Regulation No. 131 and UNECE Regulation No. 152. This
proposal and the UNECE regulations both specify a forward collision
warning and automatic emergency braking. Several lead vehicle AEB
scenarios are nearly identical, including the lead vehicle stopped and
lead vehicle moving scenarios. The pedestrian crossing path scenario
specified in UNECE Regulation No. 152 is substantially similar to this
NPRM. As discussed in the preamble, this proposed rule differs from the
UNECE standards in the areas of maximum test speed and the minimum
level of required performance. This proposed rule uses higher test
speeds and a requirement that the test vehicle avoid contact. This
approach would increase the repeatability of the test and maximize the
realized safety benefits of the rule.
Incorporation by Reference
Under regulations issued by the Office of the Federal Register (1
CFR 51.5(a)), an agency, as part of a proposed rule that includes
material incorporated by reference, must summarize material that is
proposed to be incorporated by reference and discuss the ways the
material is reasonably available to interested parties or how the
agency worked to make materials available to interested parties.
In this NPRM, NHTSA proposes to incorporate by reference six
documents into the Code of Federal Regulations, one of which is already
incorporated by reference. The document already incorporated by
reference into 49 CFR part 571 is ASTM E1337, ``Standard Test Method
for Determining Longitudinal Peak Braking Coefficient (PBC) of Paved
Surfaces Using Standard Reference Test Tire.'' ASTM E1337 is a standard
test method for evaluating peak braking coefficient of a test surface
using a standard reference test tire using a trailer towed by a
vehicle. NHTSA uses this method in all of its braking and electronic
stability control standards to evaluate the test surfaces for
conducting compliance test procedures.
NHTSA is also proposing to incorporate by reference into part 571
SAE J2400 ``Human Factors in Forward Collision Warning System:
Operating Characteristics and User Interface Requirements.'' SAE J2400
is an information report that is intended as a starting point of
reference for designers of forward collision warning systems. NHTSA
would incorporate this document by reference solely to specify the
location specification and symbol for a visual forward collision
warning.
NHTSA is proposing to incorporate by reference four ISO standards
into 49 CFR part 596. The first of these standards is ISO 3668:2017,
``Paints and varnishes--Visual comparison of colour of paints.'' This
document specifies a
[[Page 38716]]
method for the visual comparison of the color of paints against a
standard. This method would be used to verify the color of certain
elements of the pedestrian test mannequin NHTSA is proposing to use in
PAEB testing. Specifically, NHTSA is using these procedures in order to
determine that the color of the hair, torso, arms, and feet of the
pedestrian test mannequin is black and that the color of the legs are
blue.
NHTSA is also proposing to incorporate by reference ISO 19206-
2:2018(E), ``Road vehicles--Test devices for target vehicles,
vulnerable road users and other objects, for assessment of active
safety functions--Part 2: Requirements for pedestrian targets.'' This
document addresses the specification for a test mannequin. It is
designed to resemble the characteristics of a human, while ensuring the
safety of the test operators and preventing damage to subject vehicles
in the event of a collision during testing. NHTSA is referencing many,
but not all, of the specifications of ISO 19206-2:2018(E), as discussed
in section VIII.A of this NPRM.
NHTSA is also proposing to incorporate by reference ISO 19206-
3:2021(E), ``Test devices for target vehicles, vulnerable road users
and other objects, for assessment of active safety functions--Part 3:
Requirements for passenger vehicle 3D targets.'' This document provides
specification of three-dimensional test devices that resemble real
vehicles. Like the test mannequin described in the prior paragraph, it
is designed to ensure the safety of the test operators and to prevent
damage to subject vehicles in the event of a collision during testing.
NHTSA is referencing many, but not all, of the specifications of ISO
19206-3:2021(e), as discussed in section VIII.B of this NPRM.
Finally, NHTSA is proposing to incorporate by reference ISO 19206-
4:2020, ``Road vehicles--test devices for target vehicles, vulnerable
road users and other objects, for assessment of active safety
functions--Part 4: Requirements for bicyclists targets.'' This standard
describes specifications for bicycle test devices, which are
representative of adult and child sizes. However, NHTSA is not
proposing to use a bicycle test device during testing. Rather, this
standard is incorporated by reference solely because it contains
specifications for color and reflectivity, including skin color, that
NHTSA is applying to its pedestrian test mannequin.
All standards proposed to be incorporated by reference in this NPRM
are available for review at NHTSA's headquarters in Washington, DC, and
for purchase from the organizations promulgating the standards. The
ASTM standard presently incorporated by reference into other NHTSA
regulations is also available for review at ASTM's online reading
room.\261\
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\261\ https://www.astm/org/READINGLIBRARY/.
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Unfunded Mandates Reform Act
The Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires
agencies to prepare a written assessment of the costs, benefits, and
other effects of proposed or final rules that include a Federal mandate
likely to result in the expenditures by States, local or tribal
governments, in the aggregate, or by the private sector, of more than
$100 million annually (adjusted annually for inflation with base year
of 1995). Adjusting this amount by the implicit gross domestic product
price deflator for 2021 results in an estimated current value of $165
million (2021 index value of 113.07/1995 index value of 68.60 = 1.65).
The assessment may be included in conjunction with other assessments,
as it is here.
A proposed rule on lead vehicle AEB and PAEB is not likely to
result in expenditures by State, local or tribal governments of more
than $100 million annually. However, it is estimated to result in the
estimated expenditure by automobile manufacturers and/or their
suppliers of $282 million annually (estimated to be $27.38 per
passenger car and $11.74 per light truck annually). This range in
estimated cost impacts reflects that the estimated incremental costs
depend on a variety of lead vehicle AEB hardware and software that
manufacturers plan to install (in vehicles used as ``baseline'' for the
cost estimate). The final cost will greatly depend on choices made by
the automobile manufacturers to meet the lead vehicle AEB and PAEB test
requirements. These effects have been discussed in this Preliminary
Regulatory Impact Analysis in Chapter 5.3.
The Unfunded Mandates Reform Act requires the agency to select the
``least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule.'' As an alternative, the
agency considered a full-vehicle dynamic test to evaluate the
capability of lead vehicle AEB and PAEB systems to prevent crashes or
mitigate the severity of crashes. Based on our experience on conducting
vehicle tests for vehicles equipped with lead vehicle AEB and PAEB
where we utilize a reusable surrogate target crash vehicle and test
mannequins instead of conducting the test with an actual vehicle as the
target, we determined that full vehicle-to-vehicle crash tests can have
an undesired amount of variability in vehicle kinematics. Unlike
vehicle-to-vehicle tests, the lead vehicle AEB and PAEB tests with a
surrogate target vehicle is conducted in a well-controlled test
environment, which results in an acceptable amount of variability. In
addition, the agency's lead vehicle AEB and PAEB tests with surrogate
target vehicle and pedestrian were able to reveal deficiencies in the
system that resulted in inadequate system capability in detecting and
activating the brakes. Therefore, we concluded that a full vehicle-to-
vehicle test would not achieve the objectives of the rule.
In addition, the agency evaluated data across a broad range of test
scenarios in an effort to identify the maximum range of test speeds at
which it is feasible for test vehicles to achieve a no-contact result.
The range of feasible speeds identified in the review was specified as
the mandated range in the proposed rule. Thus, there are no alternative
test procedures available that would improve the ability of
manufacturers to achieve no-contact results. In turn, the agency
concluded that lead vehicle AEB and PAEB systems designed to meet the
no-contact requirement at speeds outside the ranges specified in the
proposed rule would not achieve the objectives of the rule.
Executive Order 13609 (Promoting International Regulatory Cooperation)
The policy statement in section 1 of E.O. 13609 states, in part,
that the regulatory approaches taken by foreign governments may differ
from those taken by U.S. regulatory agencies to address similar issues
and that, in some cases, the differences between the regulatory
approaches of U.S. agencies and those of their foreign counterparts
might not be necessary and might impair the ability of American
businesses to export and compete internationally. The E.O. states that,
in meeting shared challenges involving health, safety, labor, security,
environmental, and other issues, international regulatory cooperation
can identify approaches that are at least as protective as those that
are or would be adopted in the absence of such cooperation, and that
international regulatory cooperation can also reduce, eliminate, or
prevent unnecessary differences in regulatory requirements. NHTSA
requests public comment on the ``regulatory approaches taken by foreign
governments'' concerning the subject matter of this rulemaking.
[[Page 38717]]
Regulation Identifier Number
The Department of Transportation assigns a regulation identifier
number (RIN) to each regulatory action listed in the Unified Agenda of
Federal Regulations. The Regulatory Information Service Center
publishes the Unified Agenda in April and October of each year. You may
use the RIN contained in the heading at the beginning of this document
to find this action in the Unified Agenda.
Plain Language
Executive Order 12866 requires each agency to write all rules in
plain language. Application of the principles of plain language
includes consideration of the following questions:
Have we organized the material to suit the public's needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?
If you have any responses to these questions, please write to us
with your views.
XII. Public Participation
How long do I have to submit comments?
Please see the DATES section at the beginning of this document.
How do I prepare and submit comments?
Your comments must be written in English.
To ensure that your comments are correctly filed in the
Docket, please include the Docket Number shown at the beginning of this
document in your comments.
Your comments must not be more than 15 pages long. (49 CFR
553.21). We established this limit to encourage you to write your
primary comments in a concise fashion. However, you may attach
necessary additional documents to your comments. There is no limit on
the length of the attachments.
If you are submitting comments electronically as a PDF
(Adobe) File, NHTSA asks that the documents be submitted using the
Optical Character Recognition (OCR) process, thus allowing NHTSA to
search and copy certain portions of your submissions. Comments may be
submitted to the docket electronically by logging onto the Docket
Management System website at http://www.regulations.gov. Follow the
online instructions for submitting comments.
You may also submit two copies of your comments, including
the attachments, to Docket Management at the address given above under
ADDRESSES.
Please note that pursuant to the Data Quality Act, in order for
substantive data to be relied upon and used by the agency, it must meet
the information quality standards set forth in the OMB and DOT Data
Quality Act guidelines. Accordingly, we encourage you to consult the
guidelines in preparing your comments. OMB's guidelines may be accessed
at http://www.whitehouse.gov/omb/information-regulatory-affairs/information-policy/. DOT's guidelines may be accessed at http://www.transportation.gov/dot-information-dissemination-quality-guidelines.
How can I be sure that my comments were received?
If you wish Docket Management to notify you upon its receipt of
your comments, enclose a self-addressed, stamped postcard in the
envelope containing your comments. Upon receiving your comments, Docket
Management will return the postcard by mail.
How do I submit confidential business information?
