[Federal Register Volume 86, Number 247 (Wednesday, December 29, 2021)]
[Rules and Regulations]
[Pages 74270-74307]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27538]



[[Page 74269]]

Vol. 86

Wednesday,

No. 247

December 29, 2021

Part III





Department of Transportation





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National Highway Traffic Safety Administration





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49 CFR Part 571





Federal Motor Vehicle Safety Standards; Bus Rollover Structural 
Integrity; Final Rule

  Federal Register / Vol. 86 , No. 247 / Wednesday, December 29, 2021 / 
Rules and Regulations  

[[Page 74270]]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2021-0088]
RIN 2127-AK96


Federal Motor Vehicle Safety Standards; Bus Rollover Structural 
Integrity

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Final rule.

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SUMMARY: NHTSA is issuing this final rule to establish Federal Motor 
Vehicle Safety Standard (FMVSS) No. 227, ``Bus rollover structural 
integrity,'' to enhance the rollover structural integrity of over-the-
road buses (motorcoaches), and other buses with a gross vehicle weight 
rating (GVWR) greater than 11,793 kilograms (kg) (26,000 pounds (lb)). 
This final rule, issued pursuant to the Moving Ahead for Progress in 
the 21st Century Act (MAP-21), requires the buses to provide a 
``survival space'' in a rollover test to protect occupants from 
possible collapse of the bus structure around them. In addition, to 
reduce the likelihood of ejection, this final rule prohibits emergency 
exits from opening in the rollover test. This final rule ensures that 
bus roofs and side wall panels will resist deformation and intrusion 
into the occupant space in rollover crashes, and reduces the risk of 
emergency exits becoming ejection portals in a crash.

DATES: The effective date of this final rule is: December 30, 2024. 
Optional early compliance is permitted.
    Petitions for reconsideration: Petitions for reconsideration of 
this final rule must be received not later than February 14, 2022.

ADDRESSES: Petitions for reconsideration of this final rule must refer 
to the docket number set forth above and be submitted to the 
Administrator, National Highway Traffic Safety Administration, 1200 New 
Jersey Avenue SE, Washington, DC 20590. Note that all petitions 
received will be posted without change to https://www.regulations.gov, 
including any personal information provided.
    Privacy Act: Please see the Privacy Act heading under Rulemaking 
Analyses and Notices.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may contact 
James Myers, NHTSA Office of Crashworthiness Standards, telephone 202-
493-0031, fax 202-493-2990. For legal issues: Deirdre Fujita, NHTSA 
Office of Chief Counsel, telephone 202-366-2992, fax 202-366-3820. 
Address: National Highway Traffic Safety Administration, U.S. 
Department of Transportation, 1200 New Jersey Avenue SE, West Building, 
Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
    a. Introduction
    b. How This Final Rule Differs From the Notice of Proposed 
Rulemaking
    c. NTSB Recommendations
    d. Costs and Benefits
    e. NHTSA's Determination of MAP-21 Requirements and 
Considerations
    f. Retrofitting
II. Introduction
III. NHTSA's Statutory Authority
    a. National Traffic and Motor Vehicle Safety Act (Safety Act)
    b. MAP-21 (The Motorcoach Enhanced Safety Act of 2012)
IV. Safety Need (FARS 2004-2018 Data Analysis)
V. Summary of the NPRM
VI. High Level Summary of the Comments
VII. Scope and Purpose of the Rule
VIII. Applicability of the Rule
    a. Medium-Size Buses (Buses With a GVWR of 4,536 to 11,793 kg 
(10,000-26,000 lb))
    b. Large Buses
IX. School Bus Derivative Buses
X. Performance Requirements
    a. Severity of the Rollover Test
    b. Intrusion Into the Survival Space
    c. Luggage Racks and Seat Anchorages
    d. Emergency Exits
XI. Glazing Issues
    a. Side Glazing on the Non-Struck Side of the Bus
    b. Type of Glazing
    c. Moon Roofs
    d. Struck-Side Window Evaluations
XII. Test Procedure Issues
    a. Ballasting the Vehicle
    b. Vehicle Fluids
    c. Additional Tools for Survival Space Evaluation During Testing
XIII. Other Issues
    a. ECE R.66 Alternative Compliance Methods
    b. Regulatory Alternatives
    1. FMVSS No. 216
    2. FMVSS No. 220
    c. Additional MAP-21 Considerations
XIV. Lead Time
XV. Retrofitting Used Buses
XVI. Overview of Costs and Benefits
XVII. Rulemaking Analyses and Notices

I. Executive Summary

a. Introduction

    This final rule substantially improves motorcoach safety. It 
establishes an FMVSS to improve the resistance of motorcoach roofs and 
side wall panels to deformation and intrusion into the occupant 
compartment in rollover crashes, and fulfills a mandate in section 
32703(b)(1) of MAP-21. This final rule also accords with section 
32703(b)(2) of MAP-21 by requiring emergency exits to remain closed in 
a rollover to prevent partial and complete ejection of passengers.
    This final rule achieves longstanding NHTSA and Departmental goals 
to enhance motorcoach safety. NHTSA identified four priority areas in 
which to improve the safety of motorcoaches and other large buses: 
Requiring passenger seat belts, improved rollover structural integrity, 
improved emergency evacuation, and fire safety.\1\ With this final 
rule, NHTSA has completed research and rulemaking on the first two 
priority areas and completed research on the other two.
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    \1\ See ``NHTSA's Approach to Motorcoach Safety,'' Docket No. 
NHTSA-2007-28793. In NHTSA's plan, ``motorcoach'' referred to inter-
city transport buses. In 2009, DOT also issued a Motorcoach Safety 
Action Plan that addressed additional factors, such as driver 
fatigue and operator maintenance schedules. An update to the 
Departmental plan was issued in December 2012, https://www.fmcsa.dot.gov/sites/fmcsa.dot.gov/files/docs/Motorcoach-Safety-Action-Plan-2012.pdf. This final rule is an action included in the 
Departmental plan.
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    Congress also focused on these and other areas in incorporating the 
Motorcoach Enhanced Safety Act of 2012 into MAP-21 (Pub. L. 112-141). 
Among other matters, MAP-21 directed NHTSA (as delegated by the 
Secretary of Transportation) to require seat belts in ``motorcoaches,'' 
a term, Congress stated, that has the same meaning given the term 
``over-the-road bus'' in section 3038(a)(3) of the Transportation 
Equity Act for the 21st Century (49 U.S.C. 5310 note). An over-the-road 
bus (OTRB) is a bus characterized by an elevated passenger deck located 
over a baggage compartment.\2\ NHTSA has used the term ``over-the-road 
bus'' in the FMVSSs issued pursuant to the MAP-21 mandates. For 
example, NHTSA fulfilled MAP-21's seat belt mandate by amending FMVSS 
No. 208, ``Occupant crash protection,'' to require seat belts in each 
passenger seating position in OTRBs, as well as in other buses that are 
not OTRBs (non-OTRBs) with a GVWR greater than 11,793 kg (26,000 
lb).\3\ (For the convenience of the reader, NHTSA uses the term ``large 
buses'' in this final rule to refer to OTRBs regardless of GVWR and 
non-OTRBs with a GVWR

[[Page 74271]]

greater than 11,793 kg (26,000 lb), with some exceptions.)
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    \2\ Under section 32701(6) of the Motorcoach Enhanced Safety 
Act, ``motorcoach'' does not include a bus used in public 
transportation provided by, or on behalf of, a public transportation 
agency, or a school bus.
    \3\ 78 FR 70416, November 25, 2013; denial of petitions for 
reconsideration, 81 FR 19902, April 6, 2016.
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    Section 32703(b)(1) of MAP-21 also directed NHTSA to pursue 
rulemaking for OTRBs to establish improved roof and roof support 
standards that substantially improve the resistance of bus roofs to 
deformation and intrusion in rollovers. MAP-21 requires NHTSA to adopt 
a final rule if NHTSA determines that such standards meet the 
requirements and considerations in subsections (a) and (b) of section 
30111 of the National Traffic and Motor Vehicle Safety Act.\4\ As 
discussed in this final rule, NHTSA has made such a determination 
regarding an FMVSS for all large buses.
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    \4\ MAP-21, section 32703(b) and (b)(1)).
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    This final rule complements the November 2013 seat belt rule. With 
all new large buses manufactured since 2016 required to have lap and 
shoulder seat belts for passengers, increasing numbers of passengers 
can be belted. This final rule establishing FMVSS No. 227 will ensure 
that these belted passengers will be significantly protected against 
unreasonable risk of injury in frontal crashes and significantly 
protected against the risk of ejection in rollovers. Hand-in-hand with 
the seat belt rule, this final rule enhances the safety of these belted 
passengers by providing a ``survival space'' in a rollover, a space 
where the belted occupants are protected from intruding structures such 
as a collapsing roof or a detached luggage rack. The new standard's 
improvements to the roof and sidewall strength of the buses will also 
protect unbelted occupants against structural failure of the bus 
compartment. This final rule improves transportation safety for the 
most vulnerable in our society since more than half of motorcoach trips 
are made by children and senior citizens.\5\ It furthers transportation 
equity by providing the same occupant crash protection to these 
passengers as the protection provided to occupants of other passenger 
motor vehicles,\6\ by reducing deaths and injuries due to the crushing 
of the roof into the occupant compartment in rollover crashes.
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    \5\ ``Motorcoach Census 2013, A Study of the Size and Activity 
of the Motorcoach Industry in the United States and Canada in 
2012,'' American Bus Association Foundation, February 27, 2014.
    \6\ Passenger vehicles under 4,536 kg (10,000 lb) GVWR are 
subject to the requirements of FMVSS No. 216, ``Roof crush 
resistance; Applicable unless a vehicle is certified to Sec.  
216a,'' or to FMVSS No. 216a, ``Roof crush resistance, Upgraded 
standard.''
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    This final rule applies to all new large buses, with limited 
exceptions. The standard does not apply to school buses, prison buses, 
buses with perimeter seating, or to transit buses that are not OTRBs. 
School buses already meet an FMVSS for roof strength, which is FMVSS 
No. 220, ``School bus rollover protection'' (49 CFR 571.220). In 
response to comments, NHTSA has also decided not to apply the standard 
to ``school bus derivative buses,'' which this final rule defines as 
buses built on a school bus platform. These vehicles may not have 
school bus lights and stop arms meeting FMVSS No. 108 and No. 131, 
respectively, or seating systems meeting FMVSS No. 222, ``School bus 
seating and passenger protection,'' but the buses have safety systems 
that are otherwise identical to school buses regarding their emergency 
exits, rollover protection (FMVSS No. 220), bus body joint strength, 
and fuel system integrity. The vehicles could be certified as meeting 
the FMVSSs for ``school buses'' if they had school bus lights meeting 
FMVSS No. 108, stop arms meeting FMVSS No. 131, and seating systems 
meeting FMVSS No. 222. Because school bus derivative buses already meet 
the roof crush resistance requirements in FMVSS No. 220, it would be 
redundant to require the buses to meet Standard No. 227 established by 
this final rule.
    The test for the large buses adopted by this final rule is the 
complete vehicle rollover test of United Nations Economic Commission 
for Europe (ECE) Regulation 66, ``Uniform Technical Prescriptions 
Concerning the Approval for Large Passenger Vehicles with Regard to the 
Strength of their Superstructure,'' (ECE R.66).\7\ The test simulates a 
real-world rollover crash of a large bus. The test bus is placed on a 
tilting platform that is 800 mm (24 inches) above a smooth and level 
concrete surface. One side of the tilting platform along the length of 
the bus is raised at a steady rate of not more than 5 degrees/second 
until the vehicle becomes unstable, rolls off the platform, and impacts 
the concrete surface below. Some commenters to the August 6, 2014 
notice of proposed rulemaking (NPRM) (79 FR 46090) thought that the 
test was too lenient, but NHTSA believes that those views are mistaken. 
As explained in this preamble, this test imparts severe crash forces 
that the buses must resist. FMVSS No. 227 prohibits any intrusion into 
the ``survival space'' by any part of the vehicle outside the survival 
space, except for minute objects weighing less than 15.0 grams, such as 
pebbles of glazing, or bolts and screws, which do not pose an 
unreasonable risk to safety for occupants.
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    \7\ Dated February 2006, https://live.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/r066r1e.pdf. ECE R.66 defines 
``superstructure'' as ``the load-bearing components of the bodywork 
as defined by the manufacturer, containing those coherent parts and 
elements which contribute to the strength and energy absorbing 
capability of the bodywork, and preserve the residual space in the 
rollover test.'' ``Bodywork'' means ``the complete structure of the 
vehicle in running order, including all the structural elements 
which form the passenger compartment, driver's compartment, baggage 
compartment and spaces for the mechanical units and components.''
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    The ``survival space'' requirement ensures at least a minimum level 
of structural integrity for the buses by prohibiting intrusions into 
the occupant space that can cause harm. It establishes ``improved roof 
and roof support standards'' that substantially improve the resistance 
of the roof to deformation and intrusion, in accordance with MAP-21. It 
ensures that buses are constructed so that structures outside of the 
survival space, such as luggage racks and large pieces of glazing, do 
not enter the survival space in the rollover.
    The requirement that emergency exits remain shut during and after 
the rollover test reduces the likelihood of emergency exits becoming 
ejection portals during rollovers, which is a goal consistent with MAP-
21. Section 32703(b)(2) of MAP-21 requires NHTSA to consider requiring 
advanced glazing \8\ standards for each motorcoach portal and ``other 
portal improvements to prevent partial and complete ejection of 
motorcoach passengers, including children.'' In NHTSA's motorcoach 
tests conducted during development of this rulemaking, roof and side 
emergency exits opened during the rollover event and the panes of 
advanced glazing popped out of their mounting. The requirement that 
emergency exits remain closed is a ``portal improvement'' established 
pursuant to section 32703(b)(2). Additionally, the requirement that the 
glazing panels not intrude into the survival space by detaching from 
the non-struck side of the bus will ensure the glazing panels remain 
intact in their mounting during bus rollover crashes and not form 
ejection portals.\9\
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    \8\ MAP-21 (section 32702(1)) defines ``advanced glazing'' as 
``glazing installed in a portal on the side or the roof of a 
motorcoach that is designed to be highly resistant to partial or 
complete occupant ejection in all types of motor vehicle crashes.'')
    \9\ On May 6, 2016 (81 FR 27904), NHTSA issued an NPRM proposing 
to establish FMVSS No. 217a to improve glazing materials used in 
motorcoaches and other large buses. The NPRM proposed an impactor 
test of glazing material to simulate the loading from an average 
size adult male impacting a window on the opposite side of a large 
bus in a rollover. Countermeasures used to meet the test would 
likely involve the use of advanced glazing. This final rule adopting 
FMVSS No. 227 would complement FMVSS No. 217a by improving the 
securement of the advanced glazing in the buses.

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[[Page 74272]]

b. How This Final Rule Differs From the Notice of Proposed Rulemaking 
(NPRM)

    The most noteworthy differences between this final rule and the 
NPRM \10\ are highlighted below.
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    \10\ NPRM, August 6, 2014 (79 FR 46090).
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    1. This final rule adopts the NPRM's proposed ECE R.66 full vehicle 
test to improve the roof and structural integrity of OTRBs (except for 
a few buses with unique configurations), and non-OTRBs with a GVWR 
greater than 11,793 kg (26,000 lb)). The agency proposed to exclude 
non-OTRBs with perimeter seating from the standard. After evaluation of 
the comments received, this final rule excludes all perimeter seating 
buses, as there is not a sufficient reason to distinguish between buses 
just based on the location of a luggage compartment. Further, all 
prison buses are excluded due to the unique interior configuration of 
the buses, as are school bus derived buses, as the latter vehicles 
already meet NHTSA's school bus roof crush resistance standard.
    2. This final rule adopts the NPRM's proposed prohibition that no 
part of the bus that is outside the survival space shall intrude into 
the survival space, both during movement of the tilting platform or 
resulting from impact of the bus on the impact surface. However, given 
the high force applications imparted to the bus structure in the 
rollover test, this final rule permits debris caused by the impact to 
fall into the survival space, such as small glazing pebbles or bolts 
and screws. The objects must not weigh more than 15.0 grams.
    3. This final rule does not adopt the NPRM's proposal that each 
anchorage of an interior overhead luggage rack or other compartment 
must not completely separate from its mounting structure during 
movement of the tilting platform or resulting from impact of the bus on 
the impact surface. This final rule also does not adopt the NPRM's 
proposal that seat anchorages must not become dislodged during the 
test. Under the NPRM, those proposed prohibitions would have applied 
even if the luggage rack does not enter the survival space, or the seat 
anchorages dislodged within the survival space. NHTSA has decided that 
the primary purpose of this rulemaking is to establish a roof strength 
and crush resistance standard that improves the resistance of roofs to 
deformation and intrusion, i.e., by providing a survival space to 
occupants in rollovers. The purpose is achieved by prohibiting any 
structure, such as overhead luggage racks, from intruding into the 
survival space. By prohibiting overhead luggage racks from impeding 
into the survival space in the rollover, overhead luggage racks will 
have to be better anchored to the bus wall than they had in the past so 
that they do not detach and intrude into the survival space in the 
test. Thus, the proposed luggage rack provision is not needed to ensure 
that a survival space is provided since luggage racks are prohibited 
from intruding on the survival space. Similarly, the proposed seat 
anchorage provision is not necessary to achieve a survival space for 
occupants.
    4. This final rule does not adopt the proposed provision that each 
side window glazing opposite the impacted side of the vehicle must 
remain attached to its mounting structure so as not to allow the 
passage of a 102 mm (5-inch) diameter sphere. The sphere test was 
proposed to ensure that, after the rollover test, the glazing remain 
firmly attached to its mounting. Because the primary purpose of this 
rulemaking is to provide a necessary survival space to occupants in 
rollovers, the purpose is achieved by prohibiting panes of glazing from 
falling into the survival space. The proposed requirement that the 
glazing not form openings is not germane to the survival space 
specification and unnecessarily complicates this rulemaking.
    These changes and others are discussed in this preamble.

c. NTSB Recommendations

    This final rule accords with the following National Transportation 
Safety Board (NTSB) recommendations that NTSB issued to NHTSA to 
improve motorcoach safety.
    In an NTSB Highway Special Investigation Report (1999), Bus 
Crashworthiness Issues,\11\ NTSB cited an October 1971 rollover of a 
1970 Motor Coach Industries (MCI) bus as justification for the 
following recommendations:
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    \11\ National Transportation Safety Board. 1999, Bus 
Crashworthiness Issues. Highway Special Investigation Report NTSB/
SIR-99/04. Washington, DC.
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    ``H-99-50 (MW): In 2 years, issue performance standards for 
motorcoach roof strength that provide maximum survival space for all 
seating positions and that take into account current typical motorcoach 
window dimensions.''
    ``H-99-51: Once performance standards have been developed for 
motorcoach roof strength, require newly manufactured motorcoaches to 
meet those standards.''
    In November 2009, after investigating an August 2008 Sherman, Texas 
bus crash,\12\ the NTSB issued two safety recommendations. In this 
rollover crash, the failure of the overhead luggage rack on the vehicle 
impeded passenger egress and rescue efforts. Thus, NTSB stated that the 
Sherman accident and NHTSA's motorcoach testing indicate that the lack 
of standards for overhead luggage racks on motorcoaches leaves 
passengers at risk of serious injury from interaction with overhead 
luggage racks in a crash and made the following recommendations:
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    \12\ NTSB/HAR-09/02 PB2009-916202; Motorcoach Run-Off-the-Bridge 
and Rollover Sherman, Texas August 8, 2008; October 2009; https://www.ntsb.gov/investigations/AccidentReports/Reports/HAR0902.pdf, 
last accessed 09/08/2021.
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    ``H-09-23: Develop performance standards for newly manufactured 
motorcoaches to require that overhead luggage racks remain anchored 
during an accident sequence.''
    ``H-09-24: Develop performance standards for newly manufactured 
motorcoaches that prevent head and neck injuries from overhead luggage 
racks.''
    This final rule is consistent with the above NTSB recommendations. 
NHTSA is issuing performance standards for motorcoach roof strength 
that provide a survival space for all seating positions and is 
requiring new motorcoaches to meet those requirements. The standard 
established by this final rule requires that overhead luggage racks 
remain anchored during a rollover such that they do not enter the 
requisite survival space and injure passengers in the survival space.

d. Costs and Benefits

    NHTSA has examined the benefits and costs of this final rule to 
ensure that the agency adopts only those amendments that contribute to 
improved safety and that are consistent with the directives of MAP-21 
and the principles for regulatory decision-making set forth in 
Executive Order 12866, Regulatory Planning and Review. Over the 15-year 
period between 2004 and 2018, on average 22 fatalities occurred 
annually to occupants of these buses. Though a relatively small 
percentage of overall traffic fatalities, data show that rollover 
crashes are particularly deadly for large buses. Among the 122 fatal 
crashes, 56 were rollover crashes resulting in 189 fatalities. This 
final rule enhances passenger protection in rollover crashes in a 
reasonable and achievable way. As discussed in the next section, NHTSA 
adopts this final rule because a rollover structural integrity standard 
meets the requirements and considerations in

[[Page 74273]]

subsections (a) and (b) of section 30111 of the Safety Act. This rule 
provides safety to passengers in a reasonable, objective, and cost-
effective manner while harmonizing the standard internationally.
    NHTSA has determined this rulemaking to be cost beneficial.\13\
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    \13\ NHTSA has developed a Final Regulatory Evaluation (FRE) 
that discusses issues relating to the potential costs, benefits and 
other impacts of this regulatory action. The FRE is available in the 
docket for this final rule and may be obtained by downloading it or 
by contacting Docket Management at the address or telephone number 
provided at the beginning of this document.
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    The agency estimates the annual cost of this final rule to be 
between $4.81 million and $11.84 million (see Table 1 below). The 
countermeasures may include stronger roof structure, support pillars, 
side walls, shock resistant latches for emergency exits, and improved 
window mounting, resulting in material costs for each bus covered under 
this final rule ranging from $325 to $591. We estimate the total weight 
increase will range from 181 to 356 kilograms (kg) (399 to 784 pounds 
(lb)) for each of these buses and cost an additional $1,862 to $4,790 
in fuel per vehicle over the lifetime of the vehicle.
    We estimated the benefits of this rule taking into account the 
benefits attributable to the agency's final rules on seat belts and 
electronic stability control (ESC), as those rules also applied to this 
universe of vehicles. We estimate that requiring the subject buses to 
meet the rollover structural integrity performance criteria will save 
approximately 2-3 lives annually. In addition, we expect that the rule 
will reduce the number of seriously injured occupants by 4 annually. 
Thus, we estimate that approximately 3.12 equivalent lives are saved 
annually if 15 percent of occupants use seat belts, and approximately 
2.45 equivalent lives are saved annually (undiscounted) if 90 percent 
of occupants use seat belts (see Table 2 below).
    The cost per equivalent life saved is estimated to be $2.48 million 
to $4.99 million when belt use is estimated to be 15 percent, and $3.17 
million to $6.38 million when belt use is estimated to be 90 percent 
(see Table 3 below). The net cost/benefit impact ranges from a net 
benefit of $13.09 million to $23.31 million if seat belt usage is 15 
percent. If the seat belt usage rate is 90 percent, the estimated net 
cost/benefit impact ranges from a net benefit of $8.25 million to a net 
benefit of $16.97 million (see Table 4 below). While the cost and 
benefits of this rule will vary depending on the material/fuel costs 
per vehicle and on the belt use rate, per all available information 
this final rule will be cost beneficial.

