[Federal Register: October 21, 2008 (Volume 73, Number 204)]
[Rules and Regulations]
[Page 62743-62786]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21oc08-7]
[[Page 62743]]
-----------------------------------------------------------------------
Part III
Department of Transportation
-----------------------------------------------------------------------
National Highway Traffic Safety Administration
-----------------------------------------------------------------------
49 CFR Part 571
Federal Motor Vehicle Safety Standards; Seating Systems, Occupant Crash
Protection, Seat Belt Assembly Anchorages, School Bus Passenger Seating
and Crash Protection; Final Rule
[[Page 62744]]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2008-0163]
RIN 2127-AK09
Federal Motor Vehicle Safety Standards; Seating Systems, Occupant
Crash Protection, Seat Belt Assembly Anchorages, School Bus Passenger
Seating and Crash Protection
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This final rule upgrades the school bus passenger crash
protection requirements of Federal Motor Vehicle Safety Standard
(FMVSS) No. 222. This final rule requires new school buses of 4,536
kilograms (10,000 pounds) or less gross vehicle weight rating (GVWR)
(``small school buses'') to have lap/shoulder belts in lieu of the lap
belts currently required. This final rule also sets performance
standards for seat belts voluntarily installed on school buses with a
GVWR greater than 4,536 kilograms (10,000 pounds) (``large school
buses''). Each State or local jurisdiction may decide whether to
install seat belts on these large school buses. Other changes to school
bus safety requirements include raising the height of seat backs from
508 mm (20 inches) to 610 mm (24 inches) on all new school buses and
requiring a self-latching mechanism on seat bottom cushions that are
designed to flip up or be removable without tools.
DATES: The effective date of this final rule is April 20, 2009. The
requirement for lap/shoulder belts on small school buses applies to
small school buses manufactured on or after October 21, 2011. Likewise,
the requirement that voluntarily-installed seat belts in large school
buses must meet the performance and other requirements specified by
this final rule applies to large school buses manufactured on or after
October 21, 2011. The requirement for the 24-inch seat backs and the
self-latching seat bottom cushions apply to school buses manufactured
on or after October 21, 2009.
Petitions for reconsideration: Petitions for reconsideration of
this final rule must be received not later than December 5, 2008.
ADDRESSES: Petitions for reconsideration of this final rule must refer
to the docket and notice number set forth above and be submitted to the
Administrator, National Highway Traffic Safety Administration, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: For non-legal issues, Mr. Charles
Hott, Office of Vehicle Safety Standards (telephone: 202-366-0247)
(fax: 202-366-4921), NVS-113. For legal issues, Ms. Dorothy Nakama,
Office of the Chief Counsel (telephone: 202-366-2992) (fax: 202-366-
3820), NCC-112. These officials can be reached at the National Highway
Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington,
DC 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Introduction
II. Background
III. Studies
IV. Guiding Principles
a. Comments in Favor of a Federal Requirement for Belts on Large
School Buses
b. Other Issues Concerning Belts on Large School Buses
c. Comments in Favor of a Federal Ban of Lap Belts in Large
School Buses
d. Comments on Use of Section 402 Highway Safety Grant Funds
1. Use of Existing Federal Grant Funds to Purchase Seat Belts
2. Additional Federal Grant Funds to Purchase Seat Belts
V. Overview of Upgrades to Occupant Crash Protection Standards
a. Summary of the NPRM Proposed Upgrades
b. Overview of Comments
c. How This Final Rule Differs From the NPRM
d. Post-NPRM Testing
e. Organization of Discussion
VI. Upgrades for All School Buses
a. Seat Back Height
b. Seat Cushion Latches
VII. Upgrades for Small School Buses
a. Requiring Lap/Shoulder Belts
b. Raising the Weight Limit for Small School Buses
c. FMVSS No. 207, Seating Systems
VIII. Upgrades for Large School Buses
Requiring Voluntarily Installed Belts to Meet Performance
Requirements
IX. Performance and Other Requirements for Vehicle Belt Systems
a. Minimum Seat Width Requirements and Calculating W and Y
1. Flex-Seats
2. Using W and Rounding Up
3. Definitions
b. FMVSS No. 210, Seat Belt Anchorages
1. Height of the Torso Belt Anchorage
2. Anchorage Adjustability
3. Clarifications of Torso Anchorage Location
4. Integration of the Seat Belt Anchorages Into the Seat
Structure
5. Minimum Lateral Anchorage Separation
6. Anchorage Strength
c. Quasi-Static Test for Lap/Shoulder Belts on All School Buses
1. Background
2. Comments and Agency Responses
d. Belt Length
X. Lead Time
XI. Rulemaking Analyses and Notices
I. Introduction
This final rule upgrades the school bus occupant protection
requirements of the Federal motor vehicle safety standards, primarily
by amendments to FMVSS No. 222, ``School bus passenger seating and
crash protection'' (49 CFR 571.222), and also by amendments to FMVSS
Nos. 207, 208, and 210 relating to the strength of the seating system
and seat belt anchorages. The notice of proposed rulemaking (NPRM)
preceding this final rule was published on November 21, 2007 (72 FR
65509; Docket No. NHTSA-2007-0014). This final rule also provides
information to state and local jurisdictions for them to consider when
deciding whether they should order seat belts on large school buses
(school buses with a GVWR greater than 4,536 kilograms (kg) (10,000
pounds (lb)), and responds to comments on the agency's discussion in
the NPRM of recommended ``best practices'' concerning the belts on the
large buses.\1\
---------------------------------------------------------------------------
\1\ ``School bus'' is defined in 49 CFR 571.3 as a bus that is
sold, or introduced in interstate commerce, for purposes that
include carrying students to and from school or related events, but
does not include a bus designed and sold for operation as a common
carrier in urban transportation. A ``bus'' is a motor vehicle,
except a trailer, designed for carrying more than 10 persons. In
this NPRM, when we refer to ``large'' school buses, we refer to
those school buses with GVWRs of more than 4,536 kg (10,000 lb).
These large school buses may transport as many as 90 students.
``Small'' school buses are school buses with a GVWR of 4,536 kg
(10,000 lb) or less. Generally, these small school buses seat 15
persons or fewer, or have one or two wheelchair seating positions.
---------------------------------------------------------------------------
This final rule's most significant changes to FMVSS No. 222
involve:
Requiring small school buses to have a Type 2 seat belt
assembly (a combination of pelvic and upper torso restraints (see FMVSS
No. 209, S3), referred to in this document as a ``lap/shoulder belt'')
at each passenger seating position (these buses are currently required
to have lap belts);
Increasing the minimum seat back height requirement from
508 millimeters (mm) (20 inches) from the seating reference point
(SgRP) to 610 mm (24 inches) for all school buses;
Incorporating test procedures into the standard to test
lap/shoulder belts in small school buses and voluntarily-installed lap
and lap/shoulder belts in large school buses to ensure both the
strength of the anchorages and the compatibility of the seat with
compartmentalization; and
[[Page 62745]]
Requiring all school buses with seat bottom cushions that
are designed to flip up or be removable, typically for easy cleaning,
to have a self-latching mechanism.
The first three upgrades are based on the findings of NHTSA's
school bus research program, discussed in detail later in this
preamble, which the agency conducted in response to the Transportation
Equity Act for the 21st Century (TEA-21).\2\ Requiring small school
buses to have lap/shoulder belts for all passengers and raising the
seat back height on all school buses to 610 mm (24 inches) makes the
highly protective interior of the school bus even safer. Further, as
new designs of lap/shoulder belts intended for large school buses are
emerging in the marketplace, the third initiative will require lap/
shoulder belts to be complementary with compartmentalization, ensuring
that the high level of passenger crash protection is enhanced and not
degraded by any seat belt system.
---------------------------------------------------------------------------
\2\ The fourth initiative, for self-latching mechanisms,
responds to an NTSB recommendation to NHTSA (H-84-75).
---------------------------------------------------------------------------
This rulemaking engaged the agency and public in a new dialogue on
the merits of seat belts on large school buses. It also provided a
forum for a fresh look at divergent positions on the belt issue and an
opportunity to explore the implications of the school bus research
results, the innovation of new technologies, and the realities of
current pupil transportation needs. About 127 individuals and
organizations commented on the NPRM, with many taking the position that
lap/shoulder belts should be required on large school buses and with
many opposed to that idea. Some individuals further sought to have the
agency prohibit the installation of lap belts on large school buses.
Many commenters focused on the emerging seat belt technology that would
enable school bus manufacturers to install lap/shoulder belts on large
school buses without reducing passenger capacity, and asked NHTSA to
ensure that the performance requirements under consideration would not
prohibit that technology. Others did not believe any type of belt
system should be encouraged for large school buses.
After consideration of the comments, we make final most of the
technical changes to the FMVSSs proposed in the NPRM, but have adjusted
test procedures and some performance requirements to accommodate the
emerging seating design technologies. We have also listened to each of
the comments in support of and in opposition to the various issues
involved in this rulemaking and have adjusted some of our views, while
affirming others.
However, this final rule cannot and does not definitively conclude
the debate as to whether a State or local jurisdiction should require
seat belts on its large school buses. Under the National Traffic and
Motor Vehicle Safety Act (``Safety Act'') (49 U.S.C. 30101 et seq.) the
agency is to prescribe motor vehicle safety standards that are
practicable, meet the need for motor vehicle safety, and that are
stated in objective terms. Under the Safety Act, ``motor vehicle
safety'' means 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 * * *.'' 49 U.S.C. 30102(a)(8). After
considering all available information, including the comments to the
NPRM, we cannot conclude that a requirement for seat belts on large
school buses will protect against an unreasonable risk of accidents or
an unreasonable risk of death or injury in an accident. That is, based
on available information, a science-based, data-driven determination
that there should be a Federal requirement for the belts cannot be
supported at this time. Whether the same conclusion can be made by a
State or local jurisdiction is a matter for local decision-makers and
we encourage them to make the decisions most appropriate for their
individual needs to most safely transport their students to and from
school.
This final rule provides the most up-to-date information known to
the agency on seat belts on large school buses. It discusses principles
that the agency has weighed about belts on large buses and attempts to
clear up some misunderstanding expressed in some of the comments about
the benefits of belts in school bus side impacts and rollover crashes.
It affirms that States should have the choice of ordering seat belts on
their large school buses since the belts could enhance the already very
safe passenger protection afforded by large school buses, and makes
sure that these voluntarily-installed belts will not degrade
compartmentalization.
II. Background
The Motor Vehicle and Schoolbus Safety Amendments of 1974 directed
NHTSA to issue motor vehicle safety standards applicable to school
buses and school bus equipment. In response to this legislation, NHTSA
revised several of its safety standards to improve existing
requirements for school buses, extended ones for other vehicle classes
to those buses, and issued new safety standards exclusively for school
buses. FMVSS No. 222, one of a set of new standards for school buses,
improves protection to school bus passengers during crashes and sudden
driving maneuvers.
Effective since 1977, FMVSS No. 222 contains occupant protection
requirements for school bus seating positions and restraining barriers.
Its requirements for school buses with GVWR's of 4,536 kg (10,000
pounds) or less (small school buses) differ from those for school buses
with GVWR's greater than 4,536 kg (10,000 pounds) (large school buses),
because the ``crash pulse'' or deceleration experienced by the small
school buses is typically more severe than that of the large buses in
similar collisions. For the small school buses, the standard includes
requirements that all seating positions must be equipped with lap (Type
1) or lap/shoulder (Type 2) seat belt assemblies and anchorages for
passengers.\3\ NHTSA decided that seat belts were necessary on small
school buses to provide adequate crash protection for the occupants.
For the large school buses, FMVSS No. 222 relies on requirements for
``compartmentalization'' to provide passenger crash protection.
Investigations of school bus crashes prior to issuance of FMVSS No. 222
found the school bus seat was a significant factor in causing injury.
NHTSA found that the seat failed the passengers in three principal
respects: By being too weak, too low, and too hostile (39 FR 27584;
July 30, 1974). In response to this finding, NHTSA developed a set of
requirements which comprise the ``compartmentalization'' approach.
---------------------------------------------------------------------------
\3\ Lap/shoulder belts and appropriate anchorages for the driver
and front passenger (if provided) seating position, lap belts or
lap/shoulder and appropriate anchorages for all other passenger
seating positions.
---------------------------------------------------------------------------
Compartmentalization ensures that passengers are cushioned and
contained by the seats in the event of a school bus crash by requiring
school bus seats to be positioned in a manner that provides a compact,
protected area surrounding each seat. If a seat is not
compartmentalized by a seat back in front of it, compartmentalization
must be provided by a padded and protective restraining barrier. The
seats and restraining barriers must be strong enough to maintain their
integrity in a crash, yet flexible enough to be capable
[[Page 62746]]
of deflecting in a manner which absorbs the energy of the occupant.
They must meet specified height requirements and be constructed, by use
of substantial padding or other means, so that they provide protection
when they are impacted by the head and legs of a passenger.
Compartmentalization minimizes the hostility of the crash environment
and limits the range of movement of an occupant. The
compartmentalization approach ensures that high levels of crash
protection are provided to each passenger independent of any action on
the part of the occupant.
NHTSA has considered the question of whether seat belts should be
required on large school buses from the inception of
compartmentalization and the school bus safety standards. NHTSA has
been repeatedly asked to require belts on buses, has repeatedly
reanalyzed the issue, and has repeatedly concluded that
compartmentalization provides a high level of safety protection that
obviates the safety need for a Federal requirement necessitating the
installation of seat belts. Further, the agency has been acutely aware
that a decision on requiring seat belts in large school buses cannot
ignore the implications of such a requirement on pupil transportation
costs. The agency has been attentive to the fact that, as a result of
requiring belts on large school buses, school bus purchasers would have
to buy belt-equipped vehicles regardless of whether seat belts would be
appropriate for their needs. Prior to today's rulemaking, NHTSA has
concluded that those costs should not be imposed on all purchasers of
school buses when large school buses are currently extremely safe. In
the area of school transportation especially, where a number of needs
are competing for limited funds, persons responsible for school
transportation might want to consider other alternative investments to
improve their pupil transportation programs which can be more effective
at reducing fatalities and injuries than seat belts on large school
buses, such as by acquiring additional new school buses to add to their
fleet, or implementing improved pupil pedestrian and driver education
programs. Since each of these efforts competes for limited funds, the
agency has maintained that those administrators should decide how their
funds should be allocated.
Nonetheless, throughout the past 30 years that compartmentalization
and the school bus safety standards have been in effect, the agency has
openly and continuously considered the merits of a seat belt
requirement for large school buses.\4\ The issue has been closely
analyzed by other parties as well, such as the National Transportation
Safety Board, and the National Academy of Sciences. Various reports
have been issued, the most significant of which are described below.