If you wish to submit any information under a claim of
confidentiality, you should submit three copies of your complete
submission, including the information you claim to be confidential
business information, to the Chief Counsel, NHTSA, at the address given
above under FOR FURTHER INFORMATION CONTACT. In addition, you should
submit two copies, from which you have deleted the claimed confidential
business information, to Docket Management at the address given above
under ADDRESSES. When you send a comment containing information claimed
to be confidential business information, you should include a cover
letter setting forth the information specified in our confidential
business information regulation. (49 CFR part 512). To facilitate
social distancing during COVID-19, NHTSA is temporarily accepting
confidential business information electronically. Please see https://www.nhtsa.gov/coronavirus/submission-confidential-business-information
for details.
Will the agency consider late comments?
We will consider all comments that Docket Management receives
before the close of business on the comment closing date indicated
above under DATES. To the extent possible, we will also consider
comments that Docket Management receives after that date. If Docket
Management receives a comment too late for us to consider in developing
the final rule, we will consider that comment as an informal suggestion
for future rulemaking action.
How can I read the comments submitted by other people?
You may read the comments received by Docket Management at the
address given above under ADDRESSES. The hours of the Docket are
indicated above in the same location. You may also see the comments on
the internet. To read the comments on the internet, go to http://www.regulations.gov. Follow the online instructions for accessing the
dockets.
Please note that, even after the comment closing date, we will
continue to file relevant information in the Docket as it becomes
available. Further, some people may submit late comments. Accordingly,
we recommend that you periodically check the Docket for new material.
XIII. Appendices to the Preamble
Appendix A: Description of Technologies
For the convenience of readers, this section describes various
technologies of an AEB system. An AEB system employs multiple sensor
technologies and sub-systems that work together to sense a crash
imminent scenario and, where applicable, automatically apply the
vehicle brakes to avoid or mitigate a crash. Current systems utilize
radar- and camera-based sensors, and the agency is aware of emerging
technologies such as lidar and infrared sensors. AEB builds upon
electronic stability control (ESC) technology joined with a perception
system, and ESC itself is an extension of antilock braking system (ABS)
technologies. It also builds upon older forward collision warning-only
(FCW-only) systems.
Radar-Based Sensors
At its simplest form, radar is a time-of-flight sensor that
measures the time between when a radio wave is transmitted, and its
reflection is recorded. This time-of-flight is then used to calculate
the distance to the object that caused the reflection. More information
about the reflecting object,
[[Page 38718]]
such as speed, can be determined by comparing the output signal to the
input signal. Typical automotive applications use a type of radar
called Frequency Modulated Continuous Wave radar. This radar system
sends out a radio pulse where the pulse frequency rises through the
duration of the pulse. This pulse is reflected off the object and the
radar sensor compares the reflected signal to the original pulse to
determine the range and relative speed.
Radar sensors are widely used in AEB applications, for many
reasons. These sensors can have a wide range of applicability, with
automotive grade radar sensing ranges on the order of 1 meter (3 ft) up
to over 200 meters (656 ft). Radar sensors are also relatively
unaffected by time of day, precipitation, fog, and many other adverse
weather conditions. Automotive radar systems typically operate on
millimeter wave lengths, easily reflecting off even the smallest
metallic surfaces found on vehicles. Radio waves tend to penetrate soft
materials, such as rubber and plastic, allowing these sensors to be
mounted in the front ends of vehicles behind protective and visually
appealing grilles and bumper fascia.
Radar-based sensors have limitations that impact their
effectiveness. Radar is a line-of-sight sensor, in that it only
operates in the direction the receiving antenna is pointed and
therefore has a limited angular view. Also, while radar is excellent at
identifying radar-reflective objects, the nature of the radar
reflection makes classification of those objects difficult. In
addition, objects that do not reflect radio waves easily, such as
rubber, plastic, humans, and other soft objects, are difficult for
radar-based sensors to detect. Lastly, because forward facing radar
sensors are usually mounted inside the front end of equipped vehicles,
damage caused from front-end collisions can lead to alignment issues
and reduced effectiveness.
Camera Sensors
Cameras are passive sensors that record optical data using digital
imaging chips, which are then processed to allow for object detection
and classification. They are an important part of most automotive AEB
systems, and one or more cameras are typically mounted behind the front
windshield, often high up near the rearview mirror. This provides a
good view of the road, and the windshield wipers can provide a way to
clear debris, dirt, and other contaminates from the windshield in front
of the sensor.
Camera-based imaging systems are one of the few sensor types that
can determine both color and contrast information. This makes them able
to recognize and classify objects such as road signs, other vehicles,
and pedestrians, much in the same way the human eye does. In addition,
systems that utilize two or more cameras can see stereoscopically,
allowing the processing system to determine range information along
with detection and classification.
Like all sensor systems, camera-based sensors have their benefits
and limitations. Monocular camera systems lack depth perception and are
poor at determining range, and even stereoscopic camera systems are not
ideal for determining speed. Because cameras rely on the visible
spectrum of light, conditions that make it difficult to see, such as
rain, snow, sleet, fog, and even dark unlit areas, decrease the
effectiveness of perception checks of these systems. It is also
possible for the imaging sensor to saturate when exposed to excessive
light, such as driving towards the sun. For these reasons, camera
sensors are often used in conjunction with other sensors like radar.
Thermal Imaging Systems
While rare in the current generation of AEB systems, suppliers of
AEB technologies are looking at advanced sensor technologies to augment
the limitations of camera/radar systems. Thermal imaging systems are
one such advanced sensor. Very similar to cameras, thermal imaging
systems are optical sensors that record visual information. The
difference is that, where cameras rely on the visible spectrum of
light, thermal imaging systems rely on infrared radiation, also known
as thermal radiation.
Infrared radiation is the part of the electromagnetic spectrum
between visible light and microwave radiation. Typically, the
wavelengths range from 750 nm up to 1 mm. This spectrum also
corresponds to the energy output by warm bodies, making these sensors
ideal for use in dark areas where traditional cameras may have
difficulties. Thermal imaging systems can be particularly useful for
darkness detection of pedestrians. They can also have an active
component, either a blanket infrared flood light or an infrared laser
system, to augment the passive collection of a camera.
These systems, however, also have limitations. They may not be able
to differentiate between multiple hot bodies, and in the presence of
thermal insulation, such as a jacket or cold weather clothing, warm
bodies can appear cold and difficult to differentiate from the
background. Reflectivity of the detected object as well as the ambient
environment can affect the performance of these systems.
Lidar
Lidar, or Light Detection and Ranging is a laser-based time-of-
flight sensor that uses pulses of visual light to determine distances
between the sensor and an object. Much like radar, by calculating the
amount of time between the transmission and reception of a pulse of
light, a lidar system can determine the distance to the object. These
sensors are one of the primary sensors in prototype automated driving
systems under development for future AEB systems.\262\
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\262\ SAE J3016, ``Taxonomy and Definitions for Terms Related to
Driving Automation Systems for On-Road Motor Vehicles,'' APR2021,
defines an automated driving system as the hardware and software
that are collectively capable of performing the entire dynamic
driving task on a sustained basis, regardless of whether it is
limited to a specific operational design domain.
---------------------------------------------------------------------------
Because a lidar system uses lasers for range-finding, it can infer
exact measurements of most objects surrounding a vehicle, including
other vehicles and pedestrians. Because of how accurately lidar can
measure distances and speeds, it is very good at determining the
differences between cars, pedestrians, cyclists, light posts, road
signs, and many other obstacles in the path of a vehicle. With proper
control software, a lidar sensor can detect things like lane
boundaries.
Limitations of lidar tend to be similar to those of both camera
systems and radar systems. lidar is an active system, so it is
unaffected by dark lighting conditions, but it can be severely degraded
by rain, sleet, fog, or snow. It is a line-of-sight sensor and cannot
see through certain objects in the way that radar can. Its maximum
effective range is often limited by surface reflectivity, illumination
saturation (driving towards the sun or other bright light), and
environmental attenuation, such as hazy conditions or heat shimmer.
Other limiting factors are the large computational processing needs to
adequately utilize the lidar sensor, and its currently high costs.
Electronically Modulated Braking Systems
Automatic actuation of the vehicle brakes requires more than just
systems to sense when a collision is imminent. Regardless of how good a
sensing system is, hardware is needed to physically apply the brakes
without relying on the driver to modulate the brake pedal. The
automatic braking system relies on two foundational
[[Page 38719]]
braking technologies, antilock braking systems and electronic stability
control.
Antilock brakes are a foundational braking technology that
automatically controls the degree of wheel slip during braking to
prevent wheel lock and minimize skidding, by sensing the rate of
angular rotation of the wheels and modulating the braking force at the
wheels to keep the wheels from slipping. Modern ABS systems have wheel
speed sensors and independent brake modulation at each wheel and can
increase and decrease braking pressures as needed.
ESC builds upon the antilock brakes with the addition of at least
two sensors, a steering wheel angle sensor and an inertial measurement
unit. These sensors allow the ESC controller to determine the intended
steering direction (from the steering wheel angle sensor), compare it
to the actual vehicle direction, and then modulate braking forces at
each wheel, without the driver applying input to the brake pedal, to
induce a counter yaw when the vehicle starts to lose lateral stability.
AEB uses the hardware needed for ESC and automatically applies the
brakes to avoid certain scenarios where a crash with a vehicle or
pedestrian is imminent.
Forward Collision Warning
Using the sensors described above, coupled with an alert mechanism
and perception calculations, a FCW system is able to monitor a
vehicle's speed, the speed of the vehicle in front of it, and the
distance between the two vehicles. If the FCW system determines that
the distance from the driver's vehicle to the vehicle in front of it is
too short and the closing velocity between the two vehicles is too
high, the system warns the driver of an impending rear-end collision.
Typically, FCW systems are comprised of two components: a sensing
system, which can detect a vehicle in front of the driver's vehicle,
and a warning system, which alerts the driver to a potential crash
threat. The sensing portion of the system may consist of forward-
looking radar, camera systems, lidar, or a combination of these.
Warning systems in use today provide drivers with a visual display,
such as an illuminated telltale on the instrument panel, an auditory
signal (e.g., beeping tone or chime), and/or a haptic signal that
provides tactile feedback to the driver (e.g., rapid vibrations of the
seat pan or steering wheel or a momentary brake pulse) to alert the
driver to an impending crash so that the driver may manually intervene
(e.g., apply the vehicle's brakes or make an evasive steering maneuver)
to avoid or mitigate the crash.
FCW systems alone are designed to warn the driver, but do not
provide automatic braking of the vehicle (some FCW systems use haptic
brake pulses to alert the driver of a crash-imminent driving situation,
but they are not intended to effectively slow the vehicle). Since the
first introduction of FCW systems, the technology has advanced so that
it is now possible to couple those sensors, software, and alerts with
the vehicle's service brake system to provide additional functionality
covering a broader portion of the safety problem.