                                         Table 1--Estimated Annual Costs
                                                 [2020 Dollars]
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----------------------------------------------------------------------------------------------------------------
Potential Costs:
    Material Costs per Vehicle..............  $325 to $591.
    Material Costs, Total New Fleet.........  $0.71 million to $1.30 million.
Fuel Costs per Vehicle @ 3%.................  $2,441 to $4,790.
Fuel Costs per Vehicle @ 7%.................  $1,862 to $3,654.
Fuel Costs, Total New Fleet.................  $4.10 million to $10.54 million.
                                             -------------------------------------------------------------------
    Total Annual Cost.......................  $4.81 million to $11.84 million.
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                   Table 2--Estimated Annual Benefits
                  [Undiscounted equivalent lives saved]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
15 percent belt usage................................               3.12
90 percent belt usage................................               2.45
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                 Table 3--Cost per Equivalent Life Saved
        [Across 3% and 7% discount, in millions of 2020 dollars]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
15 percent belt usage................................          2.48-4.99
90 percent belt usage................................          3.17-6.38
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                                      Table 4--Annualized Costs and Benefits
                                          [In millions of 2020 dollars]
----------------------------------------------------------------------------------------------------------------
                                                            Annual costs     Annual benefits      Net Benefits
----------------------------------------------------------------------------------------------------------------
15% belt usage:
    3% Discount Rate...................................         6.08-11.84              29.40        17.56-23.31
    7% Discount Rate...................................          4.81-9.34              22.43        13.09-17.61
90% belt usage:
    3% Discount Rate...................................         6.08-11.84              23.05        11.21-16.97
    7% Discount Rate...................................          4.81-9.34              17.59         8.25-12.78
----------------------------------------------------------------------------------------------------------------

e. NHTSA's Determination of MAP-21 Requirements and Considerations

    Section 32703(b) and (b)(1) of MAP-21 direct NHTSA: (a) To 
establish improved roof and roof support standards for motorcoaches 
that substantially improve the resistance of motorcoach roofs to 
deformation and intrusion to prevent serious occupant injury in 
rollover crashes involving motorcoaches; if (b) NHTSA determines that 
such standards meet the requirements and considerations set forth in 
subsections (a) and (b) of section 30111 of the Safety Act. In 
addition, section 32703(b)(2) directs NHTSA to consider portal 
improvements to prevent partial and

[[Page 74274]]

complete ejection of motorcoach passengers, including children, if such 
standards meet the requirements and considerations set forth in 
subsections (a) and (b) of section 30111 of the Safety Act.
    NHTSA has determined that the standard issued by this final rule 
meets the requirements and considerations of section 30111(a) and (b) 
of the Safety Act.
Section 30111(a)
    The provision at 49 U.S.C. 30111(a) of the Safety Act authorizes 
the Secretary (NHTSA, by delegation) to prescribe Federal motor vehicle 
safety standards that are practicable, meet the need for motor vehicle 
safety, and are stated in objective terms. ``Motor vehicle safety'' is 
defined in the Safety Act as ``the performance of a motor vehicle or 
motor vehicle equipment in a way that protects the public against 
unreasonable risk of accidents occurring because of the design, 
construction, or performance of a motor vehicle, and against 
unreasonable risk of death or injury in an accident, and includes 
nonoperational safety of a motor vehicle.'' \14\
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    \14\ 49 U.S.C. 30102(a)(8).
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    NHTSA has determined that the standard issued by this final rule 
meets the requirements and considerations of section 30111(a) of the 
Safety Act. The standard is practicable, since it is based on the 2006 
ECE R. 66 complete vehicle rollover test. New buses sold in Europe and 
other countries have been designed to meet the ECE R.66 rollover test 
requirements for over a decade. Further, NHTSA has conducted the 
vehicle rollover test of ECE R.66 in developing the NPRM. The three bus 
rollover tests the agency conducted using the ECE R.66 complete vehicle 
rollover test procedure showed that the test is feasible and practical 
for evaluating how well a bus structure maintains occupant survival 
space in a rollover. The standard is also cost beneficial, and thus is 
economically practicable.
    Standard No. 227 meets the need for safety. Two of the real-world 
rollover crashes examined for this rule involved buses that had 
complete roof separation during the rollovers.\15\ Almost all the 
passengers in those two crashes were ejected due to the loss of the bus 
roofs. This standard will increase the likelihood that bus structures 
maintain their roof structure and provide a residual survival space for 
the vehicle occupants. Studies of bus structures before and after 
implementation of ECE R.66 have concluded those requirements are 
effective in protecting bus occupants in rollover crashes.\16\ A bus 
design in use prior to ECE R.66 experienced complete structural 
collapse of the roof in a rollover crash with one and a half full 360 
degree rolls down a 6-meter embankment. That bus model redesigned to 
meet ECE R.66 requirements was able to maintain adequate survival space 
in a rollover crash with two and a quarter full 360 degree rolls down a 
9-10 meter embankment.\17\
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    \15\ These rollover crashes occurred in Turrell, Arkansas in 
2004 and Mexican Hat, Utah in 2008.
    \16\ Matolcsy, M. (2007), ``The Severity of Bus Rollover 
Accidents,'' Enhanced Safety of Vehicles (ESV) Paper 07-152, 20th 
ESV Conference, Lyon, France. Available at: https://www-esv.nhtsa.dot.gov/Proceedings/20/07-0152-O.pdf, last accessed April 
26, 2021.
    \17\ Matolcsy, M. (2006), ``Rollover accident with ejection of 
occupants.'' Informal working document of GRSG, No. GRSG-91-7. GRSG, 
91st session, Geneva, October 2006.
---------------------------------------------------------------------------

    This final rule meets the need for safety on many fronts. NHTSA's 
Motorcoach Safety Action Plan targeted safety improvements for buses to 
reduce the incidence of fatalities and serious injuries caused by bus 
rollover accidents. The seat belt requirements in FMVSS No. 208 \18\ 
for large buses provided a means for belted bus occupants to remain 
within the survival space in a crash. Buses designed to FMVSS No. 227 
will provide a survival space for bus occupants. Anti-ejection 
requirements adopted for bus window portals \19\ will reduce the 
incidence of partial ejection of belted occupants as well as reduce the 
occurrence of partial or full ejection of unbelted occupants. Further, 
NHTSA has proposed to establish an FMVSS to require advanced glazing 
that is highly resistant to occupant ejection for each motorcoach 
portal, pursuant to section 32703(b)(2) of MAP-21.\20\ This final rule 
adopting FMVSS No. 227 would complement FMVSS No. 217a by improving the 
securement of the advanced glazing in the buses.
---------------------------------------------------------------------------

    \18\ 78 FR 70416, November 25, 2013.
    \19\ 81 FR 27904, May 6, 2016.
    \20\ May 6, 2016 (81 FR 27904), supra.
---------------------------------------------------------------------------

    The available information shows this final rule is cost beneficial. 
NHTSA estimates that requiring the subject buses to meet the 
performance criteria in this final rule will save approximately 2-3 
lives and prevent 4 serious injuries annually. NHTSA estimates the net 
benefits range from $8.3 million to $23.3 million.
    Standard No. 227 is stated in objective terms. The residual 
survival space is well defined, based upon a specified boundary at each 
transverse cross-section of the vehicle, with the cross-sections 
bounded by specified forwardmost and rearmost vehicle landmarks. 
Potential intrusion into the residual survival space may be objectively 
measured using standard test measurement methodologies-such as 
templates representing the outline of the residual survival space and 
high-speed video. The FMVSS No. 227 test procedure matches the full 
vehicle test procedure of ECE R.66. Studies have shown the ECE R.66 
full vehicle rollover test to be a relatively severe loading condition 
replicating real-world bus rollover crashes.\21\
---------------------------------------------------------------------------

    \21\ Matolcsy, M. (2007), ``The Severity of Bus Rollover 
Accidents,'' Enhanced Safety of Vehicles (ESV) Paper 07-152, 20th 
ESV Conference, Lyon, France. Available at: https://www-esv.nhtsa.dot.gov/Proceedings/20/07-0152-O.pdf, last accessed April, 
26 2021.
---------------------------------------------------------------------------

Section 30111(b)
    The provision at 49 U.S.C. 30111(b) specifies that, when 
prescribing such standards, the Secretary must consider all relevant, 
available motor vehicle safety information, consult with the states as 
appropriate, consider whether a standard is reasonable, practicable, 
and appropriate for the types of motor vehicles or motor vehicle 
equipment for which it is prescribed, and consider the extent to which 
the standard will carry out the statutory purpose of section 30101 of 
the Act. Section 30101 states that the purpose of the statute is to 
reduce traffic accidents and deaths and injuries resulting from traffic 
accidents, and that it is therefore necessary to prescribe FMVSS, and 
to carry out needed safety research and development.
    NHTSA has issued this final rule in accordance with section 
30111(b). As discussed throughout this document, the agency concludes, 
after comprehensive reviews of relevant available safety information 
that includes over 15 years of crash data and development of a NHTSA 
plan for motorcoach safety,\22\ that adopting FMVSS No. 227 meets the 
requirements and considerations of the Safety Act. NHTSA has provided 
the public with opportunities to review and provide input on the 
agency's safety plan and comment on adoption of this structural 
integrity final rule when it was in proposed form. This final rule 
accords with National Transportation Safety Board Recommendations H-99-
50, H-99-51, H-09-23, and H-09-24, and NHTSA expects wide public 
support overall for this final rule. NHTSA has determined that FMVSS 
No. 227 is reasonable and appropriate for the

[[Page 74275]]

vehicles to which the standard applies for improving bus occupant 
protection in rollover crashes and that establishing FMVSS No. 227 
meets the purpose and policy of the Safety Act.
---------------------------------------------------------------------------

    \22\ NHTSA's Approach to Motorcoach Safety (2007), (Docket No. 
NHTSA-2007-28793-001), supra.
---------------------------------------------------------------------------

f. Retrofitting

    NHTSA has decided not to require existing large buses to meet the 
requirements adopted today for new buses. None of the commenters 
supported a retrofitting requirement. Based on its tests of older 
buses, the agency believes that many existing buses may need major 
structural changes to the vehicle's sidewall and roof structure to meet 
the requirements adopted in this document. Such structural changes are 
likely to be cost-prohibitive, making retrofitting impracticable.

II. Introduction

    Over the 15-year period between 2004 and 2018, data from NHTSA's 
Fatality Analysis Reporting System (FARS) indicate there were 122 fatal 
crashes involving large buses. These crashes resulted in 326 occupant 
fatalities (274 passenger and 52 driver fatalities). During this 
period, on average 22 fatalities occurred annually to occupants of 
these buses.
    Data indicate that rollover crashes are a particular safety problem 
for these buses. Among the 122 fatal crashes, 56 were rollover crashes 
resulting in 189 fatalities. While fatal rollover crashes constitute 
about 43 percent of all fatal crashes involving these bus types, they 
represent about 58 percent of all the occupant fatalities. Further, 56 
percent of the rollover crash fatalities were attributable to occupant 
ejections (106 ejection fatalities out of the total of 189 fatalities 
in bus rollover crashes).
    Congress was especially concerned about motorcoach rollover crashes 
in passing provisions of MAP-21 relevant to this final rule. MAP-21 
requires DOT to ``establish improved roof and roof support standards 
for motorcoaches that substantially improve the resistance of 
motorcoach roofs to deformation and intrusion to prevent serious 
occupant injury in rollover crashes involving motorcoaches'' if such 
standards meet the requirements and considerations set forth in 
subsections (a) and (b) of section 30111 of title 49, United States 
Code.\23\ Under MAP-21, ``motorcoach'' means an OTRB, but does not 
include a bus used in public transportation provided by, or on behalf 
of, a public transportation agency, or a school bus. MAP-21 \24\ also 
directs DOT to consider ``portal improvements to prevent partial and 
complete ejection of motorcoach passengers, including children.''
---------------------------------------------------------------------------

    \23\ MAP-21, section 32703(b)-(b)(1).
    \24\ Id., section 32703(b)(2).
---------------------------------------------------------------------------

    In accordance with MAP-21 and the Safety Act, we have issued this 
rollover-specific rule to apply to buses associated with an 
unreasonable risk of fatal rollover involvement. Thus, this final rule 
applies to OTRBs, and to all non-OTRBs with a GVWR greater than 11,793 
kg (26,000 lb) (large buses), with some exceptions. The final rule 
excludes school buses, prison buses, non-OTRB transit buses, and buses 
with perimeter seating.\25\ We have applied this rule to meet the 
requirements and considerations of MAP-21 and the Safety Act.
---------------------------------------------------------------------------

    \25\ Under the standard, a bus with perimeter seating is a bus 
with 7 or fewer designated seating positions rearward of the 
driver's seating position that are forward-facing or can convert to 
forward-facing without the use of tools.
---------------------------------------------------------------------------

    NHTSA is enhancing the safety of large buses in rollovers both by 
providing a survival space in the occupant compartment, and by reducing 
the likelihood of emergency exits opening during bus rollovers and 
becoming ejection portals. NHTSA achieved an important first step 
enhancing the safety of the buses in rollovers by the November 25, 2013 
final rule that requires lap/shoulder belts for all passengers in large 
capacity buses.\26\ This final rule builds on the rollover protection 
provided by seat belts by ensuring the buses provide a protective 
survival space for belted and unbelted retained occupants in rollovers. 
The 2013 seat belt rule significantly increased the ability of 
occupants of large buses to be retained in the bus structure in 
rollover crashes. This final rule provides the retained occupants a 
survival space in the bus structure, and strengthens the bus structure 
and emergency exit portals to protect unbelted occupants as well.
---------------------------------------------------------------------------

    \26\ NHTSA estimates that seat belts are 77 percent effective in 
preventing fatalities in rollover crashes.
---------------------------------------------------------------------------

III. NHTSA's Statutory Authority

    NHTSA is issuing this final rule pursuant to and in accordance with 
its authority under the National Traffic and Motor Vehicle Safety Act 
and the relevant provisions of MAP-21.

a. National Traffic and Motor Vehicle Safety Act (Safety Act)

    Under 49 United States Code (U.S.C.) Chapter 301, Motor Vehicle 
Safety (49 U.S.C. 30101 et seq. ), 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 (section 30111(a)). ``Motor vehicle safety'' is defined 
in the Safety Act (section 30102(a)(8)) as ``the performance of a motor 
vehicle or motor vehicle equipment in a way that protects the public 
against unreasonable risk of accidents occurring because of the design, 
construction, or performance of a motor vehicle, and against 
unreasonable risk of death or injury in an accident, and includes 
nonoperational safety of a motor vehicle.'' ``Motor vehicle safety 
standard'' means a minimum standard for motor vehicle or motor vehicle 
equipment performance (section 30102(a)(9)). When prescribing such 
standards, the Secretary must consider all relevant available motor 
vehicle safety information (section 30111(b)(1)). The Secretary must 
also consider whether a proposed standard is reasonable, practicable, 
and appropriate for the particular type of motor vehicle or motor 
vehicle equipment for which it is prescribed (section 30111(b)(3)) and 
the extent to which the standard will further the statutory purpose of 
reducing traffic accidents and associated deaths and injuries (section 
30111(b)(4)). The responsibility for promulgation of FMVSSs is 
delegated to NHTSA (49 CFR 1.95).

b. MAP-21 (Incorporating the Motorcoach Enhanced Safety Act of 2012)

    NHTSA is issuing this final rule in accordance with MAP-21, which 
incorporates the ``Motorcoach Enhanced Safety Act of 2012'' into 
Subtitle G.\27\ Section 32703(b) of MAP-21 requires the Secretary 
(NHTSA by delegation) to prescribe regulations that would address 
certain aspects of motorcoach crash performance within two years if the 
agency determines that the standards would meet the requirements and 
considerations of section 30111(a) and (b) of the National Traffic and 
Motor Vehicle Safety Act.\28\
---------------------------------------------------------------------------

    \27\ Moving Ahead for Progress in the 21st Century Act, Public 
Law 112-141 (Jul. 6, 2012).
    \28\ Id. at section 32703(b).
---------------------------------------------------------------------------

    There are two subsections of section 32703(b) that are particularly 
relevant to this final rule. Subsection (b)(1) specifies that the 
Secretary is to establish improved roof and roof support standards that 
``substantially improve the resistance of motorcoach roofs to 
deformation and intrusion to prevent serious occupant injury in 
rollover crashes involving motorcoaches.'' Subsection (b)(2) directs 
the Secretary to ``consider advanced glazing standards for each 
motorcoach portal and [to] consider other portal

[[Page 74276]]

improvements to prevent partial and complete ejection of motorcoach 
passengers, including children.'' \29\
---------------------------------------------------------------------------

    \29\ While this final rule is mainly aimed at addressing the 
rollover structural integrity of specific large bus types, the 
reduced deformation of the bus structure would ensure that any 
advanced glazing installed on portals would be retained on their 
mounting and reduce the risk of occupant ejection in rollover 
crashes. Further, the requirement that emergency exits should not 
open during the rollover test would also ensure that the exits do 
not become ejection portals. Thus, both subsection (b)(1) and 
subsection (b)(2) are relevant to this rule.
---------------------------------------------------------------------------

    MAP-21 contains other provisions pertaining to this rulemaking. 
Section 32702 states that ``motorcoach'' has the meaning given to the 
term ``over-the-road bus'' in section 3038(a)(3) of the Transportation 
Equity Act for the 21st Century (TEA-21).\30\ Section 3038(a)(3) of 
TEA-21 (see 49 U.S.C. 5310 note) defines ``over-the-road bus'' as ``a 
bus characterized by an elevated passenger deck located over a baggage 
compartment.'' However, section 32702 of MAP-21 excludes transit buses 
and school buses from the ``motorcoach'' definition.\31\
---------------------------------------------------------------------------

    \30\ Moving Ahead for Progress in the 21st Century Act, Public 
Law 112-141, section 32702(6).
    \31\ Id. at section 32702(6)(A)-(B).
---------------------------------------------------------------------------

    MAP-21 further directs the Secretary to apply any regulation 
prescribed in accordance with section 32703(b) to all motorcoaches 
manufactured more than 3 years after the date on which the regulation 
is published.\32\ In addition, the Secretary may assess the 
feasibility, benefits, and costs of applying any requirement 
established under section 32703(b)(2) to ``motorcoaches manufactured 
before the date on which the requirement applies to new motorcoaches'' 
(retrofit).\33\ Finally, MAP-21 also authorizes the Secretary to 
combine the required rulemaking actions as the Secretary deems 
appropriate.\34\
---------------------------------------------------------------------------

    \32\ Id. at section 32703(e)(1).
    \33\ Id. at section 32703(e)(2). ``Retrofit Assessment for 
Existing Motorcoaches.''
    \34\ Id. at section 32706.
---------------------------------------------------------------------------

IV. Safety Need (FARS 2004-2018 Data Analysis)

    This rulemaking is conducted pursuant to the requirements of the 
Safety Act and MAP-21. It investigates whether there are unreasonable 
safety risks associated with rollover crashes in OTRB transportation, 
and if there are such risks, whether those safety risks can be 
reasonably reduced by having at least minimum levels of performance 
specified for rollover structural integrity and portal improvements.
    This rulemaking improves occupant safety in large bus rollover 
crashes. While developing the November 25, 2013 seat belt final rule, 
NHTSA found that most fatalities in OTRB crashes are attributable to 
rollovers. Because more than half of the rollover fatalities are 
attributable to ejections, NHTSA issued a seat belt requirement to 
mitigate those ejections.
    Enhancing the structural integrity of the interior of these buses 
works together with the seat belt rule. More occupants will be able to 
be retained in the bus compartment because of the belts, so it makes 
sense to require a survival space that protects these restrained 
occupants in a rollover. Moreover, regardless of whether occupants are 
belted, data \35\ show that the risk of serious injuries and fatalities 
can be reduced by improving the vehicle structure to protect occupants 
against collapsing roofs and bus components falling or intruding into 
the survival space. Additionally, emergency exits should remain closed 
in a crash, as an open exit forms a portal through which occupants 
could be completely or partially ejected. This final rule adopts 
requirements to meet these objectives.\36\
---------------------------------------------------------------------------

    \35\ Ma[eacute]tolcsy, M (2012), ``Passenger's Ejection in Bus 
Rollover Accident,'' FISITA 2012 World Automotive Congress, paper 
F2012 F02-005. Available at https://unece.org/DAM/trans/doc/2012/wp29grsg/GRSG-103-02e.pdf. Last accessed May 03, 2021.
    \36\ This final rule does not address the issue of glazing 
breaking in a rollover crash that would result in openings through 
which occupants could be completely or partially ejected even if 
emergency exits remain closed. This matter is addressed in the 2016 
NPRM for advanced glazing (81 FR 27904), supra.
---------------------------------------------------------------------------

Updated Data Analysis (FARS Data 2004-2018)
    After the August 6, 2014 NPRM, NHTSA re-analyzed FARS data files 
for the years 2004 to 2018 to assess the impacts of this 
rulemaking.\37\ The bus body types coded in FARS are ``school bus,'' 
``transit bus,'' ``cross country/intercity bus'' to represent OTRBs 
(motorcoaches), ``other bus'' to represent other types of buses, and 
``unknown bus'' to represent buses that could not be categorized into 
the other four bus body type categories. Since 2011, a new bus body 
type, ``van-based buses'' was included. We also examined the FARS body 
type ``Large Van'' for van-based bus crashes for the years 2004-2018 
where the vehicle was used to transport people. The buses can also be 
categorized by their GVWR: GVWR less than or equal to 10,000 lb, GVWR 
greater than 10,000 lb and less than or equal to 26,000 lb, and GVWR 
greater than 26,000 lb. The manner in which a bus was used is coded in 
FARS as ``school bus,'' ``intercity bus,'' ``transit/city bus,'' 
``shuttle bus,'' and ``modified for personal/private use.''
---------------------------------------------------------------------------

    \37\ Later in this preamble we discuss our analysis of updated 
data regarding buses with a GVWR of 10,000-26,000 lb.
---------------------------------------------------------------------------

    To assess the benefits and costs of this rule, the agency selected 
buses of body type ``over-the-road bus (OTRB)'' regardless of GVWR \38\ 
and ``other bus,'' ``unknown bus'' and ``van-based bus'' body types 
with a GVWR greater than 26,000 lb, regardless of the manner in which 
they were used.\39\ NHTSA also included fatal crashes of large vans 
with a GVWR greater than 26,000 lb used for transporting people (used 
as intercity bus, charter/tour bus, commuter bus, and shuttle bus) and 
found none for the 15-year period from 2004 to 2018.
---------------------------------------------------------------------------

    \38\ All OTRBs (cross country/intercity buses) are covered under 
MAP-21.
    \39\ Crashes and fatalities of unknown GVWR buses were 
proportionally distributed amongst the known values.
---------------------------------------------------------------------------

    For the 15-year period from 2004 to 2018, there were a total of 326 
bus occupant fatalities in the bus types covered by of FMVSS No. 227 
(see Table 5). Among these fatalities, 230 were occupants of OTRBs with 
a GVWR greater than 26,000 lb, 15 were occupants of OTRBs with GVWR 
<26,000 lb, and 81 were occupants in buses coded as ``other bus,'' 
``unknown bus,'' and ``van-based bus'' with a GVWR greater than 26,000 
lb. In this 15-year period, fatalities among occupants of OTRBs account 
for 75 percent of the 326 fatalities.

                                    Table 5--Bus Crash Occupant Fatalities in the Bus Types Covered by FMVSS No. 227
                                                                  [FARS data 2004-2018]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Unknown bus
                          Year                              OTRB  GVWR      OTRB  GVWR    Other bus GVWR   GVWR  >26,000  Van-based GVWR       Total
                                                            <26,000 lb      >26,000 lb       >26,000 lb         lb           >26,000 lb
--------------------------------------------------------------------------------------------------------------------------------------------------------
2004....................................................               0              23               4               0  ..............              27
2005....................................................               0              10               3               4  ..............              17

[[Page 74277]]

 
2006....................................................               0               8               2               3  ..............              13
2007....................................................               1              18               8               0  ..............              27
2008....................................................               0              38               2               0  ..............              40
2009....................................................               0               9               1               0  ..............              10
2010....................................................               0              11               1               0  ..............              12
2011....................................................               0              30               0               0  ..............              30
2012....................................................               2              12               1               0               1              16
2013....................................................               9               8               3               1               0              21
2014....................................................               1              18               5               1               0              25
2015....................................................               0              12               3               6               0              21
2016....................................................               1               8              26               0               0              35
2017....................................................               1               5               1               0               0               7
2018....................................................               0              13               5               0               0              18
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................              15             230              65              15               1             326
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The bus occupant fatalities were further classified by the type of 
crash (rollover, front, side, rear). FARS also coded fatal bus events 
``other'' that could not be classified into one of the four crash 
types. The bus occupant fatalities in these ``other'' bus crash types 
were further analyzed and found to result from occupants jumping or 
falling off the bus, bus fire, explosion inside the bus, heavy object 
falling on an occupant, and fatal injuries to an occupant that are not 
crash related. Because these fatalities were not crash related, we did 
not include them in the count of bus crash fatalities.
    In the 15-year period from 2004 to 2018, there were 122 fatal bus 
crashes of bus types covered by FMVSS No. 227, among which 71 involved 
OTRBs with a GVWR greater than 26,000 lb (Table 6). Among the 122 
crashes, 56 were rollover events, 59 were frontal crashes, 7 were side 
crashes, and 0 were rear crashes.

                          Table 6--Fatal Crashes of Bus Types Covered by FMVSS No. 227
                                                [FARS 2004-2018]
----------------------------------------------------------------------------------------------------------------
     Bus body type and GVWR          Rollover         Frontal          Side            Rear            Total
----------------------------------------------------------------------------------------------------------------
OTRB (GVWR <=26,000 lb).........               7               2               0               0               9
OTRB (GVWR >26,000 lb)..........              35              33               3               0              71
Other (GVWR >26,000 lb).........              11              18               3               0              32
Unknown (GVWR >26,000 lb).......               3               5               1               0               9
Van-based (GVWR >26,000 lb).....               0               1               0               0               1
                                 -------------------------------------------------------------------------------
    Total.......................              56              59               7               0             122
----------------------------------------------------------------------------------------------------------------

    The 122 fatal bus crashes (involving bus types covered under FMVSS 
No. 227) resulted in 326 bus occupant fatalities (52 drivers and 274 
passengers), as shown in Table 7. Among these fatalities, 189 persons 
(11 drivers, 178 passengers) died in 56 rollover crashes. In contrast, 
116 persons (40 drivers, 76 passengers) died in 59 frontal crashes. Bus 
rollover crashes accounted for 58 percent of the total bus occupant 
fatalities and 65 percent of the passenger fatalities.
    These data show the devastating nature of bus rollover events, 
where a significant number of fatal or serious injuries can occur in a 
single bus rollover event. Among the 189 fatalities in bus rollover 
events, 149 fatalities (79 percent) were in OTRBs with a GVWR greater 
than 26,000 lb.

         Table 7--Bus Occupant Fatalities in Crashes of Bus Types Covered by FMVSS No. 227 by Bus Body Type, GVWR, Crash Type, and Occupant Type
                                                                  [FARS data 2004-2018]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Rollover              Front               Side                Rear              All types        Total
                                           ----------------------------------------------------------------------------------------------------   Driv
          Bus body type and GVWR                                                                                                                 
                                                                                                                                                  Pass
--------------------------------------------------------------------------------------------------------------------------------------------------------
OTRB (GVWR <=26,000 lb)...................         2        11         1         1         0         0         0         0         3        12        15
OTRB (GVWR >26,000 lb)....................         7       142        25        46         1         9         0         0        33       197       230
Other (GVWR >26,000 lb)...................         1        23        12        23         0         6         0         0        13        52        65
Unknown (GVWR >26,000 lb).................         1         2         2         5         0         5         0         0         3        12        15
Van-based (GVWR >26,000 lb)...............         0         0         0         1         0         0         0         0         0         1         1
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................        11       178        40        76         1        20         0         0        52       274       326
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 74278]]

    NHTSA also examined bus rollover events by the ejection status of 
occupants, among bus types covered by FMVSS No. 227 (see Table 8). 
Among the 178 passenger fatalities in bus rollover events, 98 were to 
occupants ejected or partially ejected from the bus.

   Table 8--Bus Occupant Fatalities in Rollovers in Bus Types Covered by FMVSS No. 227 by Bus Body Type, GVWR,
                                       Occupant Type, and Ejection Status
                                                [FARS 2004-2013]
----------------------------------------------------------------------------------------------------------------
                                                              Driver                         Passenger
             Bus body type and GVWR              ---------------------------------------------------------------
                                                    Not ejected       Ejected       Not ejected       Ejected
----------------------------------------------------------------------------------------------------------------
OTRB (GVWR <=26,000 lb).........................               0               2               4               7
OTRB (GVWR >26,000 lb)..........................               3               4              60              82
Other bus (GVWR >26,000 lb).....................               0               1              16               7
Unknown bus (GVWR >26,000 lb)...................               0               1               0               2
Van-based bus (GVWR >26,000 lb).................               0               0               0               0
                                                 ---------------------------------------------------------------
    Total.......................................               3               8              80              98
----------------------------------------------------------------------------------------------------------------

    These data show that while transportation by OTRBs (and other 
similar large buses) is an overall safe form of transportation, given 
the high occupancy of these vehicles, a significant number of fatal or 
serious injuries can occur in a single crash. This is especially true 
in bus rollover crashes that result in occupant ejections.