---------------------------------------------------------------------------
\4\ Through the years, NHTSA has been petitioned about seat
belts on large school buses. (See, e.g., denials of petitions to
require seat belt anchorages, 41 FR 28506 (July 12, 1976), 48 FR
47032 (October 17, 1983); response to petition for rulemaking to
prohibit the installation of lap belts on large school buses, 71 FR
40057 (July 14, 2006).)
---------------------------------------------------------------------------
III. Studies
National Transportation Safety Board, 1987
In 1987, the National Transportation Safety Board (NTSB) reported
on a study of forty-three post-standard school bus crashes investigated
by the Safety Board. NTSB concluded that most fatalities and injuries
in school bus crashes occurred because the occupant seating positions
were directly in line with the crash forces, and that seat belts would
not have prevented those injuries and fatalities. (NTSB/SS-87/01,
Safety Study, Crashworthiness of Large Post-standard School Buses,
March 1987, National Transportation Safety Board.)
National Academy of Sciences, 1989
A 1989 National Academy of Sciences (NAS) study concluded that the
overall potential benefits of requiring seat belts on large school
buses were insufficient to justify a Federal mandate for installation.
The NAS also stated that funds used to purchase and maintain seat belts
might be better spent on other school bus safety programs with the
potential to save more lives and reduce more injuries. (Special Report
222, Improving School Bus Safety, National Academy of Sciences,
Transportation Research Board, Washington, DC, 1989)
National Transportation Safety Board, 1999
In 1999, the NTSB reported on six school bus crashes it
investigated in which passenger fatalities or serious injuries occurred
away from the area of vehicle impact. The NTSB found
compartmentalization to be an effective means of protecting passengers
in school bus crashes. However, because many of those passengers
injured in the six crashes were believed to have been thrown from their
compartments, NTSB believed other means of occupant protection should
be examined. (NTSB/SIR-99/04, Highway Safety Report, Bus
Crashworthiness Issues, September 1999, National Transportation Safety
Board)
National Academy of Sciences, 2002
In 2002, the NAS published a study that analyzed the safety of
various transportation modes used by school children to get to and from
school and school-related activities. The report concluded that each
year there are approximately 815 school transportation fatal injuries
per year. Two percent were school bus-related, compared to 22 percent
due to walking/bicycling, and 75 percent from passenger car crashes,
especially those with teen drivers. The report stated that changes in
any one characteristic of school travel can lead to dramatic changes in
the overall risk to the student population. Thus, the NAS concluded, it
is important for school transportation decisions to take into account
all potential aspects of changes to requirements to school
transportation. (Special Report 269, ``The Relative Risks of School
Travel: A National Perspective and Guidance for Local Community Risk
Assessment,'' Transportation Research Board of the National Academies,
2002)
National Highway Traffic Safety Administration, 2002
In 2002, NHTSA studied school bus safety (2002 School Bus Safety
Study). Based on this research, the agency issued a Congressional
Report that detailed occupant safety on school buses and analyzed
options for improving occupant safety. (``Report to Congress, School
Bus Safety: Crashworthiness Research, April 2002,'' http://www-
nrd.nhtsa.dot.gov/departments/nrd-11/SchoolBus/SBReportFINAL.pdf)
(hereinafter ``2002 Report to Congress''). The agency provided
additional analysis of these data in a Technical Analysis supporting
the NPRM (``2007 Technical Analysis'').\5\
---------------------------------------------------------------------------
\5\ ``NHTSA Technical Analysis to Support Upgrading the
Passenger Crash Protection in School Buses (September 2007),''
Docket No. NHTSA-2007-0014.
---------------------------------------------------------------------------
TEA-21 directed NHTSA to study and assess school bus occupant
safety and analyze options for improvement. In response, the agency
developed a research program to determine the real-world effectiveness
of FMVSS No. 222 requirements for school bus passenger crash
protection, evaluate alternative passenger crash protection systems in
controlled laboratory tests, and provide findings to support rulemaking
activities to upgrade the passenger crash protection for school bus
passengers.
The research program consisted of NHTSA first conducting a full-
scale school bus crash test to determine a representative crash pulse.
The crash
[[Page 62747]]
test was conducted by frontally impacting a conventional style school
bus (Type C) into a rigid barrier at 30 mph (48.3 km/h). The impact
speed was chosen to ensure that sufficient energy would be imparted to
the occupants in order to evaluate the protective capability of
compartmentalization, plus provide a level at which other methods for
occupant injury mitigation could be evaluated during sled testing. A 30
mph (48 km/h) impact into the rigid barrier is also equivalent to two
vehicles of similar size impacting at a closing speed of approximately
60 mph (96 km/h), which represents a severe frontal crash.
In the crash test, we used Hybrid III 50th percentile adult male
dummies (representing adult and large teenage occupants), 5th
percentile adult female (representing an average 12-year-old (12YO)
occupant), and a 6-year-old child dummy (representing an average 6
year-old (6YO) occupant). The dummies were seated so that they were as
upright as possible and as rearmost on the seat cushion as possible.
The agency evaluated the risk of head injury recorded by the dummies
(Head Injury Criterion (HIC15)), as well as the risk of chest (chest
G's) and neck injury (Nij),\6\ as specified in FMVSS No. 208 ``Occupant
crash protection.''
---------------------------------------------------------------------------
\6\ The injury assessment reference values (IARVs) for these
measurements are the thresholds used to assess new motor vehicles
with regard to frontal occupant protection as specified in FMVSS No.
208. HIC15 is a measure of the risk of head injury, Chest G is a
measure of chest injury risk, and Nij is a measure of neck injury
risk. For HIC15, a score of 700 is equivalent to a 30 percent risk
of a serious head injury (skull fracture and concussion onset). In a
similar fashion, Chest G of 60 equates to a 60 percent risk of a
serious chest injury and Nij of 1 equates to a 22 percent risk of a
serious neck injury. For all these measurements, higher scores
indicate a higher likelihood of risk. For example, a Nij of 2
equates to a 67 percent risk of serious neck injury while a Nij of 4
equates to a 99 percent risk. More information regarding these
injury measures can be found at NHTSA's Web site (http://www-
nrd.nhtsa.dot.gov/pdf/nrd-11/airbags/rev_criteria.pdf).
---------------------------------------------------------------------------
NHTSA then ran frontal crash test simulations at the agency's
Vehicle Research and Test Center (VRTC), using a test sled to evaluate
passenger protection systems. Twenty-five sled tests using 96 test
dummies of various sizes utilizing different restraint strategies were
conducted that replicated the acceleration time history of the school
bus full-scale frontal impact test. The goal of the laboratory tests
was to analyze the dummy injury measures to gain a better understanding
of the effectiveness of the occupant crash protection countermeasures.
In addition to injury measures, dummy kinematics and interaction with
restraints (i.e., seat backs and seat belts, as well as each other)
were also analyzed to provide a fuller understanding of the important
factors contributing to the type, mechanism, and potential severity of
any resulting injury.
NHTSA studied three different restraint strategies: (a)
Compartmentalization; (b) lap belt (with compartmentalization); and (c)
lap/shoulder belt (with compartmentalization).
Within the context of these restraint strategies, various boundary
conditions were evaluated: (a) Seat spacing--483 mm (19 inches), 559 mm
(22 inches) and 610 mm (24 inches); (b) seat back height--nominally 508
mm (20 inches) and 610 mm (24 inches); and (c) fore/aft seat occupant
loading.\7\ Ten dummies were tested with misused or out-of-position
(OOP) lap or shoulder restraints. The restraints were misused by
placing the lap belt too high up on the waist, placing the lap/shoulder
belt placed behind the dummy's back, or placing the lap/shoulder belt
under the dummy's arm.
---------------------------------------------------------------------------
\7\ Unbelted occupants in the aft seat will affect the
kinematics of belted occupants in the fore seat due to seat back
deformation. Similarly, belted occupant loading of the fore seat
back through the torso belt will affect the compartmentalization for
unbelted occupants in the aft seat.
---------------------------------------------------------------------------
The agency found the following with regard to compartmentalization:
Head injury measures were low for all dummy sizes, except
when override \8\ occurred.
---------------------------------------------------------------------------
\8\ Override means an occupant's head or torso translates
forward beyond the forward seat back providing compartmentalization.
---------------------------------------------------------------------------
High head injury values (greater than the IARV) or dummy-
to-dummy contacts beyond the biofidelic range of the test dummy were
produced when the large male dummy overrode the seat in front of it,
while the high-back seats lessened the override.
Low chest injury measures were observed for all dummy
sizes.
Two 50th percentile male dummies in a seat were not well
compartmentalized, as evidenced by head and neck injury measures being
greater than the IARVs, due to large forward seat back deformation.
Based on dummy motion and interaction with each other,
compartmentalization was sensitive to seat back height for the 50th
percentile male dummy.
Compartmentalization of 6YO and 5th percentile female
dummies did not appear to be sensitive to rear loading conditions.
Compartmentalization of the 50th percentile male dummy did
not appear to be sensitive to seat spacing for the 50th percentile male
dummy.
The average neck injury values for the 6YO and 5th
percentile female dummy tests were above the IARV.
The agency found the following with regard to lap belts:
Head and chest injury values were low for all dummy sizes.
The average neck injury value was greater than the IARV
for all test dummies, and was 70 percent above for the 5th percentile
female dummy.
Neck injury values increased for the 5th percentile female
dummy when the seat spacing was increased from 483 mm (19 inches) to
559 mm (22 inches).
The agency found the following with regard to properly worn lap/
shoulder belts:
Head, chest and neck injury values were low for all size
dummies and below those seen in the compartmentalization and lap belt
results.
Average head injury values were, at most, about half those
seen in the compartmentalization and lap belt results.
Neck injury values increased with application of rear
loading for the 6YO and 5th percentile female dummies.
Lap/shoulder belt systems would require approximately 380
mm (15 inches) of seat width per passenger seating position. The
standard school bus bench seat is 990 mm (39 inches) wide, and is
considered a three-passenger seat. If the width of the seat bench were
increased to 1,143 mm (45 inches) for both seats on the left and right
side of the school bus, the aisle width would be reduced to an
unacceptable level.
NHTSA found that, for improperly worn lap/shoulder belts:
Placing the shoulder belt behind the dummy's back resulted
in dummy motion and average dummy injury values similar to lap belt
restraint.
Placing the shoulder belt under the dummy's arm provided
more restraint on dummy torso motions than when the belt is placed
behind the back. Average dummy injury values for the 6YO were about the
same as seen with lap/shoulder belts and 5th percentile female dummy
injury values were between those seen in lap/shoulder belts and lap
belts.
It is important to note that these sled tests simulated only a
severe, 30 mph (48.3 km/h) frontal crash condition. Therefore, the
agency was not able to conclude that the higher neck injury measures
associated with the lap belt in these tests would translate to an
overall greater safety risk. Lap belts could retain the occupants in
side impact, rollover, or lower speed frontal crashes, which occur with
a greater frequency.
[[Page 62748]]
IV. Guiding Principles
School buses are one of the safest forms of transportation in the
U.S. Every year, approximately 474,000 public school buses,
transporting 25.1 million children to and from school and school-
related activities,\9\ travel an estimated 4.8 billion route miles.\10\
Over the 11 years ending in 2005, there was an annual average of 26
school transportation related fatalities (11 school bus occupants
(including drivers and passengers) and 15 pedestrians).\11\ Six of the
bus occupant fatalities were school-age children, with the remaining
fatalities being adult drivers and passengers.\12\ On average, there
were 9 crashes per year in which an occupant was killed. The school bus
occupant fatality rate of 0.23 fatalities per 100 million vehicle miles
traveled (VMT) is more than six times lower than the overall rate for
motor vehicles of 1.5 per 100 million VMT.\13\
---------------------------------------------------------------------------
\9\ School Transportation News, Buyers Guide 2007.
\10\ This value was reported by School Bus Fleet 2007 Fact Book.
\11\ ``Traffic Safety Facts--School Transportation Related
Crashes,'' NHTSA, DOT HS 810 626. The data in this publication
account for all school transportation-related deaths in transporting
students to and from school and school related activities. This
includes non-school buses used for this purpose when these vehicles
are involved in a fatal crash.
\12\ For the crashes resulting in the 11 annual school bus
occupant fatalities, 51 percent of the fatalities and 52 percent of
the crashes were from frontal collisions. Traffic Safety Facts 2005,
School Transportation-Related Crashes, DOT HS 810 626.
\13\ Traffic Safety Facts 2005, DOT HS 810 631.
---------------------------------------------------------------------------
The 2002 School Bus Safety Study provided fresh findings about
possible enhancements to large school bus occupant crash protection
that could be achieved through the use of lap/shoulder seat belts.\14\
The results validated the possibility that a passenger who has a seat
on the school bus and who was belted with a lap/shoulder belt could
have an even lower risk of head and neck injury in a severe crash than
on current large school buses.\15\ However, given the existing safety
of being transported on large school buses, exemplified by the low
number of children that are seriously injured or killed, the societal
benefit of further reducing, at a cost, an already extremely low
likelihood of serious injury or death merited an open and robust
debate. The agency grappled with whether Federal enhancements of an
already very safe vehicle were reasonable and appropriate, especially
when the cost of installing and maintaining lap/shoulder belts on the
buses could impact the ability of transportation providers to transport
children to or from school or related events or spend funds on other
avenues affecting pupil safety.
---------------------------------------------------------------------------
\14\ NHTSA's Preliminary Regulatory Evaluation accompanying the
NPRM included the benefits of seat belts in rollover crashes and the
Final Regulatory Evaluation accompanying this final rule will
include the benefits of seat belts in side impacts.
\15\ The tests were in a controlled laboratory investigation so
assumptions are made about how representative the laboratory tests
were of the real world, e.g., how representative the test dummies
were of children, the sled test of an actual vehicle crash, the
magnitude of the crash replicated as compared to real-world school
bus crashes, and the ability of purchasers to purchase the belts
without incurring an unreasonable trade-off in pupil transportation
safety elsewhere.
---------------------------------------------------------------------------
Funds provided for pupil transportation are limited, and monies
spent on lap/shoulder belts on large school buses usually draw from the
monies spent on other crucial aspects of school transportation. Other
pupil transportation expenses include purchases of new school buses to
ensure that as many children as possible are provided school bus
transportation, driver and pupil training on safe loading practices
(most of the school bus-related fatalities occur outside the bus while
children are being loaded or unloaded), on operational costs, such as
fuel costs, and on upkeep and maintenance of school buses and school
bus equipment. Given the tradeoff between installing seat belts on
large school buses and implementing other safety measures that could
benefit pupil transportation or other social welfare initiatives, and
given that large school buses are already very safe, we believed that
States should be permitted the choice of deciding whether belts should
be part of their large school bus purchases.