From a functional perspective, research suggests that active
braking systems, such as AEB, provide greater safety benefits than
warning systems, such as FCW systems. However, NHTSA has found that
current AEB systems often integrate the functionalities of FCW and AEB
into one frontal crash prevention system to deliver improved real-world
safety performance and high consumer acceptance. FCW can now be
considered a component of lead vehicle AEB. As such, this NPRM
integrates FCW directly into the performance requirements for AEB--Lead
Vehicle. This integration would also enable the agency to assess
vehicles' compliance with the proposed FCW and AEB requirements at the
same time in a single test.
Automatic Emergency Braking--Lead Vehicle
Unlike systems that only alert, AEB systems (systems that
automatically apply the brakes), are designed to actively help drivers
avoid or mitigate the severity of rear-end crashes. AEB--Lead Vehicle
has been previously broken down into two primary functions, crash
imminent braking and dynamic brake support. CIB systems provide
automatic braking when forward-looking sensors indicate that a crash is
imminent and the driver has not applied the brakes, whereas DBS systems
use the same forward-looking sensors, but provide supplemental braking
after the driver applies the brakes when sensors determine that driver-
applied braking is insufficient to avoid an imminent rear-end crash.
This NPRM does not split the terminology of these functionalities and
instead discusses them together as ``AEB.'' In some crash situations,
AEB functions independently of the driver's use of the brake pedal
(CIB), while in other situations, the vehicle uses the driver's pedal
input to better evaluate the situation and avoid the crash (DBS). This
proposal considers each function necessary to address the safety need
and presents a performance-based regulatory approach that can permit
the detailed application of each function to be based on the specific
vehicle application and the manufacturer's approach to meeting the
standard.
In response to an FCW or a driver noticing an imminent crash
scenario, a driver may initiate braking to avoid a rear-end crash. In
situations where the driver's braking is insufficient to prevent a
collision, the AEB system can automatically supplement the driver's
braking action to prevent or mitigate the crash. Similar to FCW
systems, AEB systems employ forward-looking sensors such as radar,
cameras, infrared, and/or lidar sensors to detect vehicles in the path
directly ahead and monitor the subject vehicle's operating conditions
such as speed or brake application. However, AEB systems can also
actively supplement braking to assist the driver, whereas FCW systems
serve only to warn the driver of a potential crash threat.
If a driver does not take action to apply the brakes when a rear-
end crash is imminent, AEB systems utilize the same types of forward-
looking sensors to apply the vehicle's brakes automatically to slow or
stop the vehicle. The amount of braking applied varies by manufacturer,
and several systems are designed to achieve maximum vehicle
deceleration just prior to impact. In reviewing model year 2017-2019
NCAP crash imminent braking test data, NHTSA observed a deceleration
range of 0.31 to 1.27 g. This NPRM does not directly require a
particular deceleration capability but specifies situations in which
crash avoidance must be achieved. Avoidance may be produced by the
automatic application of the subject vehicle brakes or by automatically
supplementing the deceleration achieved by driver's braking action in
the case where the subject vehicle brakes are manually applied.
Pedestrian Automatic Emergency Braking
PAEB systems function like lead vehicle AEB systems, but detect
pedestrians instead of leading vehicles. PAEB uses information from
forward-looking sensors to actively and automatically apply the
vehicle's brakes when a pedestrian is in front of the vehicle and the
driver has not acted to avoid the impending impact. Similar to lead
vehicle AEB, PAEB systems typically use cameras to determine whether a
pedestrian is in imminent danger of being struck by the vehicle, but
some systems may use a
[[Page 38720]]
combination of cameras, radar, lidar, and infrared sensors.
A camera's field of view plays a key role in the type of pedestrian
crashes that a PAEB system can assist in avoiding. Cameras used for
PAEB can provide the information required by the system to provide
crash protection in situations where the pedestrian is either directly
in the path of a vehicle or is entering the path of the vehicle while
the vehicle is moving straight ahead.
Sensor performance may be limited by the availability of
environmental lighting. The cameras used in PAEB systems rely on
reflected light in the same way as a human eye. As such, the vehicle's
integration of headlighting systems along with the tuning of camera
exposure rates and sensor light sensitivities are important
considerations in producing an PAEB system that assists in avoiding
pedestrian crashes that happen at night. The permeance limits proposed
in this NPRM can be achieved with radar and camera system technologies.
Appendix B: International Activities
International AEB Testing Standards
NHTSA has considered other vehicle testing organizations' AEB test
procedures as part of the development of this proposal. The ISO has
published Standard 22733-1, ``Road vehicles--Test method to evaluate
the performance of autonomous emergency braking systems.'' This ISO
standard does not set minimum performance requirements for lead vehicle
AEB systems or any pass/fail conditions. Instead, the standard sets
forth a test procedure using progressively increasing speeds at which a
vehicle equipped with lead vehicle AEB approaches a stationary or
moving surrogate vehicle until it makes contact.
The surrogate vehicle specified is the vehicle target defined in
ISO 19206- 3:2021, ``Road vehicles--Test devices for target vehicles,
vulnerable road users and other objects, for assessment of active
safety functions--Part 3: requirements for passenger vehicle 3D
targets.''
ISO is developing but has not published Standard 22733-2 describing
tests for PAEB systems. SAE International has published recommended
practice J3087, ``Automatic emergency braking (AEB) system performance
testing,'' defining the conditions for testing AEB and FCW systems.
This standard defines test conditions, test targets, test scenarios,
and measurement methods, but, like ISO 22733-1, does not provide
performance criteria. Unlike ISO 22733-1, SAE J3087 does not require
specific speed ranges for test execution. Test scenarios are employed
where the lead surrogate vehicle is stopped, moving at a constant
slower speed, or decelerating, broadly similar to that proposed in this
NPRM. SAE International Standard J3116, ``Active Safety Pedestrian Test
Mannequin Recommendation,'' provides recommendations for the
characteristics of a surrogate that could be used in testing of active
pedestrian safety systems, but there is no SAE International standard
defining test procedures for PAEB systems.
International AEB Regulation
The United Nations (UN) Economic Commission for Europe (ECE)
Regulation No. 152 ``Uniform provisions concerning the approval of
motor vehicles with regard to the Advanced Emergency Braking System
(AEBS) for M1 and N1 vehicles,'' \263\ provides definitions and
standards for AEB Systems for signatory nations to the ``1958
Agreement.'' \264\ Some signatories mandate the regulation and others
accept it as ``if-fitted.'' ECE Regulation No. 152 describes the timing
of warnings, mode of warnings, required minimum deceleration, and
allowable impact speeds for AEB tests for both stationary lead
surrogate vehicles and lead surrogate vehicles moving at 20 km/h. Each
test run is conducted ``in absence of driver's input,'' (i.e., testing
CIB but not DBS). A ``false reaction test'' is also specified, where a
vehicle must pass between two parked vehicles without issuing a warning
or applying the brakes. AEB systems are required to operate between 10
km/h and 60 km/h, and cannot be deactivated at speeds above 10 km/h.
---------------------------------------------------------------------------
\263\ As defined in the Addenda to the 1958 Agreement, inclusive
of Amendments published Dec 21, 2021. https://unece.org/transport/vehicle-regulations-wp29/standards/addenda-1958-agreement-regulations-141-160.
\264\ United Nations Economic Commission for Europe. Agreement
concerning the Adoption of Harmonized Technical United Nations
Regulations for Wheeled Vehicles, Equipment and Parts which can be
Fitted and/or be Used on Wheeled Vehicles and the Conditions for
Reciprocal Recognition of Approvals Granted on the Basis of these
United Nations Regulations (Revision 3). (Original: 1958; Current,
as amended: 20 Oct. 2017). https://unece.org/trans/main/wp29/wp29regs. The U.S. is not a signatory to the 1958 Agreement.
---------------------------------------------------------------------------
ECE Regulation No. 152 also describes requirements and test
procedures for PAEB systems, including specification of minimum
daylight lighting conditions (which match this NPRM) and surrogates.
Test scenarios for PAEB systems include a test for a crossing test
mannequin, and a false positive test where a test mannequin is parallel
with and outside of the subject vehicle's path, and the vehicle must
not issue a warning or provide braking. Further specifications test for
electrical failure and compliance with deactivation requirements (if
equipped). A ``car to bicycle'' test and required standards are also
specified, which our proposed regulation does not include.
For both the ``car to car'' and ``car to pedestrian'' tests,
performance requirements are differentiated for M1 passenger vehicles
and N1 goods carrying vehicles at different loaded masses and at
different speeds; for some speed and weight combinations, collision
avoidance is required. Starting at 38 km/h (24 mph), the standard
specifies a maximum allowable impact speed; in contrast, our proposed
regulation requires collision avoidance at up to 80 km/h (50 mph)
without driver intervention. Up to 10 percent of test runs in any
category can be failed and the system would still be given
certification.
International AEB Consumer Testing
Internationally, several organizations also test vehicles' lead
vehicle AEB systems to provide safety information to consumers. Euro
NCAP, Australasian NCAP, and Korean NCAP each test lead vehicle AEB
systems using scenarios similar to NHTSA's NCAP, where the lead vehicle
test device is stationary, moving more slowly, or decelerating. ASEAN
NCAP, China NCAP, and Japan NCAP each test vehicle lead vehicle AEB
systems using stationary or slower-moving lead vehicle scenarios. Latin
NCAP tests lead vehicle AEB systems using slower moving or decelerating
lead vehicle scenarios. As discussed further in this notice, NHTSA will
require collision avoidance over a range of subject vehicle test
speeds; in contrast, Euro NCAP, Australasian NCAP, Korean NCAP, Chinese
NCAP, and Japan NCAP each test AEB starting at 10 km/h and increase the
speed during progressive test runs until the vehicle strikes the
surrogate. There are no false positive tests, and points are awarded
based on the speed at which the vehicle surrogate was struck.
Euro NCAP, China NCAP, Japan NCAP, and Korean NCAP each test PAEB
systems in crossing path scenarios with a test mannequin. Euro NCAP and
China NCAP further test PAEB systems for pedestrians walking parallel
along the subject vehicle's forward path. Euro NCAP also tests PAEB
systems for vehicles turning into a crossing test mannequin's path at
an intersection. A variety of lighting conditions are used depending
upon the scenario tested, with each organization conducting PAEB tests
using daylight
[[Page 38721]]
conditions, darkness conditions with streetlights, or darkness
conditions without streetlights for at least one of their tests. There
are no false positive tests, and for each test, the testing programs
award points or provide a rating based on each vehicle's AEB
performance.
Euro NCAP specifies the test mannequin in its ``Articulated
Pedestrian Target Specification Document,'' \265\ which sets
specifications for size, color, motion patterns, and detectability by
vehicle sensors. China NCAP, Japan NCAP, and Korean NCAP use the same
specifications, either by reference or substantially similar
translation. These specifications are used by the test mannequin
supplier to IIHS and NHTSA research.
---------------------------------------------------------------------------
\265\ European Automobile Manufacturers' Association (ACEA),
February 2016, ``Articulated Pedestrian Target Specification
Document,'' Version 1.0. https://www.acea.auto/publication/articulated-pedestrian-target-acea-specifications/.