V. Summary of the NPRM

    The NPRM underlying this final rule published August 6, 2014 (79 FR 
46090). The agency proposed adoption of a new FMVSS No. 227 to set 
performance requirements that large buses must meet when tested using 
the full vehicle ECE R.66 test.
    In support of the NPRM, the agency researched two existing roof 
crush/rollover standards: FMVSS No. 220, ``School bus rollover 
protection,'' and ECE R.66, ``Uniform Technical Prescriptions 
Concerning the Approval of Large Passenger Vehicles with Regard to the 
Strength of their Superstructure.'' \40\ The agency purchased three 
different bus models for this test program. Two older models were 
selected because they were representative of the range of roof 
characteristics (such as design, material, pillars, shape, etc.) of 
large bus roofs in the U.S. fleet. The vehicles selected were two 12.2 
meters (m) (40 feet) long model year (MY) 1992 MCI model MC-12, and two 
12.2 m (40 feet) long MY 1991 Prevost model (Prevost) LeMirage buses. 
The agency also procured a MY 2000 MCI bus, Model 102-EL3, that was 
13.7 m (45 foot) in length. All five of the buses purchased were tested 
to requirements in either FMVSS No. 220 or ECE R.66. A summary of the 
testing program can be found in the NPRM, supra, in section IV.b (79 FR 
46100-46102).\41\
---------------------------------------------------------------------------

    \40\ ECE R.66 defines ``superstructure'' as ``the load-bearing 
components of the bodywork as defined by the manufacturer, 
containing those coherent parts and elements which contribute to the 
strength and energy absorbing capability of the bodywork, and 
preserve the residual space in the rollover test.'' ``Bodywork'' 
means ``the complete structure of the vehicle in running order, 
including all the structural elements which form the passenger 
compartment, driver's compartment, baggage compartment and spaces 
for the mechanical units and components.'' (Footnote added.)
    \41\ For further information on the four older buses tested, a 
detailed discussion of the tests and results are available in the 
docket entry NHTSA-2007-28793-0019. For further information on the 
newer vehicle tested, see the test report, ``ECE Regulation 66 Based 
Research Test of Motorcoach Roof Strength, 2000 MCI 102-EL3 Series 
Motorcoach, NHTSA No.: MY0800,'' October 1, 2009, Report No.: ECE 
66-MGA-2009-001, which can be found on NHTSA's website. https://www-nrd.nhtsa.dot.gov/database/aspx/searchmedia2.aspx?database=v_=6797&mediatype=r&r_;tstno=6797, 
Report 8. Step-by-step instructions on accessing the research report 
can be found in a memorandum in Docket No. NHTSA-2007-28793-0025.
---------------------------------------------------------------------------

Applicability
    NHTSA proposed FMVSS No. 227 to apply to: (a) All new OTRBs, 
regardless of GVWR; and (b) all new buses other than OTRBs with a GVWR 
greater than 11,793 kg (26,000 lb), including prison buses and double-
decker buses.\42\ NHTSA focused on improving the rollover protection of 
buses with a GVWR greater than 26,000 lb because these were high-
occupancy vehicles with an exceptionally high involvement in fatal 
rollovers. The agency also focused on the buses to which the agency's 
November 25, 2013 final rule on passenger seat belts applied.
---------------------------------------------------------------------------

    \42\ Excepted from the NPRM were all school buses, and non-OTRB 
transit buses and non-OTRBs with perimeter seating.
---------------------------------------------------------------------------

Performance Requirements
    The NPRM proposed performance requirements that the buses must meet 
when subjected to a dynamic rollover test. The proposed test procedure 
replicated a rollover crash in a controlled manner. In the proposed 
test, the bus is placed on a tilting platform that is 800 mm (31.50 
inches) above a smooth and level concrete surface. One side of the 
tilting platform along the length of the vehicle is raised at a steady 
rate of not more than 5 degrees/second until the vehicle becomes 
unstable, rolls off the platform, and impacts the concrete surface 
below with its roof leading edge. The rollover structural integrity 
test is illustrated below in Figure 1.
BILLING CODE 4910-59-P

[[Page 74279]]

[GRAPHIC] [TIFF OMITTED] TR29DE21.001

BILLING CODE 4910-59-C
    NHTSA proposed that the agency could position the bus such that 
either side (right or left) of the vehicle may be tested for 
compliance, at the agency's option. The NPRM proposed that a mass of up 
to 68 kg (150 lb) (ballast) be secured in each designated seating 
position (DSP) equipped with a seat belt.
    The main proposed performance requirements were as follows:
    (1) Intrusion into the survival space by any part of the vehicle 
outside the survival space would be prohibited;
    (2) Each anchorage of all seats and interior overhead luggage racks 
and compartments would be prohibited from completely separating from 
its mounting structure during movement of the tilting platform or from 
impact of the bus on the impact surface; \43\
---------------------------------------------------------------------------

    \43\ One reason for the proposal for overhead luggage racks was 
to further enhance structural integrity. NHTSA thought that, to meet 
the luggage rack retention requirement, a bus would have to limit 
its deformation and ``racking'' in the test. ``Racking'' means the 
tilting of the sides of the bus relative to the bus floor. The 
retention requirement would have applied to luggage racks regardless 
of their position relative to the survival space. If the rack 
separated from its mounting it would be a failure, even if the 
overhead luggage rack did not enter the survival space.
---------------------------------------------------------------------------

    (3) Emergency exits would be required to remain shut during the 
test, and, after the test, be operable in the manner required under 
FMVSS No. 217, ``Bus emergency exits and window retention and 
release''; and,
    (4) Each side window glazing on the non-impacted side and roof of 
the vehicle would be required to remain attached to its mounting such 
that there is no opening that allows the passage of a 102 mm (4 inch) 
diameter sphere when a force of no more than 22 Newtons (N) is applied 
to the sphere at any vector in a direction from the interior to the 
exterior of the vehicle.
    The proposed requirements described in paragraphs (2), (3) and (4) 
are beyond those specified in ECE R.66. The ECE regulation mainly 
assesses the strength of the ``superstructure'' \44\ in preventing 
intrusion into the survival space (ECE R.66 uses the term ``residual 
space'' rather than survival space). The regulation specifies that the 
superstructure of the vehicle shall have sufficient strength such that 
no part of the vehicle that is outside the residual space at the start 
of the test (e.g., pillars, luggage racks) shall intrude into the 
residual space during the test.
---------------------------------------------------------------------------

    \44\ ECE R.66 Revision 1 defines ``superstructure'' as ``the 
load-bearing components of the bodywork as defined by the 
manufacturer, containing those coherent parts and elements which 
contribute to the strength and energy absorbing capability of the 
bodywork, and preserve the residual space in the rollover test.''
---------------------------------------------------------------------------

VI. High Level Summary of the Comments

    NHTSA received 19 comments on the NPRM from commenters that 
included large bus manufacturers producing large buses domestically and 
abroad (Van Hool, TEMSA, Prevost, MCI, Daimler EvoBus, Daimler Trucks/
Thomas Built Buses, IC Bus), small (final-stage) manufacturers 
(Hemphill Brothers (Hemphill), NiteTrain Coach (NiteTrain)), a bus 
industry group (American Bus Association (ABA)), a

[[Page 74280]]

glazing industry group (Enhanced Protective Glass Automotive 
Association (EPGAA)), motorcoach operators (Greyhound, Hemphill, 
NiteTrain \45\), the National Transportation Safety Board (NTSB), a 
research laboratory (Florida A&M University's and Florida State 
University's Crashworthiness and Impact Analysis Laboratory (CIAL)), a 
consumer advocacy group (Advocates for Highway Safety (Advocates)), a 
group of families of passengers involved in six bus crashes, and two 
private citizens.
---------------------------------------------------------------------------

    \45\ Both Hemphill and NiteTrain describe themselves not only as 
manufacturers of ``entertainer buses'' but also providers of 
motorcoach transportation services to the entertainment industry, 
operating the vehicles under contractual arrangements. Hemphill 
states that the majority of the contractual arrangements for 
operating the motorcoaches exceed 30 days, with many contracts 
covering periods of more than one year. Both Hemphill and NiteTrain 
describe ``entertainer buses'' as customized vehicles that include 
kitchens, bathrooms, bedrooms and lounging areas. Passengers are 
members of entertainment groups, including the lead artists, band 
members, road managers, stage hands and others, traveling on the 
road to different performance venues.
---------------------------------------------------------------------------

    There was almost unanimous support for an FMVSS on large bus 
structural integrity, but differing views on what that standard should 
require. European bus manufacturers Van Hool and TEMSA opposed the 
proposed requirements and test procedures that differed from ECE R.66, 
believing that the ECE R.66 test was appropriate for assessing the 
strength of the bus superstructure and that subsystems such as seats, 
overhead racks, emergency exits, and glazing should not be assessed 
under the proposed standard. ABA concurred with this view. Daimler 
Trucks/Thomas Built Buses and IC Bus generally supported the intent and 
requirements of the NPRM but supported incorporating the test procedure 
of FMVSS No. 220, ``School bus rollover protection'' (49 CFR 571.220), 
rather than the test of ECE R.66, for school bus derived buses.
    Hemphill and NiteTrain expressed concern about the test burdens on 
small manufacturers and suggested, as did ABA and Prevost, excluding 
entertainer buses from the standard. MCI and Van Hool suggested 
excluding prison transport buses and double-decker buses, respectively.
    Consumers and consumer groups believed the proposal was not 
stringent enough or sufficiently representative of a high speed 
motorcoach rollover crash involving a bus sliding down an embankment. 
There were concerns expressed about the sphere test not representing 
the force imposed by an unbelted passenger thrown against the bus 
window. EPGAA believed that the proposed requirements should have 
accounted more for the potential use of advanced glazing as an 
ejection-mitigation countermeasure.
    NTSB and CIAL believed the proposed standard should apply to all 
non-OTRBs with a GVWR greater than 4,536 kg (10,000 lb), rather than 
just to non-OTRBs with a GVWR greater than 11,793 kg (26,000 lb). NTSB 
also suggested the proposed performance requirements should apply to 
``moon roofs'' and to side emergency doors.
    No commenter supported a retrofit requirement.

VII. Scope and Purpose of the Rule

    NHTSA proposed in the NPRM that the scope of FMVSS No. 227 would be 
to establish performance requirements for bus rollover structural 
integrity, and that the purpose of the standard would be to reduce 
death and injuries resulting from the structural collapse of the bus 
body structure, the unintended opening of emergency exits, and the 
detachment of window glazing, seats, and overhead luggage racks.
    Van Hool, TEMSA, and the ABA opposed the scope of the proposed 
requirements and test procedures. The commenters believed that the ECE 
R.66 test was appropriate for assessing the strength of the bus 
``superstructure'' but that subsystems such as seats, overhead racks, 
emergency exits, and glazing should not be assessed under FMVSS No. 
227. Those commenters, and Prevost, believed that the ECE R.66 rollover 
test is only designed for, and is capable only of, providing an 
evaluation of the bus superstructure strength.
    ECE R.66 defines ``superstructure'' as ``the load-bearing 
components of the bodywork as defined by the manufacturer, containing 
those coherent parts and elements which contribute to the strength and 
energy absorbing capability of the bodywork, and preserve the residual 
space in the rollover test.'' ECE R.66 requires that the superstructure 
of the bus must have sufficient strength to ensure that, during and 
after the rollover test, no part of the vehicle that is outside the 
survival space at the start of the test intrudes into the survival 
space during the test.
Agency Response
    This final rule adopts the NPRM's proposed prohibition that no part 
of the bus that is outside the survival space shall intrude into the 
survival space, both during movement of the tilting platform or 
resulting from impact of the bus on the impact surface.\46\ However, 
after consideration of the comments, NHTSA has decided not to adopt the 
NPRM's proposal that each anchorage of an interior overhead luggage 
rack or other compartment must not completely separate from its 
mounting structure during movement of the tilting platform or resulting 
from impact of the bus on the impact surface or that seat anchorages 
not become dislodged during the test.
---------------------------------------------------------------------------

    \46\ In response to comments, however, the final rule permits 
detritus and other debris caused by the impact to fall into the 
survival space, such as small glazing pebbles or bolts and screws. 
The objects must not weigh more than 15.0 grams. This issue is 
discussed in detail below.
---------------------------------------------------------------------------

    Under the NPRM, those proposed prohibitions would have applied even 
if the luggage rack does not enter the survival space, or the seat 
anchorages dislodge within the survival space. NHTSA has decided that 
the primary purpose of this rulemaking is to establish a roof strength 
and crush resistance standard that improves the resistance of the bus 
superstructure to deformation and intrusion, i.e. , by providing a 
survival space to occupants in rollovers. The purpose is achieved by 
prohibiting any structure, such as overhead luggage racks, from 
intruding into the survival space. By prohibiting overhead luggage 
racks from impeding into the survival space in the rollover, overhead 
luggage racks will have to be better anchored to the bus wall than they 
had been in the past, so that they do not detach and intrude into the 
survival space in the test. Thus, the proposed luggage rack provision 
is not needed to provide a survival space, since luggage racks are 
prohibited from intruding into the survival space. By being securely 
anchored so that they do not fall into the survival space, luggage 
racks will be less likely to impede egress in an emergency, or fall and 
cause head and neck injuries to occupants.
    NHTSA has decided against adopting the NPRM's proposal that seat 
anchorages must not become dislodged during the test. The agency 
believes the seat anchorage provision is not necessary to achieve a 
survival space for occupants. NHTSA proposed the requirement for the 
retention of seat anchorages because of the agency's test of the MY 
1991 Prevost LeMirage bus.\47\ In the test, anchorages of a seat with a 
restrained mid-size adult male dummy completely separated from its bus 
attachment location, allowing the seat to fall across the bus with the 
restrained dummy attached to the seat. NHTSA believed at the NPRM stage 
that the

[[Page 74281]]

failure of the seat anchorages during the rollover test presented a 
significant safety risk to restrained occupants in bus rollover events 
and reduced the effectiveness of seat belts.
---------------------------------------------------------------------------

    \47\ A summary of the test may be found in the NPRM, supra, in 
section IV.b 79 FR 46100-46102.
---------------------------------------------------------------------------

    However, after considering the comments and other information, 
NHTSA concludes a specific requirement in FMVSS No. 227 for seat 
anchorages to remain completely attached is unnecessary for several 
reasons. First, the seat anchorages in the MY 1991 Prevost LeMirage 
separated from the bus because the seat was bolted to unreinforced 
sheet metal of the bus sidewall. In NHTSA's test of the newer MY 2000 
MCI bus Model 102-EL3, none of the seats anchorages failed--despite the 
fact that certain seats were ballasted with either a 150 lb 
anthropomorphic ballast or with 150 lb steel weights. That is, the 
seats remained attached even while tested under highly demanding 
conditions, with the ballasts attached to the seats. This test of the 
MY 2000 MCI bus demonstrates that bus seat anchorage designs have 
improved since the MY 1991 and 1992 buses NHTSA tested in its test 
program.
    Second, it is likely the connectivity strength of seat anchorage 
designs have improved even more since the design of the MY 2000 bus 
because of the agency's 2013 final rule requiring lap/shoulder belts on 
all large buses. The final rule requires the lap/shoulder belts to be 
integral to the bus seats, and that the belt anchorage, together with 
the seat anchorage to the bus, meet the rigorous strength requirements 
of FMVSS No. 210, ``Seat belt assembly anchorages'' (49 CFR 571.210). 
FMVSS No. 210 requires seat anchorages, attachment hardware, and 
attachment bolts to withstand loads of 13,345 N (3,000 lb) applied 
simultaneously to the lap belt portion and the shoulder belt portion of 
the Type 2 restraint system. The seat anchorages of new large buses 
meeting FMVSS No. 210 will be reinforced over and beyond the design of 
a MY 2000 bus, which reduces the risk even further that the seats will 
detach from the bus structure in a rollover as had been observed in the 
tests of the MY 1991 and 1992 buses. Thus, adding a specific 
requirement in FMVSS No. 227 for the seat anchorages to remain 
completely attached duplicates the seat anchorage retention 
requirements of FMVSS No. 210.
    The agency's bus rollover tests found that glazing panels vacated 
their window mountings during the rollover. In adopting the proposal 
that items outside of the survival space must not enter the survival 
space, this final rule prohibits large panes of glazing falling into 
the survival space from the non-struck side of the bus and injuring 
occupants. Strengthening the structure of the bus and glazing mountings 
to resist the rollover crash forces that act to pop out window glazing 
is an important ``portal improvement'' to prevent partial and complete 
ejection of motorcoach passengers,'' as directed by MAP-21 section 
32703(b)(2). Further, strengthening the frames is critical to rollover 
safety if the subject buses employ advanced glazing that mitigate the 
risk of occupant ejection in rollovers. NHTSA research into advanced 
glazing as a means of mitigating occupant ejection \48\ revealed the 
need for significant improvement in the structural integrity of 
motorcoaches before the benefits of advanced glazing materials could be 
achieved. FMVSS No. 227's survival space requirement will help prevent 
glazing from popping out or otherwise detaching from its window mount 
and will help ensure the safety countermeasures are retained in the 
window frames in a crash.
---------------------------------------------------------------------------

    \48\ Martec Limited, ``Motorcoach Glazing Retention Test 
Development For Occupant Impact During a Rollover,'' August 2006; 
Docket No. NHTSA-2002-11876-0015. Among other things, this research 
found that advanced glazing, such as laminate glazing, could pop out 
of its mounting due to torsional deformation of the structure around 
the window.
---------------------------------------------------------------------------

    This final rule adopts the requirement for emergency exits to 
remain closed. This requirement is beyond ECE R.66 but is needed to 
address concerns relevant to the U.S. NHTSA's bus rollover tests found 
that emergency exit windows and roof hatches opened during the 
rollover. NHTSA considers open emergency exits potential safety 
hazards, as open emergency exits create unsafe ejection portals during 
a rollover crash. Approximately two-thirds of the fatalities in bus 
rollover crashes in this country involve occupants ejected from the 
bus. Reducing the likelihood of ejections through these portals by 
upgrading latches and hinges will reduce the fatality risk in rollovers 
and conform to the mandate of MAP-21 section 32703(b)(2).
    ABA states that NHTSA placed too much emphasis on preventing 
unbelted passenger ejection rather than on ensuring the integrity of 
the body structure. It also states that the FMVSS No. 227 requirements 
that are not in ECE R.66 replicate the benefits already achieved 
through the bus seat belt rule.
    NHTSA does not agree that FMVSS No. 227 overemphasizes unbelted 
passengers. Passengers using seat belts, and those that do not, will 
benefit from the standard by being protected from collapsing bus 
structures or contact with loose heavy objects. The requirements of 
FMVSS No. 227 supplement, and do not replicate, the agency's final rule 
on passenger seat belts. With belted passengers more likely to be 
retained in the bus interior because of the belts, FMVSS No. 227 
improves the protective attributes of the occupant compartment in which 
they are retained. FMVSS No. 227 will benefit unbelted occupants by 
helping retain glazing in window frames and providing at least a 
minimum level of protection against dangerous structural collapse into 
the occupant compartment. The requirement that emergency exits remain 
closed during the rollover test increases the likelihood that emergency 
exits do not become ejection portals during rollover crashes, including 
crashes involving more than a quarter turn. These requirements will 
benefit belted and unbelted occupants, as keeping side window exits 
closed protects against partial ejection of belted occupants and 
partial and complete ejections of unbelted occupants, including 
children.

VIII. Applicability of the Rule

    NHTSA proposed to apply FMVSS No. 227 to high-occupancy vehicles 
with an unreasonably high involvement in fatal rollovers, and on which 
Congress focused in MAP-21.\49\ NHTSA proposed to apply FMVSS No. 227 
to buses to which the agency's November 25, 2013 final rule on 
passenger seat belts applied.\50\ NHTSA's view in the NPRM was that 
FMVSS No. 227 should apply to those buses with seat belts, so that a 
survival space could be provided to the belted occupants.\51\
---------------------------------------------------------------------------

    \49\ MAP-21 Subtitle G, the ``Motorcoach Enhanced Safety Act of 
2012,'' defined ``motorcoach'' as having the meaning given the term 
``over-the-road bus'' in section 3038(a)(3) of TEA-21 (49 U.S.C. 
5310 note) but did not include a transit bus or a school bus. Under 
MAP-21, an over-the-road bus is a bus characterized by an elevated 
passenger deck located over a baggage compartment.
    \50\ NHTSA's seat belt rule applied to all new over-the-road 
buses regardless of GVWR, including transit buses, prison buses, and 
perimeter-seating buses). The rule also applied to non-OTRBs that 
have a GVWR greater than 11,793 kg (26,000 lb), except for non-OTRB 
transit buses, prison buses, and perimeter-seating buses. The seat 
belt rule did not apply to school buses.
    \51\ The proposed rollover structural integrity requirements 
applied to all new over-the-road buses regardless of GVWR (except 
for school buses). The rule also applied to all new non-OTRBs with a 
GVWR greater than 11,793 kg (26,000 lb), except for school buses, 
transit buses, and perimeter-seating buses.
---------------------------------------------------------------------------

    The agency received a number of comments relating to the proposed 
applicability of FMVSS No. 227. Two commenters requested us to include 
medium-size buses (buses with a GVWR between 4,536-11,793 kg (10,000-
26,000 lb), two suggested excluding

[[Page 74282]]

entertainer buses, one suggested excluding prison transport buses and 
another suggested excluding double-decker buses.

a. Medium-Size Buses (Buses With a GVWR of 4,536 to 11,793 kg (10,000-
26,000 lb))

    In the NPRM, NHTSA proposed not applying FMVSS No. 227 to medium-
size buses. NHTSA based the decision on an analysis of crash data for 
medium-size buses. The agency examined 2000-2009 FARS data showing 42 
occupant fatalities in buses with a GVWR between 4,536-11,793 kg 
(10,000-26,000 lb), of which 24 fatalities were a result of 13 rollover 
crashes. Over the ten-year period between 2000-2009, medium-size buses 
were associated with an average of 1.3 rollover crashes per year and 
2.4 fatalities per year. In contrast, there was an average of 3.2 
rollover crashes annually among large buses (OTRBs and non-OTRBs with a 
GVWR greater than 11,793 kg (26,000 lb)). These large bus rollover 
crashes resulted in an average of 11.4 fatalities per year. Among all 
fatalities occurring in rollover crashes in buses coded in FARS as 
``cross-country,'' ``other,'' and ``unknown'' with a GVWR greater than 
4,536 kg (10,000 lb), 83 percent were in buses with a GVWR greater than 
11,793 kg (26,000 lb).
    Two commenters (NTSB, CIAL) disagreed with the agency and commented 
that NHTSA should include medium-sized buses in the applicability of 
FMVSS No. 227.\52\
---------------------------------------------------------------------------

    \52\ While CIAL focused on paratransit medium-size buses, it 
requests applying FMVSS No. 227 to all medium-size buses. Further, 
as its comment does show that paratransit buses have a different 
safety concern compared other medium-size buses, we are responding 
to the comment about the whole weight class rather than specifically 
regarding paratransit buses only.
---------------------------------------------------------------------------

NTSB Comment
    NTSB commented that medium-size buses are often used in a similar 
fashion as motorcoaches with GVWRs over 11,793 kg (26,000 lb). It 
disagreed with the data analysis in the NPRM showing that medium-size 
buses do not have the same crash involvement as OTRBs and non-OTRBs 
with a GVWR over 11,793 kg (26,000 lb). NTSB stated that FARS has 
coding issues that may result in undercounting fatalities for the 
medium-size bus type. It references several crashes that it believes 
were not counted in the FARS database and suggest that the University 
of Michigan's Buses Involved in Fatal Accidents (BIFA) database has a 
more accurate classification of crashes.
Agency Response
    NTSB correctly pointed out that we had not included the data that 
NTSB discussed in its comment. We have updated our FARS data analysis 
on medium-size buses to include these data. Even with the adjustment, 
however, our analyses find that medium-size buses do not pose a 
sufficient safety need to warrant application of FMVSS No. 227 to the 
buses.
    After NTSB commented, NHTSA carefully reexamined and updated FARS 
data to determine whether the agency under-counted the medium-size bus 
fatalities. We specifically used FARS data from 2004 to 2018 to 
ascertain the fatalities attributable to medium-size buses.
    FARS has five relevant categories for medium-size buses that are 
non-OTRBs: ``other bus,'' ``unknown bus,'' ``van-based bus,'' ``school 
bus,'' and ``transit bus.'' Due to the intended scope of this 
rulemaking, NHTSA focused on only the first three categories.
    To assure the dataset was complete, NHTSA also reexamined the FARS 
body types to check to make sure all medium-size buses were included in 
the analysis. There had been a change in FARS body codes in 2010. Prior 
to 2010, van-based buses with GVWRs less than or equal to 10,000 lb 
were coded as body type code 21, ``large van.'' In 2010, body code 55 
was added to the FARS coding manual (van-based bus with a GVWR greater 
than 4,536 kg (10,000 lb)). With that change, NHTSA considered whether, 
for the FARS data files before 2010, it was possible that some van-
based buses with a GVWR greater than 4,536 kg (10,000 lb) were 
classified under body code 21. Consequently, NHTSA searched for crashes 
involving body code 21 with a GVWR greater than 10,000 lb and with a 
bus use codes of ``intercity,'' ``charter/tour,'' ``transit/commuter,'' 
``shuttle'' \53\ to see if there were any other rollover crashes 
involving types of vehicles that could be considered ``medium-size 
buses.'' We identified three rollover crashes, as shown in Table 9 
below.
---------------------------------------------------------------------------

    \53\ FARS has bus use categories of not a bus, school, 
intercity, charter/tour, transit/commuter, shuttle, modified for 
personal/private use, not reported, and unknown. Among these bus use 
categories, the large vans that were used as charter/tour, 
intercity, commuter, and shuttle were relevant to this rulemaking. 
Therefore, only the large vans with these bus use codes were 
included.
---------------------------------------------------------------------------

    Table 9 below shows the number of medium-size bus crashes with a 
fatality, over a fifteen-year period.

  Table 9--Fatal Bus Occupant Crashes of Medium-Size Buses (GVWR 10,000 lb to 26,000 lb) That are Non-OTRBs, by
                                        the Body Type and the Crash Mode
                                                [FARS 2004-2018]
----------------------------------------------------------------------------------------------------------------
            Body type                Rollover         Frontal          Side            Rear            Total
----------------------------------------------------------------------------------------------------------------
Other bus.......................               7               8               3               1              19
Unknown bus.....................               3               2               0               0               5
Van-based bus...................               9              20               8               2              39
Large van (used as intercity,                  3               6               5               2              16
 tour, commuter, or shuttle
 buses).........................
                                 -------------------------------------------------------------------------------
    Total.......................              22              36              16               5              79
----------------------------------------------------------------------------------------------------------------

    The data show that there were 79 fatal medium-size bus crashes 
between 2004 and 2018, of which 22 of the 79 crashes were rollover 
crashes. For the purposes of determining the safety need of applying 
FMVSS No. 227 to medium-size buses, NHTSA will focus only on rollover 
crashes, as the harm the standard is intended to address, and the 
countermeasures that will be installed pursuant to that harm, only 
result from rollovers.
    Table 10, below, shows the total number of medium-size bus 
fatalities attributable to various crash types.