Bearing in mind the already excellent safety record of large school
buses and the real-world demands on pupil transportation providers, we
did not believe that the available information indicated that seat
belts on large school buses would address an unreasonable risk of
injury or fatality, and so we did not propose in the NPRM that they be
required by the FMVSS to be installed on these vehicles. However, we
did want to provide the public the information we obtained from the
school bus research program about the enhancements that lap/shoulder
belts achieved in the sled test program. Further, in the NPRM, we
wanted to inform transportation providers of the concern that
purchasers should consider lap/shoulder belts on large school buses
only if there would be no reduction in the number of children that are
transported to or from school or related events on large school buses.
We believed that reducing bus ridership would likely result in more
student fatalities, since walking and private vehicles are less safe
than riding a large school bus without seat belts.
We sought in the NPRM to articulate a best practices approach. We
thought that the best practice would be for local decision-makers to
consider the already excellent safety record of school buses, the
economic impact on school systems incurred by the costs of seat belts
and the impact that lap/shoulder belts have on the seating capacity of
large school buses. We indicated that, if ample funds were available
for pupil transportation, and pupil transportation providers could
order and purchase a sufficient number of school buses needed to
provide school bus transportation to all children, pupil transportation
providers should consider installing lap/shoulder belts on large school
buses. If a State were to determine that lap/shoulder belts were in its
best interest, we encouraged the State to install those systems.
a. Comments in Favor of a Federal Requirement for Belts on Large School
Buses
Widely divergent views were expressed in the comments to the NPRM
as to whether seat belts should be required or permitted to be
optional. Many commenters, including State and local jurisdictions,
supported the approach of allowing purchasers the choice of deciding
whether to include seat belts on their large school buses rather than
of mandating the belts. The National School Transportation Association
(NSTA) \16\ stated that States and local districts should be given the
option of whether to require seat belts on their school buses because
States and local districts are in the best position to determine the
most effective use of their limited resources, and because NSTA
believed that entities that affirmatively choose to equip their buses
with lap/shoulder belts are more likely to provide the necessary
support to ensure that the belts are worn. However, several State
groups were concerned that the NPRM's reference to the availability of
402 funds for the purchase and installation of seat belts on school
buses could result in the states funding less-essential highway safety
activities to the detriment of potentially more effective and
worthwhile highway safety programs, such as buckle-up programs and
those combating drunk or aggressive driving. There was widespread
support of NHTSA's view that bus occupancy must
[[Page 62749]]
not be reduced due to installation of belt systems. Many comments
wanted to make sure that the final rule would permit new flexible
school bus seat designs that have emerged in the marketplace (lap/
shoulder belts on these bench seats can be adjusted to provide two lap/
shoulder belts for two average-size high school students or three lap/
shoulder belts for three elementary school students). Some advocacy
groups embraced the NPRM as facilitating their efforts to get seat
belts installed on large school buses.
---------------------------------------------------------------------------
\16\ NSTA states that it is an association of private businesses
providing transportation services to public school districts and
private schools across the country.
---------------------------------------------------------------------------
However, several commenters (e.g., the National Association for
Pupil Transportation (NAPT) and the New York Association for Pupil
Transportation (NYAPT)) \17\ expressed concern that not enough is known
about belt systems to proceed with the rulemaking. These commenters
were concerned whether seat belts could reduce the overall safety of
school buses. NAPT believed that NHTSA should ensure that lap/belt
systems do not negatively affect compartmentalization in any respect,
and should quantify ``the marginal safety benefits (if any)'' that lap/
shoulder belts provide beyond compartmentalization. The commenter
stated that NHTSA should consider whether the belts could reduce safety
through incorrect use, by impeding emergency evacuation, and by
reducing safety in side impacts and rollovers (the commenter did not
explain the concerns it had with the belts affecting side impact and
rollover performance). NAPT believed that on-going agency research
(discussed in the 2002 Report to Congress) should be completed before
further action on this rulemaking is taken by NHTSA.
---------------------------------------------------------------------------
\17\ The NAPT describes itself as a nonprofit organization that
supports people who transport children to and from school. Its
membership organizations include professional school transportation
personnel in both the public and private sector, school bus
manufacturers, and aftermarket service and product suppliers. The
NYAPT represents supervisors and managers of both public school and
private operators employed in local schools in New York State.
---------------------------------------------------------------------------
Similarly, the NTSB expressed concern that lap/shoulder belts have
not been sufficiently researched in non-frontal crash modes, e.g.,
side, oblique and rollover crashes.
In contrast, notwithstanding the discussion in the NPRM that the
agency was not proposing a requirement for belts in large school buses,
many commenters urged the agency to go beyond what was proposed in the
NPRM and require lap/shoulder belts on large school buses.\18\ The
National Coalition for School Bus Safety (NCSBS) stated that if lap/
shoulder belts coupled with compartmentalization affords ``optimum
protection'' as stated in the NPRM, lap/shoulder belts should be
required on large school buses to provide occupants side and rollover
crash protection. The commenter indicated that even though ``there has
been no documentation of mortality or morbidity due to the 20 inch seat
back height or failure of cushion retention,'' NHTSA proposed to
increase seat back height and require self-latching cushions. The
commenter believed that ``[t]his stands in sharp contrast with scores
of documented fatalities and severe injuries proven to result'' in side
and rollover crashes due to the absence of seat belts on large school
buses.\19\
---------------------------------------------------------------------------
\18\ As noted earlier, many other commenters opposed the idea of
a requirement for belts on large school buses.
\19\ No data was provided by the commenter explaining or
supporting its reference to those fatalities and injuries; we know
of no such data and cannot substantiate this statement.
---------------------------------------------------------------------------
Similarly, the West Brook Bus Crash Families (WBBCF) \20\ believed
that the use of seat belts, in any vehicle, saves lives and reduces
injuries and urged the agency to require seat belts on large school
buses. The commenter believed that ``many `real world' considerations
are conspicuously absent from consideration without explanation'' and
that the agency's ``cost/benefit `balance' is arbitrary and
capricious.'' WBBCF stated that speculation based on reductions in
``manufacturer capacity'' of bus seating ``are confined to a few
elementary school routes and often resolved though [sic] better route
scheduling.'' The commenter believed that ``[t]here is a complete
absence of any real world evidence causally linking reduction in school
bus seating capacity to increased risk of death or injury of
alternative forms of travel.'' In addition, the commenter stated that
``NHTSA should clearly state the proven increases in occupant
protection resulting from lap/shoulder belts use: 45-60% in frontal
collision, 70% in rollover and lateral collisions for which
compartmentalization alone is `incomplete' and ineffective.'' The
commenter believed that this effective rate would result in ``predicted
life-saving and injury-reducing benefits of lap-shoulder belts using
real world data (5-8 lives saved each year; 3,000-5,000 injuries
reduced annually.'' The commenter questioned why the agency did not
research whether belts could enhance compartmentalization in side
crashes and rollovers in the 2002 School Bus Safety Study. In addition,
the commenter believed that NHTSA should calculate the associated
reductions in personal and societal costs due to lap/shoulder belts in
terms of medical, insurance and liability expense, physical disability
and trauma, emotional trauma, and lost education days. Further, the
commenter also believed that NHTSA should have acknowledged a finding
of the American Academy of Pediatrics that between 6,000 and 10,000
children per year are injured in school bus accidents, and that, the
commenter believed, many of these injuries could be reduced by a lap/
shoulder belt requirement.
---------------------------------------------------------------------------
\20\ WBBCF states that it is a parent advocacy organization
comprised of parents and family members of the 2006 West Brook High
School girls' varsity soccer team, Beaumont, Texas. It states that
in March 2006, a motor coach bus transporting the team to a playoff
game overturned, killing two teammates and injuring others. The
comment states that WBBCF was formed to advocate safer bus travel
for school children, including the addition of lap/shoulder seat
belts in school buses and motor coaches.
---------------------------------------------------------------------------
Some commenters (e.g., the NCSBS and WBBCF) believed that lap/
shoulder belts on large school buses should also be required to
reinforce the message to children that they should ``buckle-up'' while
riding in passenger cars and other private vehicles. NCSBS also stated
that lap/shoulder belts would reduce driver distraction by improving
student behavior, which in turn will help reduce driver distraction and
the frequency of school bus crashes due to driver distraction.
Adding another facet to the comments were responses from school bus
drivers and other school bus personnel. School bus drivers were
universally opposed to having belts on the buses, believing that the
belts were unnecessary, that they would impede emergency egress, and
that drivers have limited means to get students to buckle up. George
Davis of the Fayette County Schools bus shop expressed concern about
the agency's calling lap/shoulder belts coupled with
compartmentalization ``optimum crash protection.'' He was concerned
that there was an implication that those who might choose to spend
their resources on safety-related items other than belts would be going
against the ``best practices'' discussed in the NPRM. He stated that it
should be up to each purchaser to determine whether to purchase seat
belts on large school buses, and that if a purchaser decides not to
purchase the belts, then they are also determining what is the ``best
practice'' for their needs.
Agency Response
After reviewing all the data, including the comments on the NPRM,
NHTSA again concludes that large school buses
[[Page 62750]]
that meet our school bus safety standards without seat belts do not
pose an unreasonable risk of death or injury in an accident. Thus, we
do not find a safety need for a Federal mandate for seat belts on large
school buses. However, our statutory authority expressly permits State
or local jurisdictions to prescribe safety standards that impose higher
performance requirements than the Federal safety standards for vehicles
that are for the State's own use, such as school buses. Accordingly, we
affirm that States and local jurisdictions should continue to be
offered the choice of whether to order seat belts on their large school
buses since the belts could provide enhancements to
compartmentalization. We agree with NSTA that entities that
affirmatively choose to equip their buses with lap/shoulder belts are
more likely to provide the necessary support to ensure that the belts
are worn properly. They are also more likely to be willing and able to
instruct their students and drivers on emergency egress procedures
affected by the belts. States and local districts need to examine the
safest means of transport for their children, and this approach lets
them decide how to spend their funds. Further, the performance
requirements of this final rule for voluntarily-installed belts will
help ensure that the belts enhance and do not degrade
compartmentalization.
However, we are not able to concur with those commenters suggesting
that lap/shoulder belts should be required on large school buses. The
agency had to balance several compelling principles in this rulemaking.
First, the agency considered the safety risks to which children on
large school buses are exposed (how are children being injured or
killed in school bus-related crashes) and whether seat belts would
reduce that risk. Data indicate that children who are killed in school
bus-related crashes are typically killed outside of the school bus as
they are being loaded or unloaded onto the vehicle, by motorists
passing the bus or by the school bus itself.\21\ Inside the bus, the
children are typically killed when they are in the direct zone of
intrusion of the impacting vehicle or object. In the loading zone
event, seat belts will not have an effect on preventing the fatality.
In the intrusion zone, seat belts will similarly be unlikely to be
effective in preventing the fatality, even in side impacts. In a
rollover situation where there is ejection, the belts would have a
beneficial effect, but the incidence of fatal ejections in rollover
accidents occurring from a large school bus is rare.
---------------------------------------------------------------------------
\21\ ``Traffic Safety Facts 2006: School Transportation-Related
Crashes,'' DOT HS 810 813.
---------------------------------------------------------------------------
WBBCF believed that ``NHTSA should clearly state the proven
increases in occupant protection resulting from lap/shoulder belt use:
45-60 percent in frontal collisions, 70 percent in rollover and lateral
collisions for which compartmentalization alone is `incomplete' and
ineffective.'' The effectiveness statistics to which WBBCF refers \22\
are those that have been determined based on the crash experience of
passenger cars and other light duty vehicles, although the
effectiveness in passenger vehicles is much less than 70 percent in
side impacts. These vehicles' crash experiences are different from that
of large school buses. As noted earlier in this preamble, fatalities in
frontal crashes of high severity are infrequent. In school bus side
crashes, fatalities usually occur only in the area of intrusion from a
heavy truck. Seat belts provide no benefit for an occupant sitting in
an intrusion zone when struck by a large intruding object, but can
provide benefits for those away from the intrusion zone. Although belts
are effective in reducing the risk of fatality in rollovers due to
ejection, there are very few fatal ejections in large school bus
rollover crashes.
---------------------------------------------------------------------------
\22\ The correct effectiveness estimates in fatality reduction
for passenger cars is 50 percent for frontal impacts, 74 percent for
rollover crashes and 21 percent in side impacts.
---------------------------------------------------------------------------
Nonetheless, seat belts may have some effect on reducing the risk
of harm in frontal, side and rollover crashes, as they can help
restrain occupants within the seat and not move about in the vehicle
interior toward injurious surfaces.\23\ For this final rule we have
estimated the benefits that would accrue from the addition and correct
use of lap/shoulder belts on large and small school buses in these
crashes. For frontal crashes, we have estimated the benefits of the
belts by using the sled test data obtained from the 2002 School Bus
Safety Study, comparing dummy injury values with lap/shoulder belts
versus injury values with compartmentalization. This analysis is
explained in detail in the FRE accompanying this final rule. With
regard to the estimated effectiveness of seat belts in large school bus
side and rollover crashes, we have used the effectiveness statistics of
74 percent for rollover crashes and 21 percent for side impacts
attributed to seat belts in passenger cars because no other information
about the possible effect of belts in buses is available. With those
data, we have estimated the benefits associated with the addition and
correct use of lap/shoulder belts on large and small school buses.
---------------------------------------------------------------------------
\23\ It is noted that raising the seat back height on school
buses as required by this rule achieves a portion of that risk
reduction for unbelted passengers on school buses. In the agency's
2002 School Bus Research Program, with compartmentalization, low
head injury values were observed for all dummy sizes, except when
override occurred. High-back seats were shown to prevent override.
---------------------------------------------------------------------------
The 2002 NAS study indicated that approximately 800 school aged-
children are killed annually in motor vehicle crashes during normal
school travel hours, among which only 0.5 percent were passengers on
school buses and 1.5 percent were pedestrians involved in school bus
related crashes. Seventy-five percent of the annual fatalities were to
occupants in passenger vehicles and 24 percent were to those walking or
riding a bicycle. Based on this study, the agency concluded that by far
the safest means for students to get to school is by a school bus, and
all efforts should be made to get as many students as possible onto
school buses.