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List of Subjects
49 CFR Part 571
Imports, Incorporation by Reference, Motor vehicle safety, Motor
vehicles, and Tires.
49 CFR Part 596
Automatic emergency braking, Incorporation by Reference, Motor
vehicle safety, Test devices.
In consideration of the foregoing, NHTSA proposes to amend 49 CFR
chapter V as follows:
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
0
1. The authority citation for part 571 continues to read as follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.95.
0
2. Amend Sec. 571.5 by:
0
a. Revising paragraph (d)(34);
0
b. Redesignating paragraphs (l)(49) and (50) as paragraphs (l)(50) and
(51), respectively; and
0
c. Adding new paragraph (l)(49).
The revisions and additions read as follows:
Sec. 571.5 Matter incorporated by reference.
* * * * *
(d) * * *
(34) ASTM E1337-19, ``Standard Test Method for Determining
Longitudinal Peak Braking Coefficient (PBC) of Paved Surfaces Using
Standard Reference Test Tire,'' approved December 1, 2019, into
Sec. Sec. 571.105; 571.121; 571.122; 571.126; 571.127; 571.135;
571.136; 571.500.
* * * * *
(l) * * *
(49) SAE J2400, ``Human Factors in Forward Collision Warning
System: Operating Characteristics and User Interface Requirements,''
August 2003 into Sec. 571.127.
* * * * *
0
3. Add Sec. 571.127 to read as follows:
Sec. 571.127 Standard No. 127; Automatic emergency braking systems
for light vehicles.
S1. Scope. This standard establishes performance requirements for
automatic emergency braking (AEB) systems for light vehicles.
S2. Purpose. The purpose of this standard is to reduce the number
of deaths and injuries that result from crashes in which drivers do not
apply the brakes or fail to apply sufficient braking power to avoid or
mitigate a crash.
S3. Application. This standard applies to passenger cars and to
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating of 4,536 kilograms (10,000 pounds) or less.
S4. Definitions.
Adaptive cruise control system is an automatic speed control system
that allows the equipped vehicle to follow a lead vehicle at a pre-
selected gap by controlling the engine, power train, and service
brakes.
Ambient illumination is the illumination as measured at the test
surface, not including any illumination provided by the subject
vehicle.
Automatic emergency braking (AEB) system is a system that detects
an imminent collision with vehicles, objects, and road users in or near
the path of a vehicle and automatically controls the vehicle's service
brakes to avoid or mitigate the collision.
Brake pedal application onset is when 11 N of force has been
applied to the brake pedal.
Forward collision warning is an auditory and visual warning
provided to the vehicle operator by the AEB system that is designed to
induce immediate forward crash avoidance response by the vehicle
operator.
Forward collision warning onset is the first moment in time when a
forward collision warning is provided.
Headway is the distance between the lead vehicle's rearmost plane
normal to its centerline and the subject vehicle's frontmost plane
normal to its centerline.
Lead vehicle is a vehicle test device facing the same direction and
preceding a subject vehicle within the same travel lane.
Lead vehicle braking onset is the point at which the lead vehicle
achieves a deceleration of 0.05 g due to brake application.
Pedestrian test mannequin is a device used during AEB testing, when
approaching pedestrians, meeting the specifications of subpart B of 49
CFR part 596.
Small-volume manufacturer means an original vehicle manufacturer
that produces or assembles fewer than 5,000 vehicles annually for sale
in the United States.
Steel trench plate is a rectangular steel plate often used in road
construction to temporarily cover sections of pavement unsafe to drive
over directly.
Subject vehicle is the vehicle under examination for compliance
with this standard.
Travel path is the path projected onto the road surface of a point
located at the intersection of the subject vehicle's frontmost vertical
plane and longitudinal vertical center plane, as the subject vehicle
travels forward.
Vehicle Test Device is a device meeting the specifications set
forth in subpart C of 49 CFR part 596.
S5. Requirements.
(a) Except as provided in paragraphs (b) and (c) of this section
S5, vehicles manufactured on or after [the first September 1 that is
three years after publication of a final rule] must meet the
requirements of this standard.
(b) The following lower-speed performance test requirements apply
to vehicles manufactured on or after [the first September 1 that is
three years after date of publication of a final rule] and before [the
first September 1 that is four years after the date of publication of a
final rule].
(1) For testing in the darkness condition using lower beam
headlamps with an intended overlap of 50 percent, the subject vehicle
test speed in S8.3.1(g) is any speed between 10 km/h and 40 km/h.
(2) For testing in the darkness condition using lower beam
headlamps, the subject vehicle test speed in S8.4.1(e) is any speed
between 10 km/h and 50 km/h.
(3) For testing in the darkness condition, the subject vehicle test
speed in S8.5.1(f) is any speed between 10 km/h and 60 km/h.
(c) The requirements of paragraphs (a) and (b) of this section S5
do not apply to small-volume manufacturers, final-stage manufacturers
and alterers until one year after the dates specified in those
paragraphs.
S5.1. Requirements when approaching a lead vehicle.
S5.1.1. Forward Collision Warning. A vehicle is required to have a
forward
[[Page 38722]]
collision warning system, as defined in S4 of this section, that
provides an auditory and visual signal to the driver of an impending
collision with a lead vehicle when traveling at any forward speed
greater than 10 km/h (6.2 mph). The auditory signal must have a high
fundamental frequency of at least 800 Hz, a duty cycle of 0.25-0.95,
and tempo in the range of 6-12 pulses per second. The visual signal
must be located according to SAE J2400 (incorporated by reference see
Sec. 571.5), paragraph 4.1.14 and must include the symbol in the
bottom right of paragraph 4.1.16. Line of sight is based on the
forward-looking eye midpoint (Mf) as described in S14.1.5.
of Sec. 571.111 of this part. The symbol must be red in color and
steady-burning.
S5.1.2. Automatic Emergency Braking. A vehicle is required to have
an automatic emergency braking system, as defined in S4 of this
section, that applies the service brakes automatically when a collision
with a lead vehicle is imminent. The system must operate when the
vehicle is traveling at any forward speed greater than 10 km/h (6.2
mph).
S5.1.3. Performance Test Requirements. The vehicle must provide a
forward collision warning and subsequently apply the service brakes
automatically when a collision with a lead vehicle is imminent such
that the subject vehicle does not collide with the lead vehicle when
tested using the procedures in S7 under the conditions specified in S6.
The forward collision warning is not required if adaptive cruise
control is engaged.
S5.2. Requirements when approaching pedestrians.
S5.2.1. Forward Collision Warning. A vehicle is required to have a
forward collision warning system, as defined in S4 of this section,
that provides an auditory and visual signal to the driver of an
impending collision with a pedestrian. The auditory signal must have a
high fundamental frequency of at least 800 Hz, a duty cycle of 0.25-
0.95, and tempo in the range of 6-12 pulses per second. The visual
signal must be located according to SAE J2400, (incorporated by
reference see Sec. 571.5), paragraph 4.1.14 and must include the crash
icon in the bottom right of paragraph 4.1.16. Line of sight is based on
the forward-looking eye midpoint (Mf) as described in
S14.1.5. of Sec. 571.111. The symbol must be red in color and steading
burning. The system must operate at any forward speed greater than 10
km/h (6.2 mph).
S5.2.2. Automatic Emergency Braking. A vehicle is required to have
an automatic emergency braking system, as defined in S4 of this
section, that applies the service brakes automatically when a collision
with a pedestrian is imminent when the vehicle is traveling at any
forward speed greater than 10 km/h (6.2 mph).
S5.2.3. Performance Test Requirements. The vehicle must
automatically apply the brakes and alert the vehicle operator such that
the subject vehicle does not collide with the pedestrian test mannequin
when tested using the procedures in S8 under the conditions specified
in S6.
S5.3. False Activation. The vehicle must not automatically apply
braking that results in peak additional deceleration that exceeds what
manual braking would produce by 0.25g or greater, when tested using the
procedures in S9 under the conditions specified in S6.
S5.4. Malfunction Detection. The system must continuously detect
system malfunctions, including malfunctions caused solely by sensor
obstructions. If the system detects a malfunction that prevents the
system from meeting the requirements specified in S5.1, S5.2, or S5.3,
the system must provide the vehicle operator with a telltale
notification that the malfunction exists.
S6. Test Conditions.
S6.1. Environmental conditions.
S6.1.1. Temperature. The ambient temperature is any temperature
between 0 [deg]C and 40 [deg]C.
S6.1.2. Wind. The maximum wind speed is no greater than 10 m/s (22
mph) during lead vehicle avoidance tests and 6.7 m/s (15 mph) during
pedestrian avoidance tests.
S6.1.3. Ambient Lighting.
(a) Daylight testing.
(1) The ambient illumination on the test surface is any level at or
above 2,000 lux.
(2) Testing is not performed while driving toward or away from the
sun such that the horizontal angle between the sun and a vertical plane
containing the centerline of the subject vehicle is less than 25
degrees and the solar elevation angle is less than 15 degrees.
(b) Dark testing.
(1) The ambient illumination on the test surface is any level at or
below 0.2 lux.
(2) Testing is performed under any lunar phase.
(3) Testing is not performed while driving toward the moon such
that the horizontal angle between the moon and a vertical plane
containing the centerline of the subject vehicle is less than 25
degrees and the lunar elevation angle is less than 15 degrees.
S6.1.4. Precipitation. Testing is not conducted during periods of
precipitation or when visibility is affected by fog, smoke, ash, or
other particulate.
S6.2. Road conditions.
S6.2.1. Test Track Surface and Construction. The tests are
conducted on a dry, uniform, solid-paved surface. Surfaces with debris,
irregularities, or undulations, such as loose pavement, large cracks,
or dips are not used.
S6.2.2. Surface Friction. The road test surface produces a peak
friction coefficient (PFC) of 1.02 when measured using an American
Society for Testing and Materials (ASTM) F2493 standard reference test
tire, in accordance with ASTM E1337-19 (incorporated by reference, see
Sec. 571.5), at a speed of 64 km/h (40 mph), without water delivery.
S6.2.3. Slope. The test surface has any consistent slope between 0
percent and 1 percent.
S6.2.4. Markings. The road surface within 2 m of the intended
travel path is marked with zero, one, or two lines of any configuration
or color. If one line is used, it is straight. If two lines are used,
they are straight, parallel to each other, and at any distance from 2.7
m to 4.5 m apart.
S6.2.5. Obstructions. Testing is conducted such that the vehicle
does not travel beneath any overhead structures, including but not
limited to overhead signs, bridges, or gantries. No vehicles,
obstructions, or stationary objects are within 7.4 m of either side of
the intended travel path except as specified.
S6.3. Subject vehicle conditions.
S6.3.1. Malfunction notification. Testing is not conducted while
the AEB malfunction telltale specified in S5.4 is illuminated.