[[Page 74283]]



                                  Table 10--Fatalities in Medium-Size Buses by Body Type, Crash Mode, and Occupant Type
                                                                    [FARS 2004-2018]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Rollover              Front               Side                Rear              All types
                 Body type                 ----------------------------------------------------------------------------------------------------   Total
                                              Driv      Pass      Driv      Pass      Driv      Pass      Driv      Pass      Driv      Pass
--------------------------------------------------------------------------------------------------------------------------------------------------------
Other bus.................................         1        18         5         7         1         2         0         1         7        28        35
Unknown bus...............................         0         6         1         1         0         0         0         0         1         7         8
Van-based bus.............................         4         7        12        28         1         8         1         1        18        44        66
Large van (used as intercity, tour,                1         8         3         7         0         7         1         2         5        24        29
 commuter, or shuttle buses)..............
                                           -------------------------------------------------------------------------------------------------------------
    Total (above).........................         6        39        21        43         2        17         2         4        31       103       134
--------------------------------------------------------------------------------------------------------------------------------------------------------

    For the three relevant medium-size bus types and the large vans 
used as buses, there were 45 total fatalities (6 driver fatalities and 
39 passenger fatalities) in rollover crashes for the fifteen-year 
period. Over the 15-year period 2004-2018, there were an average of 1.5 
fatal medium-size bus rollover crashes, with an average of 3.0 bus 
occupant fatalities per year.These values are small compared to those 
of large buses. According to data from FARS 2004-2018, there was an 
average of 3.7 fatal rollover crashes involving large buses (GVWR 
greater than 11,793 kg (26,000 lb)) (including OTRBs), resulting in an 
average of 11.7 occupant fatalities per year. There are significantly 
higher average rates of annual fatal crashes and fatalities for large 
buses compared to medium-size buses.
    While the average rates of annual fatal crashes and fatalities for 
large buses are significantly higher than those of medium-size buses, 
the fleet size of large buses is significantly smaller than that of 
medium-size buses. There are an estimated 2,200 large buses (GVWR 
greater than 11,793 kg (26,000 lb)) (including OTRBs) produced 
annually, compared to approximately 15,000 buses with a GVWR between 
4,536-11,793 kg (10,000-26,000 lb) produced annually.\54\ Table 11, 
below, summarizes these figures.
---------------------------------------------------------------------------

    \54\ Evaluation of the Market for Small-to-Medium-Sized Cutaway 
Buses, Federal Transit Administration Project#: M1-26-7208.07.1, 
December 2007, available at https://www.transit.dot.gov/sites/fta.dot.gov/files/docs/AnEvaluationofMarketforSmalltoMediumSizedCutawayBuses.pdf, last 
accessed November 04, 2016.
---------------------------------------------------------------------------

    These data mean that there is a considerable disparity between the 
fatal rollover crash involvement for large buses versus medium-size 
buses. Not only are large buses involved in more than twice as many 
rollover crashes on average annually, they also have about four times 
the number of occupant fatalities annually in rollover crashes than 
medium-size buses. Further, taking into consideration the almost seven-
fold difference in annual production between large buses and medium-
size buses (the annual production of large buses is about 1/7th of the 
annual production of medium-size buses), the safety need for FMVSS No. 
227 is substantially higher for large buses than for medium-size buses.

 Table 11--Summary Statistics for Fatal Rollover Crashes and Occupant Fatalities for Large Buses (Including all
                                          OTRBs) and Medium-Size Buses
                                           [From 2004 to 2018 (FARS)]
----------------------------------------------------------------------------------------------------------------
                                                                    Avg. annual     Avg. annual
                            Bus size                                 rollover        rollover       Avg. annual
                                                                      crashes       fatalities      fleet sales
----------------------------------------------------------------------------------------------------------------
Large Bus (greater than 26,000 lb GVWR) and all OTRBs...........             3.7            11.7           2,200
Medium-Size Bus (GVWR of 10,000-26,000 lb)......................             1.5             3.0          15,000
----------------------------------------------------------------------------------------------------------------

    With regard to the question whether there is a safety need to apply 
FMVSS No. 227 to medium-size buses, NHTSA's answer is no, the data do 
not show such a need at this time. The difference between the fatal 
rollover crash involvement between large and medium-size buses may be 
attributable to medium-size bus designs (e.g. , medium-size buses may 
have a lower center of gravity compared to heavy buses, affecting crash 
involvement and/or severity, or have better vehicle controllability for 
a variety of reasons), or may reflect a difference in how the buses are 
used. Regardless, the data dissuade NHTSA from applying FMVSS No. 227 
in a one-size-fits-all manner to all buses. NHTSA concludes there is 
not a substantial safety need to apply the standard to medium-size 
buses.
    NHTSA does not concur with NTSB's view that the BIFA database 
provides more relevant statistics than NHTSA's database. The BIFA 
database only includes data up to 2010, and so more recent crash data 
are not available. Since 2010, NHTSA has improved the accuracy of its 
crash data collection on buses and has expanded the bus category to 
include van-based buses. NHTSA's updated analysis using the FARS data 
files more accurately includes the mid-size bus crash information.
    NTSB stated that the statistics from BIFA indicate that 128 medium-
size buses were involved in fatal crashes, resulting in 58 occupant 
fatalities between 2000-2009. This information does not show whether 
these crashes were rollover crashes (the crashes relevant to this 
rulemaking), or whether the 58 occupants were killed in rollovers. 
Despite the lack of specific data about the nature and severity of the 
crashes, NHTSA undertook an analysis assuming that all the crashes NTSB 
referenced were rollover crashes, and that all 58 fatalities were 
attributable to rollovers. NHTSA found that, even with this assumption, 
the data still show a large disparity between the rollover crashes 
associated with large buses versus medium-size buses. Even if all 58 
fatalities were attributable to rollover crashes, such crashes would 
contribute

[[Page 74284]]

to, on average, 5.8 deaths annually (58 fatalities/10 years). In this 
hypothetical scenario, large buses would still be associated with 1.3 
times the number of fatalities compared to medium-size buses each 
year--while the annual production of large buses would continue to be 
around 1/7th of the annual production of medium-size buses. Thus, even 
when factoring in the crash data suggested by NTSB and making 
assumptions about the data that likely includes more crashes and 
fatalities than actually occurred in medium-size buses, the data again 
show an absence of a safety need for applying FMVSS No. 227 to medium-
size buses.
    For the reasons above and in the NPRM, NHTSA declines to extend 
FMVSS No. 227 to medium-size buses.
CIAL Comment
    CIAL argued that the proposed standard should apply to medium-size 
paratransit buses because buses meeting the proposed standard would be 
safer for passengers. It indicated it has been researching medium-size 
paratransit buses designed to meet FMVSS No. 220 \55\ and found that 
buses meeting FMVSS No. 220 fail a dynamic rollover test based ``on the 
concept of survival space.'' The commenter stated that six buses it 
tested showed a failure mode ``in which a weak frontal structure 
allowed for excessive deformation to occur in the front portion of the 
bus body.''
---------------------------------------------------------------------------

    \55\ The requirements in FMVSS No. 220 apply to school buses. 
The test in FMVSS No. 220 places a uniformly distributed vertical 
force pushing directly downward on the top of the bus with a platen.
---------------------------------------------------------------------------

Agency Response
    NHTSA declines to make the suggested change. CIAL's comment did not 
provide a basis to conclude there is a safety need to adopt the FMVSS 
No. 227 test for medium-size buses. (See response, above, to NTSB on 
this issue.) CIAL states that its evaluation using finite element 
models of medium-size paratransit buses shows that paratransit buses 
meeting FMVSS No. 220 failed to meet a ``survival space'' criterion of 
a Florida state vehicle standard. While CIAL's comparison of the 
performance of paratransit buses under the requirements in FMVSS No. 
220 and ECE R.66 was based on simulations, NHTSA conducted the physical 
tests specified in the two standards on the same large bus models. 
NHTSA's rollover testing of motorcoaches indicated that large buses 
that did not meet the ECE R.66 survival space requirement also failed 
the FMVSS No. 220 requirements.
    Additionally, as noted earlier, over the 15-year period 2004-2018, 
there were an average of 1.5 fatal medium-size bus rollover crashes, 
with an average of 3 bus occupant fatalities per year. These data apply 
to all medium-size buses and therefore, the average annual number of 
rollover crashes and fatalities associated with medium-size paratransit 
buses would be extremely small. The fact that the vehicles did not meet 
the survival space criterion is not commensurate with a need to apply 
FMVSS No. 227 to the vehicle type at the FMVSS level. We decline to 
make the requested change, for the reasons provided above and in the 
NPRM.

b. Large Buses

Entertainer Buses
    NHTSA proposed to apply FMVSS No. 227 to all OTRBs as they were 
defined in MAP-21. In doing so, NHTSA intended to cover all the buses 
Congress directed the agency to address in MAP-21, regardless of GVWR.
Comments Received
    Hemphill and NiteTrain, manufacturers and operators of over-the-
road entertainer buses, expressed concern about the test burdens on 
small final-stage manufacturers of these vehicles, and suggested 
excluding entertainer buses from the standard. Prevost, a manufacturer 
of both complete motorcoaches and incomplete vehicles (``shells''), 
also commented in favor of excluding entertainer buses. According to 
Hemphill and NiteTrain, their entertainer buses are built from 
incomplete bus shells purchased from Prevost. The shells consist of the 
window exits, roof exits, sidewall, and roof structure.
    NiteTrain and Hemphill stated that since they do not alter the 
safety structure of their purchased motorcoach shells, any compliance 
with the new standard should be the responsibility of the shell 
manufacturer. ABA commented that NHTSA should consider entertainer 
buses a distinct type of motor vehicle and decide ``on a case-by-case 
basis, the extent to which each element of the motorcoach safety 
requirements should be made applicable.''
Agency Response
    NHTSA has decided not to apply FMVSS No. 227 to over-the-road 
perimeter-seating buses. The agency's decision to scale back the scope 
of FMVSS No. 227 is based on an analysis of safety need, and not on a 
finding that small manufacturers cannot certify compliance with the 
standard. There are ways small manufacturers may certify to FMVSS No. 
227 that would not impose undue burdens on the manufacturers. For a 
discussion of those options, see the August 6, 2014 NPRM preceding this 
final rule (79 FR 46116-46117), and the Regulatory Flexibility Act 
analysis below in this final rule.
    Instead, NHTSA has reassessed the need to apply FMVSS No. 227 to 
OTRBs with perimeter seating after considering that non-OTRBs with 
perimeter seating are excluded from the standard. NHTSA does not find a 
reason to distinguish between OTRB with perimeter seating and non-OTRB 
with perimeter seating, when the safety data indicate no relevant 
differences between the vehicles based on safety need. OTRB with 
perimeter seating do not present a greater risk of injury due to the 
failure of the structural integrity of the buses compared to non-OTRBs 
with perimeter seating.
    Section 32703(a) of MAP-21 mandated NHTSA to prescribe a seat belt 
rule for lap/shoulder belts for motorcoaches (i.e. , which MAP-21 
basically defined as over-the-road buses, except transit buses and 
school buses) and did not provide NHTSA discretion in applying the 
requirement. Thus, the 2013 seat belt rule issued pursuant to section 
32703(a) applied uniformly to all over-the-road buses. NHTSA also 
applied the rule to non-OTRBs, but had discretion to draw distinctions 
among buses in that bus category, as appropriate. NHTSA drew on that 
discretion to design a rule that excluded non-OTRBs with perimeter 
seating from the belt requirement, based on an absence of a safety need 
for the belts.
    NHTSA drafted the FMVSS No. 227 NPRM preceding this final rule to 
apply the proposed structural integrity requirements to the buses that 
were subject to the lap/shoulder belt requirements adopted by the 2013 
MAP-21 final rule. The agency believed that there was a need to ensure 
enhanced structural integrity of the interior of buses subject to the 
seat belt rule, to better protect the restrained occupants who, due to 
the belts, will be retained in the bus interior.\56\ The NPRM excluded 
from proposed FMVSS No. 227 perimeter seating buses, but not if they 
were OTRBs.\57\
---------------------------------------------------------------------------

    \56\ 79 FR 46096, col. 1.
    \57\ The proposed definition of ``perimeter-seating bus'' is ``a 
bus with 7 or fewer designated seating positions rearward of the 
driver's seating position that are forward-facing or can convert to 
forward-facing without the use of tools and is not an over-the-road 
bus.'' (S3.) NHTSA excluded perimeter-seating buses that were not 
over-the-road buses from the seat belt rule because perimeter-
seating buses are often used in shuttle operations.

---------------------------------------------------------------------------

[[Page 74285]]

    However, after considering the comments, NHTSA has decided not to 
apply FMVSS No. 227 to perimeter-seating buses as a class. In the seat 
belt final rule, NHTSA applied the belt requirement to OTRBs with 
perimeter seating, and not to non-OTRB with perimeter seating, because 
of a statutory mandate to require the seat belts in all OTRBs. There is 
no such mandate about the applicability of FMVSS No. 227. NHTSA has 
discretion under MAP-21 (section 32703(b)) to determine whether a 
rollover structural integrity standard and an anti-ejection portal 
improvement standard meet the requirements and considerations of 
section 30111(a) and (b) of the Safety Act.\58\ After considering 
section 30111(a) and (b), NHTSA has decided it would not be appropriate 
to distinguish between perimeter-seating buses depending only on 
whether they are OTRBs or not.
---------------------------------------------------------------------------

    \58\ NHTSA is authorized under the Vehicle Safety Act to issue 
motor vehicle safety standards that ``shall be practicable, meet the 
need for motor vehicle safety, and be stated in objective terms'' 
(49 U.S.C. 30111(a)). When prescribing a motor vehicle safety 
standard, NHTSA considers, inter alia, relevant available motor 
vehicle safety information, whether a standard is reasonable, 
practicable, and appropriate for the particular type of motor 
vehicle or motor vehicle equipment for which it is prescribed, and 
the extent to which the standard will carry out the purpose and 
policy of the Act, i.e. , reduce traffic accidents and deaths and 
injuries resulting from traffic accidents (49 U.S.C. 30111(b)).
---------------------------------------------------------------------------

    NHTSA developed its motorcoach safety plan to protect the public 
against unreasonable risk of death or injury in high-occupancy 
vehicles.\59\ In the Executive Summary in NHTSA's 2013 seat belt final 
rule, NHTSA stated: ``One of the guiding principles NHTSA considers in 
determining the priorities of our rulemaking projects is to protect the 
public against unreasonable risk of death or injury in high-occupancy 
vehicles. In 2007, NHTSA published a comprehensive plan to research 
improvements to bus safety, entitled, `NHTSA's Approach to Motorcoach 
Safety.' '' [Footnote omitted.] In contrast, perimeter-seating OTRBs 
are low-occupancy vehicles compared to conventional inter-city buses 
that have primarily forward-facing seating. NHTSA has decided to 
exclude both OTRBs with perimeter-seating and non-OTRBs with perimeter-
seating from this final rule, based on an absence of a safety need to 
include the buses. It is reasonable not to distinguish between the two 
kinds of perimeter-seating buses in applying the standard to the 
vehicles because of an absence of reasons to distinguish. This final 
rule treats both kinds of buses with perimeter seating (OTRB and non-
OTRB) the same under FMVSS No. 227.
---------------------------------------------------------------------------

    \59\ 78 FR 70416, November 25, 2013. The preamble also makes 
repeated reference to ``high-occupancy'' buses in its analyses of 
crash data involving the subject buses.
---------------------------------------------------------------------------

    It should be noted that Hemphill and NiteTrain indicate that they 
obtain a bus ``shell'' from an incomplete vehicle manufacturer, such as 
Prevost.\60\ Prevost manufactures both complete motorcoaches and 
incomplete vehicles (``shells''). The agency believes that, following 
establishment of this FMVSS No. 227, Prevost will offer for sale in the 
U.S. incomplete vehicle shells that meet the structural integrity 
requirements of ECE R.66 (the standard on which FMVSS No. 227 is 
based), because most of their final-stage manufacturer customers will 
produce buses that are subject to FMVSS No. 227. For customers that 
produce buses that are excluded from FMVSS No. 227, for liability and 
competitive marketing reasons, it would make little commercial sense to 
offer shells that do not meet ECE R. 66 to customers, or for customers 
to buy such shells. Thus, even if perimeter-seating buses are excluded 
from FMVSS No. 227, manufacturers will likely produce buses using these 
ECE R.66 shells, which will result in vehicles that provide 
significantly improved structural integrity in a rollover crash. When 
the bus superstructure is strengthened to meet FMVSS No. 227 there will 
be less deformation of the bus structure and reduced torsional loads on 
interior structures, such as partitions, and reduced risk of intrusion 
into the occupant space. This means that perimeter-seating buses, even 
though excluded from the standard, will provide enhanced structural 
integrity in a rollover. Hemphill commented that partitions will ``add 
support to the roof of our coaches and significantly increase the 
roof's integrity'' and will ``significantly reduce any intrusion into 
the survival space'' in a rollover. While the commenter did not provide 
data or evidence to support its claim, NHTSA concurs that minor 
modifications to the vehicle structure, such as by installation of 
partitions, will not degrade the integrity of the superstructure of the 
bus, and that even these perimeter-seating buses will provide 
protection against roof collapse in a rollover.
---------------------------------------------------------------------------

    \60\ Incomplete vehicle manufacturers such as Prevost are large 
manufacturers.
---------------------------------------------------------------------------

Prison Transport Buses
    The NPRM proposed to apply FMVSS No. 227 to prison transport buses 
(78 FR 70416). MCI, a manufacturer of prison transport buses, disagreed 
with this proposal. MCI expressed concern about the need to partition 
these buses to provide cells, believing that each customer's unique 
cell configuration could affect the test results of the standard. MCI 
states it would not be practicable to fulfill a one-of-a-kind bus order 
by building a second bus for testing to meet MCI's certification 
responsibilities.
Agency Response
    NHTSA agrees to exclude prison buses from FMVSS No. 227 but not for 
the reason given by MCI. Due to the nature of the vehicle type, prison 
vehicle interior configurations/partitions may vary considerably. 
However, NHTSA does not require the kind of certification burden MCI 
describes. A manufacturer does not have to build a replicate vehicle to 
test to enable the manufacturer to certify compliance with the 
standard. A discussion of various certification methods available to 
manufacturers can be found in the August 6, 2014 NPRM preceding this 
final rule (79 FR 46116-46117), and in the Regulatory Flexibility Act 
analysis below in this final rule.
    NHTSA is excluding prison buses because the FMVSS No. 227 is not 
appropriate for the bus type. The agency does not know how many prison 
buses are manufactured each year, but does not believe there is a 
substantial number of such vehicles produced. Regardless of the number 
of vehicles produced, bus superstructures sold in the U.S. are likely 
to be strengthened to meet FMVSS No. 227 after this final rule becomes 
effective. With the strengthened superstructures, there will be less 
deformation of the bus structure and reduced torsional loads on 
interior structures, such as partitions. Thus, the agency has not found 
justification to apply FMVSS No. 227 to prison buses, as minor 
modifications to the vehicle structure, such as by installation of 
partitions, are unlikely to affect the structural integrity of the 
vehicles.
Double-Decker Buses
    The NPRM proposed to apply FMVSS No. 227 to double-decker buses. 
Buses with open-roof sections would not have the open section assessed 
for compliance but the closed-roof sections would be. Double-decker 
buses with closed-roof sections on the lower and top levels would have 
both levels assessed for compliance. Since we saw no difference in the 
potential safety risks of double-decker buses and other large buses 
covered under our proposal, we proposed applying FMVSS No. 227 to the 
bus type.

[[Page 74286]]

Comments Received
    NTSB and Coach USA (a large motorcoach operator) supported applying 
FMVSS No. 227 to double-decker buses. NTSB stated it would be 
appropriate to test the portions of the bus where bus structure could 
intrude on the vehicle occupants. Coach USA supported applying the same 
requirements to lower/enclosed sections of open-top double-decker 
buses, and stated that its double-decker buses already comply with the 
ECE R.66 test. In contrast, Van Hool stated that in Europe ECE R.66 can 
be applied to double-deckers only at the request of the manufacturer 
and referenced a document to argue that the number of fatalities that 
are attributable to double-decker buses is lower than those 
attributable to other buses.
Agency Response
    This final rule applies FMVSS No. 227 to double-decker buses as 
proposed. Double-decker buses are being used for intercity/interstate 
transport of large numbers of passengers.\61\
---------------------------------------------------------------------------

    \61\ See e.g., Megabus website, http://us.megabus.com/, last 
accessed October 24, 2016.
---------------------------------------------------------------------------

    We do not concur with Van Hool that there should not be a safety 
concern with double-decker buses. The document that Van Hool referenced 
to support its view consists only of meeting notes from a UN ECE 
informal working group meeting on ECE R.66.\62\ The meeting notes 
stated that a representative from Spain presented information about bus 
crashes, but the notes did not include statistics about double-decker 
buses. Further, the notes included a point made by a person from the 
International Road and Transport Union expressing concern that the 
increased mass of the superstructure of a double-decker bus above the 
vehicle's center of gravity might suggest that the double-decker bus 
should be subject to the ECE R.66 requirements. We do not see any 
information in the meeting notes that suggested that the safety risk is 
lower for these types of buses.
---------------------------------------------------------------------------

    \62\ https://www.unece.org/fileadmin/DAM/trans/doc/2008/wp29grsg/GRSG-95-07e.pdf (last accessed Feb-23-2017).
---------------------------------------------------------------------------

    Further, we believe that the design characteristics and physics of 
double-decker buses suggest that double-decker buses are at least as 
susceptible to the rollover crash risk as the other buses covered under 
this final rule. Double-decker buses can have GVWRs fifteen to twenty 
percent greater than single-deck OTRBs.\63\ A Swedish study \64\ on 
occupant fatalities in bus crashes concluded that--
---------------------------------------------------------------------------

    \63\ Van Hool TX Luxury Touring Coach GVWRs are 50,700 lb (40'' 
vehicle length) and 54,000 lb (45'' vehicle length). Van Hool TD925 
double-decker buses are GVWR 62,000 lb (45'' vehicle length). 
Vehicle data from https://www.abc-companies.com/ com/, last accessed 
October 24, 2016.
    \64\ Albertsson, Pontus; Occupant Casualties In Bus And Coach 
Traffic; 2005; ISBN 91-7305-829-7.

    The height of a double-deck vehicle may be 60-80 [centimeters] 
higher than a corresponding single deck vehicle. In case of a 
rollover with a double-deck vehicle, the greater [the] distance from 
the [center] of gravity in the upper compartment[,] the greater 
[the] increase of the rotation velocity. This, in turn, will 
increase the [ground] impact [leading to] greater risk for injuries 
---------------------------------------------------------------------------
as a consequence.

    Thus, the available information does not support Van Hool's 
contention that there is little crash risk associated with double-
decker buses. While the agency seeks to harmonize with ECE regulations 
to the extent possible, we believe applying FMVSS No. 227 to double-
decker buses will meet a safety need in this country. According to 
Coach USA, its double-decker buses already meet the ECE R.66 
requirements, which illustrates the practicability of the buses'' 
meeting FMVSS No. 227.
    This final rule makes a slight clarification in the regulatory text 
of FMVSS No. 227 relating to double-decker buses. The standard would 
not apply to a level of a bus that does not have a permanent roof over 
the level, such as the upper level of a double-decker bus that does not 
have a permanent roof over the upper level. However, a double-decker 
bus that is open-top in the rear half of the bus but permanently 
closed-top for the front half of the bus is subject to the requirements 
of FMVSS No. 227 for the front half of the top of the bus (as well as 
for the entire enclosed lower section of the bus).

IX. School Bus Derivative Buses

    Daimler Trucks North America (DTNA) \65\ and IC Bus, LLC (IC Bus) 
manufacture school and commercial buses and certify the vehicles to 
FMVSS No. 220, ``School bus rollover protection,'' and FMVSS No. 221, 
``School bus body joint strength.'' The commenters suggest that NHTSA 
permit buses meeting FMVSS No. 221 the option of meeting FMVSS No. 220 
rather than FMVSS No. 227. They state that the buses are similar in 
appearance to school buses but are sold for non-school related 
purposes. The commenters contend that the operating environment for 
these buses is closer to that of school buses than intercity buses and 
that the vehicles should be subject to the school bus safety standards 
for rollover protection (FMVSS No. 220) and joint strength (FMVSS No. 
221) rather than FMVSS No. 227.
---------------------------------------------------------------------------

    \65\ DTNA states that it manufactures school buses under the 
Thomas Built Bus brand.
---------------------------------------------------------------------------

Agency Response
    We agree with the commenters and have excluded school bus 
derivative buses from FMVSS No. 227. This is because the buses already 
provide a survival space by meeting FMVSS No. 220, ``School bus 
rollover protection,'' and do not need to meet the requirements of 
FMVSS No. 227.
    FMVSS No. 227 defines ``school bus derivative buses'' in a manner 
reflecting that the buses are built on a school bus platform for sale 
in the U.S. The buses have safety systems that are identical to school 
buses regarding their fuel systems, bus body joint strength, emergency 
exits and roof crush resistance. The vehicles could be certified as 
meeting the FMVSSs for ``school buses'' if they had seating systems 
meeting FMVSS No. 222, ``School bus seating and passenger protection'' 
(49 CFR 571.222), and school bus lights and stop arms meeting FMVSS No. 
108 and No. 131, respectively. NHTSA is excluding the buses to avoid 
redundancy in the FMVSSs. Thus, the definition is designed to exclude 
only vehicles that could be certified to the school bus FMVSSs and not 
other large buses.
    DTNA and IC Bus argue that their school bus derived commercial 
buses operate under conditions more similar to those of school buses 
than OTRBs. The ``applications'' in which the commercial buses are used 
are described by DTNA as ``church activity, retirement community, 
college campus, boys and girls club, parks and recreation department 
and airport shuttles.'' IC Bus echoes that description and adds 
``support of emergency responders.'' NHTSA agrees that these 
applications describe usage that is more local in nature than that of 
intercity OTRBs. NHTSA recognizes, however, that once purchased, 
operators of the vehicles could use school bus-derivative buses in ways 
other than that described by DTNA and IC Bus, so in analyzing the 
commenters'' suggestion NHTSA must consider the likelihood that the 
buses may not be used like school buses.
    It is a fact that FMVSS No. 220 has a record of rollover safety in 
school buses. The standard has been applied to school buses since 1977. 
School bus derivative buses are already manufactured to meet the school 
bus roof crush resistance

[[Page 74287]]

requirements in FMVSS No. 220. NHTSA believes these buses already have 
improved roofs and roof supports that substantially improve the 
resistance of the roofs to deformation and intrusion compared to buses 
that do not meet FMVSS No. 220.\66\ To avoid redundancy in the FMVSSs, 
this final rule permits these buses the option of meeting FMVSS No. 220 
when tested in accordance with the test procedures of FMVSS No. 220, 
instead of the ECE R.66-based rollover test requirements of FMVSS No. 
227.
---------------------------------------------------------------------------

    \66\ In addition, as DTNA and IC Bus point out, the vehicles 
also meet FMVSS No. 221, which adds to the structural integrity of 
the vehicles. The purpose of FMVSS No. 221 is to reduce deaths and 
injuries resulting from the structural collapse of school bus bodies 
in crashes.
---------------------------------------------------------------------------

    The agency is not permitting buses other than school bus derivative 
buses to meet FMVSS No. 220. Buses other than school bus derivative 
buses have been designed such that they have a higher center of gravity 
and/or utilize larger windows than school buses. These characteristics 
can lead to a higher incidence of occupant ejections during rollovers. 
Thus, the dynamic rollover test in ECE R.66 affords the agency an 
opportunity to set a minimum level of performance for the ejection-
mitigating features of non-school bus derivative buses, such as 
emergency exits closure and side window glazing retention during a 
rollover crash.