When making regulatory decisions on possible enhancements, the
agency must bear in mind how improvements in one area might have an
adverse effect on programs in other areas. The net effect on safety
could be negative if the costs of purchasing and maintaining the seat
belts and ensuring their correct use results in non-implementation or
reduced efficacy of other pupil transportation programs that affect
child safety. For example, some schools are currently eliminating
school bus service for extracurricular activities or shrinking areas of
school bus service due to high fuel prices.\24\ Given that very few
school bus-related serious injuries and fatalities would be prevented
by a requirement mandating seat belts on large school buses, we could
not assure that overall safety would not be adversely affected,
particularly given the many competing demands on school resources and
the widely varying and unique circumstances associated with
transporting children in each of these districts. Nonetheless, this
final rule does not prevent the installation of seat belts on school
buses and provides appropriate performance requirements for these
systems when they are installed.
---------------------------------------------------------------------------
\24\ http://www.usatoday.com/news/education/2008-07-09-
schoolbuses_N.htm.
---------------------------------------------------------------------------
It is worth noting, however, that our analysis of the data
indicates that installing lap/shoulder seat belts on all large school
buses would cost between
[[Page 62751]]
$183 and $252 million.\25\ Those belts would save about 2 lives per
year if every child wore them on every trip. This estimate reflects the
potential benefits of lap/shoulder belts in frontal, side, and rollover
crashes. In addition, correctly worn lap/shoulder belts could prevent
about 1,900 crash injuries each year if every child wore them on every
trip. These benefits would be achieved at a cost of between $23 and $36
million per equivalent life saved. However, to achieve these benefits,
school districts that choose to install belts on large school buses
must have a program to ensure that belts are worn and worn correctly by
the school bus passengers. If belts are not worn, they will offer no
benefits to the passengers. If belts are worn incorrectly, e.g.,
shoulder belt tucked behind the passenger's back, they will not only
not provide the desired additional protection, but may cause injuries.
Absent a program to ensure belts are worn and worn correctly, the
benefits of seat belts on large school buses will be lower than the
numbers shown in our analysis, which assumes 100% belt use and all
belts used correctly.\26\
---------------------------------------------------------------------------
\25\ The range in costs includes both 55 passenger buses (with
loss of seating capacity) and 66 passenger buses with flexible
seating (with no loss of seating capacity). However, they do not
include the costs of a program to ensure correct belt usage.
\26\ If, for example, only 50 percent of passengers were to wear
seat belts, the benefits estimated above would be halved and the
cost per equivalent life saved would rise to between $46 and $72
million.
---------------------------------------------------------------------------
In the NPRM, the agency emphasized its concern that installing lap/
shoulder seat belts on large school buses would reduce the passenger
capacity of the buses. After NHTSA completed its NPRM but before it
published the NPRM in the Federal Register, seating system
manufacturers Takata Corp. (Takata)/M2KLLC(M2K) \27\ and the Safeguard
Division of Indiana Mills Manufacturing Inc. (IMMI) separately
approached the agency to introduce their ``flexible seating systems''
(or ``flex-seats.'') (As noted earlier in this preamble, these seating
systems have lap/shoulder belts and are reconfigurable to accommodate
either three smaller students or two larger students.) Many of the
commenters referred to these systems with approval and asked NHTSA to
ensure that the FMVSS No. 222 requirements under consideration would
not prohibit flex-seat technology.
---------------------------------------------------------------------------
\27\ Takata (also known as TK Holdings) and M2K jointly
developed a flexible occupancy seat.
---------------------------------------------------------------------------
We have accommodated flexible seating systems (hereafter referred
to as flexible occupancy seats or flex-seats), as requested, to
facilitate the use of these new belt systems. However, although flex-
seats may provide a way of offering lap/shoulder belts without
lessening capacity on an individual given bus, there will still be a
cost premium for outfitting school buses with the lap/shoulder belts,
maintaining the seats, and training students and drivers on their use.
The emergence of flex-seats on the market does not change our position
concerning a Federal need to require lap/shoulder belts on large school
buses.
On the capacity issue, WBBCF stated that it perceived the agency as
speculating on its concerns about reduced seating capacity due to
installation of lap/shoulder belts. The commenter stated that
reductions in ``manufacturer capacity'' of bus seating ``are confined
to a few elementary school routes and often resolved though [sic]
better route scheduling.'' The commenter believed that ``[t]here is a
complete absence of any real world evidence causally linking reduction
in school bus seating capacity to increased risk of death or injury of
alternative forms of travel.''
The agency believes that to some extent, the new flexible occupancy
seats may have resolved some of the capacity reduction issues
associated with the earlier versions of lap/shoulder belt seats in
school buses. However, to the extent that transportation providers
decide to use the older lap/shoulder belt equipped school bus seats,
the extent of capacity reduction would depend on each route and may not
always be resolved through better routing. In response to the WBBCF
concern that there is an absence of any real world date linking
reduction in school bus capacity to increased risk of death or injury,
we disagree. The 2002 NAS study clearly shows that a reduction in
school bus ridership would lead to children seeking a less safe form of
transportation to and from school, leading to an increased risk of
serious/fatal injury. The capacity of school buses, along with other
characteristics such as bus length and overall weight, is often
considered by transportation providers when determining which buses can
be used for each route. To the extent that the same size bus could have
less seating capacity and the transportation provider would not have
sufficient resources to add additional buses and drivers, it could
impact the level of school transportation service provided.
Some commenters advocating a requirement for belts on buses
believed that NHTSA did not correctly analyze the pros and cons of a
requirement for lap/shoulder belts on large school buses. The NCSBS
thought it was inconsistent for NHTSA to not propose to require seat
belts on large school buses even though it proposed to require higher
seat backs and self-latching seat cushions, especially when, the
commenter stated, ``there has been no documentation of mortality or
morbidity due to the 20 inch seat back height or failure of cushion
retention.'' In response, as part of good governance, NHTSA has the
responsibility to assess whether each of its initiatives would be cost
effective and propose those that are. The requirements on manufacturers
and purchasers must involve the best use of its resources. The
proposals for the higher seat backs was found to be effective and would
not lead to reduced seating capacity or other negative consequences. We
could not make the same determination about a Federal mandate to
require lap/shoulder seat belts on all large school buses. The
potential impact on pupil transportation resources from a Federal
mandate may lead to higher overall risk.
WBBCF stated its belief that NHTSA should have acknowledged a
finding of the American Academy of Pediatrics (AAP) that between 6,000
and 10,000 children per year are injured in school bus accidents, and
that, the commenter believed, many of these injuries could be reduced
by a lap/shoulder belt requirement. The AAP study referenced by WBBCF
indicated that there are approximately 17,000 school bus related
nonfatal injuries annually. Ninety-seven percent of those injured in
the AAP study were treated and released from the hospital. The study
used a sample of students treated in hospital emergency rooms for
injuries which had the word ``school bus'' in the case description to
generate an estimated nationwide total number of people injured. These
numbers include injuries that are not traffic related such as slip and
falls while boarding/alighting (injuries that cannot be prevented by
any occupant protection system.) The study indicated that the school
bus injuries were from the following causes:
Crash Related--7,206
Boarding/Alighting--84,056
Slip/Fall--1,162
Traffic, noncrash--860
Other/unknown--3,749
In contrast to the AAP study, to determine the number of school bus
crash related injuries, NHTSA used real world data where the injury
resulted from a crash involving a vehicle in transport and on a public
road. The number of crash related injuries reported in the AAP study
correlates closely with our estimates of child passengers in school
buses injured in school bus-related crashes
[[Page 62752]]
(approximately 7,300 injuries annually.) Of these 7,300 injuries, NHTSA
estimated that 94 percent were minor and non-incapacitating injuries.
Based on this analysis, we believe that the 97 percent injured in the
AAP study that were treated and released from the hospital only
sustained minor injuries.
Regarding WBBCF's comment that NHTSA should calculate the
associated reductions in personal and societal costs due to lap/
shoulder belts in terms of medical, insurance and liability expense,
physical disability and trauma, emotional trauma, and lost education
days, the Preliminary Regulatory Evaluation (PRE) for the NPRM included
such factors in its estimates. Likewise, the Final Regulatory
Evaluation for this final rule also takes into account the
comprehensive value of an injury and statistical life, which includes
all of those factors relating to medical, insurance, pain and suffering
and lost work days.
Finally, regarding Mr. Davis's comment, we agree that the best
practice is for each purchaser to determine whether to purchase seat
belts on large school buses and that part of such a decision is the
thorough assessment of how the school's resources should be spent. We
agree that if after weighing all the considerations a purchaser decides
not to purchase the belts, then it is also determining what is best for
its needs.
b. Other Issues Concerning Belts on Large School Buses
NHTSA does not agree that this rulemaking should be delayed until
completion of the side impact research mentioned in the 2002 Report to
Congress. In response to NYAPT, our side impact protection
countermeasure research is still ongoing. We have been actively
pursuing this research and expect to complete it soon. However,
completion of this research is not critical to implementing regulations
specific to the areas discussed in the NPRM or this final rule, such as
seat belts, raising the seat back height, or requiring seat bottom
cushions to be self-latching. The research in those areas has been
completed. The ongoing research with respect to side impact
improvements will in no way affect the outcome of the previous
research, or the policies, performance and decisions related to this
final rule.
Further, we do not believe that additional research is necessary to
show ``that the newly developed systems adequately protect children of
all sizes in severe side impacts'' as suggested by the NTSB. For near
side impact, the agency's 2002 testing and the NTSB studies have well
documented that seat belts will provide very limited occupant
protection for those in direct line with the impact force. This is
similar to near side occupants in passenger vehicles and the current
agency school bus side impact research is geared to address this
condition.
With regard to the belief that seat belts on large school buses
should also be required to reinforce the message to children that they
should wear belts in passenger vehicles, NHTSA studied the issue in
1985. The agency found that children were able to understand that the
bus environment was different than that of a passenger car, and that
not having belts on school buses did not dilute the buckle up message
for family vehicles.\28\ NHTSA did a follow-up literature review in
2007 and determined that the results of the 1985 study are likely
unchanged. See, ``School Bus Seat Belts and Carryover Effects in
Elementary School-Aged Children'', which we have placed in the docket
for this final rule.
---------------------------------------------------------------------------
\28\ Gardner, A. M., Plitt, W., & Goldhammer, M. (1986).
``School bus safety belts: Their use, carryover effects and
administrative issues,'' (Final Report No. DOT HS 806 965).
Washington, DC: National Highway Traffic Safety Administration.
---------------------------------------------------------------------------
c. Comments in Favor of a Federal Ban of Lap Belts in Large School
Buses
In the NPRM, we decided against prohibiting lap belts on large
school buses. Although we acknowledged that laboratory research,
including our own on lap belted dummies, showed relatively poor
performance of lap belts in large school buses, we could not conclude
that the addition of lap belts in large school buses reduced overall
occupant protection such that they should be banned. We noted that lap
belts were required in three states (New York (NY) (1987), New Jersey
(1994), Florida (2001)), in many other school districts, and in
special-needs equipped school buses. We stated that our examination of
NY State school bus crash data for lap belt equipped and non-belt
equipped buses could not conclude that lap belts either helped or hurt
occupant injury outcomes.
A number of commenters to the NPRM wanted NHTSA to ban lap belts.
The NTSB believed that NHTSA's 2002 school bus test program showed that
lap belts ``afford occupants little if any safety benefit above that
achieved by compartmentalization alone and may cause additional neck
and abdominal injury.'' The NTSB and the National Association of State
Directors of Pupil Transportation Services (NASDPTS) \29\ believed that
since lap belts are not an acceptable means of occupant protection in
passenger cars, light trucks, or small school buses, lap-only belts
should not be installed on large school buses. Similarly, NYAPT
believed that NHTSA should prohibit the installation of lap belts on
school buses and clearly state what the commenter believed were the
inherent risks associated with their use. In addition, the commenter
stated that few NY school districts require the use of lap belts by
student passengers. Accordingly, it believed that the agency's
statements in the NPRM relating to the evaluation of New York crash
data should be corrected. The commenter stated that the agency should
not have determined that the data from New York is inconclusive, but
rather that seat belt usage in school buses is so minimal and
inconsistent that there is no relevant data to analyze and compare.
---------------------------------------------------------------------------
\29\ The NASDPTS states that it represents State directors
responsible for school transportation in each state, school bus
manufacturers and other industry suppliers, school transportation
contractors, and associations with memberships that include
transportation officials, drivers, trainers and technicians.
---------------------------------------------------------------------------
Agency Response
In response to NYAPT's comment, we stand by our statement in the
NPRM that we cannot conclude that lap belts either helped or hurt
occupant injury outcomes. It was not possible to estimate lap belt
performance or effectiveness.
Crash data have consistently shown that lap belts are a good safety
device in passenger vehicles, even though lap/shoulder belts are more
effective when worn properly. We currently allow a lap belt in the
front center seat of a passenger vehicle, and we allow lap belts in
medium to heavy vehicles over 4,536 kg (10,000 pounds) GVWR. Lap belts
have been shown to be almost as effective as lap/shoulder belts in
rollover crashes, and benefit far side occupants in side impacts
involving these vehicles.
The NPRM did not propose to ban lap belts on large school buses and
we decline to concur at this time that lap belts should be prohibited
on large school buses. The large school bus environment is different
from that of small school buses, passenger cars, and small trucks and
vans, and experiences less severe crash forces. Thus, the type of
restraint that is appropriate for each may differ. A state might want
to install seat belts on their school buses to supplement
compartmentalization in side or rollover crashes, and we are unable to
conclude that if they do, they must install lap/shoulder belts, given
[[Page 62753]]
the additional cost and potential reduced capacity associated with such
Type 2 restraints over lap belts and the absence of real-world injury
data.
d. Comments on Use of Section 402 Highway Safety Grant Funds
In the NPRM, we noted that certain highway safety grant funds may
continue to be used to fund the purchase and installation of seat belts
(lap or lap/shoulder) on school buses. Annually, all States, the
District of Columbia, Puerto Rico, the Bureau of Indian Affairs, and
the U.S. territories receive NHTSA section 402 State and Community
Highway Safety Formula Grant Funds. A wide range of behavioral highway
safety activities that help reduce crashes, deaths, and injuries,
including seat belt-related activities, qualify as eligible costs under
the section 402 program. Each State determines how to allocate its
funds based on its own priorities and identified highway safety
problems as described in an annual Highway Safety Plan (HSP). We stated
that, as with all proposed expenditures of section 402 funds, the
purchase and installation of seat belts on school buses must be
identified as a need in the State's HSP and comply with all
requirements under 23 U.S.C. Part 1200. Section 402 funds may not be
used to purchase the school bus in its entirety, but may fund only the
incremental portion of the bus cost directly related to the purchase
and installation of seat belts.