S6.3.2. Sensor obstruction. All sensors used by the system and any
part of the vehicle immediately ahead of the sensors, such as plastic
trim, the windshield, etc., are free of debris or obstructions.
S6.3.3. Tires. The vehicle is equipped with the original tires
present at the time of initial sale. The tires are inflated to the
vehicle manufacturer's recommended cold tire inflation pressure(s)
specified on the vehicle's placard or the tire inflation pressure
label.
S6.3.4. Brake burnish.
(a) Vehicles subject to Sec. 571.105 are burnished in accordance
with S7.4 of that section.
(b) Vehicles subject to Sec. 571.135 are burnished in accordance
with S7.1 of that section.
S6.3.5. Brake temperature. The average temperature of the service
brakes on the hottest axle of the vehicle during testing, measured
according to
[[Page 38723]]
S6.4.1 of Sec. 571.135, is between 65 [deg]C and 100.[deg]C prior to
braking.
S6.3.6. Fluids. All non-consumable fluids for the vehicle are at
100 percent capacity. All consumable fluids are at any level from 5 to
100 percent capacity.
S6.3.7. Propulsion battery charge. The propulsion batteries are
charged at any level from 5 to 100 percent capacity.
S6.3.8. Cruise control. Cruise control, including adaptive cruise
control, is configured under any available setting.
S6.3.9. Adjustable forward collision warning. Forward collision
warning is configured in any operator-configurable setting.
S6.3.10. Engine braking. A vehicle equipped with an engine braking
system that is engaged and disengaged by the operator is tested with
the system in any selectable configuration.
S6.3.11. Regenerative braking. Regenerative braking is configured
under any available setting.
S6.3.12. Headlamps.
(a) Daylight testing is conducted with the headlamp control in any
selectable position.
(b) Darkness testing is conducted with the vehicle's lower beams or
upper beams active.
(c) Prior to performing darkness testing, headlamps are aimed
according to the vehicle manufacturer's instructions. The weight of the
loaded vehicle at the time of headlamp aiming is within 10 kg of the
weight of the loaded vehicle during testing.
S6.3.13. Subject vehicle loading. The vehicle load, which is the
sum of any vehicle occupants and any test equipment and
instrumentation, does not exceed 277 kg. The load does not cause the
vehicle to exceed its GVWR or any axle to exceed its GAWR.
S6.3.14. AEB system initialization. The vehicle is driven at a
speed of 10 km/h or higher for at least one minute prior to testing,
and subsequently the starting system is not cycled off prior to
testing.
S6.4. Equipment and Test Devices.
S6.4.1. The vehicle test device is specified in 49 CFR part 596
subpart C. Local fluttering of the lead vehicle's external surfaces
does not exceed 10 mm perpendicularly from the reference surface, and
distortion of the lead vehicle's overall shape does not exceed 25 mm in
any direction.
S6.4.2. Adult Pedestrian Test Mannequin is specified in 49 CFR part
596 subpart B.
S6.4.3. Child Pedestrian Test Mannequin is specified in 49 CFR part
596 subpart B.
S6.4.4. The steel trench plate used for the false activation test
has the dimensions 2.4 m x 3.7 m x 25 mm and is made of ASTM A36 steel.
Any metallic fasteners used to secure the steel trench plate are flush
with the top surface of the steel trench plate.
S7. Testing when approaching a lead vehicle.
S7.1. Setup.
(a) The testing area is set up in accordance with Figure 2.
(b) Testing is conducted during daylight.
(c) For reference, Table 1 to S7.1 specifies the subject vehicle
speed (VSV), lead vehicle speed (VLV), headway,
and lead vehicle deceleration for each test that may be conducted.
(d) The intended travel path of the vehicle is a straight line
toward the lead vehicle from the location corresponding to a headway of
L0.
(e) If the road surface is marked with a single or double lane
line, the intended travel path is parallel to and 1.8 m from the inside
of the closest line. If the road surface is marked with two lane lines
bordering the lane, the intended travel path is centered between the
two lines.
(f) For each test run conducted, the subject vehicle speed
(VSV), lead vehicle speed (VLV), headway, and
lead vehicle deceleration will be selected from the ranges specified.
Table 1 to S7.1--Test Parameters When Approaching a Lead Vehicle
--------------------------------------------------------------------------------------------------------------------------------------------------------
Speed (km/hr)
----------------------------------------- Headway (m) Lead vehicle decel (g) Manual brake application
VSV VLV
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stopped Lead Vehicle................ Any 10-80.............. 0 ...................... ...................... No.
Any 70-100............. 0 ...................... ...................... Yes.
Slower Lead Vehicle................. Any 40-80.............. 20 ...................... ...................... No.
Any 70-100............. 20 ...................... ...................... Yes.
Decelerating Lead Vehicle........... 50..................... 50 Any 12-40............. Any 0.3-0.5........... No.
50..................... 50 Any 12-40............. Any 0.3-0.5........... Yes.
80..................... 80 Any 12-40............. Any 0.3-0.5........... No.
80..................... 80 Any 12-40............. Any 0.3-0.5........... Yes.
--------------------------------------------------------------------------------------------------------------------------------------------------------
S7.2. Headway calculation. For each test run conducted under S7.3
and S7.4, the headway (L0), in meters, providing 5 seconds
time to collision (TTC) is calculated. L0 is determined with
the following equation where VSV is the speed of the subject vehicle in
m/s and VLV is the speed of the lead vehicle in m/s:
L0 = TTC0 x (VSV-VLV)
TTC0 = 5
S7.3. Stopped lead vehicle.
S7.3.1. Test parameters.
(a) For testing with no subject vehicle manual brake application,
the subject vehicle test speed is any speed between 10 km/h and 80 km/
h, and the lead vehicle speed is 0 km/h.
(b) For testing with manual brake application of the subject
vehicle, the subject vehicle test speed is any speed between 70 km/h
and 100 km/h, and the lead vehicle speed is 0 km/h.
S7.3.2. Test conduct prior to forward collision warning onset.
(a) The lead vehicle is placed stationary with its longitudinal
centerline coincident to the intended travel path.
(b) Before the headway corresponds to L0, the subject
vehicle is driven at any speed, in any direction, on any road surface,
for any amount of time.
(c) The subject vehicle approaches the rear of the lead vehicle.
(d) Beginning when the headway corresponds to L0, the
subject vehicle speed is maintained within 1.6 km/h of the test speed
with minimal and smooth accelerator pedal inputs.
(e) Beginning when the headway corresponds to L0, the
subject vehicle heading is maintained with minimal steering input such
that the travel path does not deviate more than 0.3 m laterally from
the intended travel path and the subject vehicle's yaw rate does not
exceed 1.0 deg/s.
S7.3.3. Test conduct after forward collision warning onset.
(a) The accelerator pedal is released at any rate such that it is
fully released within 500 ms. This action is omitted for vehicles
tested with cruise control active.
[[Page 38724]]
(b) For testing conducted with manual brake application, the
service brakes are applied as specified in S10. The onset of brake
pedal application occurs 1.0 0.1 second after forward
collision warning onset.
(c) For testing conducted without manual brake application, no
manual brake application is made until the test completion criteria of
S7.3.4 are satisfied.
S7.3.4. Test completion criteria. The test run is complete when the
subject vehicle comes to a complete stop without making contact with
the lead vehicle or when the subject vehicle makes contact with the
lead vehicle.
S7.4. Slower-moving lead vehicle.
S7.4.1. Test parameters.
(a) For testing with no subject vehicle manual brake application,
the subject vehicle test speed is any speed between 40 km/h and 80 km/
h, and the lead vehicle speed is 20 km/h.
(b) For testing with manual brake application of the subject
vehicle, the subject vehicle test speed is any speed between 70 km/h
and 100 km/h, and the lead vehicle speed is 20 km/h.
S7.4.2. Test conduct prior to forward collision warning onset.
(a) The lead vehicle is propelled forward in a manner such that the
longitudinal center plane of the lead vehicle does not deviate
laterally more than 0.3m from the intended travel path.
(b) The subject vehicle approaches the lead vehicle.
(c) Beginning when the headway corresponds to L0, the
subject vehicle and lead vehicle speed is maintained within 1.6 km/h of
the test speed with minimal and smooth accelerator pedal inputs.
(d) Beginning when the headway corresponds to L0, the
subject vehicle and lead vehicle headings are be maintained with
minimal steering input such that the subject vehicle's travel path does
not deviate more than 0.3 m laterally from the centerline of the lead
vehicle, and the yaw rate of the subject vehicle does not exceed 1.0 deg/s prior to the forward collision warning onset.
S7.4.3. Test conduct after forward collision warning onset.
(a) The subject vehicle's accelerator pedal is released at any rate
such that it is fully released within 500 ms. This action is omitted
for vehicles tested with cruise control active.
(b) For testing conducted with manual braking application, the
service brakes are applied as specified in S10. The onset of brake
pedal application is 1.0 0.1 second after the forward
collision warning onset.
(c) For testing conducted without manual braking application, no
manual brake application is made until the test completion criteria of
S7.4.4 are satisfied.
S7.4.4. Test completion criteria. The test run is complete when the
subject vehicle speed is less than or equal to the lead vehicle speed
without making contact with the lead vehicle or when the subject
vehicle makes contact with the lead vehicle.
S7.5. Decelerating lead vehicle.
S7.5.1. Test parameters.
(a) The subject vehicle test speed is 50 km/h or 80 km/h, and the
lead vehicle speed is identical to the subject vehicle test speed.
(b) [Reserved]
S7.5.2. Test conduct prior to lead vehicle braking onset.
(a) Before the 3 seconds prior to lead vehicle braking onset, the
subject vehicle is be driven at any speed, in any direction, on any
road surface, for any amount of time.
(b) Between 3 seconds prior to lead vehicle braking onset and lead
vehicle braking onset:
(1) The lead vehicle is propelled forward in a manner such that the
longitudinal center plane of the vehicle does not deviate laterally
more than 0.3 m from the intended travel path.
(2) The subject vehicle follows the lead vehicle at a headway of
any distance between 12 m and 40 m.
(3) The subject vehicle's speed is maintained within 1.6 km/h of
the test speed with minimal and smooth accelerator pedal inputs prior
to forward collision warning onset.
(4) The lead vehicle's speed is maintained within 1.6 km/h.
(5) The subject vehicle and lead vehicle headings are maintained
with minimal steering input such that their travel paths do not deviate
more than 0.3 m laterally from the centerline of the lead vehicle, and
the yaw rate of the subject vehicle does not exceed 1.0
deg/s until onset of forward collision warning.
S7.5.3. Test conduct following lead vehicle braking onset.
(a) The lead vehicle is decelerated to a stop with a targeted
average deceleration of any value between 0.3g and 0.5g. The targeted
deceleration magnitude is achieved within 1.5 seconds of lead vehicle
braking onset and is maintained until 250 ms prior to coming to a stop.