X. Performance Requirements

    The NPRM proposed performance requirements that buses must meet 
when subjected to a tilt rollover test. In the proposed test, the bus 
is placed on a tilting platform that is 800 mm (31.50 inches) above a 
smooth and level concrete surface. One side of the tilting platform 
along the length of the vehicle is raised at a steady rate of not more 
than 5 degrees/second until the vehicle becomes unstable, rolls off the 
platform, and impacts the concrete surface below with its roof leading 
edge. The major points of this testing method involve a quarter-turn 
roll of the bus onto its side (so that it strikes the top corner of the 
bus superstructure on a rigid surface) and ballasting the vehicle to 
simulate the load that the bus would be carrying in a rollover crash. 
This test creates a high-severity test condition that encompasses the 
majority of real-world bus rollovers.

a. Severity of the Rollover Test

    EPGAA, Advocates, the families of bus crash victims (the families), 
and Ms. Stoos, express concern that the proposed test evaluation is not 
severe enough to replicate the conditions of real-world bus rollovers. 
The families and Advocates state that the rollover test should include: 
Vehicle rollovers greater than 90 degrees (one quarter roll); high 
vehicle speed prior to rollover; embankments; and impacts that may 
occur after the rollover. Advocates references a 2007 glazing retention 
test development study commissioned by NHTSA and Transport Canada to 
illustrate its point (``Motor Coach Glazing Retention Test Development 
For Occupant Impact During A Rollover,'' Martec Technical Report # TR-
06-16, Rev 4, August 2006 (``Martec study'') \67\ ).
---------------------------------------------------------------------------

    \67\ Docket No. NHTSA-2002-11876-0015.
---------------------------------------------------------------------------

Agency Response
    NHTSA does not agree with the commenters' argument that FMVSS No. 
227's test is not a reasonable representation of a severe rollover 
crash. As discussed below, research papers, test reports, simulation 
analyses, and reports on the efficacy of the ECE R.66 test support the 
implementation of the test.
    FMVSS No. 227's test is highly stringent, accounting for the 
potential real-world rollover crash forces that are imparted on the bus 
superstructure in a rollover crash. The test creates a force near the 
top corner of the bus in the transition from the sidewall to the roof. 
This application of force is representative of a bus rolling over into 
a drainage ditch along a highway; however, in the FMVSS No. 227 test, 
the bus strikes a hard surface that is more rigid than the typical 
earthen drainage ditches along the roadside. The hard surface results 
in the energy from the rollover being absorbed by the bus and not 
shared between the bus and the ground. This hard surface contact makes 
FMVSS No. 227's rollover test more stringent than similar rollovers 
into earthen embankments. Matolcsy, M. (2007), ``The Severity of Bus 
Rollover Accidents,'' 20th International Technical Conference for the 
Enhanced Safety of Vehicles, Paper 989, Lyon, France.\68\ The test also 
gives the agency a repeatable, reproducible, and practical method to 
evaluate bus structural integrity during rollover crashes.
---------------------------------------------------------------------------

    \68\ Available at: https://www-esv.nhtsa.dot.gov/Proceedings/20/07-0152-O.pdf.
---------------------------------------------------------------------------

    It can appear to the eye that crashes involving multiple quarter-
turn rolls along the ground are more severe than a single quarter-turn 
rollover onto rigid pavement that ends instantly, all other things 
being equal. The significant difference is that the multiple quarter-
turn roll loads an entire side, then the roof, then the other side, 
next the wheels/suspension/floor, and so on until the bus comes to a 
rest. The multiple quarter-turn rollover dissipates the crash energy 
across major portions of the vehicle structure over a relatively long 
duration. The vehicle structure in a multiple quarter-turn crash is not 
managing or absorbing all of the crash energy at once. Single quarter-
turn rollovers, in which the crash forces are reacted over a short 
duration by relatively weak localized components of the vehicle 
structure, require the entire vehicle structure to be stronger. 
Therefore, the more stringent rollover test is one in which the energy 
of the crash is applied instantaneously, such that the vehicle needs to 
manage and absorb all the energy applied at the same time.
    The demanding nature of the ECE R.66 test incorporated into FMVSS 
No. 227 is discussed at length in the 2007 report, which evaluated the 
sufficiency of the test for adoption into R.66.\69\ The report's author 
notes that early work on ECE R.66 considered different types of 
rollover scenarios during deliberations to ``find an appropriate 
standard approval rollover test.'' For the issue of conducting a test 
with multiple turns (i.e., the bus rolling more than a quarter-turn), 
the study concluded that the ECE R.66-based test imparts more loads on 
the bus superstructure than other potential tests that included 
multiple turns. This was found even though the tests with multiple 
turns began with a bus raised higher from its final end of test resting 
place--i.e., the other tests began with greater potential energy than 
the ECE R.66-based test.
---------------------------------------------------------------------------

    \69\ Matolcsy, M. (2007), supra.
---------------------------------------------------------------------------

    Figure 3, below, shows the three rollover tests that were analyzed 
during development of ECE R.66.

[[Page 74288]]

[GRAPHIC] [TIFF OMITTED] TR29DE21.002

    The study compared the quarter-turn ECE R.66 test to other tests in 
which the bus traveled a greater distance during the test and rolled 
multiple times. The research conducted a series of tests under three 
test scenarios using the same bus type. In the end, the research showed 
test ``c,'' which is essentially ECE R.66, produced results that 
imparted the greatest loads on the bus superstructure. The test series 
further showed that bus reinforcements to provide survival space in 
test ``b'' needed further reinforcement to provide sufficient survival 
space in test ``c.'' From these data, it was found that, while a test 
could simulate a crash with more total energy (e.g., test conditions 
``a'' and ``b'' under which the bus begins the test with higher 
potential energy), the long dissipation of that energy over multiple 
rolls during the crash significantly reduces the damage imparted to the 
bus superstructure during the test.
---------------------------------------------------------------------------

    \70\ Id.
---------------------------------------------------------------------------

    NTSB and Advocates request that the agency consider a test 
involving more than a quarter-turn rollover. The commenters did not 
elaborate on how many more turns of a vehicle rollover they would like 
the agency to adopt. The agency has no data on the number of quarter-
turns that occur in a bus rollover since the FARS database does not 
capture that crash detail. Nonetheless, the Matolcsy report, supra, 
explains how buses developed to meet the requirements of ECE R.66 have 
maintained survival space when those buses have experienced rollovers 
beyond a quarter-turn and down embankments. This information suggests 
that FMVSS No. 227 will lead to buses capable of providing bus 
passengers with a survival space and lowered risk of ejection during 
rollover crashes greater than a quarter-turn.
    The Matolcsy report provides additional examples of real-world 
improvements manufacturers have made to buses in response to ECE R.66 
requirements, including photographs of how bus interior compartments 
looked post-crash before and after application of ECE R.66 to the 
vehicles. A bus that was not designed to comply with ECE R.66 
experienced structural collapse in a rollover crash with one and a half 
full 360 degree rolls down a 6-meter embankment similar to the one 
depicted above in Figure 3(b). In contrast, a bus designed to meet ECE 
R.66 requirements was able to maintain adequate survival space in a 
rollover crash with two and a quarter full 360 degree rolls down a 9-10 
meter embankment similar to the crash depicted in Figure 3(b) above.
    In its comments, Advocates references a research project on 
motorcoach window glazing in which the research used finite element 
(FE) models to compare the loads on the bus structure in different 
simulation tests where the bus carried different lateral speeds into 
its crash with the impact surface.\71\ The simulation scenarios in the 
research included: (1) No lateral speed with 800 mm drop (replicating 
ECE R.66), (2) 30 kilometers per hour (km/h) lateral speed with 400 mm 
drop, and (3) 30 km/h lateral speed with 800 mm drop.\72\
---------------------------------------------------------------------------

    \71\ See Comment from the Advocates for Highway Safety, Docket 
No. NHTSA-2014-0085-0016, page 5 and 6. The comment references the 
2007 NHTSA report, National Motor Coach Glazing Test Development for 
Occupant Impact during a Rollover. (NHTSA-2002-11876).
    \72\ See Martec Technical Report # TR-06-16; ``Motor Coach 
Glazing Retention Test Development For Occupant Impact During A 
Rollover,'' (Joint NHTSA and Transport Canada Program; Final 
Report); Docket No. NHTSA-2002-11876-0015.
---------------------------------------------------------------------------

    Advocates refers to a statement by the researchers that the ECE 
R.66 test is not the most stringent test condition. NHTSA notes that 
the statement reflected only a preliminary finding of Phase I of the 
study and was later corrected.\73\ The preliminary results in Phase I 
were refined in Phase II of the study. After improving their analysis 
methodology and conducting the simulation again in Phase II, the 
researchers conclude that the ECE R.66 test is the more stringent test 
when compared to tests that incorporated a lateral speed.\74\ As can be 
seen in the Table 12 data, the ECE R.66 rollover produced higher 
rollover contact forces than rollover simulations with the ECE R.66 
drop height and an initial lateral velocity.
---------------------------------------------------------------------------

    \73\ The authors stated that the models used for the first phase 
were not detailed and were ``only expected to provide rough-order-
of-magnitude roof/ground [contact] forces.''
    \74\ Id.

[[Page 74289]]



                                                     Table 12--Comparison of Roof Impact Forces \75\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Rollover Scenario
                                 -----------------------------------------------------------------------------------------------------------------------
                                             No. 1 (ECE R.66)                         No. 2 (400 mm)                          No 3. (800 mm)
                                 -----------------------------------------------------------------------------------------------------------------------
                                        Phase I             Current             Phase I             Current             Phase I             Current
--------------------------------------------------------------------------------------------------------------------------------------------------------
Contact Surface.................  Roof perimeter....  Window Posts......  Roof Perimeter &    Window posts......  Roof Perimeter....  Window Posts.
                                                                           Window Posts.
Peak contact Force (N)..........  4,065,900.........  2,831,593.........  4,538,964.........  2,468,656.........  3,920,160.........  2,696,370.
Average Impact Force (N)........  1,481,100.........  1,219,995.........  2,271,342.........  891,627...........  1,960,137.........  1,149,529.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    When a bus traveling at highway speeds tips and begins a multiple-
turn roll, the energy in the crash will not be completely transferred 
to the vehicle structure at the first impact. A significant portion of 
the energy will go towards sustaining the rolling motion of the bus. 
Thus, while the vehicle would sustain more impacts during this extended 
rollover crash, the loads on the superstructure would be lower than the 
ECE R.66-based test. Further, even if the bus turned only once at 
highway speed, landed on its side, and slid on the side, the single 
impact at highway speed would load an entire side of the bus structure, 
rather than just a corner of the bus superstructure. This flat-faced, 
wide application of the load dissipates the energy and enables the bus 
to better withstand the load than the more stringent concentrated load 
application of FMVSS No. 227. The friction from the sliding of the bus 
on the surface of the ground also dissipates the kinetic energy of the 
crash over a longer period--further reducing the load on the vehicle 
superstructure In short, FMVSS No. 227 presents a severe real-world 
application of crash loads on the superstructure, and does so in a 
controlled, objective manner appropriate for an FMVSS compliance test.
---------------------------------------------------------------------------

    \75\ Id., table from report, page 14.
---------------------------------------------------------------------------

    Advocates also discuss a crash variation where the bus may hit an 
embankment or other ``vertical surface'' type object. This crash 
variation may or may not increase the total energy to be dissipated 
during the crash, but the load concentration may change. However, even 
with different potential objects loading the structure, we believe that 
the loads to which the superstructure is subjected might be similar in 
some respects to the loading to which the superstructure is exposed 
when tested under FMVSS No. 227. While no embankment or other 
``vertical surface''-type object is a part of the test, the vehicle 
superstructure's loading during the test is akin to the concentrated 
force that is applied when striking a ``vertical surface.'' The test 
involves loading the entirety of the energy in the test onto a 
concentrated section of the structure (i.e. , the corner of the roof). 
Thus, we believe that FMVSS No. 227 reflects an aspect of the 
``vertical surface'' and other crash variations about which Advocates 
is concerned.\76\
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    \76\ NHTSA also notes that, at this time, the petitioner's 
request to incorporate vertical surfaces to mimic a motorcoach 
accident scenario is impractical to meet. To adopt an objective, 
repeatable and meaningful test maneuver that incorporates highway 
speeds and vertical surfaces for the bus to impact, NHTSA should 
have additional information on what speed is representative, how to 
trip the bus to initiate a roll, what vertical surface objects are 
representative, etc. Such information is now unavailable. Further, a 
test incorporating highway speeds and vertical surfaces is currently 
not practical as the test conditions are exceedingly difficult to 
replicate, and pose inordinate safety risks to technicians 
conducting the test.
---------------------------------------------------------------------------

    For the above reasons, NHTSA concludes that the ECE R.66-based test 
adopted in this final rule is an effective high-stringency test. The 
test substantially increases the likelihood that large buses will 
withstand the crash forces in a real-world rollover crash and provide a 
survival space to occupants.\77\ FMVSS No. 227 addresses motorcoach 
crashes that are more than quarter-turn crashes, without having to 
expose the vehicles to the exact same conditions. Given that all 
available information indicate that the FMVSS No. 227 test sufficiently 
replicates a deadly rollover crash, we are adopting the ECE R.66-based 
test in this final rule.
---------------------------------------------------------------------------

    \77\ Advocates also points to an NTSB Preliminary Report on a 
crash of a 1996 Setra Motorcoach operated by AM USA Express, Inc. 
Comparing the image of that bus (post-crash) in the NTSB Preliminary 
Report to a bus that NHTSA tested using ECE R.66 in research. 
Advocates argues that the ECE R.66 test fails to represent real-
world crash conditions. Advocates does not present any information 
regarding the roof structures of these vehicles and whether their 
structures are similar enough to compare the severity of the crash 
conditions. There is insufficient information to make any reasonable 
conclusions comparing the crash severity in these two cases.
---------------------------------------------------------------------------

b. Intrusion Into the Survival Space

    The NPRM proposed to prohibit intrusion into the ``survival 
space,'' demarcated in the vehicle interior from approximately the rear 
wall of the bus to 600 mm (24 inches) in front of the front surface of 
the seat back of the front row seats, by any part of the vehicle 
outside the survival space.
    The purpose of the proposal is to guard against inadequate survival 
provided to occupants, especially belted ones, due to collapsing 
sidewalls, roof structure, or other objects. We intended the 
requirement to complement our standard requiring seat belts for 
passengers on the subject buses, to ensure that passengers retained in 
their seats will have a survival space protecting them from collapsing 
vehicle structure. Our research found structural intrusions into the 
survival space in the tested MY 1991, MY 1992, and MY 2000 buses. The 
NPRM proposed to define the vehicle survival space in a specific manner 
(see S4 of the proposed standard, 79 FR 46119-46120). The NPRM also 
proposed use of ``survival space templates'' in the compliance test.
    Overall, commenters concurred with the survival space concept, 
suggesting small changes to the proposal.
    MCI suggested that the survival space requirements should account 
for variations in vehicle floor heights so that the same height space 
can be provided in each vehicle segment. MCI requested survival space 
be defined relative to the forward and rear floor height of each 
segment of the vehicle.
    NHTSA does not believe there is a need to change the survival space 
definition in response to MCI. The survival space definition already 
accounts for variations in interior compartment floor height front-to-
rear and side-to-side in the vehicle.
    However, the agency does believe it should clarify two ambiguities 
in the survival space definition. First, the ``survival space'' 
definition is clarified by defining ``occupant compartment'' to mean a 
space within the vehicle interior intended for driver and passenger 
use, excluding any space occupied by fixed appliances such as bars, 
kitchenettes, or toilets. Second, the definition of ``survival space'' 
is made clearer with regard to a forward-most seat that is not forward-
facing. The specification of the centerline used to locate the 
reference point for the transverse vertical plane was not entirely 
clear in the NPRM. The ``longitudinal'' centerline should be

[[Page 74290]]

specified for the most forward point on the most forward seat. Further, 
the direction that the most forward seat faces will affect the relative 
positioning of the transverse vertical plane to this seat. This final 
rule therefore modifies the definition of survival space to specify 
that the front boundary of the survival space is a transverse vertical 
plane determined relative to the most forward seat \78\ in the 
passenger deck when the seat is in its forward-most position and its 
seat back is in the manufacturer's nominal design riding position. This 
transverse vertical plane is, (1) for a forward-facing seat, 600 mm in 
front of the most forward point on the longitudinal centerline of the 
front surface of the seat back, (2) for a rearward-facing seat, through 
the most forward point on the longitudinal centerline of the seat back, 
and (3) for a side-facing seat, through the most forward point on the 
seat, including the seat back, seat arm rest, and seat cushion.
---------------------------------------------------------------------------

    \78\ This seat could be a passenger seat, the driver's seat, or 
a temporary (jump) seat.
---------------------------------------------------------------------------

Intrusion of Items Into the Survival Space
    MCI expresses concern that small glass shards falling from a window 
into the survival space may be a failure per the language of S5.1 \79\ 
of the NPRM.
---------------------------------------------------------------------------

    \79\ 79 FR 46120. The NPRM proposed the following regulatory 
text (S5.1): No part of the vehicle which is outside the survival 
space shall intrude into the survival space during the movement of 
the tilting platform or resulting from impact of the vehicle on the 
impact surface.
---------------------------------------------------------------------------

    That was not NHTSA's intent in issuing this rule, but the agency 
agrees the proposed language could be read to produce such an outcome. 
NHTSA's intent in maintaining a survival space was to ``set a minimum 
level of structural integrity for these buses, to help prevent 
dangerous structural intrusions into the occupant survival space.'' 
\80\ The intent of the survival space requirement was to ensure ``that 
the roof and sidewalls will be able to withstand the racking forces of 
a rollover crash.'' \81\ The purpose of retaining the window glazing to 
its mounting structure was to ``ensure that the vehicle's structural 
integrity will prevent heavy glazing panels from falling into the 
passenger compartment and becoming ejection portals.'' \82\ We used 
``massive'' and ``heavy'' to describe the window glazing panels and 
discussed a need to ``[reduce] risk of injury from falling panels of 
glazing and occupant ejections.'' As NHTSA's intent was not to require 
protection from ``small glass shards'' during the bus rollover, this 
final rule has clarified the requirements to reflect this view, as 
discussed below.
---------------------------------------------------------------------------

    \80\ 79 FR 46092, August 6, 2014.
    \81\ Id.
    \82\ Id.
---------------------------------------------------------------------------

    NHTSA is providing in FMVSS No. 227 that objects of a minute size 
may intrude into the survival space. As to the size of the objects, the 
commenters do not provide a suggested definition for ``small glass 
shards.'' NHTSA thus turned to analyzing the Federal glazing standard 
to determine how the standard describes acceptably ``small'' glass 
shards regarding occupant safety. Glazing material used in motor 
vehicles must meet the requirements of FMVSS No. 205, ``Glazing 
materials'' (49 CFR 571.205). FMVSS No. 205 specifies that ``[g]lazing 
materials for use in motor vehicles must conform to ANSI/SAE Z26.1-
1996'' \83\ unless FMVSS No. 205 provides otherwise.
---------------------------------------------------------------------------

    \83\ American National Standard for Safety Glazing Materials for 
Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land 
Highways-Safety Standard (ANSI/SAE Z26.1-1996).
---------------------------------------------------------------------------

    ANSI/SAE Z26.1-1996 allows ``small particles'' to disengage from 
the glazing material during some of the laminated glazing \84\ impact 
tests, though there is no express definition of ``small particles'' in 
ANSI/SAE Z26.1-1996. There is a 227 g (0.5 lb) 9.14 m (30 feet) ball 
drop impact test \85\ in the ANSI standard for laminated glazing. The 
ball drop test allows ``total separation of glass from the reinforcing 
or strengthening material'' that does ``not exceed 1935 square 
millimeters (mm \2\) (3 square inches (in \2\)) on either side.'' 
(During the rollover testing the agency conducted in support of the 
FMVSS No. 227 NPRM, laminated glazing panels did shatter, but no 
discernable amount of the glazing material came free from the 
interlayer material.)
---------------------------------------------------------------------------

    \84\ The requirements for the tempered glazing fracture test in 
the American National Standards Institute (ANSI) standard require 
that ``no individual fragment free from cracks and obtained within 3 
minutes subsequent to test shall weigh more than 4.25 gram (g) (0.15 
ounce (oz)).''
    \85\ ANSI/SAE Z26.1-1996, S5.12
---------------------------------------------------------------------------

    The ANSI/SAE Z26.1-1996 maximum glazing separation size of 1935 mm 
\2\ (3 in \2\) for laminated glazing evaluated using the ANSI ball drop 
test is helpful in indicating ANSI's determination of the maximum size 
of glazing that may enter the survival space without causing injury. 
Glazing pieces 1935 mm \2\ (3 in \2\) or smaller are not massive or 
heavy, and the likelihood that they will cause serious blunt trauma 
injury is significantly lower compared to contact with an entire 84 kg 
(185 lb) glazing panel in a crash.
    However, NHTSA further considered MCI's comment that ``a failure of 
a single fastener (such as a rivet) that is part of the attachment of 
the parcel rack assembly could be deemed a failure of the test.'' The 
agency decided that small items other than glazing pieces (e.g. , a 
bolt) should be allowed to enter the survival space if small glazing 
pieces are allowed. Given that the potential for injury caused by 
pieces entering the survival space is a function of the mass of the 
item, we decided to limit the items allowed to enter the survival space 
by the mass of the item.
    As to what that mass should be, we again turned to ANSI/SAE Z26.1-
1996 and glazing characteristics to start. The ANSI standard permits 
pieces of laminated glazing of 1935 mm\2\ (3 in\2\) to separate (break 
off) in the 227 g (0.5 lb) 9.14 m ball drop impact test. We estimate 
that laminated glazing has a glass thickness of approximately 2.5 mm 
for each glass layer, and a glass density \86\ of about 0.00251 g/mm\3\ 
(1.445 ounce (oz)/in\3\). Thus, a piece of laminated glazing of 1935 
mm\2\ (3 in\2\) has a mass of approximately 12 grams (g) (0.43 oz). 
Factoring in a 3 g (0.11 oz) tolerance, we are prohibiting intrusion 
into the survival space by any part of the vehicle outside the survival 
space other than items with a mass of less than 15.0 grams (0.53 oz). 
Tempered glazing shatters into tiny pebbles that are significantly 
smaller and lighter than pieces of broken laminated glazing. The 
shattered pieces of tempered glazing would weigh significantly less 
than 15.0 grams (0.53 oz).
---------------------------------------------------------------------------

    \86\ Glass density value from https://www.saflex.com/en/AutoReduceVehicleWeight.aspx I couldn't access this 4/20/20.
---------------------------------------------------------------------------

C. Luggage Racks and Seat Anchorages

    As discussed above in this preamble, the NPRM proposed to prohibit 
any anchorage of an interior overhead luggage rack or compartment or 
anchorage of a vehicle seat from completely separating from its 
mounting structure during the movement of the tilting platform or 
resulting from impact of the bus on the impact surface. After reviewing 
the comments, NHTSA has decided not to adopt the proposed requirements.
    Under the NPRM, those proposed prohibitions would have applied even 
if the luggage rack does not enter the survival space, or the seat 
anchorages dislodged within the survival space. NHTSA has decided that 
the primary purpose of this rulemaking is to establish a roof strength 
and crush resistance standard that improves the resistance of roofs to 
deformation and intrusion, i.e., by providing a survival

[[Page 74291]]

space to occupants in rollovers. The purpose is achieved by prohibiting 
any structure, such as overhead luggage racks, from intruding into the 
survival space. By prohibiting overhead luggage racks from impeding 
into the survival space in the rollover, overhead luggage racks will 
have to be better anchored to the bus wall than they had been in the 
past so that they do not detach and intrude into the survival space in 
the test. Thus, the proposed luggage rack provision is not needed to 
provide a survival space, since luggage racks are prohibited from 
intruding into the survival space. By being securely anchored so that 
they do not fall into the survival space, luggage racks will be less 
likely to impede egress in an emergency, or fall and cause head and 
neck injuries to occupants.
    NHTSA has decided against adopting the NPRM's proposal that seat 
anchorages must not become dislodged during the test. The agency 
believes the seat anchorage provision is not necessary to achieve a 
survival space for occupants. NHTSA proposed the requirement for the 
retention of seat anchorages because of the agency's test of the MY 
1991 Prevost LeMirage bus.\87\ In the test, all seats on the opposite 
side of the impact detached from their sidewall mounting. A seat with a 
restrained mid-size adult male dummy completely separated from its 
anchorages and fell across the bus with the restrained dummy attached 
to the seat. NHTSA believed at the NPRM stage that the failure of the 
seat anchorages during the rollover test presented a significant safety 
risk to restrained occupants in bus rollover events and reduced the 
effectiveness of seat belts.
---------------------------------------------------------------------------

    \87\ A summary of the test may be found in the NPRM, supra, in 
section IV.b 79 FR 46100-46102.
---------------------------------------------------------------------------

    However, after considering the comments and other information, 
NHTSA concludes a requirement that the seat anchorages remain 
completely attached is unnecessary. In NHTSA's test of the MY 2000 MCI 
bus Model 102-EL3, all of the seats remained attached to their original 
anchorages. The seats were ballasted with either a 150 lb 
anthropomorphic ballast or with 150 lb steel weights, which is to say 
the seats remained attached even while tested under highly demanding 
conditions. This test of the MY 2000 MCI bus demonstrates that bus seat 
designs have improved since the MY 1991 and 1992 buses NHTSA tested in 
its test program.
    Second, NHTSA believes the seat anchorage designs are likely to 
have improved even more since the design of the MY 2000 bus because of 
the agency's 2013 final rule requiring lap/shoulder belts on all large 
buses. The final rule requires the lap/shoulder belts to be integral to 
the bus seats, and that the belt anchorage, together with the seat 
anchorage, meet the rigorous strength requirements of FMVSS No. 210, 
``Seat belt assembly anchorages'' 49 CFR 571.210. FMVSS No. 210 
requires seat anchorages, attachment hardware, and attachment bolts to 
withstand loads of 13,345 N (3,000 lb) applied simultaneously to the 
lap belt portion and the shoulder belt portion of the Type 2 restraint 
system. Thus, the seat anchorages of new large buses meeting FMVSS No. 
210 will be reinforced over and beyond the design of a MY 2000 bus, 
which reduces the likelihood even further that the seats will detach 
from the bus structure in a rollover as observed in the tests of the MY 
1991 and 1992 buses. Thus, the proposed seat anchorage provision is not 
necessary to achieve a survival space for occupants.