1. Use of Existing Federal Grant Funds To Purchase Seat Belts
In response to the NPRM, the Governors Highway Safety Association
(GHSA), Georgia Governor's Office of Highway Safety (GOHS), and
Maryland Department of Transportation wrote that although lap/shoulder
belts on large school buses is an important safety issue, the biggest
danger to children, as evidenced by years of data, is in the area
around school buses and on the way to and from school. The commenters
stated that emphasizing the use of Federal 402 funds for school bus
safety represents a significant shift in Federal policy, but there is
no evidence to support such a shift. They expressed concern that the
impact on the 402 program is potentially enormous and devastating to a
State's highway safety program, could eliminate a State's entire
apportionment and still barely pay for the costs of the improvement.
They believe that from a cost/benefit perspective, this solution
threatens many other higher priority objectives, including impaired
driving prevention, child passenger safety, and aggressive driving. For
example, Maryland stated that in the past 10 years, there has been one
school bus occupant-related fatality in the State of Maryland. In
contrast, the commenter stated, in 2006 in Maryland there were 199
fatal crashes involving alcohol, 79 fatal crashes involving aggressive
drivers, 95 fatal crashes involving pedestrians, 83 fatal crashes
involving motorcycles, and 102 fatal crashes involving young drivers.
Maryland expressed the view that because of media coverage of recent
school bus crashes, ``states may be pressured to spend federal highway
safety money for this purpose [seat belts on large school buses], at
the expense of many competing highway safety needs.''
The GOHS stated that in the NPRM, NHTSA chose not to calculate the
costs of installing seat belts on large school buses, because
installation is voluntary. It stated its belief that local school
districts that wish to install safety belts on large school buses would
incur sizable costs. The GOHS also stated that most school districts
identify the specifications for new school buses and then they put the
specifications out to bid. They further stated that costs of
improvements are not individualized, but are part of the overall cost
of the new bus design. It would therefore be difficult for school
districts to determine the incremental cost of a single improvement and
then invoice the state highway safety office just for the improvement.
Agency Response
NHTSA does not agree that using Federal safety grant money to
install safety equipment on school buses represents a significant shift
in Federal policy. For example, when we issued final rules in the early
1990s requiring stop arms and upgraded mirror systems on school buses
as a means to provide enhanced protection for children who ride school
buses, we specifically allowed Federal safety grant funds to be used to
purchase the newly specified school bus safety equipment.
Nothing in this final rule changes the fact that deciding how to
use section 402 grant funds is at the discretion of each State. If a
State should decide that lap/shoulder belts on large school buses is a
safety priority, NHTSA is simply stating that the Federal safety grant
funds may be used to purchase the belts. If a State should choose to
purchase seat belts, its decision must be based on the State's own
priorities identified in its Annual Highway Safety Plan and comply with
all requirements under 23 CFR Part 1200. Section 402 funds may not be
used to purchase the entire school bus, but may fund only the
incremental portion of the bus' cost that is directly related to the
purchase and installation of seat belts. NHTSA has also determined that
in addition to using section 402 funds, 23 U.S.C. section 406 Safety
Belt Performance Grant Funds can be used to fund the incremental
portion directly related to the purchase and installation of seat belts
on school buses.
NHTSA is aware that many important safety issues compete for
funding from each State's Federal safety grant funds. Therefore, it is
imperative that each State base its selection for fundable projects on
its highway safety priorities. For States considering the installation
of seat belts on large school buses, NHTSA has provided estimates of
the cost to install seat belts in large school buses in the Preliminary
Regulatory Evaluation that was available in the docket (NHTSA-2007-
0014-0005.1) for the NPRM. NHTSA believes that in order to determine
the incremental cost of seat belts on large school buses, when it
orders the school buses, it would be a simple matter for the State to
ask the school bus manufacturer for an itemized list of options,
including seat belts.
2. Additional Federal Grant Funds To Purchase Seat Belts
The GOHS, North Carolina Dept. of Public Instruction, the National
Association of State Directors of Pupil Transportation Services
(NASDPTS), and the Texas Department of Transportation all sought
additional funding for school bus improvements in NHTSA's next
reauthorization. The commenters believe that additional funding is
needed in order to make a change in school bus seating viable on a
widespread basis. They asked NHTSA to establish a ``separate designated
federal fund source'' (using NASDPTS' words) to offset the additional
cost of lap/shoulder belts on school buses, either within section 402
or apart from it. The commenters stated that existing funds are
insufficient to implement lap/shoulder belts without significant
cutbacks in other highway safety initiatives. NADSPTS commented: ``When
this NPRM was introduced, the general public was given the impression
through the media and news releases that school bus lap/shoulder belt
funding would be made available, not that we would have to compete for
existing section 402 funds.''
NHTSA Response
NHTSA has not identified any additional funds that can be used as a
separate set-aside for the purchase of seat belts on school buses.
NHTSA emphasizes that it makes available
[[Page 62754]]
existing Federal safety grant funds only if a State, in its Annual
Highway Safety Plan, includes school bus safety initiatives related to
improving the protection of children that ride in school buses.
V. Overview of Upgrades to Occupant Crash Protection Standards
a. Summary of the NPRM Proposed Upgrades
After considering the findings of NHTSA's 2002 School Bus Safety
Study, the NPRM proposed several sets of upgrades to the school bus
safety requirements. The first set of upgrades involved improving the
compartmentalized school bus interior for all school buses. Seat back
height was proposed to be increased from 508 mm (20 inches) to 610 mm
(24 inches) to reduce the potential for passenger override in a crash.
We also proposed to require self-latching mechanisms for school buses
with seat bottom cushions that are designed to flip up or be removable
without tools.
The second set of upgrades proposed to require small school buses
to have lap/shoulder belts instead of just lap belts. The lap/shoulder
belt systems were to fit all passengers from ages 6 through adult, to
be equipped with retractors, to meet the existing anchorage strength
requirements for lap/shoulder belts in FMVSS No. 210, and to meet new
requirements for belt anchor location and torso belt adjustability. The
seat belts were to meet a ``quasi-static'' test requirement to help
ensure that seat backs incorporating lap/shoulder belts are strong
enough to withstand the forward pull of the torso belts in a crash and
the forces imposed on the seat from unbelted passengers to the rear of
the belted occupants. A minimum seat belt width of 380 mm (15 inches)
was proposed for belted occupants. In addition, the vehicles had to
meet FMVSS No. 207 because the load in some seating configurations
imposed by FMVSS No. 207 is greater than the load that would be imposed
by FMVSS No. 222's seat performance requirements.
The third set of upgrades involved requirements for voluntarily-
installed seat belts on large school buses. For large school buses with
voluntarily-installed lap/shoulder belts, it was proposed that the
vehicle meet the requirements described above for lap/shoulder belts on
small school buses, except the quasi-static test would be slightly
revised for the large school buses to account for crash characteristic
differences between the vehicles. (Due to the mass and other
characteristics of the vehicles, in crashes typically small school
buses are subject to higher severity crash forces than are large school
buses.) Further, we did not propose to apply FMVSS No. 207 to large
school buses.
b. Overview of Comments
Commenters \30\ generally supported the proposed increase in seat
back height, citing the increased compartmentalization and safety
benefits that higher seat backs would provide. Some seat manufacturers
and members of the general public asked that seat backs be made even
higher than the proposed 610 mm (24 inches), to protect against
whiplash or to meet Federal head restraint standards. On the other
hand, most school bus drivers and some members of the general public
opposed raising the seat back height, mainly due to concerns about
decreased driver visibility of students and potential discipline
problems. Similarly, most comments also acknowledged the safety benefit
of self-latching mechanisms for seat cushions. However, the NTSB
commented that the weight required to activate the latching mechanism
(that of a 6-year-old child) did not guarantee attachment of the
cushion.
---------------------------------------------------------------------------
\30\ The commenters included school bus seat and restraint
manufacturers or consultants (AmSafe Commercial Products (AmSafe),
C.W. White Company (CEW), Concepts Analysis Corp., Freedman Seating
Company, IMMI, M2K, Takata, school bus manufacturers and their
professional associations (Blue Bird Corp., Girardin Minibus Inc.,
IC Corp. (IC), National Truck Equipment Association/Manufacturers
Council of Small School Buses (MCSSB), and Thomas Built Buses, Inc.,
the NTSB, the National Association of State Directors of Pupil
Transportation Services (NASDPTS), numerous other organizations, and
the general public.
---------------------------------------------------------------------------
There was widespread support for the proposed requirement for lap/
shoulder belts on all small school buses from the commenters (school
bus seat and restraint manufacturers, transportation providers and
other organizations). A number of commenters asked that ``small school
bus'' be redefined to include similarly built buses that have a GVWR of
over 4,536 kg (10,000 pounds). In addition, the National Child Care
Association was concerned that the NPRM, if made final, would result in
increased costs for the multifunction school activity bus.
Commenters generally supported the proposed performance standards
for school buses, with bus, seat, and restraint manufacturers providing
detailed comments on technical aspects of the test procedures and
performance requirements. Many commenters asked NHTSA to ensure that
the proposed seat width minimum of 380 millimeters (mm) (15 inches) did
not prohibit flex-seats.
c. Post-NPRM Testing
To support this final rule, NHTSA performed additional research
after the NPRM was published. The testing was done to verify analyses
used to derive NPRM test values and to address questions raised by
comments to the NPRM. Below, we provide a brief description of the
post-NPRM testing and how some of the results affected this final rule.
A more complete discussion of the post-NPRM testing can be found in the
technical document supporting this final rule (2008 Technical
Analysis).\31\
---------------------------------------------------------------------------
\31\ ``NHTSA Technical Analysis to Support the Final Rule
Upgrading Passenger Crash Protection in School Buses,'' September
2008.
---------------------------------------------------------------------------
Both dynamic and static testing was performed. The tested seats
were lap/shoulder equipped and manufactured by CEW, IMMI and Takata.
The CEW seat is a unified frame seat back design with two fixed lap/
shoulder belts. The IMMI and Takata seats are flex-seat designs with
configurations of 3 and 2 occupants per bench. The IMMI design has a
dual-frame seat back, with the outer frame providing
compartmentalization of the rearward occupants and the inner frame
anchoring the lap/shoulder belt for the occupant of the seat.
Sled testing of school bus seats was performed in a manner similar
to the 2002 School Bus Safety Study.\32\ However, testing was performed
using both the large and small school bus crash pulse, rather than just
the large school bus pulse use in previous testing. This testing helped
the agency gain general insight into the dynamic performance of flex-
seat designs.
---------------------------------------------------------------------------
\32\ ``NHTSA Vehicle Research and Test Center's Technical Report
on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School
Buses,'' September 2008. See docket for this final rule.
---------------------------------------------------------------------------
The small school bus sled testing was also specifically performed
to verify the proposed torso body block pull force applied in the
quasi-static test. The proposed value had been derived through
mathematical calculation using Newtonian mechanics and measurements
made in large school bus pulse sled testing. The results of the new
testing confirm that the proposed small school bus torso body block
pull force is appropriate.
The small school bus sled testing was also useful in verifying the
peak dynamic loading on the entire seat structure. These data were used
in our analysis of the need for implementing
[[Page 62755]]
the FMVSS No. 207 requirements to the seats during the FMVSS No. 210
testing.
The agency performed extensive testing to address comments related
to the proposed quasi-static test.33 34 A particular focus
of this testing was the many issues raised by potential allowance of
flex-seats in the final rule. Through this test work, the agency
determined that it would be appropriate to increase the preload and the
zone where the torso body blocks are initially placed.\35\ We also
determined that the quasi-static test could be applied to flex-seats in
all potential seating configurations. A similar determination was made
when flex-seats were tested to the FMVSS No. 210 requirements for seat
belt anchorages. The FMVSS No. 210 testing can be performed on flex-
seats in all potential seating configurations.
---------------------------------------------------------------------------
\33\ Id.
\34\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for
Various School Bus Seats Equipped with Type 2 Seat Belts, Test
Procedure Development Testing,'' General Testing Laboratories, Inc.,
August 2008. See docket for this final rule.
\35\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for
Various School Bus Seats Equipped With Type 2 Seat Belts, Torso
Block Preload and Positioning,'' General Testing Laboratories, Inc.,
July 2008. See docket for this final rule.
---------------------------------------------------------------------------
To address comments specific to dual-frame seats, the agency also
verified the ability to measure seat back displacement in the quasi-
static test in addition to, and separate from, anchor point
displacement.
d. How This Final Rule Differs From the NPRM
The following are the most important differences between the final
rule and the NPRM:
1. The minimum seat width requirement is revised to accommodate
flexible occupancy seats (flex-seats). Further, quasi-static loading
requirements appropriate for flexible occupancy seats are adopted.
2. The quasi-static test at S5.1.5 of FMVSS No. 222 will limit the
displacement of the torso belt anchor point and the seat back, rather
than just the anchor point. This change was made to make the
requirement more performance oriented, and not unnecessarily restrict
seat designs that incorporate other than unified frame design. Further,
to address practicability concerns, the performance limit on anchor
point displacement is revised to allow the equivalent of four degrees
of additional rotation.
3. In the quasi-static test, the energy absorption requirement will
specify that the seat back force-deflection signature must stay below
the upper bounds of existing force/deflection zone upper boundary of
FMVSS No. 222. In addition, the torso belt adjustment must be
maintained during the test.
4. To accommodate flex-seats, the torso anchor point minimum height
requirement of FMVSS No. 210 will allow, but not require, the center
seating positions in flex-seats to only accommodate an occupant as
large as an average 10-year-old child, rather than an adult male. Such
a center seating position is defined as a ``small occupant seating
position'' (SOSP) and will be marked as such by way of a label on the
seat belt for that seating position. In addition, the minimum lateral
anchorage separation requirement is modified to allow a reasonable
accommodation of existing designs of flex-seats and non-flex-seats.\36\
---------------------------------------------------------------------------
\36\ To address small occupant seating positions, in FMVSS No.
208, ``Occupant crash protection,'' dimensions of a 10-year-old
child are added to the provisions (at S7.1.5) that specify
dimensions of the occupant that must be restrained by a seat.
---------------------------------------------------------------------------
e. Organization of Discussion
The discussion of the amendments made by this final rule are
organized as follows: Upgrades for all school buses (seat back height;
cushion latches); upgrades for small school buses (requiring lap/
shoulder belts; FMVSS No. 207; other issues); upgrades for large school
buses (requiring voluntarily installed belts to meet performance
requirement,); performance requirements for vehicles with seat belt
systems (seat width requirements; seat belt anchorage requirements
(FMVSS No. 210); quasi-static test; other issues).