(b) After forward collision warning onset, the subject vehicle's
accelerator pedal is released at any rate such that it is fully
released within 500 ms. This action is omitted for vehicles with cruise
control active.
(c) For testing conducted with manual braking application, the
service brakes are applied as specified in S10. The brake pedal
application onset occurs 1.0 0.1 second after the forward
collision warning onset.
(d) For testing conducted without manual braking application, no
manual brake application is made until the test completion criteria of
S7.5.4 are satisfied.
S7.5.4. Test completion criteria. The test run is complete when the
subject vehicle comes to a complete stop without making contact with
the lead vehicle or when the subject vehicle makes contact with the
lead vehicle.
S8. Testing when approaching a pedestrian.
S8.1. Setup.
S8.1.1. General.
(a) For reference, Table 2 to S8.1.1 specifies the subject vehicle
speed (VSV), the pedestrian test mannequin speed
(VP), the overlap of the pedestrian test mannequin, and the
lighting condition for each test that may be conducted.
(b) The intended travel path of the vehicle is a straight line
originating at the location corresponding to a headway of
L0.
(c) If the road surface is marked with a single or double lane
line, the intended travel path is parallel to and 1.8 m from the inside
of the closest line. If the road surface is marked with two lane lines
bordering the lane, the intended travel path is centered between the
two lines.
(d) For each test run conducted, the subject vehicle speed
(VSV) will be selected from the range specified.
Table 2 to S8.1.1--Test Parameters When Approaching a Pedestrian
--------------------------------------------------------------------------------------------------------------------------------------------------------
Speed (km/h)
Direction Overlap (%) Obstructed ------------------------------------ Lighting condition
VSV VP
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crossing Path................... Right................. 25 No.................... Any 10-60......... 5 Daylight.
Right................. 50 No.................... Any 10-60......... Daylight.
[[Page 38725]]
Right................. 50 No.................... Any 10-60 *....... Lower Beams.
Right................. 50 No.................... Any 10-60......... Upper Beams.
Right................. 50 Yes................... Any 10-50......... Daylight.
Left.................. 50 No.................... Any 10-60......... 8 Daylight.
Stationary...................... Right................. 25 No.................... Any 10-55......... 0 Daylight.
Any 10-55 *....... Lower Beams.
Any 10-55......... Upper Beams.
Along-Path...................... Right................. 25 No.................... Any 10-65......... 5 Daylight.
Any 10-65 *....... Lower Beams.
Any 10-65 *....... Upper Beams.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Lower speed performance test requirements apply prior to [the first September 1 that is four years after publication of a final rule]. See S5(b).
S8.1.2. Overlap. As depicted in Figure 1 to this section, overlap
describes the location of the point on the front of the subject vehicle
that would make contact with a pedestrian if no braking occurred.
Overlap is the percentage of the subject vehicle's overall width that
the pedestrian test mannequin traverses. It is measured from the right
or the left, depending on the side of the subject vehicle where the
pedestrian test mannequin originates. For each test run, the actual
overlap will be within 0.15 m of the specified overlap.
S8.1.3. Pedestrian Test Mannequin.
(a) For testing where the pedestrian test mannequin is secured to a
moving apparatus, the pedestrian test mannequin is secured so that it
faces the direction of motion. The pedestrian test mannequin leg
articulation starts on apparatus movement and stops when the apparatus
stops.
(b) For testing where the pedestrian test mannequin is stationary,
the pedestrian test mannequin faces away from the subject vehicle, and
the pedestrian test mannequin legs remain still.
S8.2. Headway calculation. For each test run conducted under S8.3,
S8.4, and S8.5, the headway (L0), in meters, between the
front plane of the subject vehicle and a parallel contact plane on the
pedestrian test mannequin providing 4.0 seconds time to collision (TTC)
is calculated. L0 is determined with the following equation
where VSV is the speed of the subject vehicle in m/s and
VP-y is the component of speed of the pedestrian test
mannequin in m/s in the direction of the intended travel path:
L0 = TTC0 x (VSV - VP-y)
TTC0 = 4.0
S8.3. Pedestrian crossing road.
S8.3.1. Test parameters and setup (unobstructed from right).
(a) The testing area is set up in accordance with Figure 3 to this
section.
(b) Testing is conducted in the daylight or darkness conditions,
except that testing with the pedestrian at the 25 percent overlap is
only conducted in daylight conditions.
(c) Testing is conducted using the adult pedestrian test mannequin.
(d) The movement of the pedestrian test mannequin is perpendicular
to the subject vehicle's intended travel path.
(e) The pedestrian test mannequin is set up 4.0 0.1 m
to the right of the intended travel path.
(f) The intended overlap is 25 percent from the right or 50
percent.
(g) The subject vehicle test speed is any speed between 10 km/h and
60 km/h.
(h) The pedestrian test mannequin speed is 5 km/h.
S8.3.2 Test parameters and setup (unobstructed from left).
(a) The testing area is set up in accordance with Figure 4 to this
section.
(b) Testing is conducted in the daylight condition.
(c) Testing is conducted using the adult pedestrian mannequin.
(d) The movement of the pedestrian test mannequin is perpendicular
to the intended travel path.
(e) The pedestrian test mannequin is set up 6.0 0.1 m
to the left of the intended travel path.
(f) The intended overlap is 50 percent.
(g) The subject vehicle test speed is any speed between 10 km/h and
60 km/h.
(h) The pedestrian test mannequin speed is 8 km/h.
S8.3.3. Test parameters and setup (obstructed).
(a) The testing area is set up in accordance with Figure 5 to this
section.
(b) Testing is conducted in the daylight condition.
(c) Testing is conducted using the child pedestrian test mannequin.
(d) The movement of the pedestrian test mannequin is perpendicular
to the intended travel path.
(e) The pedestrian test mannequin is set up 4.0 0.1 m
to the right of the intended travel path.
(f) The intended overlap is 50 percent.
(g) Two vehicle test devices are secured in stationary positions
parallel to the intended travel path. The two vehicle test devices face
the same direction as the intended travel path. One vehicle test device
is directly behind the other separated by 1.0 0.1 m. The
left side of each vehicle test device is 1.0 0.1 m to the
right of the vertical plane parallel to the intended travel path and
tangent with the right outermost point of the subject vehicle when the
subject vehicle is in the intended travel path.
(h) The subject vehicle test speed is any speed between 10 km/h and
50 km/h.
(i) The pedestrian test mannequin speed is 5 km/h.
S8.3.4. Test conduct prior to forward collision warning or vehicle
braking onset.
(a) The subject vehicle approaches the crossing path of the
pedestrian test mannequin.
(b) Beginning when the headway corresponds to L0, the
subject vehicle speed is maintained within 1.6 km/h of the test speed
with minimal and smooth accelerator pedal inputs.
(c) Beginning when the headway corresponds to L0, the
subject vehicle heading is maintained with minimal steering inputs such
that the subject vehicle's travel path does not deviate more than 0.3 m
laterally from the intended travel path, and the yaw rate of the
subject vehicle does not exceed 1.0 deg/s prior to any
automated braking onset.
(d) The pedestrian test mannequin apparatus is triggered at a time
such that the pedestrian test mannequin meets the intended overlap,
subject to the criteria in S8.1.2. The pedestrian test mannequin
achieves its intended speed within 1.5 m after the apparatus begins to
move and maintains its intended speed within 0.4 km/h until the test
[[Page 38726]]
completion criteria of S8.3.6 are satisfied.
S8.3.5. Test conduct after either forward collision warning or
vehicle braking onset.
(a) After forward collision warning or vehicle braking onset, the
subject vehicle's accelerator pedal is released at any rate such that
it is fully released within 500 ms. This action is omitted for vehicles
with cruise control active.
(b) No manual brake application is made until the test completion
criteria of S8.3.6 are satisfied.
(c) The pedestrian mannequin continues to move until the completion
criteria of S8.3.6 are satisfied.
S8.3.6. Test completion criteria. The test run is complete when the
subject vehicle comes to a complete stop without making contact with
the pedestrian test mannequin, when the pedestrian test mannequin is no
longer in the path of the subject vehicle, or when the subject vehicle
makes contact with the pedestrian test mannequin.
S8.4. Stationary pedestrian.
S8.4.1. Test parameters and setup.
(a) The testing area is set up in accordance with Figure 6 to this
section.
(b) Testing is conducted in the daylight or darkness conditions.
(c) Testing is conducted using the adult pedestrian test mannequin.
(d) The pedestrian mannequin is set up at the 25 percent right
overlap position facing away from the approaching vehicle.
(e) The subject vehicle test speed is any speed between 10 km/h and
55 km/h.
(f) The pedestrian mannequin is stationary.
S8.4.2. Test conduct prior to forward collision warning or vehicle
braking onset.
(a) The subject vehicle approaches the pedestrian test mannequin.
(b) Beginning when the headway corresponds to L0, the
subject vehicle speed is maintained within 1.6 km/h of the test speed
with minimal and smooth accelerator pedal inputs.
(c) Beginning when the headway corresponds to L0, the
subject vehicle heading is maintained with minimal steering inputs such
that the subject vehicle's travel path does not deviate more than 0.3 m
laterally from the intended travel path, and the yaw rate of the
subject vehicle does not exceed 1.0 deg/s prior to any
automated braking onset.
S8.4.3. Test conduct after either forward collision warning or
vehicle braking onset.
(a) After forward collision warning or vehicle braking onset, the
subject vehicle's accelerator pedal is released at any rate such that
it is fully released within 500 ms. This action is omitted with
vehicles with cruise control active.
(b) No manual brake application is made until the test completion
criteria of S8.4.4 are satisfied.
S8.4.4. Test completion criteria. The test run is complete when the
subject vehicle comes to a complete stop without making contact with
the pedestrian test mannequin, or when the subject vehicle makes
contact with the pedestrian test mannequin.
S8.5. Pedestrian moving along the path
S8.5.1. Test parameters and setup.
(a) The testing area is set up in accordance with Figure 7 to this
section.
(b) Testing is conducted in the daylight or darkness conditions.
(c) Testing is conducted using the adult pedestrian test mannequin.
(d) The movement of the pedestrian test mannequin is parallel to
and in the same direction as the subject vehicle.
(e) The pedestrian test mannequin is set up in the 25 percent right
offset position.
(f) The subject vehicle test speed is any speed between 10 km/h and
65 km/h.
(g) The pedestrian test mannequin speed is 5 km/h.
S8.5.2. Test conduct prior to forward collision warning or vehicle
braking onset.
(a) The subject vehicle approaches the pedestrian test mannequin.
(b) Beginning when the headway corresponds to L0, the
subject vehicle speed is maintained within 1.6 km/h of the test speed
with minimal and smooth accelerator pedal inputs.