d. Emergency Exits

    The NPRM proposed that emergency exits must remain shut during the 
rollover test. The agency was concerned about emergency exits opening 
during a rollover, as NHTSA had observed this to happen in the tests 
conducted prior to the NPRM. The NPRM also proposed that roof and rear 
door emergency exits must be operable in the manner required under 
FMVSS No. 217, ``Bus emergency exits and window retention and 
release,'' after the test.
Comments Received \88\
---------------------------------------------------------------------------

    \88\ ABA requested an exclusion of entertainer buses from 
requirements in FMVSS No. 217, S5.2, ``Provision of emergency 
exits.'' The request is beyond the scope of the rulemaking and is 
not addressed in this preamble.
---------------------------------------------------------------------------

    EvoBus commented that the proposal that roof exits remain closed is 
unnecessary, as it did not know that any passenger has been ejected 
through the roof exit. TEMSA requested that NHTSA move the requirement 
that side emergency exits remain closed to proposed FMVSS No. 217a. 
NTSB requested that side emergency exit doors also be required to meet 
FMVSS No. 227. Advocates suggested the requirement should apply to all 
side exits.
Agency Response
    In response to EvoBus, NHTSA has observed roof exits opening in the 
FMVSS No. 227 tests conducted in support of the NPRM. Their opening 
posed an ejection safety risk that this final rule now addresses. Crash 
data do not identify the portals through which occupants were ejected, 
so data records'' not indicating ejections through roof exits does not 
mean such ejections did not or will not occur. The final rule adopts a 
simple requirement that will reduce an ejection risk from open portals 
in the chaotic and unpredictable phases of a rollover. The cost of 
improved emergency latches is minor--$10 per coach for a total annual 
new bus fleet cost of $22,000. Congress, in enacting MAP-21, also 
wanted NHTSA to address the ejection risk from portals, and an opening 
in the bus roof caused by an open emergency exit poses an unreasonable 
risk of ejection of a child's head, limb or body, or those of an adult, 
in a rollover. NHTSA does not understand why design changes to the roof 
exits to enable them to meet the FMVSS No. 227 requirements would 
``cause opening failures,'' nor did EvoBus explain its statement.
    NHTSA does not agree with TEMSA that the requirements should be 
moved to FMVSS No. 217 or to the proposed FMVSS No. 217a. Both 217 and 
the proposed 217a do not address the dynamic torsional loads a bus 
structure transmits to the emergency exits during the rollover test in 
the manner FMVSS No. 227 does. Potential actuation of emergency exit 
latches due to inertial loading, assessed by FMVSS No. 227, is not 
assessed under current FMVSS No. 217 or proposed Standard No. 217a.
    NTSB requests that FMVSS No. 227's requirements should also apply 
to side emergency exit doors.\89\ NHTSA agrees, and had proposed that 
``emergency exits [should] remain latched to avoid becoming an ejection 
portal for unrestrained occupants,'' \90\ and that ``all emergency 
exits shall not open during the rollover structural integrity test.'' 
\91\ The final rule adopts the proposal. However, NHTSA has decided not 
to require side emergency doors and emergency windows be operable after 
the crash test. The proposed provision that the exits must be operable 
after the test goes beyond purposes of the rulemaking (to provide a 
safe survival space and to reduce the risk of ejection through 
portals).
---------------------------------------------------------------------------

    \89\ Under FMVSS No. 217, emergency exit ``windows'' and 
emergency exit ``doors'' are considered ``emergency exits,'' whereas 
an emergency exit door is a specialized type of emergency exit. 
I.e., not all emergency exits are emergency exit ``doors.''
    \90\ 79 FR 46109-46110.
    \91\ 79 FR 46110.
---------------------------------------------------------------------------

    Further, there are challenges to requiring exits on the non-struck 
side to open with the bus on its side after the test.\92\ FMVSS No. 217 
specifies force

[[Page 74292]]

requirements needed to open the exit, calculated assuming the bus is 
upright on its wheels. FMVSS No. 217 only tests the subject buses when 
they are upright, so there are no gravity considerations. If the bus 
were tested on its side, the force requirement would have to be 
calculated to a yet-undetermined level to account for the mass of the 
window, the effect of gravity, and the fact that an occupant would be 
pushing on the exit while perched on seats they climbed on. NHTSA does 
not agree with Advocates that NHTSA should conduct an FMVSS No. 217 
test after ``righting'' the bus on its wheels (buses are tested upright 
per FMVSS No. 217). The agency is concerned that righting the bus after 
the severe rollover test of FMVSS No. 227 may not be possible without 
further damaging the structural integrity of the bus. Further, 
conducting the test from inside the vehicle as per the FMVSS No. 217 
test procedure would expose lab technicians to unreasonable safety 
risks.
---------------------------------------------------------------------------

    \92\ This issue was discussed in the NPRM (79 FR 46110).
---------------------------------------------------------------------------

XI. Glazing Issues

a. Side Glazing on the Non-Struck Side of the Bus

    The NPRM proposed that each side window glazing on the non-struck 
side of the vehicle would have to remain attached to its mounting such 
that there is no opening that will allow the passage of a 102 mm (4 
inch) diameter sphere when a force of no more than 22 N is applied.
    This final rule does not adopt this provision. The sphere test was 
proposed to ensure that, after the rollover test, the glazing remain 
securely attached to its mounting. Because the primary purpose of this 
rulemaking is to provide a necessary survival space to occupants in 
rollovers, the purpose is achieved by prohibiting harmful panes of 
glazing from intruding into the survival space. The proposed 
requirement that the glazing remain securely attached to its mounting 
is redundant to the survival space specification and unnecessarily 
complicates this rulemaking.\93\
---------------------------------------------------------------------------

    \93\ Some commenters objecting to the sphere test misunderstood 
the purpose of the test. The test was not intended to simulate an 
unbelted passenger's impact onto bus window glazing during a bus 
rollover. The sphere test was intended simply to measure whether the 
bus structure retained the glazing panels in the window frame when 
subjected to a rollover. In the final rule, this would be assessed 
by the prohibition that no large object enter the survival space. 
While retention of the glazing in its mounting could reduce occupant 
ejection, whether the glazing forms an opening through which an 
ejection could occur in a rollover crash, is the subject of NHTSA's 
proposed FMVSS No. 217a and will be addressed in the context of that 
rulemaking. 81 FR 27904, May 6, 2016, supra.
---------------------------------------------------------------------------

b. Type of Glazing

    EPGAA, Greyhound and Advocates requested that the agency require 
advanced glazing material in bus windows, while Prevost, Van Hool, and 
EvoBus suggest that tempered glass should be permitted. Prevost 
expresses that ``there is a small possibility that some glazing could 
shatter when submitted to the proposed testing.'' Prevost and EvoBus 
request an exclusion of tempered glazing from the rule, or that 
shattered glazing not be considered a failure of the FMVSS No. 227 
requirements.
Agency Response
    The agency is not distinguishing among glazing types in FMVSS No. 
227 or providing exclusions of tempered glazing. The standard is 
generally performance-oriented and technology neutral, requiring window 
glazing and surrounding window frame structures on the non-struck sides 
of the bus to be manufactured so as not to unsafely intrude into the 
survival space in the rollover test. As discussed above, this final 
rule accommodates intrusion of small pebbles of tempered glass into the 
survival space. This final rule makes allowances for minute objects 
weighing less than 15.0 grams to enter the survival space, in 
recognition that it may be difficult, and unnecessary, to keep more 
miniscule pieces of glazing and other items from entering the survival 
space in the FMVSS No. 227 rollover event.
    The requirement in FMVSS No. 227 preventing bus components from 
intruding into the survival space is critical to rollover safety if the 
subject buses employ advanced glazing that mitigate the risk of 
occupant ejection in rollovers. NHTSA's research \94\ found that 
advanced glazing, such as laminated glazing, could pop out of its 
mounting due to torsional deformation of the structure around the 
window. FMVSS No. 227's survival space requirement would improve the 
structural integrity around window frames and prevent glazing from 
popping out or otherwise detaching from its window mount in a rollover.
---------------------------------------------------------------------------

    \94\ Martec Limited, ``Motorcoach Glazing Retention Test 
Development For Occupant Impact During a Rollover,'' August 2006; 
Docket No. NHTSA-2002-11876-0015.
---------------------------------------------------------------------------

c. Moon Roofs

    NTSB requested NHTSA consider including ``moon roofs'' in the 
glazing retention requirements of FMVSS No. 227. We agree with NTSB 
that ``moon roofs'' should be subject to the requirements of FMVSS No. 
227, as there is a risk of passenger ejection through glass roofs 
during a bus rollover. Rather than use the term ``moon roofs'' however, 
hereinafter we use the term ``roof panel/windows'' since the latter 
term is more descriptive and inclusive of the components we seek to 
address.
    Ejections through the roof occur in real-world crashes. From 2000-
2009, two-thirds of the rollover fatalities in the subject buses were 
ejected occupants.\95\ Two of the crashes (Turrell, Arkansas in 2004 
and Mexican Hat, Utah in 2008) discussed in the NPRM involved roof 
separation from the bus. Almost all the passengers in those two crashes 
were ejected due to the loss of the bus roofs. In such crash events, 
unrestrained passengers can still be ejected if a bus that meets the 
survival space requirements fails to keep roof panels/windows closed or 
intact. We believe that manufacturers can use the same countermeasures 
to retain roof panels/windows to the glazing frames that they use to 
keep side window glazing attached to the side window frames.
---------------------------------------------------------------------------

    \95\ 79 FR 46098; August 6, 2014.
---------------------------------------------------------------------------

    MAP-21 \96\ defines a portal as ``any opening on the front, side, 
rear, or roof of a motorcoach that could, in the event of a crash 
involving the motorcoach, permit the partial or complete ejection of 
any occupant from the motorcoach, including a young child.'' Roof 
panels/windows are portals per the MAP-21 definition. Any bus opening 
containing glazing material is a portal that can become an opening 
through which bus occupants may be partially or completely ejected if 
the glazing detaches from its mounting. The final rule's including roof 
panels/windows in FMVSS No. 227 accords with MAP-21. We will evaluate 
roof panels/windows like we do side windows. I.e., no portion of a roof 
panel/window may enter the survival space, except for objects weighing 
less than 15.0 grams, and they must remain closed.
---------------------------------------------------------------------------

    \96\ See Sec. 32072, supra.
---------------------------------------------------------------------------

d. Struck-Side Window Evaluations

    Several commenters (Advocates, Greyhound, NTSB, the families, and 
Ms. Stoos) request that the agency evaluate windows on the struck side 
as well as the non-struck side of the bus.
    Under FMVSS No. 227, the agency can roll either side of the bus. 
Thus, manufacturers must ensure that vehicles can resist the torsional 
loads imparted into the structure on either side of the bus. To the 
extent the commenters suggest the sphere test should be conducted on 
the struck-side windows

[[Page 74293]]

when the bus is resting on the ground, as discussed above the agency is 
not adopting the sphere test, or any test involving lab technicians 
entering the rolled vehicle to assess compliance with a requirement.

XII. Test Procedure Issues

a. Ballasting the Vehicle

    To simulate a real-world rollover incorporating foreseeable 
conditions that are challenging to the vehicle, NHTSA proposed to 
subject the vehicle to the forces resulting from the mass of restrained 
occupants. To achieve this, the NPRM proposed (in S6.2.5 of the 
regulatory text) that a mass up to 68 kg (150 lb) (ballast) be secured 
in each designated seating position (DSP) equipped with a seat 
belt.\97\ The ballast would represent the mass of an ``average'' 
occupant, and is the mass NHTSA uses in determining a vehicle's GVWR 
per 49 CFR part 567, ``Certification.'' NHTSA stated that ballasting is 
important because it increases the weight and center of gravity of the 
vehicle, which better simulates the forces on the vehicle structure in 
a rollover when the seats are occupied by belted passengers. Also, when 
occupants are belted into the vehicle, their mass imparts crash forces 
to the seat anchorages during a crash, which NHTSA sought to replicate 
in the test (79 FR 46105-46107).
---------------------------------------------------------------------------

    \97\ All DSPs in the buses are required to have seat belts per 
our November 25, 2013 MAP-21 final rule amending FMVSS No. 208 (78 
FR 70416).
---------------------------------------------------------------------------

    The agency indicated in the NPRM that it did not believe the method 
of ballasting or type of ballast used were of importance, as those 
factors will not significantly alter the forces imposed on the vehicle 
structure or the seat anchorages during compliance testing, so long as 
the ballast is 68 kg (150 lb) at each DSP. NHTSA noted in the NPRM that 
the NPRM differed from ECE R.66 on this issue of ballasting. ECE R.66 
specifies the option of two different methods of securing occupant 
ballast to the passenger seats.\98\ It reduces the load to 34 kg (75 
lb) when a fixed ballast is used (79 FR 46106). Further, it specifies a 
different ballasting method.\99\
---------------------------------------------------------------------------

    \98\ As discussed in the NPRM (79 FR 46107), we tested both 
types of ballasts, anthropomorphic (``water dummies'') ballasts and 
fixed steel ballasts, to determine the feasibility of each and the 
differences between the two. We found that the method of ballasting 
and type of ballast used were not important, as these factors did 
not significantly alter the forces upon the vehicle structure or the 
seat anchorages during the test, so long as the ballast is 68 kg 
(150 lb). Four commercially available ``water dummies,'' each filled 
with 68 kg (150 lb) of sand, were installed in one full row of seats 
(four seating positions) and were secured with ratchet straps that 
were configured to simulate Type 2 seat belts. Steel ballasts, 68 kg 
(150 lb) per seating position, were installed in a second full row 
of seats (four seats). In this row, steel plates were placed on top 
of each seat cushion and were secured with bolts that passed through 
the cushion and attached to a bar which clamped onto the seat frame. 
The overall center of gravity of the bus, and consequently, the 
energy absorbed in the test, was only slightly higher (less than 3 
percent) when the water dummies were used compared to when the fixed 
weights were used. The differences in forces and moments generated 
at the anchorages due to the ballasts were also small.
    \99\ In addition to specifying a different weight for fixed 
steel plate ballasts, ECE R.66 requires the ballasts be fixed to the 
seat such that its center of gravity aligns with that of the 
anthropomorphic ballast (i.e. , approximately 100 mm forward and 100 
mm above the seating reference point). However, NHTSA simply 
proposed to fix the steel ballasts to the seat because in the 
agency's research NHTSA found it difficult to position and fix the 
rigid weights per the ECE specification. We investigated whether 
affixing the rigid weights as specified by ECE R.66 is necessary and 
stated in the NPRM that it was not. The different center of gravity 
heights between the anthropomorphic ballasts and the fixed weight 
ballasts did not appear to affect the overall performance of the 
vehicle in the rollover test. 79 FR 46107.
---------------------------------------------------------------------------

Comments Received
    Several bus manufacturers commented on the proposal, all requesting 
that we adopt the ballasting approach of ECE R.66 (i.e. , the 
anthropomorphic ballast at 68 kg (150 lb) and the fixed steel plate 
ballast at 34 kg (75 lb)).\100\ All the commenters essentially argue 
that passengers in a bus, restrained by the seat belts, will not 
transfer their entire load onto the seat anchorages and bus structure 
in the same way as fixed ballasts. Therefore, commenters argue, when 
using the fixed steel plate ballasts, the ballast weight should be 34 
kg (75 lb) (i.e. , 50 percent of the weight for anthropomorphic 
ballasts).
---------------------------------------------------------------------------

    \100\ Greyhound Lines, Inc., an operator, suggested that NHTSA 
should ballast the overhead luggage racks during rollover testing. 
Ballasting of luggage rack and the lower luggage compartment of a 
motorcoach was not proposed in the August 6, 2014 NPRM and therefore 
the public was not provided a full opportunity to comment on this 
issue. ECE R.66 does not require ballasting of the luggage rack, and 
NHTSA does not see a safety need for a requirement to ballast the 
luggage racks.
---------------------------------------------------------------------------

    In support of their view that a 50 percent weight is appropriate 
for fixed ballasts, the commenters argue that ECE R.66 considers a 75-
lb weight for fixed steel ballasts equivalent to the 150-lb 
anthropomorphic ballast secured with the seat belt. Van Hool cites an 
ECE Ad Hoc Expert Group document that puts the load transferred by 
belted occupants to the vehicle structure as between 0 and 100 percent 
of the standard passenger mass of 68 kg (150 lb).\101\ Prevost and 
Daimler both cite an ECE analysis finding that 50 percent of the 
restrained occupant's weight transfers to the bus structure during a 
crash.\102\
---------------------------------------------------------------------------

    \101\ See Report about the Ad-Hoc Expert Group (AHEG) meeting 
dealing with the development of Regulation 66 (Frankfurt, 22-23, 
November, 2001), available at https://www.unece.org/fileadmin/DAM/trans/doc/2002/wp29grsg/TRANS-WP29-GRSG-82-inf02.doc (last accessed 
February 8, 2017).
    \102\ Study about the Incidence of the Use of Safety Belts with 
regard to Regulation 66 of Geneva, presented by Spain at the 81th 
Working Party on General Safety Provisions (GRSG), October, 2001, 
https://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29wgs/wp29grsg/grsginf/81/grsg81_inf09.doc (last accessed February 8, 
2017).
---------------------------------------------------------------------------

Agency Response
    NHTSA is adopting the provision to use the 68 kg (150 lb) ballast 
in NHTSA's compliance test. NHTSA does not concur that a 75-lb (50 
percent lighter weight) fixed ballast would simulate a similar amount 
of force on the seat anchorages and bus structure as a 150-lb occupant.
    Prevost's and Daimler's comments reflect the state of knowledge in 
2001, a time early in the development of ECE R.66. According to their 
cited analysis, there were no experimental data available at the time 
to evaluate the percentage of mass that should be included in the test. 
At that time, it was then theorized that 50 percent of the occupant 
weight was an appropriate estimate for the weight that a restrained 
occupant would transfer to the bus structure. However, subsequent 
published studies have found that the 50 percent value grossly 
underestimates the amount of force imparted by restrained bus 
occupants.
    As discussed in the NPRM (79 FR 46106), an Australian study that 
utilized bus section testing and computer simulations \103\ estimated 
that 93 percent of a lap/shoulder belt-restrained occupant mass, 75 
percent of a lap belt-restrained occupant mass, and 18 percent of an 
unrestrained occupant mass are effectively coupled to the vehicle 
structure during a rollover. Further, a European Commission sponsored 
study in 2003 \104\ found that the percentage of occupant mass coupled 
to the vehicle structure during a rollover is 90 percent for lap/
shoulder belted occupants and 70 percent for lap belted occupants. 
Based on these research findings, NHTSA proposed in the NPRM to use the 
full weight of 150 lb (68 kg) at all DSPs.
---------------------------------------------------------------------------

    \103\ Anderson, J., et al., ``Influence of Passengers During 
Coach Rollover,'' Cranfield Impact Centre Ltd., 18th International 
Technical Conference on the Enhanced Safety of Vehicles, Nagoya, 
Japan, Paper No. 216, 2003.
    \104\ Enhanced Coach and Bus Occupant Safety (ECBOS), Project 
No. 1999-RD.11130, European Commission, 5th Framework, August 2003.
---------------------------------------------------------------------------

    Since the NPRM, NHTSA has learned about additional studies that 
corroborate the Australian and ECE findings. An

[[Page 74294]]

Italian study \105\ reports that seat deformation is influenced by an 
occupant's weight during rollover testing. Reports co-authored by TEMSA 
106 107 conclude that 90 percent of the 
passengers' mass should be added to the rollover vehicle mass. Thus, 
the data cited by Prevost and Daimler appear to be outdated. Available 
studies now uniformly agree that more than 90 percent of the occupant 
mass is coupled with the bus during a rollover crash. Accordingly, we 
disagree with ballasting only 50 percent of the 150-lb occupant load.
---------------------------------------------------------------------------

    \105\ Belingardi, G., Martella, P., and Peroni, L., ``Coach 
Passenger Injury Risk During Rollover: Influence of the Seat and the 
Restraint System,'' 19th International Technical Conference on the 
Enhanced Safety of Vehicles, Washington DC, Paper No. 05-0439, 2005.
    \106\ Guler, M., Atahan, A., and Bayram, B, ``Effectiveness of 
Seat Belt Usage on the Rollover Crashworthiness of an Intercity 
Coach''; 21st International Technical Conference on the Enhanced 
Safety of Vehicles, Stuttgart, Germany, Paper No. 09-0205, 2009.
    \107\ Elitok, K., Guler, M., Bertan Bayram, B., and Stelzmann, 
U., ``An Investigation on the Roll-Over Crashworthiness of an 
Intercity Coach, Influence of Seat Structure and Passenger Weight,'' 
9th International LS-DYNA Users Conference, 2006.
---------------------------------------------------------------------------

    For the above reasons, we are adopting the proposed language from 
the NPRM on ballasting. Using lower weight ballast for the fixed 
ballast, as suggested by some commenters, would not adequately simulate 
the loading conditions of the average restrained occupant.\108\
---------------------------------------------------------------------------

    \108\ NHTSA asked for comment on whether, when fixed ballasts 
are used, it is necessary to specify a specific center of gravity 
for the fixed steel plate ballasts. 79 FR 46107. No comments were 
received on this issue. For the reasons in the NPRM, NHTSA believes 
it is sufficient for the steel ballasts to be placed on top of the 
seat cushion.
---------------------------------------------------------------------------

b. Vehicle Fluids

    NHTSA specified that all fluids in the vehicle, including fuel, 
would be at maximum capacity during the test. For environmental and 
test personnel safety, NHTSA proposed to use substitute fluids to 
conduct the test if the weight of the original fluid was maintained.
Comments Received
    Van Hool commented that NHTSA should not include vehicle fluid 
specifications and should permit manufacturers to replace parts of the 
bus representative masses. The commenter believed that manufacturers 
should be able to decide on these conditions and determine them for 
their bus if ``the basic features and behaviour [sic] of the 
superstructure are not influenced by it.'' Van Hool recommends that the 
agency use the ECE R.66 definition of cg to determine whether the 
manufacturer's selected vehicle conditions are appropriate for testing.
Agency Response
    We have changed the regulatory text so that vehicle fluid fill 
levels are now specified as a percentage range of the maximum capacity 
rather than only as maximum capacity. FMVSS No. 227 specifies that the 
agency will test the bus with all fluids (or replacement fluids) at 90 
to 95 percent of the maximum level for each of the fluids.
    In specific response to Van Hool, NHTSA does not believe the 
requested change is necessary. Van Hool requested that NHTSA use 
manufacturer-defined test conditions for items such as the vehicle 
fluid levels and representative masses for expensive vehicle parts, if 
the manufacturer-specified conditions maintain a specified cg. As NHTSA 
explained in the NPRM, in the U.S., manufacturers self-certify their 
products'' compliance with the FMVSSs. The test conditions specified in 
an FMVSS specify the conditions under which NHTSA will assess 
compliance. The purpose of specifying these conditions is to give 
manufacturers notice of how NHTSA will test, not to prescribe the 
testing methods that manufacturers must use to certify compliance.
    To illustrate, FMVSS No. 227 specifies that the agency will test 
the bus with all fluids (or replacement fluids) at 90 to 95 percent of 
the maximum level for each of the fluids. The standard does not require 
manufacturers to conduct the test under the same conditions. 
Manufacturers may use different testing methods to certify compliance 
with the FMVSSs. They must reasonably conclude that their vehicles will 
pass the FMVSS test when tested by NHTSA as specified in the FMVSS. It 
is not incumbent on NHTSA to specify in the FMVSSs all the possible 
testing methods a manufacturer might use as a basis for its 
certification.

c. Additional Tools for Survival Space Evaluation During Testing

    Van Hool suggested that additional evaluation tools be permitted as 
supplemental or alternatives to the proposed survival space template, 
to simplify testing. It stated that high-speed photography, video, 
deformable templates, electrical contact sensors, and other suitable 
evaluation and techniques should be permitted as part of the standard.
    After considering the comment, NHTSA has decided to change some of 
the language in the regulatory text of FMVSS No. 227 to provide more 
flexibility in the tools the agency will use to measure compliance. As 
stated in the NPRM, we intended that ``[o]ther tools could also be used 
to help determine whether there was intrusion into the survival space, 
such as deformable templates, high speed video, photography, or a 
combination of means. NHTSA could use templates and/or other means of 
determining whether intrusion occurred.'' \109\ However, describing the 
use of survival space templates in detail in the regulatory text of 
FMVSS No. 227 implies the opposite, and makes unclear NHTSA's 
flexibility to use other compliance tools that are not described in the 
regulatory text. We believe it would be more efficient for the agency 
to move the specifications on the detailed use of templates or other 
methods to a test procedure document that NHTSA's Office of Vehicle 
Safety Compliance publishes.
---------------------------------------------------------------------------

    \109\ 79 FR 46109.
---------------------------------------------------------------------------

XIII. Other Issues

a. ECE R.66 Alternative Compliance Methods

    The rollover test in this final rule is based on the complete 
vehicle test from ECE R.66. NHTSA is not adopting ECE R.66's four 
alternative options for complying with ECE R.66 requirements.\110\ The 
following options are considered by ECE R.66 to be equivalent approval 
tests: (1) A rollover structural integrity test of body sections 
representative of the vehicle, (2) quasi-static loading tests of body 
sections, (3) quasi-static calculations based on testing of components, 
and (4) computer simulation (finite element analysis) of a complete 
vehicle.\111\
---------------------------------------------------------------------------

    \110\ There are significant differences in the way a 
manufacturer demonstrates compliance with safety regulations in 
European Union and in the United States. In Europe, European 
governments use ``type approval,'' which means that they approve 
particular designs as complying with their safety standards. In the 
U.S., NHTSA issues performance standards, to which manufacturers 
self-certify that their vehicles or equipment comply. NHTSA does not 
pre-approve vehicles or equipment before sale. Under the Vehicle 
Safety Act, the FMVSSs must be objective, repeatable, and meet 
certain other statutory criteria. NHTSA enforces the FMVSSs by 
obtaining new vehicles and equipment for sale and testing them to 
the requirements in the FMVSSs according to the procedures specified 
in the standards.
    \111\ Further information regarding the alternative 
certification methods of ECE R.66 is available at: Motorcoach Roof 
Crush/Rollover Testing Discussion Paper, March 2009, Docket No. 
NHTSA-2007-28793-0019.
---------------------------------------------------------------------------