For the NPRM, NHTSA prepared a 2007 Technical Analysis that, among
other things, presented a detailed analysis of data, engineering
studies, and other information supporting these amendments. A copy of
the document was placed in Docket NHTSA-2007-0014. As indicated above,
an updated 2008 Technical Analysis has also been prepared and placed in
the docket for this final rule. In addition, several other technical
reports supporting this final rule have also been placed in the docket.
The agency refers to these documents from time to time in this
preamble.
VI. Upgrades for All School Buses
a. Seat Back Height
In the NPRM, we proposed that the minimum seat back height for
school bus seats (specified in FMVSS No. 222) be raised from a minimum
508 mm (20 inches) to 610 mm (24 inches). This increase in minimum seat
back height was supported by agency-conducted sled tests that assessed
the compartmentalization performance of 508 mm (20 inch) and 610 mm (24
inch) seat backs for large (50th percentile male) occupants. The
results of these tests indicated that 610 mm (24 inch) seat backs would
provide more effective compartmentalization for larger occupants than
508 mm (20 inch) seat backs. In tests with the higher seat back, the
extent to which the dummies overrode the seats in front of them was
lessened. The higher seat back was also effective in reducing head
contact with test dummies that were placed in seats forward of the
dummies. In tests using the 508 mm (20 inch) seat backs where dummy
head contact did occur because of override, the HIC15 values tended to
be well above the established IARVs.
In general, the commenters supported the proposal for the increase
in seat back height to 24 inches. Three school bus seat and restraint
manufacturers (Concepts Analysis Corp. (Concepts), CEW, and Takata)
supported an increase in seat back height, with CEW agreeing with the
proposed seat back height and barrier area and both Concepts and Takata
recommending that the minimum seat back be increased as set forth in
FMVSS No. 202a. Three school bus manufacturers and associations (Thomas
Built Buses, Inc. (Thomas), National Truck Equipment Association/
Manufacturers Council of Small School Buses (NTEA/MCSSB), and Girardin
Minibus, Inc. (Girardin)) agreed with the proposed increase in seat
back height. However, Thomas, NTEA/MCSSB, and Girardin requested that
this requirement not apply to the last row of seats because it was
believed that there is no rearward occupant to compartmentalize, driver
visibility through the rear window would be better, and a lower seat
back would allow for more knee room in the last row. Those opposing the
proposal expressed concern about reduced driver visibility of students.
Agency Response
This final rule increases the minimum seat back height for school
bus seats to 610 mm (24 in), as proposed in the NPRM.
1. In response to Takata et al., when FMVSS No. 202a begins to
phase-in for rear seats in the 2011 model year, it will require that
any head restraints provided in the rear outboard seats (they are
optional) must have a minimum height of 750 mm (29.5 inches) above the
H-point.\37\ This requirement will be applicable to passenger vehicles,
trucks
[[Page 62756]]
and buses, including school buses, with a GVWR of 4,536 kg (10,000
pounds) or less. Under FMVSS No. 202a, rear seats are not required to
have a head restraint but if the seat back is above 700 mm above the H-
point, it is considered a ``head restraint'' and must meet the
requirements of the standard. Outboard school bus seats meeting the 610
mm (24 inch) requirement will not have to meet the rear seat provisions
of FMVSS No. 202a unless they are over 700 mm above the H-point, or 90
mm (3.5 inches) in excess of the 610 mm (24 inch) limit. We will not
raise school bus seat back heights above 24 inches in this final rule
because the greater mass of large school buses reduces the potential
risk of whiplash for their occupants (the harm addressed by FMVSS No.
202a) in comparison to other vehicles on the road and a seat back
height of 610 mm (24 inches) will offer better whiplash protection to a
broader spectrum of school-aged children than would a height of 508 mm
(20 inches).
---------------------------------------------------------------------------
\37\ For illustration purposes, the H-point is similar to the
actual SgRP of the seat as opposed to the design SgRP. It is found
by placing the SAE J826 manikin in the seat.
---------------------------------------------------------------------------
It should be noted that this final rule only requires that seat
backs be a minimum of 610 mm (24 inches). If individual states,
counties, or school districts wish to specify a seat back higher than
610 mm (24 inches), they are free to do so. As noted above, FMVSS No.
202a would apply to small school buses with seat backs above 700 mm.
2. We are denying the request that the minimum seat back height
requirement not be applied to the last row of seats. There is no
current exemption for the seat back height of the last row of seats.
Given that there are rigid structures in a school bus rearward of the
last row, this additional seat back height will provide added potential
protection to the occupants of the last row in the event of a rear
impact. Further, the occupants of the last row should be afforded the
better whiplash protection offered by the 610 mm (24 inch) seat back.
The argument that the height should be reduced to improve driver
visibility is not persuasive. Since the row directly forward of the
last row would not be exempted from the seat back height requirement,
any decrease in driver visibility due to the seat back of the rearmost
row would be minimal. (Further discussion of the driver visibility
issue is provided below.)
Finally, it was stated that additional knee space would be
available if the last row did not have to be 610 mm (24 inches) high.
If we assume a seat back with a 12 degree angle from the vertical, the
higher seat back height would necessitate the rear seat row to move
forward approximately 21 mm (0.84 inches) [100 mm x tan(12deg.)]. This
change could be spread evenly over the entire length of the vehicle,
resulting in a negligible difference in leg room for each row of seats.
3. With regard to reduced driver visibility of the students, as
discussed in the NPRM preamble and in comments from school
transportation providers, a number of states, including Illinois, New
Jersey, New York, Ohio, North Carolina and Washington, already require
seat back heights of 610 mm (24 inches) in their school buses. We are
not aware of reports of visibility problems or insufficient discipline
of students on the buses. In fact, the Monroe-Woodbury Central School
District indicated that the 24-in seat back improved student behavior
as students were unable to easily hang over the tops of the seat backs
to interact with friends in distant rows, but instead had to converse
with passengers around him or her while staying seated. Additionally,
as pointed out by some commenters, increasing the minimum seat back
height to 610 mm (24 inches) would make the minimum seat back height
the same as the industry designations from the 2005 edition of the
National School Transportation Specification and Procedures (NSTSP) for
minimum seat back height.
4. Mr. James Hofferberth stated that NHTSA ``has failed to consider
alternative [compartmentalization] strategies, such as a reduction of
seat height to reduce cost, coupled with the provision of a vertical
transverse containment panel from the top of the seat to the ceiling of
the bus.'' To our knowledge, there is no compartmentalization strategy
such as that discussed by the commenter that has been tested and proven
in both effectiveness and feasibility as compartmentalization.
Therefore, at this time, such alternatives are not viable alternatives
to the heightened seat back approach.
b. Seat Cushion Latches
NHTSA proposed to amend S5.1.5 of FMVSS No. 222 to require latching
devices for school bus seats that have latches that allow them to flip
up or be removed for easy cleaning. We also proposed a test procedure
that would require the latch to activate when a 22 kg (48 pounds) mass
is placed on top of the seat at the seat cushion's center. The 22 kg
(48 pounds) mass is that of an average 6-year-old child. The test was
to ensure that any unlatched seat cushion would latch when a child
occupant sits on the seat.
In general, comments addressing this issue supported the proposal.
The NSTA noted that New York and Connecticut already require self-
latching mechanisms for seat cushions in their buses, and NCDPI stated
that they now require positive locking devices on their school bus
seats. They did not provide any details on the specifications they
require. CEW noted that currently, manually operated seat cushion
latches can inadvertently be left unlatched after cleaning, and that
the proposed self-latching mechanisms could ``benefit safety in a crash
situation.'' Concepts believed that this requirement ``should add only
pennies to the cost of [a] school bus seat.''
While NTSB supported a requirement for self-latching mechanisms for
school bus seat cushions, it had concerns about the proposed test
requirements regarding the mass required to activate the latch. It
stated that its concern that ``some designs of flip-up or removable
seats that comply with this standard may allow the seat to come loose
during a crash or rollover if a sufficient weight is not applied to the
seat cushion for the self-latch to activate.'' NTSB stated that the
load requirement should be removed from the proposed seat cushion
retention standard unless NHTSA can verify that all seats with this
design are hinged and cannot fully separate from the seat frame when
the latch is not activated.
Agency Response
This final rule adopts the requirement that self-latching
mechanisms be installed on school bus seat cushions that flip up or are
removable. We acknowledge that, under the requirement, some cushions
could still come loose during a crash because the latch would only be
required to activate under a 22 kg (48 pounds) mass. While latching
devices which activate under the weight of the seat cushion alone (as
NTSB suggested) would be preferred, at this time we have not received
any data indicating the minimum loads that are required to activate
latches of this type. We specify 22 kg (48 pounds) because that is the
mass of the 50th percentile 6-year-old child, i.e., a child in
kindergarten or first grade. The cushion will thus latch when a child
sits on it. We received no data in response to the NPRM that indicate
alternative loads. Therefore, we do not have the information necessary
to support removing or reducing this load requirement.
One commenter described the currently-used seat cushion latches as
``primitive'' and ``hard to open,'' and state that ``they are not
always secured fully when [they] get the seat back down.'' We believe
that such problems
[[Page 62757]]
may be the main reason why school bus seat cushions are not always
secured to the seats in current school buses. With self-latching
devices that meet the proposed requirements, a bus driver would only
have to firmly push down on the top of the seat cushion to re-attach it
after cleaning. This greatly simplifies the process of latching the
seat cushions, making it much more likely that they will be properly
attached to the seats.
Finally, regarding a comment from the National Child Care
Association, we do not require that seat cushions flip up, but rather
have adopted a requirement for self-latching mechanisms that would be
installed on seat cushions that do flip up or are removable.
VII. Upgrades for Small School Buses
a. Requiring Lap/Shoulder Belts
The agency proposed that small school buses be required to have
lap/shoulder belts at all passenger seating positions. Since the FMVSSs
were first promulgated, small school bus passenger seats have been
required to have passenger lap belts (defined as Type 1 belts in FMVSS
No. 209) as specified in FMVSS No. 208, belts that meet the lap belt
strength requirements specified in FMVSS No. 210. Lap/shoulder belts
provide an increased level of protection from lap belts in small school
buses by reducing the potential of head and neck injuries in frontal
impacts.
All commenters supported the proposal. Accordingly, this final rule
adopts the requirement for the reasons stated in the NPRM. The seat
belt systems are required to meet the performance requirements of FMVSS
Nos. 208, 210, and 222 as discussed in the NPRM and this final rule.
(Under current requirements, the seat belts already must meet FMVSS No.
209, ``Seat belt assemblies.'')
b. Raising the Weight Limit for Small School Buses
Historically the dividing line between what is considered a
``large'' and a ``small'' school bus is the GVWR delineation. School
buses with a GVWR above 4,536 kg (10,000 pounds) are large school
buses, while school buses with a GVWR of 4,536 kg (10,000 pounds) or
less are small school buses.
In response to the NPRM, several commenters suggested raising the
weight limit for small school buses from 4,536 kg (10,000 pounds) to
6,576 kg (14,500 pounds). IMMI stated that the small school bus
requirement that lap/shoulder belts be installed at all seating
positions should apply to all school buses that are built on a van
chassis, which are known in the industry as type ``A'' school buses.
The commenter stated that these consist of type ``A-1'' school buses,
which have a GVWR of 4,536 kg (10,000 pounds) or less, and type ``A-2''
school buses, which have a GVWR that can range up to 6,576 kg (14,500
pounds). IMMI explained that both the type A-1 and the type A-2 buses
are built on similar van chassis, and so they are both exposed to
similar operating and crash environments. Another commenter stated that
the National School Transportation Specifications and Procedures
(NSTSP) for school bus types defines Type A-1 school buses as having an
upper weight limit of 6,576 kg.\38\ Thus, this comment suggested, it
would be easier to determine which school buses must comply with the
lap/shoulder belt requirement if NHTSA's definition of small school
buses followed the NSTSP recommendation.
---------------------------------------------------------------------------
\38\ This information is different than that provided by IMMI,
but the difference is inconsequential to the commenters' arguments.
---------------------------------------------------------------------------
Agency Response
The suggestion to raise the weight cut-off for small school buses
to include Type A-1 buses with a GVWR below 6,576 kg (14,500 pounds)
may have, but it is beyond the scope of this rulemaking. We also note
that the suggested change in weight limit is not trivial. Expanding the
small school bus category as suggested would result in a substantial
increase in the fleet percentage of small school buses, i.e., from 7.2
to 24 percent.
c. FMVSS No. 207, Seating Systems
In the NPRM, we proposed to apply FMVSS No. 207 to small school
buses with lap/shoulder belts because the load imposed by FMVSS No. 207
appears to be greater than the load that would be imposed by FMVSS No.
222's seat performance requirements at S5.1.3.
There was no consensus between commenters. CEW disagreed with the
proposal to apply the FMVSS No. 207 loading to small school buses. It
explained that ``[m]any of our customers request that we pull the FMVSS
No. 210 test to higher forces than those required by NHTSA to insure
that they have a `safety margin' above NHTSA's requirement * * * Most
of our customers ask us to pass FMVSS No. 210 by 110% or 120% * * * If
FMVSS No. 207 and FMVSS No. 210 are added and customers still want 110%
and 120%, we would be adding safety factors to safety factors, as well
as undue additional costs.'' In contrast, IMMI agreed that FMVSS No.
207 should apply to all small schools buses and ``all van-based, A type
school buses, regardless of their GVWR.''
Blue Bird Corp. (Blue Bird) disagreed with the proposal. Using the
data the agency provided in the NPRM, it provided an extensive analysis
showing that for a seat bench with three lap/shoulder belts, the FMVSS
No. 210 load is 130 percent [18,000 pounds/(11,802 + 2,040) pounds] of
the total dynamic load on the seat, plus the load that would be imposed
by FMVSS No. 207.
If the final rule makes FMVSS No. 207 applicable to small school
buses with lap/shoulder belts, Blue Bird requested an exemption for a
``davenport'' mounted seat which ``consists of separate seat cushion
and seat back assemblies of wood or plastic, foam, and upholstery
fastened to the bus body structure forming the front and top of the
engine compartment.'' However, Blue Bird stated that it was unaware of
such rear engine configurations for small school buses.
Agency Response
With respect to Blue Bird's analysis, the commenter used the peak
total force on the seat in the large bus sled tests performed by the
agency (35,000 N (7,869 pounds)).\39\ Using an assumption expressed in
the NPRM (regarding the quasi-static test) that belt loads for the
small school bus situation would be 1.5 times that of the large school
bus, the commenter estimated that the total seat force for a small
school bus seat occupied by two persons would be 52,000 N (11,803
pounds).\40\
---------------------------------------------------------------------------
\39\ These seats were occupied by two 50 percentile male Hybrid
III dummies.