(c) Beginning when the headway corresponds to L0, the
subject vehicle heading is maintained with minimal steering inputs such
that the travel path does not deviate more than 0.3 m laterally from
the intended travel path, and the yaw rate of the subject vehicle does
not exceed 1.0 deg/s prior to any automated braking onset.
(d) The pedestrian test mannequin apparatus is triggered any time
after the distance between the front plane of the subject vehicle and a
parallel contact plane on the pedestrian test mannequin corresponds to
L0. The pedestrian test mannequin achieves its intended
speed within 1.5 m after the apparatus begins to move and maintains its
intended speed within 0.4 km/h until the test completion criteria of
S8.5.4 are satisfied.
S8.5.3. Test conduct after either forward collision warning or
vehicle braking onset.
(a) After forward collision warning or vehicle braking onset, the
subject vehicle's accelerator pedal is released at any rate such that
it is fully released within 500 ms. This action is omitted for vehicles
with cruise control active.
(b) No manual brake application is made until the test completion
criteria of S8.5.4 are satisfied.
S8.5.4. Test completion criteria. The test run is complete when the
subject vehicle slows to speed below the pedestrian test mannequin
travel speed without making contact with the pedestrian test mannequin
or when the subject vehicle makes contact with the pedestrian test
mannequin.
S9. False AEB activation.
S9.1. Headway calculation. For each test run to be conducted under
S9.2 and S9.3, the headway (L0, L2.1, L1.1), in meters, between the
front plane of the subject vehicle and either the steel trench plate's
leading edge or the rearmost plane normal to the centerline of the
vehicle test devices providing 5.0 seconds, 2.1 seconds, and 1.1
seconds time to collision (TTC) is calculated. L0, L2.1, and L1.1 are
determined with the following equation where VSV is the speed of the
subject vehicle in m/s:
Lx = TTCx x (VSV)
TTC0 = 5.0
TTC2.1 = 2.1
TTC1.1 = 1.1
S9.2. Steel trench plate.
S9.2.1. Test parameters and setup.
(a) The testing area is set up in accordance with Figure 8.
(b) The steel trench plate is secured flat on the test surface so
that its longest side is parallel to the vehicle's intended travel path
and horizontally centered on the vehicle's intended travel path.
(c) The subject vehicle test speed is 80 km/h.
(d) Testing may be conducted with manual brake application.
S9.2.2. Test conduct.
(a) The subject vehicle approaches the steel trench plate.
(b) Beginning when the headway corresponds to L0, the
subject vehicle speed is maintained within 1.6 km/h of the test speed
with minimal and smooth accelerator pedal inputs.
(c) Beginning when the headway corresponds to L0, the
subject vehicle heading is maintained with minimal steering input such
that the travel path does not deviate more than 0.3 m laterally from
the intended travel path, and the yaw rate of the subject vehicle does
not exceed 1.0 deg/s.
(d) If forward collision warning occurs, the subject vehicle's
accelerator pedal is released at any rate such that it is fully
released within 500 ms. This action is omitted for vehicles with cruise
control active.
[[Page 38727]]
(e) For tests where no manual brake application occurs, manual
braking is not applied until the test completion criteria of S9.2.3 are
satisfied.
(f) For tests where manual brake application occurs, the subject
vehicle's accelerator pedal, if not already released, is released when
the headway corresponds to L2.1 at any rate such that it is
fully released within 500 ms.
(g) For tests where manual brake application occurs, the service
brakes are applied as specified in S10. The brake application pedal
onset occurs at headway L1.1.
S9.2.3. Test completion criteria. The test run is complete when the
subject vehicle comes to a stop prior to crossing over the leading edge
of the steel trench plate or when the subject vehicle crosses over the
leading edge of the steel trench plate.
S9.3. Pass-through.
S9.3.1. Test parameters and setup.
(a) The testing area is set up in accordance with Figure 9.
(b) Two vehicle test devices are secured in a stationary position
parallel to one another with a lateral distance of 4.5 m 0.1 m between the vehicles' closest front wheels. The centerline
between the two vehicles is parallel to the intended travel path.
(c) The subject vehicle test speed is 80 km/h.
(d) Testing may be conducted with manual subject vehicle pedal
application.
S9.3.2. Test conduct.
(a) The subject vehicle approaches the gap between the two vehicle
test devices.
(b) Beginning when the headway corresponds to L0, the
subject vehicle speed is maintained within 1.6km/h with minimal and
smooth accelerator pedal inputs.
(c) Beginning when the headway corresponds to L0, the
subject vehicle heading is maintained with minimal steering input such
that the travel path does not deviate more than 0.3 m laterally from
the intended travel path, and the yaw rate of the subject vehicle does
not exceed 1.0 deg/s.
(d) If forward collision warning occurs, the subject vehicle's
accelerator pedal is released at any rate such that it is fully
released within 500 ms.
(e) For tests where no manual brake application occurs, manual
braking is not applied until the test completion criteria of S9.3.3 are
satisfied.
(f) For tests where manual brake application occurs, the subject
vehicle's accelerator pedal, if not already released, is released when
the headway corresponds to L2.1 at any rate such that it is
fully released within 500 ms.
(g) For tests where manual brake application occurs, the service
brakes are applied as specified in S10. The brake application onset
occurs when the headway corresponds to L1.1.
S9.3.3. Test completion criteria. The test run is complete when the
subject vehicle comes to a stop prior to its rearmost point passing the
vertical plane connecting the forwardmost point of the vehicle test
devices or when the rearmost point of the subject vehicle passes the
vertical plane connecting the forwardmost point of the vehicle test
devices.
S10. Subject Vehicle Brake Application Procedure.
S10.1. The procedure begins with the subject vehicle brake pedal in
its natural resting position with no preload or position offset.
S10.2. At the option of the manufacturer, either displacement
feedback or hybrid feedback control is used.
S10.3. Displacement feedback procedure. For displacement feedback,
the commanded brake pedal position is the brake pedal position that
results in a mean deceleration of 0.4g in the absence of AEB system
activation.
(a) The mean deceleration is the deceleration over the time from
the pedal achieving the commanded position to 250 ms before the vehicle
comes to a stop.
(b) The pedal displacement controller depresses the pedal at a rate
of 254 mm/s 25.4 mm/s to the commanded brake pedal
position.
(c) The pedal displacement controller may overshoot the commanded
position by any amount up to 20 percent. If such an overshoot occurs,
it is corrected within 100 ms.
(d) The achieved brake pedal position is any position within 10
percent of the commanded position from 100 ms after pedal displacement
occurs and any overshoot is corrected.
S10.4. Hybrid brake pedal feedback procedure. For hybrid brake
pedal feedback, the commanded brake pedal application is the brake
pedal position and a subsequent commanded brake pedal force that
results in a mean deceleration of 0.4g in the absence of AEB system
activation.
(a) The mean deceleration is the deceleration over the time from
the pedal achieving the commanded position to 250 ms before the vehicle
comes to a stop.
(b) The hybrid controller displaces the pedal at a rate of 254 mm/s
25.4 mm/s to the commanded pedal position.
(c) The hybrid controller may overshoot the commanded position by
any amount up to 20 percent. If such an overshoot occurs, it is
corrected within 100 ms.
(d) The hybrid controller begins to control the force applied to
the pedal and stops controlling pedal displacement 100 ms after pedal
displacement occurs and any overshoot is corrected.
(e) The hybrid controller applies a pedal force of at least 11.1 N.
(f) The applied pedal force is maintained within 10 percent of the
commanded brake pedal force from 350 ms after commended pedal
displacement occurs and any overshoot is corrected until test
completion.
Figure 1 to Sec. 571.127--Percentage Overlap Nomenclature
[[Page 38728]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.050
Figure 2 to Sec. 571.127--Setup for Lead Vehicle Automatic Emergency
Braking
[GRAPHIC] [TIFF OMITTED] TP13JN23.051
Figure 3 to Sec. 571.127--Setup for Pedestrian, Crossing Path, Right
[[Page 38729]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.052
Figure 4 to Sec. 571.127--Setup for Pedestrian, Crossing Path, Left
[[Page 38730]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.053
Figure 5 to Sec. 571.127--Setup for Pedestrian, Obstructed
[[Page 38731]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.054
Figure 6 to Sec. 571.127--Setup for Pedestrian Along-Path Stationary
[[Page 38732]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.055
Figure 7 to Sec. 571.127--Setup for Pedestrian Along-Path Moving
[[Page 38733]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.056
Figure 8 to Sec. 571.127--Steel Trench Plate
[GRAPHIC] [TIFF OMITTED] TP13JN23.057
Figure 9 to Sec. 571.127--Pass-Through
[[Page 38734]]
[GRAPHIC] [TIFF OMITTED] TP13JN23.058
0
4. Add part 596 to read as follows.
PART 596--AUTOMATIC EMERGENCY BRAKING TEST DEVICES
0
1. The authority citation for part 596 reads as follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.95.
Sec.
Subpart A--General
596.1 Scope.
596.2 Purpose.
596.3 Application
596.4 Definitions.
596.5 Matter incorporated by reference.
Subpart B--Pedestrian Test Devices
596.7 Specifications for pedestrian test devices.
596.8 [Reserved]
Subpart C--Vehicle Test Device
596.9 General Description
596.10 Specifications for the Vehicle Test Device
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.95.
Subpart A--General
Sec. 596.1 Scope.
This part describes the test devices that are to be used for
compliance testing of motor vehicles with motor vehicle safety
standards for automatic emergency braking.
Sec. 596.2 Purpose.
The design and performance criteria specified in this part are
intended to describe devices with sufficient precision such that
testing performed with these test devices will produce repetitive and
correlative results under similar test conditions to reflect adequately
the automatic emergency braking performance of a motor vehicle.
Sec. 596.3 Application.
This part does not in itself impose duties or liabilities on any
person. It is a description of tools that are used in compliance tests
to measure the performance of automatic emergency braking systems
required by the safety standards that refer to these tools. This part
is designed to be referenced by, and become part of, the test
procedures specified in motor vehicle safety standards, such as 49 CFR
571.127 (Standard No. 127, Automatic emergency braking systems for
light vehicles).
Sec. 596.4 Definitions.
All terms defined in section 30102 of the National Traffic and
Motor Vehicle Safety Act (49 U.S.C. chapter 301, et seq.) are used in
their statutory meaning.
Adult Pedestrian Test Mannequin (APTM) means a test device with the
appearance and radar cross section that simulates an adult pedestrian
for the purpose of testing automatic emergency brake system
performance.
Child Pedestrian Test Mannequin (CPTM) means a test device with the
appearance and radar cross section that stimulates a child pedestrian
for the purpose of testing automatic emergency brake system
performance.
Vehicle Test Device means a test device that simulates a passenger
vehicle for the purpose of testing automatic emergency brake system
performance.
Vehicle Test Device Carrier means a movable platform on which a
Lead Vehicle Test Device may be attached during compliance testing.
Pedestrian Test Device(s) means an Adult Pedestrian Test Mannequin
and/or a Child Pedestrian Test Mannequin.