Comments Received
    Bus manufacturers already producing vehicles subject to ECE R.66 
(Van Hool, TEMSA, Prevost, EvoBus) asked NHTSA to adopt the 
alternatives of ECE R.66. TEMSA believed that computer

[[Page 74295]]

simulation would be feasible if NHTSA ``defines the performance 
requirements, assumptions, calculations and validation method in the 
regulation, [and] all manufacturers make the same assumptions and 
perform the test with same simulation and analysis methods.'' Prevost 
believed that ECE R.66 alternatives may be used to prove certification 
of designs that are ``evolutions of what already exists.'' EvoBus 
believed not allowing numerical simulation imposes a burden because 
``it would be necessary to provide a vehicle with exactly the same 
specifications as the one which gave raise to questions.''
Agency Response
    This final rule adopts the complete vehicle test of ECE R.66 into 
FMVSS No. 227. By doing so, NHTSA is specifying the test procedure 
NHTSA will use to assess a vehicle's compliance with FMVSS No. 227. The 
standard will not provide for NHTSA's use of Alternatives 1 through 4 
to determine compliance. However, this does not mean that manufacturers 
must use the complete vehicle test to certify their vehicles. To the 
contrary, the Safety Act requires manufacturers to ensure their vehicle 
meet all applicable FMVSSs, and that they certify the compliance of 
their vehicle with applicable FMVSS. The Safety Act specifies that 
manufacturers may not certify if in exercising reasonable care the 
manufacturer has reason to know the certificate is false or misleading. 
This means a manufacturer may use the alternative compliance methods of 
ECE R.66 to certify its vehicles if it can do so in exercising 
reasonable care. While manufacturers must ensure that their vehicles 
will meet the requirements of FMVSS No. 227 when NHTSA tests the 
vehicles in accordance with the test procedures specified in the 
standard, they do not have to conduct the test described in FMVSS No. 
227 to certify that compliance.
    NHTSA considered ECE R.66's alternative compliance methods but 
determined that they would not be practical for the agency's compliance 
program. (See explanation in the NPRM, 79 FR 46111-46112.) The agency 
has considered the comments but has not changed its mind.
    Alternatives 1 and 2 involve testing body sections. To obtain a 
body section, NHTSA could procure it from the manufacturer, but that 
raises questions about how representative the sample would be of buses 
in actual production. Some manufacturers might make a more 
conscientious effort to produce the specimen, and so the specimen might 
not be representative of a typical mass-produced bus. NHTSA could 
section a bus itself, but that would be impractical and a waste of 
resources.
    Alternatives 1 and 2 require that the body-sections be 
representative of the entire vehicle. Determining the 
representativeness of a body-section would require input and analysis 
from the manufacturer, and even with that, determining what is 
``representative'' could be subjective and difficult for NHTSA to 
verify. (E.g., is the center of gravity of the body section 
representative of the whole vehicle?) Importantly, it might make more 
sense if the representative sample were representative of the worst-
case (weakest) section, to make sure all body sections of the bus are 
capable of passing the test. The alternatives do not make it clear that 
NHTSA could test the weakest section, and thus do not make clear that 
the entire vehicle would have to meet the standard.
    Testing an entire vehicle rather than body sections is preferable 
to NHTSA because it better ensures all body sections will be able to 
conform to FMVSS No. 227, including representative as well as worse-
case (weakest) sections of the bus. Testing an entire bus to the 
complete vehicle test is the most objective, scientific way to assure 
the entire bus structure is satisfactory and the glazing panels are 
retained.
    Regarding Alternatives 3 and 4, under the Safety Act, NHTSA is 
directed to issue performance standards,\112\ the compliance with which 
must be measured objectively.\113\ A concern with assessing compliance 
using calculations, extrapolations, and computer simulations is that 
entities may differ in opinion as to whether a manufacturer's 
calculations and computer simulations were appropriate or correctly 
made for demonstrating compliance in a particular instance. A 
manufacturer may have the knowledge of the materials and joint 
structure for their vehicles to be able to accurately model them, while 
an external entity may not be able to easily reproduce those results.
---------------------------------------------------------------------------

    \112\ In 49 U.S.C. 30102, the Vehicle Safety Act defines ``motor 
vehicle safety'' as the ``performance'' of motor vehicles or motor 
vehicle equipment in a way such as to avoid creating an unreasonable 
risk of accident to the general public. The same Act defines ``motor 
vehicle safety standards'' as minimum standards for motor vehicle or 
motor vehicle equipment ``performance.''
    \113\ In 49 U.S.C. 30111(a), the Vehicle Safety Act requires 
that Federal motor vehicle safety standards be stated in objective 
terms.
---------------------------------------------------------------------------

    The variability of assumptions in such models makes this method 
less preferable for use by NHTSA in evaluating compliance with an 
FMVSS. For example, for Alternative 3, we would need to identify the 
location of the plastic zones and plastic hinges as well as estimate 
their load-deformation curves. For Alternative 4, mathematical models 
that simulate accurately the actual rollover crash of the vehicle are 
required.
    Further, there is a concern that basing compliance on calculations 
and computer simulations may not account for differences that may occur 
between the analytical model and the vehicle as manufactured. Because 
an actual vehicle is not involved in the assessment of compliance using 
Alternatives 3 and 4, these alternatives might not account for 
variation or flaws in material properties, or quality control 
deficiencies in the manufacturing build processes. A design that looks 
acceptable ``on paper'' or in theory might not turn out so as assessed 
by testing an actual vehicle. To the extent possible, NHTSA prefers to 
test actually-manufactured vehicles, to assess not only the design of 
the vehicle, but the real-world production of the vehicle.
    In short, deficiencies in vehicle performance due to poor quality 
control of manufacturing processes, sub-standard quality of supplied 
materials or errors in the engineering analysis underlying the vehicle 
design can be better discovered when an actual vehicle is tested than 
under a compliance system using Alternatives 3 and 4.
    For these reasons, this final rule is based on the complete vehicle 
test of ECE R.66 to determine compliance. NHTSA is incorporating ECE 
R.66's compliance framework in a manner that meets the requirements of 
MAP-21 and the requirements and considerations of NHTSA's Safety Act. 
The agency emphasizes that FMVSS No. 227 does not preclude 
manufacturers from using the alternative compliance methods of ECE R.66 
to certify their vehicles. As explained in the NPRM,\114\ although an 
engineering analysis model would not be appropriate as the agency's 
method of assessing the compliance of vehicles with a Federal motor 
vehicle safety standard manufacturers are not required to use NHTSA's 
test as the basis for their certification. While the agency's test 
defined in the proposed regulatory test would be an objective test 
capable of determining which vehicles meet the minimum requirements, 
manufacturers can use other methods (such as the alternative compliance 
options in ECE

[[Page 74296]]

R.66) in certifying the compliance of their own vehicles.
---------------------------------------------------------------------------

    \114\ 79 FR 46117; August 6, 2014.
---------------------------------------------------------------------------

    Manufacturers using ECE R.66's alternatives are responsible for 
ensuring that the vehicles will meet the requirements of FMVSS No. 227 
when tested by NHTSA per the agency's procedures. However, 
manufacturers certifying compliance of their own vehicles have much 
more detailed information regarding their own vehicles and production 
methods than NHTSA and should be capable of using other methods to 
certify their vehicles. If manufacturers are confident that the data 
obtained by using the test methods described in ECE R.66's Alternatives 
1 through 4 assure conformance with the standard just as the complete 
vehicle test does, nothing precludes them from using those alternatives 
to certify their vehicles to FMVSS No. 227 with confidence.

b. Regulatory Alternatives

    In deciding on the approach adopted by this final rule, NHTSA 
examined the following alternatives.
1. FMVSS No. 216
    NHTSA considered the requirements of FMVSS No. 216, ``Roof crush 
resistance.'' FMVSS No. 216 applies to vehicles with a GVWR of 4,536 kg 
(10,000 lb) or less (light vehicles), and specifies a test that applies 
localized static loads to the upper front corners of a vehicle's roof 
and windshield area. The large buses covered under this final rule are 
larger/heavier than light vehicles and are more likely to roll along a 
longitudinal vehicle axis than yaw and pitch. Thus, in an actual 
rollover involving one of these vehicles, the entire length of the 
vehicle is loaded as in the ECE R.66 test. NHTSA believes the ECE R.66 
test is more representative of a real-world rollover of a large bus 
than the FMVSS No. 216 test since the ECE R.66 test imparts loads along 
the full length of the vehicle.
    In addition, the ECE R.66 test is a dynamic test in which 
``survival space'' performance requirements are specially designed for 
the large bus interior. There are also additional safety issues 
specific to the vehicles covered by this rule (opening of emergency 
exits, detachment of windows from their mountings) that can be 
evaluated in the dynamic event. Since two-thirds of rollover fatalities 
are due to ejections, addressing these additional safety issues is 
vital to addressing the safety problem in rollovers. Therefore, the 
agency believes that the ECE R.66 test addresses more of the safety 
needs of a large bus rollover crash than the FMVSS No. 216 test.
2. FMVSS No. 220
    FMVSS No. 220 is a school bus roof crush standard that places a 
uniformly distributed vertical force pushing directly downward on the 
top of the bus with a platen that is 914 mm (36 inches) wide and that 
is 305 mm (12 inches) shorter than the length of the bus roof. The 
standard specifies that when a uniformly distributed load equal to 1.5 
times the unloaded vehicle weight is applied to the roof of the 
vehicle's body structure through a force application plate, the 
downward vertical movement at any point on the application plate shall 
not exceed 130 mm (5.125 inches) and the emergency exits must be 
operable during and after the test.
    The agency included FMVSS No. 220 in its research into rollover 
structural integrity for large buses and, in the NPRM, tentatively 
decided the ECE R.66 test was preferable to the FMVSS No. 220 for 
motorcoaches for several reasons. First, the agency determined that an 
ECE R.66 based test is more suitable for the vehicles covered by FMVSS 
No. 227 than an FMVSS No. 220-based test because a significant portion 
of fatalities in the subject buses result from occupant ejections. 
Unlike school buses, the subject motorcoach and other large buses 
operate intercity routes and typically travel at higher speeds than 
school buses transporting children to a local educational facility. 
Further, many of the motorcoaches and subject intercity buses are 
designed with a higher center of gravity than school buses and have 
larger windows. These characteristics can lead to a higher incidence of 
occupant ejections during rollovers involving the non-school buses. The 
agency believed dynamic rollover test in ECE R.66 affords the agency 
the opportunity to better evaluate ejection-related factors such as the 
emergency exits and side window glazing retention during a rollover 
crash.
    After considering the comments, NHTSA makes the following 
decisions. As previously discussed, the agency is permitting 
manufacturers of school bus derivative buses to certify compliance with 
FMVSS No. 220 as an alternative to certifying to the ECE R.66 test in 
FMVSS No. 227. FMVSS No. 220 has been proven to adequately ensure roof 
crush protection in vehicles designed to meet the FMVSSs applying to 
school buses, so allowing school bus derivative buses to meet FMVSS No. 
220 avoids redundancy in the FMVSS. NHTSA is not permitting FMVSS No. 
220 as an alternative to FMVSS No. 227 for buses other than school bus 
derivative buses. The dynamic test in FMVSS No. 227 is a more 
representative test of real-world rollovers for motorcoaches and buses 
other than school buses and addresses safety needs arising in rollovers 
of those vehicles that FMVSS No. 220 does not address.

c. Additional MAP-21 Considerations

    In addition to the MAP-21 provisions discussed previously in this 
document, MAP-21 also directs NHTSA to consider the best available 
science, potential impacts on seating capacity, and potential impacts 
on the size/weight of motorcoaches.\115\ Further, MAP-21 directs the 
agency to consider combining the various motorcoach rulemakings 
contemplated by MAP-21 and to avoid duplicative benefits, costs, and 
countermeasures.\116\
---------------------------------------------------------------------------

    \115\ See MAP-21 section 32703(e)(1).
    \116\ See id. at section 32706(b)-(c).
---------------------------------------------------------------------------

    NHTSA considered the best available science in developing this 
final rule. The agency developed this rule based on FMVSS No. 220 and 
ECE R.66 test studies NHTSA conducted on large bus rollover structural 
integrity (see section IV of the NPRM), and after considering advanced 
glazing countermeasures (see May 6, 2016 (81 FR 27904) NPRM, supra, and 
``Motor Coach Glazing Retention Test Development For Occupant Impact 
During A Rollover,'' Martec Technical Report # TR-06-16, Rev 4, August 
2006 \117\). NHTSA considered FMVSS No. 216 and ECE R.66 alternative 
compliance methods (see sections VI of the NPRM).
---------------------------------------------------------------------------

    \117\ Docket No. NHTSA-2002-11876-0015.
---------------------------------------------------------------------------

    Coach USA provided the only response to the NPRM request for 
comment on the impact of added vehicle weight to seating capacity. It 
requested NHTSA to consider that further increases to motorcoach weight 
could make it difficult for all operators to carry a full passenger 
load while still complying with applicable vehicle and axle weight 
limits. NHTSA does not believe this final rule will adversely impact 
seating capacity. Large bus buyers expect maximum seating capacity with 
adequate luggage capacity for a given floor space or vehicle length. 
Estimates for structural weight added to a bus to meet this final rule 
are based on usage of steel.\118\ NHTSA is aware that other methods of 
reinforcing the structure (such as the use of high strength steel 
sections, rigid polyurethane foam filling to reinforce and stabilize 
thin walled hollow sections, and optimized designs that

[[Page 74297]]

redistribute the impact loads and enhance the energy absorption 
capability) may enable a large bus to withstand greater crash forces 
without increasing as much weight.\119\
---------------------------------------------------------------------------

    \118\ Final Regulatory Evaluation Large Bus Structural Integrity 
FMVSS No. 227; NHTSA Office of Regulatory Analysis and Evaluation, 
National Center for Statistics and Analysis. Available in the docket 
for this rule.
    \119\ See Lilley, K. and Mani, A., ``Roof-Crush Strength 
Improvement Using Rigid Polyurethane Foam,'' SAE Technical Paper 
960435, 1996. Available at: https://subscriptions.sae.org/content/960435/, see also Liang, C. and Le, G. Optimization of bus rollover 
strength by consideration of the energy absorption ability. 
International Journal of Automotive Technology. Vol. 11.(2) 173-185. 
Available at: https://www.springerlink.com/content/tk824863k66w0228/export-citation/.
---------------------------------------------------------------------------

    Through this final rule and our accompanying Final Regulatory 
Evaluation (FRE), the agency has considered the potential impacts of 
this rule on the size and weight of motorcoaches and other large buses 
affected by this rule.\120\ As described further in the next section 
(and in the FRE), we have considered potential weight increases to 
motorcoaches as a cost of this final rule due to increased fuel 
consumption. In the accompanying FRE, we have quantified and accounted 
for this increased fuel consumption cost in our cost-benefit analysis 
of the rule. After considering all costs, including the potential 
weight increase, the agency concludes that the requirements in this 
final rule will be cost-beneficial.
---------------------------------------------------------------------------

    \120\ ``Motorcoach'' in this paragraph has the meaning given in 
MAP-21 (OTRBs).
---------------------------------------------------------------------------

    NHTSA has designed this rule to complement the agency's 2013 final 
rule on FMVSS No. 208 requiring seat belts for passenger seating 
positions. The seat belt rule will result in increasing numbers of 
passengers buckling up on large buses. As they do so, more and more 
will be retained within the passenger compartment in crashes. NHTSA has 
designed it so that FMVSS No. 227 and FMVSS No. 208 work together to 
provide a survival space to the passengers retained within the 
passenger compartment due to the seat belts. NHTSA has also designed 
this final rule bearing in mind NHTSA's May 6, 2016 NPRM,\121\ issued 
pursuant to section 32703(b)(2) of MAP-21, that proposes to adopt an 
advanced glazing standard for large buses (OTRBs and non-OTRBs with a 
GVWR greater than 11,793 kilograms (26,000 pounds)). The reinforcements 
to the superstructure and bus body to meet FMVSS No. 227's structural 
integrity requirements will increase the likelihood that anti-ejection 
advanced glazing installed consistent with section 32703(b)(2) will be 
retained in a rollover crash.
---------------------------------------------------------------------------

    \121\ 81 FR 27904, supra.
---------------------------------------------------------------------------

    Finally, NHTSA is avoiding duplicating benefits, costs, and 
countermeasures in the motorcoach rulemakings of MAP-21. As described 
above, the agency believes that the requirements of FMVSS No. 227 work 
together with the passenger seat belt requirements of FMVSS No. 208 and 
complements an advanced glazing standard. As described in the 
accompanying FRE, the agency has estimated the benefits and costs of 
this final rule while considering the effect of seat belts on the 
subject buses and the application of the ESC rule.

XIV. Lead Time

    The agency proposed a compliance date of 3 years after publication 
of the final rule for FMVSS No. 227. MAP-21 (in section 32703(e)) 
directs that the rulemaking shall apply to all motorcoaches 
manufactured more than 3 years after the date on which the regulation 
is published as a final rule.
Comments Received
    IC Bus agreed with the proposed 3-year lead time. Van Hool stated 
``that for the requirements for the strength of superstructure 
according to the Series of Amendment 01 of UN Regulation No. 66 . . . a 
transition period of 144 months was granted.''
Agency Response
    This final rule adopts the 3-year compliance date. To enable 
manufacturers to certify to the new requirements as early as possible, 
optional early compliance with the standard is permitted. The 3-year 
date for motorcoaches is required by MAP-21. If Van Hool was requesting 
a 144-month lead time, NHTSA declines the request as contrary to MAP-
21. Further, the commenter provided no information to support or 
further explain their interest in or need for a 144-month (12-year) 
lead time for the effective date of FMVSS No. 227. Van Hool and others 
currently manufacture buses for sale to European countries including 
Italy, France, Germany, Poland, and the Netherlands.\122\ Each of these 
countries is listed under the 1958 Agreement as countries granting 
approval to buses meeting the requirements of ECE R.66. Since Van Hool 
already designs buses for ECE R.66 requirements, NHTSA believes that 
the commenter has a good foundation for manufacturing buses that meet 
the structural requirements of FMVSS No. 227.
---------------------------------------------------------------------------

    \122\ Information from review of Van Hool website press release 
information. Obtained February 24, 2017 (https://www.vanhool.be/ENG/bedrijsfinfo/historiek/historiek2009-20.html).
---------------------------------------------------------------------------

    NHTSA concludes that three years of lead time will be sufficient 
for bus manufacturers generally to make the necessary changes. The lead 
time for motorcoaches is mandated by MAP-21, but it is also reasonable. 
Van Hool and other manufacturers of buses that already meet ECE R.66 
may have to improve the type of latches used on emergency exits, and 
improve the mounting of side windows, but three years will be ample 
time to complete the design, testing, and changes in production 
necessary to certify compliance to the FMVSS No. 227 requirements.
    For manufacturers whose buses do not already meet ECE R.66, NHTSA 
believes that manufacturers will need to make structural design changes 
to their large bus models either by changing the strength of the 
sidewall and glazing frame material or the material's physical 
dimensions (i.e., thickness or width). Per the results of our test 
program conducted in support of this rulemaking, newer buses may need 
stronger side pillars to meet the glazing retention requirements, and 
redesigned mechanisms on roof exits and side window exits to ensure 
that they do not release during the impact. We believe that these 
changes can be done within three years. Further, we note that under 49 
CFR 571.8(b), manufacturers of buses other than motorcoaches built in 
two or more stages and alterers are provided an additional year of lead 
time for manufacturer certification and compliance.

XV. Retrofitting Used Buses

    The agency stated in the NPRM that, based on the agency's tests of 
older buses, major structural changes to the vehicle's entire sidewall 
and roof structure would be needed for some existing buses to meet the 
proposed rollover structural integrity requirements. NHTSA believed 
that the structural changes are likely to be cost-prohibitive, making 
retrofitting for rollover structural integrity impractical. NHTSA 
requested comments on the feasibility, benefits, and costs of any 
potential requirement to retrofit existing buses to meet FMVSS No. 227.
Comments Received
    Almost half of the respondents to the NPRM commented on the 
retrofit issue and all opposed retrofitting. IC Bus, Daimler Trucks, 
Van Hool, ABA, Greyhound, Coach USA, Prevost, and Advocates raised 
concerns about retrofit. They believed that the work involved in 
retrofitting a bus to meet FVMSS No. 227, even just the glazing aspects 
of the standard, would entail impracticable and unreasonable reworking 
of the bus structure. The complications of retrofit are exacerbated, 
they stated, by having to deal with the condition of existing

[[Page 74298]]

structures, the lack of original design information, and possible need 
for Federal oversight and approval of each bus's structural rework.
Agency Response
    NHTSA is not specifying a retrofit requirement. The agency did not 
receive or discover any new information that would alter the previous 
determination that retrofitting of existing buses would be 
impracticable and unreasonable. The agency continues to expect the 
structural changes needed for retrofitting to be substantial, and to 
involve significant costs beyond those estimated in our regulatory 
analysis for new buses. The cost impacts would likely have a 
substantial adverse impact on a significant number of small entities 
(e.g. , owner-operators of buses used for transport), without a 
commensurate safety benefit. Therefore, NHTSA reaffirms the earlier 
decision not to require retrofit of used buses to meet FMVSS No. 227.

XVI. Overview of Costs and Benefits

    Based on the FARS data over the 15-year period between 2004 and 
2018, there were a total of 56 fatal rollover crashes involving the bus 
types covered by this final rule, resulting in 189 occupant fatalities. 
Beyond the benefits attributable to the rules on seat belts and ESC for 
these vehicles, NHTSA estimates this final rule will save approximately 
3 lives annually (undiscounted) if 15 percent of occupants use seat 
belts, and approximately 2 lives annually (undiscounted) if 90 percent 
of occupants use seat belts.\123\ NHTSA estimates this final rule will 
reduce the number of seriously injured occupants by approximately 4 
annually. These estimated benefits are distinct from the passenger 
protections attributable to the seat belt and ESC requirements for 
buses covered by this final rule and are conservative estimates. As 
explained later in this section, these estimates do not count possible 
benefits to belted occupants who were saved from injury or fatality 
because of the survival space provided by FMVSS No. 227.
---------------------------------------------------------------------------

    \123\ The FRE prepared in support of this final rule assumes 
that the seat belt use rate on large buses will be between 15 
percent and the percent use in passenger vehicles, which was 90 
percent in 2009. To maintain consistency with the seat belt rule, we 
have used the same low belt usage rate estimate of 15 percent from 
that rule, and the same source of information to establish the high 
belt usage rate estimate (See 2009 National Occupant Protection Use 
Survey. More information at: https://www-nrd.nhtsa.dot.gov/pubs/811100.pdf).
---------------------------------------------------------------------------

    While belted occupants will benefit from a survival space, unbelted 
occupants will benefit as well. The belted occupant will mostly benefit 
from reduced intrusion of structures and objects into the survival 
space. The unbelted occupants will benefit from a reduced risk of 
occupant ejection. Given these differences in how occupants will 
benefit from the rule, we have estimated benefits for each group 
separately.
    Also, the benefits estimates will vary by seat belt use. Available 
research regarding seat belt use suggests that it can be highly 
variable. NHTSA has estimated the lower end of seat belt use at 15 
percent and the upper end of seat belt use at 90 percent. The agency 
assumes that, initially, belt use will be closer to the lower end (15 
percent) because passengers are not yet accustomed to seat belts on the 
buses. Many large buses in use do not have seat belts, and passengers 
have not been educated about the benefits of buckling up in a large 
bus.
    NHTSA estimates that at 3 percent and 7 percent discount rates, 
1.87 to 2.45 equivalent lives are saved annually if 15 percent of 
occupants use seat belts and 1.46 to 1.92 equivalent lives are saved 
annually if 90 percent of occupants use seat belts (see Table 13 
below).
    The agency estimates that, assuming steel is used to strengthen the 
vehicle structure to comply with the requirements in this final rule, 
material costs for each vehicle will range from $325 to $591 and cost 
between $0.71 million and $1.30 million to equip the entire new large 
bus fleet annually (see Table 14 below). NHTSA further estimates that, 
if steel is used to comply, the total weight increase will range from 
181 to 356 kg (399 to 784 lb) and cost an additional $1,862 to $4,790 
in fuel per vehicle over the lifetime of the vehicle. The total fuel 
cost for the new fleet is estimated to be $4.10 million to $10.54 
million. The total costs will be approximately $4.81 million to $11.84 
million annually. The cost per equivalent life saved is estimated to be 
between $2.48 million and $6.38 million (see Table 15 below) and net 
economic benefit is estimated to be between $8.25 million and $23.31 
million in 2020 dollars.
    The available information shows this final rule is cost beneficial. 
The above estimates for the cost per equivalent life of this rule vary 
due to uncertainties regarding seat belt use rates and the incremental 
increase in weight that is necessary to meet FMVSS No. 227. For seat 
belt use, NHTSA believes that the projected net impact on the economy 
will be closer to the estimates for the 15 percent belt use rates than 
the 90 percent belt use rate, as explained above. A large portion of 
the costs of this structural integrity rule is dependent on this 
incremental increase in weight. NHTSA does not have more specific 
information regarding the likely weight increase to these vehicles.
    The agency believes that the cost effectiveness of this rule is not 
very sensitive to changes in belt usage rates because belted passengers 
will still realize safety benefits because of this rule. Many serious 
injuries that occur in large bus crashes can occur despite a 
passenger's use of a safety belt. For example, while belted passengers 
may not be ejected, they can still be struck by the collapsing side 
wall of the bus. Therefore, even though increasing seat belt usage 
rates may mean that more passenger ejections (and fatalities) will be 
prevented by seat belts (consequently reducing the number of prevented 
ejections attributable to FMVSS No. 227), the final rule will still be 
effective in preventing serious injuries to belted passengers. Thus, we 
expect that the monetized value of the benefits of this rule is not 
very sensitive to fluctuations in seat belt use--even though the type 
of benefit will change.\124\
---------------------------------------------------------------------------

    \124\ For further information, see the FRE prepared in support 
of this final rule. The FRE discusses issues relating to the 
potential costs, benefits and other impacts of this regulatory 
action. The FRE is available in the docket for this final rule and 
may be obtained by downloading it or by contacting Docket Management 
at the address or telephone number provided at the beginning of this 
document.