\40\ Rather than the value used by Blue Bird, however, the
agency actually derived a range of potential ratios for the small to
large school bus belt loads from 1.1 to 2.4 times. We choose 1.5 in
the NPRM out of a concern for practicability in the quasi-static
test.
---------------------------------------------------------------------------
The agency now has actual measurements of total seat load in a
small school bus crash pulse, and has found that the ratio of large to
small school bus forces is about 58 percent.41 42 Using this
actual small school bus total seat loading, we have estimated the
extent to which the FMVSS No. 210 load combined with the FMVSS No. 207
load exceeds the actual measured total load on the seat.
---------------------------------------------------------------------------
\41\ ``NHTSA Technical Analysis to Support the Final Rule
Upgrading Passenger Crash Protection in School Buses,'' September
2008.
\42\ ``NHTSA Vehicle Research and Test Center's Technical Report
on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School
Buses,'' September 2008.
---------------------------------------------------------------------------
By first assuming the seat in question has three lap/shoulder belt
positions,
[[Page 62758]]
we calculate that the total FMVSS No. 210 loading is 80,064 N (18,000
pounds) [3 x 26,669 N]. This assumes that the total dynamic load on the
seat from the three occupants (for the purposes of this analysis, we
assumed the occupants were three 5th percentile females) is as we
measured in the sled testing with two 50th percentile dummies (we
assumed for this analysis that the loading from three 5th percentile
females would be about the same as the loading from the two adult
dummies). Assuming this three positions seat weighs 46.3 kg (102
pounds),\43\ the combined FMVSS Nos. 207 and 210 loading will be 146
percent of the dynamic load [(80,064 N + 46.3 kg x 20 g x 9.81)/(2 x
30,574 N)].
---------------------------------------------------------------------------
\43\ This is the value Blue Bird used in its comments for a
1,143 mm (45 inch) wide seat bench.
---------------------------------------------------------------------------
Second, by assuming a 990 mm (39 inch) wide seat with two fixed
lap/shoulder belts and a seat mass of 34.5 kg (76 pounds), we calculate
that the combined FMVSS Nos. 207 and 210 loading is 98.4 percent of the
dynamic load [(53,376 N + 34.5 kg x 20 g x 9.81)/(2 x 30,574 N)].
As these calculations have shown, depending on the number of lap/
shoulder belts on the bench and the assumed occupant sizes, the
addition of the FMVSS No. 207 loading to the FMVSS No. 210 loading
creates a condition where the total seat loading is even higher than
what might be expected to occur dynamically (as in the situation with
the three small occupants) or the total seat loading matches the
dynamic loading level fairly closely (latter situation with two adult
occupants). Accordingly, the data indicate that the FMVSS No. 207 load
is not redundant to the FMVSS No. 222 loads.
We note that, as explained below in section IX.b.6, flex-seats
would tend to be in the category of bench seats that would be
overloaded (first situation) since all three belted positions in the
maximum occupant configuration will receive the same FMVSS No. 210 belt
loading. The agency considered whether to develop a scheme by which
some small school bus seats (those with 2 fixed seating positions)
would be subject to the FMVSS No. 207 loading and some (those
configurable to 3 seating positions) would not. We decided against this
approach because it seemed to be an unnecessary complication not based
on any need to assure practicability.
Finally, we have decided against Blue Bird's recommendation to
exempt seats that might be mounted on the cover of a rear engine bus
(davenport seats). First, we note that Blue Bird stated they were not
aware such a design currently exists in small school buses. Second, the
final rule will require such a seat to have lap/shoulder belt
anchorages mounted on it, unless the seat satisfies the last row seat
exemption discussed later in this preamble. We seek to ensure that a
seat with belt anchorages attached be sufficiently robust to sustain
the additional FMVSS No. 207 seat inertial loading and that a last row
seat that does not have belt anchorages still be mounted to the vehicle
firmly enough to stay attached under its own inertial loading.
VIII. Upgrades for Large School Buses
This final rule requires voluntarily installed seat belts on large
school buses to meet performance requirements of FMVSS Nos. 208, 210,
and 222 as discussed in the NPRM and this final rule. (Under current
requirements, the seat belts already must meet FMVSS No. 209, ``Seat
belt assemblies.'') Comments to the NPRM were overwhelmingly supportive
of the objective to require voluntarily installed seat belts to meet
performance requirements.
IX. Performance and Other Requirements for Vehicle Belt Systems
a. Minimum Seat Width Requirements and Calculating W and Y
In S4.1 of FMVSS No. 222, NHTSA currently considers the number of
seating positions (W) on a bench seat to be the width of the bench seat
in millimeters, divided by 381 and rounded to the nearest whole number.
This W value is used to calculate the compartmentalization requirements
for seats on all school buses and the number of lap belt only seating
positions on small school buses that must meet the provisions of FMVSS
Nos. 208 and 210. In the NPRM, we proposed to continue to consider W to
be the number of seating positions per bench seat with optionally
provided lap belts on large school buses as well as the
compartmentalization requirements for all school buses, except that the
divisor was proposed to be 380 (for simplicity) rather than 381.
However, for the seating positions on small school buses with
required lap/shoulder belts and on large school buses with optional
lap/shoulder belts, we proposed to define the number of seating
positions (using ``Y'') in a slightly different way. Y is the total
seat width in millimeters divided by 380, rounded down to the nearest
whole number. Under the definitions of W and the proposed definition of
Y, a 1,118 mm (44 inch) wide seat would have W = 3 seating positions
for the purposes of calculating the magnitude of the
compartmentalization requirements to apply to the seat back, but only Y
= 2 seating positions for determining the lap/shoulder belts installed
on the seat.\44\ The result of this ``Y'' calculation would be that
each passenger seating position in a school bus seat with a lap/
shoulder belt would have a minimum seating width of 380 mm (15 inches).
In addition, the NPRM also proposed to adopt a requirement in FMVSS No.
222 (at S5.1.7) that each passenger seating position with a Type 2
(lap/shoulder) restraint system shall have a minimum seating width of
380 mm (15 inches). We proposed a minimum seating position width of 380
mm (15 inches) for seats with lap/shoulder belts because we sought to
ensure that lap/shoulder belt anchorages are not installed so narrowly
spaced that they would only fit the smallest occupants.
---------------------------------------------------------------------------
\44\ ``Y'' would also be used to determine the loads to be
applied to the shoulder belts for the quasi-static test, discussed
below in this preamble. See also paragraphs S5.1.6.5.5(a) and (b) of
the proposed regulatory text.
---------------------------------------------------------------------------
A new school bus seat belt technology has emerged in the
marketplace involving 990 mm (39 inch) bench school bus seats with lap/
shoulder belts that have flexible configurations (flex-seats). These
flex-seats have lap/shoulder belts that can be adjusted to provide two
lap/shoulder belts for two full average-size high school students or
three lap/shoulder belts for three elementary school students. Takata
and its partner, M2K LLC (M2K), and IMMI both produce these bench seats
with flexible occupancy seat designs. In its minimum occupancy
configurations, two 50th percentile male occupants can be accommodated
per bench. In its maximum occupancy configuration, three 6- to 10-year-
old children can be accommodated per bench. In comments to the NPRM,
many commenters (pupil transportation providers, state and local
districts, schools, individuals, advocacy groups) urged NHTSA to permit
these flexible occupancy seats in the final rule.
In comments, IMMI, Takata, M2K, and Concepts stated that while they
supported the NPRM, the provision that each seating position with a
lap/shoulder belt have a minimum width of 15 inches is design
restrictive, would reduce bus capacity, and would discourage
installation of lap/shoulder belts. IMMI, Takata, and Concepts
specifically recommended a minimum seat width of 330 mm (13 inches).
The 330 mm (13 inch) minimum seat will permit the flexible occupancy
seats that
[[Page 62759]]
IMMI and Takata manufacture. Other commenters, including Thomas, NTEA/
MCSSB, and IC Corp. (IC) also asked that the value be reduced to 330 mm
(13 inches). Thomas and NTEA/MCSSB also asked that W be used for lap/
shoulder seating positions rather than Y. They also suggested that the
divisor be 380 rather than 381 and that the result be rounded up
instead of down.
Other commenters wrote in favor of the 380 mm (15 inch) (or wider)
seat. Blue Bird, CEW and AmSafe Commercial Products (AmSafe) agreed
that 380 mm (15 inches) is the appropriate seat width value. Blue Bird
believed that since children are getting larger, smaller minimum
spacing is not in their best interest. Freedman Seating Company
(Freedman) stated that the minimum seat width should be increased to 16
inches. AmSafe stated that if three 330 mm (13 inch) positions were
allowed on a 990 mm (39 inch) bench seat, three average adult males
could attempt to use the seat, resulting in a dangerous situation if
there were a crash.
Agency Response
When we proposed that each seating position with a lap/shoulder
belt have a minimum width of 380 mm (15 inches), our stated concern was
that manufacturers not be allowed to install lap/shoulder belts in such
a narrow space that only the smallest occupants would fit. We also
acknowledged that a bench seat with 380 mm (15 inches) of width per
lap/shoulder belt position would not accommodate occupants larger than
a 5th percentile female simultaneously in every position. When
developing the NPRM, the flex-seat designs had not yet reached the
marketplace so the design restrictiveness of an absolute 380 mm (15
inch) seat width requirement was not fully recognized by the agency
during the NPRM stage.
1. Flex-Seats
The comments and presentations to the agency since the NPRM have
had us reconsider the proposed requirement for a 380 mm (15 inch)
minimum seat width and whether design flexibility could be accommodated
while assuring that seats will be wide enough for real world use by
full size high school students. We agree with the majority of those
commenting on the issue that flex-seats should be permitted as an
option for school transportation providers wishing to implement lap/
shoulder belts. Depending on the size mix of occupants being
transported, flex-seats could be helpful in maximizing the occupancy
rate of school buses.
The commenters opposing the reduction of the 380 mm (15 inches)
minimum width per lap/shoulder belted position indicated that 330 mm
(13 inches) is too small even for smaller children. They also indicated
their concern that if narrower positions were allowed, adult size
occupants might try to fit in them, potentially resulting in dangerous
situations.
It may be true that today's children are larger than children in
the past, and that would argue against reducing the 380 mm (15 inches)
specification for fixed width lap/shoulder belted positions. However,
we do not believe it justifies prohibiting flex-seats since they are
designed to accommodate occupants needing seat widths from 330 to 495
mm (13 to 19.5 inches). We agree that there is a risk that a 330 mm (13
inches) seating position on a flex-seat in a maximum occupancy
configuration may be misused by a person too large for the seat (one
who should have sat in a flex-seat in a minimum occupancy
configuration), but such misuse could be reduced through student
training.
To provide more design flexibility in FMVSS No. 222 and to
accommodate flex-seats, this final rule specifies that one lap/shoulder
belt may be installed for every 330 (13 inches) of seat bench width,
provided that the lap/shoulder belt seat can be reconfigured to have
seating positions for every 380 mm (15 inches) of seat bench width.
This ability for the seat bench width to be adjusted is specified
because, as stated in the preamble of the NPRM, we continue to believe
there is merit in limiting a manufacturer's ability to install too many
fixed position lap/shoulder seat belts on a bench seat that
accommodates only the smallest occupants.
2. Using W and Rounding Up
Both Thomas and NTEA/MCSSB indicated that the number of lap/
shoulder belt seating positions should be W instead of Y. They also
commented that after dividing the bench width by 380, the result should
be rounded up to the next integer. NHTSA disagrees with these comments.
Under the commenters' suggested methodology, a 759 mm (29.9 inches)
wide bench seat could have 3 lap/shoulder belts, with each position
providing 253 mm (10 inches) of seat width. We decline to adopt this
suggestion for the same reason we reject the idea of a fixed 330 mm (13
inches) seat, i.e., manufacturers should not be permitted to install
fixed position lap/shoulder seat belts on a bench seat that
accommodates only the smallest occupants. In addition, a bench with 253
mm (10 inches) wide seating positions cannot accommodate 6-year-old
occupants in every seating position.
3. Definitions
In this final rule, we are changing the seat width specification
and making other necessary changes to the regulatory text modifications
to permit flex-seats. To clarify the reduction in seat width and its
restriction to flex-seats, we are adding new definitions to FMVSS No.
222, as follows:
Fixed occupancy seat means a bench seat equipped with Type 2 seat
belts that has a permanent configuration regarding the number of
seating positions on the seat. The number of seating positions on the
bench seat cannot be increased or decreased.
Flexible occupancy seat means a bench seat equipped with Type 2
seat belts that can be reconfigured so that the number of seating
positions on the seat varies based on occupant size. The seat has a
minimum occupancy configuration for larger occupants and maximum
occupancy configuration for smaller occupants, and the number of
passengers capable of being carried in the minimum occupancy
configuration must differ from the number of passengers capable of
being carried in the maximum occupancy configuration.
Maximum occupancy configuration means, on a bench seat equipped
with Type 2 seat belts, an arrangement whereby the lap belt portion of
the Type 2 seat belts is such that the maximum number of occupants can
be belted.
Minimum occupancy configuration means, on a bench seat equipped
with Type 2 seat belts, an arrangement whereby the lap belt portion of
the Type 2 seat belts is such that the minimum number of occupants can
be belted.
Under these definitions, a traditional bench seat is a ``fixed
occupancy seat.'' Flex-seats (which are flexible occupancy seats) must
have both a maximum and minimum occupancy configuration. These
definitions by themselves do not detail the numbers of occupants (W or
Y) allowed in these configurations. Instead, that specification is
conveyed in S4.1(c) and (d) of FMVSS No. 222, specified by this final
rule.
Section S4.1(c) states that the number of fixed lap/shoulder seat
belt positions per bench must be Y, essentially the same as that
proposed in the NPRM. S4.1(c) also states that a flexible occupancy
seat configured to hold the minimum number of occupants must also have
Y lap/shoulder belt positions. Therefore, a 39-inch wide bench seat
will either have 2 [rounded down from (990/380)] lap/shoulder belts or
will be configurable to have 2. This assures that a seat belt equipped
bench provides a
[[Page 62760]]
sufficient number of seating positions (Y) to accommodate the number of
larger students that might be seated there.
Section S4.1(d) requires that when a flexible occupancy seat is
configured to hold the maximum number of occupants, it must have Y + 1
lap/shoulder belted positions. However, the minimum allowed bench seat
width must be no less than (Y + 1) x 330 mm (13 inches). As an example,
a 990 mm (39 inches) flexible occupancy seat may have 3 lap/shoulder
belts, of seat widths of 330 mm (13 inches), as long as the seat can be
reconfigured to have 2 lap/shoulder belts of seat widths of at least
380 mm (15 inches). For this example, the 2 lap/shoulder belt seating
positions would each be 445 mm (19.5 inches) wide.