Pedestrian Test Mannequin Carrier means a movable platform on which
an Adult Pedestrian Test Mannequin or Child Pedestrian Test Mannequin
may be attached during compliance testing.
Sec. 596.5 Matter incorporated by reference.
(a) Certain material is incorporated by reference into this part
with the approval of the Director of the Federal Register under 5
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that
specified in this section, the National Highway Traffic Safety
Administration (NHTSA) must publish notice of change in the Federal
Register and the material must be available to the public. All approved
material is available for inspection at NHTSA at the National Archives
and Records Administration (NARA). Contact NHTSA at: NHTSA Office of
Technical Information Services, 1200 New Jersey Avenue SE, Washington,
DC 20590; (202) 366-2588 and For information on the availability of
this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.htmlor email [email protected]. The material may be
obtained from the source(s) in the following paragraph of this section.
(b) International Organization for Standardization (ISO), 1, ch. de
la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland; phone: + 41 22
749 01 11 fax: + 41 22 733 34 30; website: www.iso.org/.
(1) ISO 3668:2017, ``Paints and varnishes--Visual comparison of
colour of paints,'' Third edition, 2017-05; into Sec. 596.7.
(2) ISO 19206-2:2018(E), ``Road vehicles--Test devices for target
vehicles, vulnerable road users and other objects, for assessment of
active safety functions--Part 2: Requirements for pedestrian targets,''
First edition, 2018-12; into Sec. 596.7.
(3) ISO 19206-3:2021(E), ``Test devices for target vehicles,
vulnerable road users and other objects, for assessment of active
safety functions--Part 3: Requirements for passenger vehicle 3D
targets,'' First edition, 2021-05; into Sec. 596.10.
(4) ISO I9206-4:2020(E), ``Test devices for target vehicles,
vulnerable road users and other objects, for assessment of active
safety functions--Part 4: Requirements for bicyclist targets,'' First
edition, 2020-11; into Sec. 596.7.
Subpart B--Pedestrian Test Devices
Sec. 596.7 Specifications for Pedestrian Test Devices.
(a) The words ``recommended,'' ``should,'' ``can be,'' or ``should
be'' appearing in sections of ISO 19206-2:2018(E) (incorporated by
reference, see Sec. 596.5), referenced in this section, are read as
setting forth specifications that are used.
(b) The words ``may be,'' or ``either'' used in connection with a
set of items
[[Page 38735]]
appearing in sections of ISO 19206-2:2018(E) (incorporated by
reference, see Sec. 596.5), referenced in this section, are read as
setting forth the totality of items, any one of which may be selected
by NHTSA for testing.
(c) Specifications for the Pedestrian Test Devices--(1) General
description. The Adult Pedestrian Test Mannequin (APTM) provides a
sensor representation of a 50th percentile adult male and consist of a
head, torso, two arms and hands, and two legs and feet. The Child
Pedestrian Test Mannequin (CPTM) provides a sensor representation of a
6-7-year-old child and consists of a head, torso, two arms and hands,
and two legs and feet. The arms of the APTM and CPTM are posable, but
do not move during testing. The legs of the APTM and CPTM articulate
and are synchronized to the forward motion of the mannequin.
(2) Dimensions and posture. The APTM has basic body dimensions and
proportions specified in Annex A, table A.1 in ISO 19206-2:2018
(incorporated by reference, see Sec. 596.5). The CPTM has basic body
dimensions and proportions specified in Annex A, table A.1 in ISO
19206-2:2018 (incorporated by reference, see Sec. 596.5).
(3) Visual Properties--(i) Head. The head has a visible hairline
silhouette by printed graphic. The hair is black as defined in Annex B
table B.2 of ISO 19206-4:2020, as tested in accordance with ISO
3668:2017 (both incorporated by reference, see Sec. 596.5).
(ii) Face. The head does not have any facial features (i.e., eyes,
nose, mouth, and ears).
(iii) Skin. The face, neck and hands have a skin colored as defined
Annex B, table B.2 of ISO 19206-4: 2020 (incorporated by reference, see
Sec. 596.5).
(iv) Torso and Arms. The torso and arms are black as defined in
Annex B table B.2 of ISO 19206-4:2020, as tested in accordance with ISO
3668:2017 (both incorporated by reference, see Sec. 596.5).
(v) Legs. The legs are blue as defined in Annex B table B.2 of ISO
19206-4:2020, as tested in accordance with ISO 3668:2017 (both
incorporated by reference, see Sec. 596.5).
(vi) Feet. The feet are black as defined in Annex B table B.2 of
ISO 19206-4:2020, as tested in accordance with ISO 3668:2017 (both
incorporated by reference, see Sec. 596.5).
(4) Infrared properties. The surface of the entire APTM or CPTM are
within the reflectivity ranges specified in Annex B section B.2.2 of
ISO 19206-2:2018, as illustrated in Annex B, figure B.2 (incorporated
by reference, see Sec. 596.5).
(5) Radar properties. The radar reflectivity characteristics of the
pedestrian test device approximates that of a pedestrian of the same
size when approached from the side or from behind.
(6) Radar cross section measurements. The radar cross section
measurements of the APTM and the CPTM is within the upper and lower
boundaries shown in Annex B, section B.3, figure B.6 of ISO 19206-
2:2018 when tested in accordance with the measure procedure in Annex C,
section C.3 of ISO 19206-2:2018 (incorporated by reference, see Sec.
596.5).
(7) Posture. The pedestrian test device has arms that are posable
and remain posed during testing. The pedestrian test device is equipped
with moving legs consistent with standard gait phases specified in
Section 5.6 of ISO 19206-2:2018 (incorporated by reference, see Sec.
596.5).
(8) Articulation Properties. The legs of the pedestrian test device
are in accordance with, and as described in, Annex D, section D.2 and
illustrated in Figures D.1, D.2, and D.3 of ISO 19206-2:2018
(incorporated by reference, see Sec. 596.6).
Sec. 596.8 [Reserved]
Subpart C--Vehicle Test Device
Sec. 596.9 General Description
(a) The Vehicle Test Device provides a sensor representation of a
passenger motor vehicle.
(b) The rear view of the Vehicle Test Device contains
representations of the vehicle silhouette, a rear window, a high-
mounted stop lamp, two taillamps, a rear license plate, two rear reflex
reflectors, and two tires.
Sec. 596.10 Specifications for the Vehicle Test Device.
(a) The words ``recommended,'' ``should,'' ``can be,'' or ``should
be'' appearing in sections of ISO 19206-3:2021(E) (incorporated by
reference, see Sec. 596.5), referenced in this section, are read as
setting forth specifications that are used.
(b) The words ``may be,'' or ``either,'' used in connection with a
set of items appearing in sections of ISO 19206-3:2021(E) (incorporated
by reference, see Sec. 596.5), referenced in this section, are read as
setting forth the totality of items, any one of which may be selected
by NHTSA for testing.
(c) Dimensional specifications. (1) The rear silhouette and the
rear window are symmetrical about a shared vertical centerline.
(2) Representations of the taillamps, rear reflex reflectors, and
tires are symmetrical about the surrogate's centerline.
(3) The license plate representation has a width of 300 15 mm and a height of 150 15 mm and mounted with a
license plate holder angle within the range described in 49 CFR 571.108
S6.6.3.1.
(4) The Vehicle Test Device representations are located within the
minimum and maximum measurement values specified in columns 3 and 4 of
Tables A.4 of ISO 19206-3:2021(E) Annex A (incorporated by reference,
see Sec. 596.5). The tire representations are located within the
minimum and maximum measurement values specified in columns 3 and 4 of
Tables A.3 of ISO 19206-3:2021(E) Annex A (incorporated by reference,
see Sec. 596.5). The terms ``rear light'' means ``taillamp,''
``retroreflector'' means ``reflex reflector,'' and ``high centre
taillight'' means ``high-mounted stop lamp.''
(d) Visual and near infrared specification. (1) The Vehicle Test
Device rear representation colors are within the ranges specified in
Tables B.2 and B.3 of ISO 19206-3:2021(E) Annex B (incorporated by
reference, see Sec. 596.5).
(2) The rear representation infrared properties of the Vehicle Test
Device are within the ranges specified in Table B.1 of ISO 19206-
3:2021(E) Annex B (incorporated by reference, see Sec. 596.5) for
wavelengths of 850 to 950 nm when measured according to the calibration
and measurement setup specified in paragraph B.3 of ISO 19206-3:2021(E)
Annex B (incorporated by reference, see Sec. 596.5).
(3) The Vehicle Test Device rear reflex reflectors, and at least 50
cm\2\ of the taillamp representations are grade DOT-C2 reflective
sheeting as specified in 49 CFR 571.108 S8.2.
(e) Radar reflectivity specifications. (1) The radar cross section
of the Vehicle Test Device is measured with it attached to the carrier
(robotic platform). The radar reflectivity of the carrier platform is
less than 0 dBm\2\ for a viewing angle of 180 degrees and over a range
of 5 to 100 m when measured according to the radar measurement
procedure specified in C.3 of ISO 19206-3:2021(E) Annex C (incorporated
by reference, see Sec. 596.5) for fixed-angle scans.
(2) The rear bumper area as shown in Table C.1 of ISO 19206-
3:2021(E) Annex C (incorporated by reference, see Sec. 596.5)
contributes to the target radar cross section.
(3) The radar cross section is assessed using radar sensor that
operates at 76 to 81 GHz and has a range of at least 5 to
[[Page 38736]]
100 m, a range gate length smaller than 0.6m, a horizontal field of
view of 10 degrees or more (-3dB amplitude limit), and an elevation
field of view of 5 degrees or more (-3dB amplitude).
(4) At least 92 percent of the filtered data points of the
surrogate radar cross section for the fixed vehicle angle, variable
range measurements are within the radar cross section boundaries
defined in Sections C.2.2.4 of ISO 19206-3:2021(E) Annex C
(incorporated by reference, see Sec. 596.5) for a viewing angle of 180
degrees when measured according to the radar measurement procedure
specified in C.3 of ISO 19206-3:2021(E) Annex C (incorporated by
reference, see Sec. 596.5) for fixed-angle scans.
(5) Between 86 to 95 percent of the Vehicle Test Device spatial
radar cross section reflective power is with the primary reflection
region defined in Section C.2.2.5 of ISO 19206-3:2021(E) Annex C
(incorporated by reference, see Sec. 596.5) when measured according to
the radar measurement procedure specified in C.3 of ISO 19206-3:2021(E)
Annex C (incorporated by reference, see Sec. 596.5) using the angle-
penetration method.
Issued under authority delegated in 49 CFR part 1.95 and 49 CFR
501.8.
Raymond R. Posten,
Associate Administrator for Rulemaking.
[FR Doc. 2023-11863 Filed 6-12-23; 8:45 am]
BILLING CODE 4910-59-P