                   Table 13--Estimated Annual Benefits
                        [Equivalent lives saved]
------------------------------------------------------------------------
                                       15% belt use       90% belt use
------------------------------------------------------------------------
3% Discount.......................               2.45               1.92
7% Discount.......................               1.87               1.46
------------------------------------------------------------------------


[[Page 74299]]


                    Table 14--Estimated Annual Costs
                             [2020 Dollars]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Potential Costs:
    Material Costs Per Vehicle.  $325 to $591.
    Material Costs, Total New    $0.71 million to $1.30 million.
     Fleet.
Fuel Costs per Vehicle @ 3%....  $2,441 to $4,790.
Fuel Costs per Vehicle @ 7%....  $1,862 to $3,654.
Fuel Costs, Total New Fleet....  $4.10 million to $10.54 million.
                                ----------------------------------------
    Total Annual Cost..........  $4.81 million to $11.84 million.
------------------------------------------------------------------------


                    Table 15--Cost per Equivalent Life Saved in Millions (M) of 2020 Dollars
----------------------------------------------------------------------------------------------------------------
                                                   15% belt use    15% belt use    90% belt use    90% belt use
                                                    3% discount     7% discount     3% discount     7% discount
----------------------------------------------------------------------------------------------------------------
Cost (New Vehicle + Fuel).......................      6.08-11.84       4.81-9.34      6.08-11.84       4.81-9.34
Equivalent Lives Saved..........................            2.45            1.87            1.92            1.46
Cost per Equivalent Life Saved..................       2.48-4.83       2.57-4.99       3.17-6.17       3.28-6.38
----------------------------------------------------------------------------------------------------------------

    The cost of reinforcing the roof strength and structural integrity 
of these vehicles to meet the requirements in this final rule are 
predominantly dependent upon the material and weight increases 
necessary to reinforce the superstructure. NHTSA estimates that the 
countermeasures may include stronger roof and side walls, shock 
resistant latches for emergency exits, and improved window mounting. As 
mentioned above, these material costs for each vehicle are estimated to 
be between $325 and $591. However, while the agency assumes in these 
estimates that steel is applied to reinforce the vehicle structure, the 
agency is aware that other methods of reinforcing the structure (such 
as the use of high strength steel sections, rigid polyurethane foam 
filling to reinforce and stabilize thin-walled, hollow sections, and 
optimized designs that redistribute the impact loads and enhance the 
energy absorption capability) may enable a vehicle to withstand greater 
crash forces without adding as much weight.\125\ Therefore, while our 
analysis has assumed the use of steel, the agency is aware that there 
may be other countermeasures that weigh less--which could result in 
lower fuel costs--than we have currently estimated, over the lifetime 
of the vehicle.
---------------------------------------------------------------------------

    \125\ See Lilley, K. and Mani, A., ``Roof-Crush Strength 
Improvement Using Rigid Polyurethane Foam,'' SAE Technical Paper 
960435, 1996. Available at: https://subscriptions.sae.org/content/960435/, see also Liang, C. and Le, G. Optimization of bus rollover 
strength by consideration of the energy absorption ability. 
International Journal of Automotive Technology. Vol. 11.(2) 173-185. 
Available at: https://www.springerlink.com/content/tk824863k66w0228/export-citation/.
---------------------------------------------------------------------------

    The agency also notes that, in addition to the quantifiable 
benefits mentioned above, there are other benefits arising from this 
final rule. Our economic analysis of this rule is only able to 
calculate the benefits that can be realized above and beyond the 
benefits attributable to previously-published final rules, in 
particular, the November 25, 2013 (78 FR 70416) seat belt final rule. 
In other words, we are only able to estimate the benefits to passengers 
whose serious and fatal injuries were not prevented by seat belts. When 
an occupant who would have been seriously or fatally injured in a bus 
crash is estimated as saved from such injury by a countermeasure 
previously made effective for that occupant (e.g., a seat belt), NHTSA 
no longer estimates additional benefits for that particular passenger.
    However, we believe that some people who were saved by the seat 
belt could still benefit from this rule, as the poor structural 
integrity of a bus could contribute toward a fatality or an injury for 
this saved occupant. It is important to note that while the agency 
could estimate benefits to belted passengers who still were seriously 
injured or killed notwithstanding the seat belts, because of our 
practices we do not estimate what additional benefits could be realized 
by passengers who were already considered saved from serious and fatal 
injury due to the seat belts. As the agency is unaware of any available 
information that would enable the agency to quantify this latter 
benefit, the agency's economic analysis of this rule only estimates the 
benefits to occupants who were not saved by the seat 
belts.126 127
---------------------------------------------------------------------------

    \126\ Thus, we believe our estimate of benefits is conservative, 
undercounting possible benefits to occupant who were saved from 
fatal ejection by seat belts but still seriously injured by 
collapsing structure or unrestrained heavy vehicle components 
intruding into the survival space.
    \127\ This final rule will also theoretically result in 
additional benefits by functioning to support NHTSA's proposed rule 
on FMVSS No. 217a, supra, to mitigate ejection risks through 
installation of advanced glazing. This final rule will provide for 
the structural foundation, or anchor, to retain advanced glazing to 
the vehicle when that advanced glazing is installed per the proposed 
FMVSS No. 217a. While this final rule on FMVSS No. 227 could result 
in associated benefits regarding FMVSS No. 217a, we have not 
quantified them for this rulemaking proceeding.
---------------------------------------------------------------------------

XVII. Rulemaking Analyses and Notices

Executive Order (E.O.) 12866, E.O. 13563, and DOT Rulemaking Procedures

    NHTSA has considered the impact of this final rule under Executive 
Orders 12866 and 13563, and DOT administrative rulemaking orders and 
procedures. This final rule is not considered significant and was not 
reviewed by the Office of Management and Budget under E.O. 12866.
    This final rule increases roof strength and structural integrity 
for certain large bus types by establishing requirements for 
maintaining survival space and emergency exit operability during and 
after a rollover structural integrity test. This final rule specifies a 
test procedure that tilts the vehicle on a platform until the vehicle 
becomes unstable and rolls over onto a level concrete impact surface.

[[Page 74300]]

    NHTSA has prepared a FRE for this final rule.\128\ Beyond the 
benefits attributable to rules on seat belts for this same group of 
vehicles and ESC, NHTSA estimates that this final rule will save 
approximately 3.12 equivalent lives annually if seat belt usage among 
occupants is 15 percent, and approximately 2.45 equivalent lives 
annually if seat belt usage is 90 percent. The total cost of making the 
necessary structural changes, and of lifetime fuel costs, will be 
approximately $4.81 million to $11.84 million annually (for the entire 
new fleet). The net cost per equivalent life saved is estimated to be 
between $2.48 million and $6.38 million. The benefits, costs, and other 
impacts of this rulemaking are discussed at length in the FRE.
---------------------------------------------------------------------------

    \128\ Final Regulatory Evaluation Large Bus Structural Integrity 
FMVSS No. 227; NHTSA Office of Regulatory Analysis and Evaluation, 
National Center for Statistics and Analysis. Available in the docket 
for this rule.
---------------------------------------------------------------------------

Executive Order 13609: Promoting International Regulatory Cooperation

    The policy statement in section 1 of Executive Order 13609 
provides, in part: The regulatory approaches taken by foreign 
governments may differ from those taken by U.S. regulatory agencies to 
address similar issues. 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. 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. 
International regulatory cooperation can also reduce, eliminate, or 
prevent unnecessary differences in regulatory requirements.
    As mentioned in this preamble, the agency has considered regulatory 
approaches taken by foreign governments (namely, the European Union in 
ECE R.66) and decided to base FMVSS No. 227 on ECE R.66. In addition to 
the goal of reducing unnecessary differences in regulatory requirements 
between the U.S. and its trading partners, the agency has found the ECE 
R.66 test to be the most suitable test available for ensuring a minimum 
reasonable level of protection for passengers traveling in buses that 
are associated with the highest crash risk. While NHTSA has determined 
that it is not able to adopt the entirety of ECE R.66 and has adopted 
emergency exits latching requirements which are not in ECR R.66, the 
agency has explained its rationale for its decisions in the relevant 
sections of this document.

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of rulemaking for any proposed or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small governmental jurisdictions). 
The Small Business Administration's regulations at 13 CFR part 121 
define a small business, in part, as a business entity ``which operates 
primarily within the United States.'' (13 CFR 121.105(a)). No 
regulatory flexibility analysis is required if the head of an agency 
certifies that the rule will not have a significant economic impact on 
a substantial number of small entities. The SBREFA amended the 
Regulatory Flexibility Act to require Federal agencies to provide a 
statement of the factual basis for certifying that a rule will not have 
a significant economic impact on a substantial number of small 
entities.
    NHTSA has considered the effects of this rulemaking action under 
the Regulatory Flexibility Act. Per 13 CFR 121.201, the Small Business 
Administration's size standards regulations used to define small 
business concerns, manufacturers of the vehicles covered by this rule 
fall under North American Industry Classification System (NAICS) No. 
336111, Automobile Manufacturing, which has a size standard of 1,000 
employees or fewer. NHTSA estimates that there are 26 manufacturers of 
these types of vehicles in the United States (including manufacturers 
of motorcoaches, cutaway buses, second-stage motorcoaches, and other 
types of large buses covered by this rule). Using the size standard of 
1,000 employees or fewer, we estimate that approximately 10 of these 26 
manufacturers are considered small businesses.
    I certify that this final rule will not have a significant economic 
impact on small entities. First, the agency estimates that the 
incremental costs to each vehicle would be $325 to $591 per unit to 
meet the rule. This incremental cost would not constitute a significant 
impact given that the average cost of the vehicles covered by this rule 
ranges from $200,000 to $400,000. Further, these incremental costs, 
which are very small compared to the overall cost of the vehicle, can 
ultimately be passed on to the purchaser and user.
    In addition, the agency believes that certifying compliance with 
the rule will not have a significant impact on the small manufacturers. 
These entities have various options available that they may use to 
certify compliance with the standard.
    This final rule adopts ECE R.66's compliance framework in a manner 
that meets the requirements of MAP-21 and the requirements and 
considerations of NHTSA's Safety Act. The standard will not provide for 
NHTSA's use of Alternatives 1 through 4 to determine compliance. 
However, this does not mean that manufacturers must use the complete 
vehicle test to certify their vehicles. To the contrary, the Safety Act 
requires manufacturers to ensure their vehicle meet all applicable 
FMVSSs, and that they certify the compliance of their vehicle with 
applicable FMVSS. The Safety Act specifies that manufacturers may not 
certify if in exercising reasonable care the manufacturer has reason to 
know the certificate is false or misleading. This means a manufacturer 
may use the alternative compliance methods of ECE R.66 to certify its 
vehicles if it can do so in exercising reasonable care. While 
manufacturers must ensure that their vehicles will meet the 
requirements of FMVSS No. 227 when NHTSA tests the vehicles in 
accordance with the test procedures specified in the standard, they do 
not have to conduct the test described in FMVSS No. 227 to certify that 
compliance.\129\
---------------------------------------------------------------------------

    \129\ Under the Vehicle Safety Act, a manufacturer can avoid 
civil penalties associated with a noncompliance if it showed that it 
exercised due care in certifying its vehicles. A showing of due care 
can be based on engineering analyses, computer simulations, and the 
like, and NHTSA will assess the due care upon which the 
certification is made by evaluating, among other factors, the size 
of the manufacturer and its resources. Even small manufacturers, 
however, are responsible for having a reasonable idea as to whether 
their vehicles comply with the standard. They are responsible for 
proclaiming that their vehicles will comply should NHTSA test their 
vehicle. The alternatives discussed in this section provide those 
bases for certification.
---------------------------------------------------------------------------

    One option is to certify compliance using modeling or engineering 
analyses (such as a plastic hinge analysis of portal frames of the 
vehicle). ECE R.66 itself accounts for and accommodates this compliance 
option, and this approach has been used for years by European 
manufacturers in meeting ECE R.66. An engineering analysis model is 
less preferable to the dynamic test procedure specified in this rule as 
the agency's method of assessing the

[[Page 74301]]

compliance of vehicles with an FMVSS, since the agency may not know 
enough about the assumptions to use in the model or whether the model 
in fact represents the subject vehicle as manufactured. However, unlike 
NHTSA, manufacturers have access to much more information regarding 
their own vehicles and can analyze information of sufficient detail and 
breadth about vehicle design, material characteristics and production 
processes to form a basis for their certification. They can use their 
own methods for certifying compliance of their vehicles, such as 
engineering analyses to certify their vehicles. If the basis for their 
certification is made using reasonable care, they will have met the 
requirement of section 30115 to certify the compliance of their 
vehicles. If they used reasonable care in certifying and manufacturing 
the vehicles, the likelihood that the vehicles will pass the FMVSS No. 
227 compliance test when tested by NHTSA according to the standard is 
very high.
    The manufacturer could test body sections of the vehicle, as 
contemplated by ECE R.66, Alternatives 1 and 2. The manufacturer could 
``section'' the vehicle or otherwise obtain a body section 
representative of the vehicle and of the weakest section of the 
vehicle. It could base its certification on these tests, without 
testing a full vehicle. As discussed above, they know their vehicles 
best, and can test the section most at risk of not meeting FMVSS No. 
227 to make sure the vehicle would meet the standard when tested by 
NHTSA in the complete vehicle test. This process will allow small 
manufacturers to test parts of the vehicle for compliance, and use 
their engineering expertise to calculate that the bus will meet the 
standard when NHTSA tests it in accordance with the procedure specified 
in FMVSS No. 227.
    In the event small manufacturers elect to conduct a test of a full 
vehicle, there are various methods available to reduce the costs of the 
test. One such method is by testing a vehicle which is not completely 
new. As the requirements in this final rule pertain to structural 
integrity, we believe that a manufacturer could test the relevant body 
design on an old bus chassis or other underlying structure, and could 
sufficiently assess and certify the compliance of the vehicle's 
structural integrity to FMVSS No. 227. Similarly, the agency believes 
that more costly parts of the vehicle (such as the engine and other 
portions of the powertrain) could be replaced in a complete vehicle 
test of a bus with ballast equal to the weight of the absent 
components. The small manufacturer could base its certification on such 
testing, which do not involve a destructive test of an actual vehicle.
    NHTSA notes that the product cycle of large buses subject to FMVSS 
No. 227 is much longer than other vehicle types. With a longer product 
cycle, the agency believes that the costs of certification for 
manufacturers would be further reduced as the costs of conducting 
compliance testing and the relevant analyses could be spread over a 
significantly longer period.
    This rule may affect operators of the buses--some of which may be 
small businesses--but only indirectly as purchasers of these vehicles. 
As mentioned above, NHTSA anticipates that the impact on these 
businesses will not be significant because (assuming that additional 
steel is used for compliance) the expected price increase of the 
vehicles used by these businesses is small ($325 to $591 for each 
vehicle (vehicles valued between $200,000 and $400,000)). NHTSA 
anticipates that fuel costs for these businesses will increase between 
$1,862 and $4,790 (in 2020 dollars) per vehicle over its lifetime. 
These expected increases in costs are small in comparison to the cost 
of each of these vehicles. Given that these costs will equally affect 
all operators, the small operators will be able to pass these costs 
onto their consumers. This final rule does not require retrofitting of 
vehicles on the road.

Executive Order 13132 (Federalism)

    NHTSA has examined this final rule pursuant to Executive Order 
13132 (64 FR 43255; Aug. 10, 1999) and has determined that no 
additional consultation with States, local governments, or their 
representatives is mandated beyond the rulemaking process. The agency 
has concluded that the rule does not have sufficient federalism 
implications to warrant consultation with State and local officials or 
the preparation of a federalism summary impact statement. The rule does 
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 have preemptive effect in two ways. First, the 
National Traffic and Motor Vehicle Safety Act contains an express 
preemption provision that 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 the 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 address the same aspect of performance.
    The express preemption provision described above is subject to a 
savings clause under which ``[c]ompliance 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 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 the 
existence of 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, NHTSA has considered whether 
this 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 (e.g., the language 
and structure of the regulatory text) and objectives of this final rule 
and does not foresee any potential State requirements that might 
conflict with it. NHTSA does not intend that this final rule preempt 
state tort law that would effectively

[[Page 74302]]

impose a higher standard on motor vehicle manufacturers than that 
established by this rule. Establishment of a higher standard by means 
of State tort law would not conflict with the standard issued by this 
final rule. Without any conflict, there could not be any implied 
preemption of a State common law tort cause of action.

National Environmental Policy Act

    NHTSA has analyzed this final rule for the purposes of the National 
Environmental Policy Act. The agency has determined that implementation 
of this action will not have any significant impact on the quality of 
the human environment.

Paperwork Reduction Act

    Under the procedures established by the Paperwork Reduction Act of 
1995, a person is not required to respond to a collection of 
information by a Federal agency unless the collection displays a valid 
Office of Management and Budget (OMB) control number. This rulemaking 
would not establish any new information collection requirements.

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 SAE International. The 
NTTAA directs this agency to provide Congress, through OMB, 
explanations when the agency decides not to use available and 
applicable voluntary consensus standards.
    While the agency is not aware of any voluntary standards that exist 
regarding rollover structural integrity for the large buses covered by 
this final rule, the agency has examined the applicable European Union 
standard (ECE R.66). As discussed extensively above, we have adopted an 
ECE R.66-based test, in part, to avoid requiring manufacturers to meet 
fundamentally different rollover requirements than those required in 
the European Union. The areas of this final rule that differ from ECE 
R.66, and the reasons in support, are extensively discussed in the 
earlier sections of this preamble.

Executive Order 12988

    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 issue of 
preemption is discussed above in connection with E.O. 13132. 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.

Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 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 expenditure by State, local or tribal governments, in the 
aggregate, or by the private sector, of more than $158 million annually 
(adjusted for inflation to 2020 dollars with base year of 1995). This 
final rule will not result in expenditures by State, local or tribal 
governments, in the aggregate, or by the private sector in excess of 
$158 million annually.

Plain Language

    Executive Order 12866 and E.O. 13563 require 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 inform us.

Regulation Identifier Number (RIN)

    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.

Privacy Act

    Anyone is able to search the electronic form of all comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78).

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicles, Motor vehicle safety.

    In consideration of the foregoing, NHTSA amends 49 CFR part 571 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.

Subpart B--Federal Motor Vehicle Safety Standards

0
2. Section 571.227 is added to read as follows:


Sec.  571.227  Standard No. 227; Bus rollover structural integrity.

    S1. Scope. This standard establishes performance requirements for 
bus rollover structural integrity.
    S2. Purpose. The purpose of this standard is to reduce death and 
injuries resulting from the structural collapse of the bus body 
structure in rollover crashes and from partial and complete ejections 
through emergency exits opening in such crashes.
    S3. Application.

[[Page 74303]]

    (a) Subject to S3(b), this standard applies to:
    (1) Over-the-road buses; and
    (2) Buses that are not over-the-road buses, and that have a gross 
vehicle weight rating (GVWR) greater than 11,793 kilograms (26,000 
pounds).
    (b) This standard does not apply to:
    (1) School buses, school bus derivative buses, transit buses, and 
prison buses; and
    (2) Buses with 7 or fewer designated seating positions rearward of 
the driver's seating position that are forward-facing or can convert to 
forward-facing without the use of tools.
    S4. Definitions.
    Occupant compartment means a space within the vehicle interior 
intended for driver and passenger use, excluding any space occupied by 
fixed appliances such as bars, kitchenettes, or toilets.
    Over-the-road bus means a bus characterized by an elevated 
passenger deck located over a baggage compartment.
    Prison bus means a bus manufactured for the purpose of transporting 
persons subject to involuntary restraint or confinement and has design 
features consistent with that purpose.
    School bus is defined in Sec.  571.3.
    School bus derivative bus means a bus that meets Federal motor 
vehicle safety standards for school buses regarding emergency exits 
(Sec.  571.217), rollover protection (Sec.  571.220), bus body joint 
strength (Sec.  571.221), and fuel system integrity (Sec.  571.301).
    Stop-request system means a vehicle-integrated system for passenger 
to use to signal to a vehicle operator that they are requesting a stop.
    Survival space means all points within a three-dimensional space in 
the occupant compartment as defined within the following volume:
    (1) The front boundary of the survival space is a transverse 
vertical plane forward of the most forward seat (whether passenger, or 
driver seat) when the seat back is in the manufacturer's nominal design 
riding position. This transverse vertical plane is:
    (i) For a forward-facing seat, 600 millimeters (mm) in front of the 
forward most point on the longitudinal centerline of the front surface 
of the seat back when the seat is in its forward most position;
    (ii) For a rearward-facing seat, through the most forward point 
(relative to the vehicle) on the longitudinal centerline of the seat 
back when the seat is in its forward most position with respect to the 
vehicle;
    (iii) For a side-facing seat, through the most forward point 
(relative to the vehicle) on the seat, including the seat back, seat 
arm rest, and seat cushion.
    (2) The rear boundary of the survival space is the inside surface 
of the rear wall of the occupant compartment of the vehicle.
    (3) The outer boundary of the survival space at any transverse 
cross section between, or at the front and rear boundaries, is defined 
on each side of the vehicle by the occupant compartment floor and the 
following three line segments (see Figure 1 of this section, provided 
for illustration purposes only):
    (i) Segment 1 extends vertically from the floor to an end point 
that is 500 mm above the floor and 150 mm inboard of the side wall.
    (ii) Segment 2 starts at the end point of Segment 1. The end point 
of Segment 2 is 750 mm vertically above and 250 mm horizontally inboard 
of the end point of Segment 1.
    (iii) Segment 3 is a horizontal line that starts at the end point 
of Segment 2 and ends at the vertical longitudinal center plane of the 
vehicle.
    Transit bus means a bus that is equipped with a stop-request system 
sold for public transportation provided by, or on behalf of, a State or 
local government and that is not an over-the-road bus.
    S5. Requirements. When tested under the conditions in S6 and the 
test procedures specified in S7, each bus shall meet the requirements 
in S5.1 and S5.2.
    S5.1 Survival space intrusion. No part of the vehicle that is 
outside the survival space shall intrude into the survival space during 
the movement of the tilting platform or resulting from impact of the 
vehicle on the impact surface, except as provided below in this 
paragraph.
    (a) Items separated from the vehicle and with a mass less than 15.0 
grams that enter the survival space will not be considered for this 
evaluation of survival space intrusion.
    (b) Portions of a bus over which there is not a permanent roof, 
such as the upper level of an open-top double-decker bus, will not be 
considered for this evaluation.
    S5.2 Opening of Emergency exits. Emergency exits shall not open 
during the movement of the tilting platform or resulting from impact of 
the vehicle on the impact surface.
    S6. Test conditions.
    S6.1 Tilting platform.
    S6.1.1 The tilting platform has a top surface that rests 
horizontally at its initial position and is of sufficient size to fully 
contact the bottom of the vehicle's tires, as shown in Figure 2 of this 
section (figure provided for illustration purposes only).
    S6.1.2 The top surface of the tilting platform, at its initial 
position, is 800  20 millimeters (mm) above the impact 
surface specified in S6.1.6, as shown in Figures 1 and 2 of this 
section (figures provided for illustration purposes only).
    S6.1.3 The axis of rotation of the tilting platform is a maximum of 
a 100 mm horizontal distance from the edge of the impact surface 
closest to the platform and a maximum of 100 mm below the horizontal 
plane at the top surface of the tilting platform as shown in Figure 3 
of this section (figure provided for illustration purposes only).
    S6.1.4 The tilting platform is equipped with rigid wheel supports 
on the top surface as illustrated in Figure 3 of this section (figure 
provided for illustration purposes only). At each vehicle axle, the 
wheel closest to the platform's axis of rotation is supported. The 
rigid wheel supports are positioned to make contact with the outboard 
tire sidewall of the supported wheels with the vehicle positioned as 
specified in S6.3.1 to prevent sliding of the vehicle during the test. 
Each rigid wheel support has the following dimensions:
    (a) The height above the top surface of the tilting platform is no 
greater than two-thirds of the vertical height of the adjacent tire's 
sidewall.
    (b) The width is a minimum of 19 mm.
    (c) The length is a minimum of 500 mm.
    (d) The top inboard edge has a radius of 10 mm.
    S6.1.5 While raising the platform, the tilting platform roll angle, 
measured at the outside of each wheel farthest from the pivot point, 
does not differ by more than one degree.
    S6.1.6 The impact surface is horizontal, uniform, dry, and smooth 
concrete. The impact surface covers an area that is large enough to 
ensure that the vehicle does not strike beyond the impact surface 
edges.
    S6.2 Vehicle preparation.
    S6.2.1 The vehicle's tires are inflated to the manufacturer's 
recommended tire pressure.
    S6.2.2 Test equipment may be attached securely to the bus structure 
such that the equipment does not break away from the bus structure from 
the time the tilting platform begins movement to after the vehicle 
comes to rest on the impact surface.
    S6.2.3 Fixed seats may be removed or adjustable seats repositioned 
for the installation of test equipment in the survival space. Ballast 
of any weight up to the weight of the removed seat and 68 kg per 
designated seating position

[[Page 74304]]

may be secured to the bus floor. The ballasts are not placed farther 
forward than the forward most point of the vehicle seat immediately in 
front of the removed seat, and the ballasts are not placed farther 
rearward than the rear most point of the vehicle seat immediately 
behind the removed seat.
    S6.2.4 The fuel tank is filled to any level from 90 to 95 percent 
of capacity. All other vehicle fluids are filled to any level from 90 
to 95 percent of capacity. Fluids may be substituted if the weight of 
the original fluid is maintained.
    S6.2.5 Ballasting. The vehicle is loaded to any weight up to and 
including the GVWR. Up to 68 kilograms (150 pounds) of ballast is 
installed at all designated seating positions that are equipped with 
occupant restraints. The ballast is placed on the top of each seat 
cushion and attached securely to the seat frame such that it does not 
break away from the seat from the time the tilting platform begins 
movement to after the vehicle comes to rest on the impact surface.
    S7 Rollover structural integrity test procedure. Each vehicle shall 
meet the requirements of S5 when prepared as specified in S6.2 and 
tested in accordance with the procedures set forth in paragraphs (a) 
through (f) of this S7.
    (a) Position the vehicle on the tilting platform as illustrated in 
the examples of Figures 2 and 3 of this section with its longitudinal 
centerline parallel to the tilt platform's axis of rotation, the right 
or left side facing the impact surface at NHTSA's option, and with the 
outboard tire sidewall at the widest axle within 100 mm of the axis of 
rotation. (Figures provided for illustration purposes only.)
    (b) Apply the vehicle parking brakes.
    (c) Attach a rigid wheel support to the tilting platform at each 
axle of the vehicle so that it contacts the outboard tire sidewall of 
the wheel closest to the impact surface.
    (d) Block the suspension system of the vehicle to be within 25 mm of the normal riding attitude as loaded in S6.2.5.
    (e) Vehicle windows, doors, and emergency exits are fully closed 
and latched but not locked.
    (f) Tilt the vehicle at a rate not to exceed 5 degrees/second until 
it starts to rollover on its own.
BILLING CODE 4910-59-P

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[GRAPHIC] [TIFF OMITTED] TR29DE21.003


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[GRAPHIC] [TIFF OMITTED] TR29DE21.004


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[GRAPHIC] [TIFF OMITTED] TR29DE21.005


    Issued under authority delegated in 49 CFR 1.95.

Steven Cliff,
Deputy Administrator.
[FR Doc. 2021-27538 Filed 12-28-21; 8:45 am]
 BILLING CODE 4910-59-C