Since proposed S5.1.7 is no longer needed because the minimum seat
belt width requirement for older children is now specified in S4.1(c)
and (d), proposed S5.1.7 is not adopted by this final rule.
b. Seat Belt Anchorages (FMVSS No. 210)
NHTSA proposed that requirements be added to FMVSS No. 210 that
would ensure that the seat belt anchorages on school bus seats be
designed so that the belt system will properly fit the range of
children on a school bus: the average 6-year-old (represented by the
Hybrid III 6-year-old child dummy (45 inches tall/52 pounds)); the
average 12-year-old (represented by the Hybrid III 5th percentile
female dummy (59 inches/108 pounds)); and the large high school student
(represented by the 50th percentile adult male dummy (69 inches/172
pounds)). Proper seat belt fit prevents injury and helps ensure that
the system performs properly in a crash. If the lap/shoulder seat belts
did not fit the child occupant properly, there is an increased
likelihood that the child would misuse the lap/shoulder belt system by
placing the shoulder portion under the arm or behind the back. NHTSA's
school bus research results showed that when the shoulder belt was
placed behind the back, the restraint system functioned like a lap
belt. Lap belts produced a higher risk of neck injury in the testing
program when evaluated in a simulated severe frontal crash. Further, a
torso belt anchorage located below the top of the shoulder may increase
the spinal compression loading in a crash, increase the risk of the
occupant sliding under the belt in a crash, and increase the risk of
spinal and abdominal injuries.
1. Height of the Torso Belt Anchorage
We proposed that school bus seats with lap/shoulder belts have a
minimum shoulder belt adjustment range between 280 mm (11 inches) and
520 mm (20.5 inches) above the SgRP (which was the location of the
school bus torso belt anchor point), to ensure that the shoulder belt
will fit passengers ranging in size from a 6-year-old child to a 50th
percentile adult male. We proposed a definition of ``school bus torso
belt adjusted height'' in FMVSS No. 210 as an objective means of
determining the adjustment height. We also proposed regulatory text for
FMVSS No. 208 to specify belt fit and performance characteristics for
lap/shoulder belts on school bus bench seats. Specifically, we proposed
to amend S7.1.5 \45\ to assure that the belts fit a 50th percentile 6-
year-old to a 50th percentile male.
---------------------------------------------------------------------------
\45\ The NPRM at S7.1.5 of the proposed regulatory text for
FMVSS No. 208 (72 FR at 65527) proposed that the seat belt assembly
has to operate by means of an emergency-locking retractor (ELR) or
an automatic-locking retractor (ALR). In this final rule, we have
removed the allowance for ALRs. No current lap/shoulder seat belts
on school bus seats utilize ALRs and there is no clear indication
that ALRs would provide any performance or comfort benefits compared
to emergency locking retractor (ELR) equipped lap/shoulder belts.
This will not preclude manufacturers from providing convertible
ELRs, i.e., ALR/ELR type belts, just those that function solely as
ALRs. In addition, any lap/shoulder belts in large or small school
buses must still have to meet S7.1.1.5 of FMVSS No. 208, which
specifies the lockability of belts. (The lockability feature
facilitates the installation of child restraints using the belt
system.) This is currently the situation for small school buses with
lap/shoulder belts, and was proposed and now made final by this
rulemaking for large school buses.
---------------------------------------------------------------------------
Five commenters (AmSafe, Blue Bird, CEW, IMMI and Takata) addressed
the minimum distance above the SgRP for the torso belt anchor point,
520 mm (20.5 inches), and the distance above the SgRP for the lowest
point on the adjustment range of the torso belt, 280 mm (11 inches).
CEW, AmSafe and Blue Bird supported the proposed minimum torso anchor
point height proposal. AmSafe expressed concern that a lower torso
anchor point could be dangerous to the average adult male because of
potential spinal compression during a crash.
IMMI commented that in order to allow the flexible occupancy seats,
changes would be necessary to FMVSS Nos. 208, 209, and 210. It stated
that the 520 mm (20.5 inches) minimum anchor point height in FMVSS No.
210 would need to be reduced to 394 mm (15.5 inches) so that the
``flexible configuration cannot be used by three large students.'' It
believed 394 mm (15.5 inches) would accommodate a 10-year-old child.
IMMI suggested that the minimum torso anchor point for the center
seating position of a flex-seat be located in a range between 387 and
400 mm (15.2 to 15.7 inches) above the SgRP.
Takata's comments suggested several alternatives to the torso belt
adjustment range and the torso anchor point minimum height. One Takata-
suggested alternative was to place various anthropomorphic test dummies
(ATDs) (6-year-old, 10-year-old, 5th percentile female and 50th
percentile male) in belted seating positions and then determine whether
proper belt fit could be achieved. Takata also made proposals specific
to flex-seats. One of these was to specifically not require a 330 mm
(13 inches) wide seating position to accommodate a 50th percentile
male. Another was to specifically allow the torso belt anchor point to
be a minimum of 380 mm (15 inches) from the SgRP for the center seating
position of a flex-seat, rather than 520 mm (20.5 inches) proposed in
the NPRM.
Agency Response
The Takata seat design described in comments to the NPRM (hereafter
referred to as the original Takata design or seat) differs from the
IMMI and CEW designs in that the torso anchor point itself is
adjustable rather than just the torso belt.\46\ Therefore, the proposed
language in S4.1.3.2 of FMVSS No. 210 would effectively disallow these
designs because the minimum anchor point is much less than 520 mm, even
for the outside seating positions.
---------------------------------------------------------------------------
\46\ A more recent Takata design, tested after the NPRM was
published, had fixed torso belt anchorages in all three seating
positions. Torso belt adjustment was achieved by an adjustment
device sliding on a separate length of webbing.
---------------------------------------------------------------------------
Since the original Takata design was not known to the agency until
after the NPRM was drafted, we did not consider in the NPRM stage the
use of adjustable anchorages to achieve the desired torso belt
adjustment range. After considering the comments to the NPRM, we
believe it would be appropriate to have a minimum anchorage height
specification for a fixed anchorage and an achievable position for an
adjustable anchorage. For the reasons discussed in the NPRM, for fixed
anchorages, the anchorage must be a minimum of 520 mm (20.5 in) above
the SgRP. A fixed point above 520 mm (20.5 inches) would be acceptable.
An adjustable anchorage may have a lower position of adjustment as long
as this minimum distance from the SgRP (520 mm) can be achieved.
We are adopting a different requirement for the torso anchor for
the
[[Page 62761]]
center seating position of flex-seats that is designed for elementary
school passengers only. (Elsewhere in this preamble we explain that the
standard will refer to this position as a ``small occupant seating
position'' and will define the term.) IMMI stated that the torso anchor
for this small occupant seating position was lowered in their design to
reduce the likelihood that large occupants would sit there. The lowered
torso anchor would act as a disincentive to overcrowd the flex-seat. We
agree that design disincentives to overcrowding the flex-seat are
desirable. A lower anchor point for the center seat of a flex-seat in
its maximum occupancy (3-seating position) configuration may serve as a
visual cue that only a small occupant should be located in the center
position. (In addition, as also discussed later in this preamble, we
are requiring the torso belt of a small occupant seating position to be
labeled: ``Do Not Sit In Middle Seat If Over Age 10.'' This label is to
further discourage full size occupants from using the center seating
position if it has a lower torso anchorage point.)
As to what the minimum height should be for that position, IMMI
suggested that the minimum torso anchor point height should be lowered
to a range between 387 and 400 mm (15.2 and 15.7 inches) above the
SgRP. Takata requested a minimum torso anchor point of 380 mm (15
inches). We have decided to reduce the value for the minimum allowable
anchor point height for the center seating position in a flexible
occupancy seat to 400 mm (15.7 inches), which was the upper limit of
IMMI's suggestion. We have chosen 400 mm (15.7 inches) over 380 mm (15
inches) because the higher value places the anchorage higher on the
seat vis-[agrave]-vis the child's shoulder, thus reducing the
likelihood of spinal compression loading in a crash. According to the
anthropometric data submitted by Takata, the anchor point will be above
the shoulder of an average 10-year-old occupant by at least 37 mm (1.5
inches).\47\ Since the required labeling suggests that a 10-year-old
can be accommodated by such a seating position, we believe it is
reasonable to exceed the 10-year-old shoulder height by this value to
assure the vast majority of 10-year-olds would be accommodated.
---------------------------------------------------------------------------
\47\ It was necessary to add specifications in FMVSS No. 208
that provides the weight and dimensions for a 10-year-old occupant.
In addition, this final rule specifies that lap/shoulder belts at a
SOSP need only restrain an occupant up to the size of an average 10-
year-old child.
---------------------------------------------------------------------------
2. Anchorage Adjustability
CEW, AmSafe, and Blue Bird supported the torso belt adjustment
range to ensure that lap/shoulder belts fit all passengers from an
adult.
IMMI believed that a center seating position in a flexible
occupancy seat that adjusts from 280 to 394 mm (11 to 15.5 inches)
above the SgRP would accommodate occupants from a 6-year-old to a 10-
year-old and be configured so that larger occupants would not use it.
Takata suggested that instead of the adjustment range proposed in the
NPRM, NHTSA could place various anthropomorphic test dummies (ATDs) (6-
year-old, 10-year-old, 5th percentile female and 50th percentile male)
in belted seating positions to determination whether proper belt fit
could be achieved. Alternatively, the commenter suggested, NHTSA could
specifically not require a 330 mm (13 inch) wide seating position to
accommodate a 50th percentile male.
Agency Response
For the reasons provided in the NPRM, we have decided to maintain
the adjustment range proposed for torso belts in the NPRM.
Takata's comments indicate that they believe their original design
would properly fit occupants down to the size of a 6-year-old child
even though it does not adjust down to 280 mm (11 inches) above the
SgRP. We believe that maintaining torso belt adjustability is an
objective way of ensuring that lap/shoulder belts will fit even the
smallest school bus riders. In the past, the agency has reviewed belt
fit devices in order to determine an objective fit criterion for
children riding in child restraint systems and booster seats in
automobiles, but has been unsuccessful.\48\ Therefore, we have produced
guidelines for caregivers to use to keep the torso belt off the neck
and upper abdomen.\49\ We believe that the minimum seat width and
anchor spacing, along with the general design constraints, will provide
sufficient belt fit without establishing additional ``belt fit''
requirements with test dummies. The adjustment range proposed for torso
belts is practicable, objective and clear, and all other commenters on
this issue agreed that adjustment to the 280 mm (11 inches) level is
appropriate to address the full range of potential occupants.
---------------------------------------------------------------------------
\48\ 70 FR 51720, 51722-51728 (August 31, 2005; Docket No.
NHTSA-2005-21245). See also 69 FR 13503, (March 23, 2004; Docket
NHTSA-99-5100).
\49\ See, e.g., tip 3 of Transportation Safety Tips for
Children http://www.nhtsa.dot.gov/people/injury/childps/newtips/
index.htm. ``The lap belt must fit low and tight across the upper
thighs. The shoulder belt should rest over the center of the
shoulder and across the chest.''
---------------------------------------------------------------------------
The location of the anchorage is shown below in Figure 1.
BILLING CODE 4910-59-P
[[Page 62762]]
[GRAPHIC] [TIFF OMITTED] TR21OC08.053
3. Clarifications of Torso Anchorage Location
i. Blue Bird asked if the reference to ``more than 10 degrees from
the horizontal plane'' in the proposed definition of ``school bus torso
belt adjusted height'' in S3 of FMVSS No. 210 was meant to state ``from
the vertical plane.'' The answer is no. We believe that the commenter
may have misunderstood the definition and the concept behind it. This
definition was added to FMVSS No. 210 to provide an objective means of
determining the height position of the torso belt. Fundamental to the
concept of correct positioning of a torso belt is that the anchorage
not be below the shoulder, which could result in compressive loads on
the spine in a frontal crash. The horizontal plane is relevant to see
where the torso belt anchorage is located relative to the top of the
shoulder.
However, because the definition was unclear to the commenter, we
have decided to add a small clarification to the definition to specify
that the height is measured from the SgRP.
ii. Takata also stated that in addition to vertical position, the
lateral position of the torso belt relative to the midsagittal plane is
also important. We agree with Takata that lateral position of the torso
anchor point will also influence belt fit. However, the agency will
leave this parameter to the discretion of the manufacturer so it might
be optimized in the context of the required vertical adjustment range.
[[Page 62763]]
4. Integration of the Seat Belt Anchorages Into the Seat Structure
The NPRM proposed that the seat belt anchorages, both torso and
lap, be required to be integrated into the seat structure. This
proposal was made because we were concerned that if we did not, some
manufacturers could incorporate seat belt anchorages into other
structures in the school bus, potentially injuring unbelted school bus
passengers in a crash, or obstructing passengers during emergency
egress. We also requested comment on whether there were anchorage
designs, other than those integrated into the seat back, that would not
impede emergency evacuation or potentially cause injury to unbelted
passengers.
In its comments, CEW stated that it was ``not aware of a seat belt
anchor design (other than being integrated into the structure of the
seat) that would not impede access/egress to an emergency exit or
become a source of injury or hazard.'' IMMI agreed with the requirement
proposed in the NPRM that seat belt anchors be integrated into the seat
structure for most seats, but requested an exception for the last row
of ``Type D'' school buses. Their rationale for the exemption was:
The seats in such a row are integral with the vehicle body
structure and most commonly, the torso restraint retractors at such
seats are mounted into the bus body structure, and the shoulder
belts are routed over the upper edge or through the seat back. The
lap belt anchorages are also incorporated into the lower structure
of the davenport. This design helps bus manufacturers minimize seat
back thickness in order to optimize seat spacing for maximizing
capacity. And restraints mounted in this manner can not impede
access to emergency exits or become an injury hazard to unbelted
passengers.
In opposition to the proposal were Thomas, IC, NTEA/MCSSB, and
Girardin, which stated that seat belt anchorages, at least for certain
bus types or seat positions, do not need to be integrated into the seat
structure. Alternatively, Thomas requested that ``anchorages integrated
into the bus body structure be permitted in the last seating row'' for
all bus sizes.
Thomas and NTEA/MCSSB both commented that seat belts should not be
required to be integrated into the seat structure for small school
buses. They stated that some anchorages could be installed on the bus
floor, sidewall, or roof, and stated that ``[t]hese installations could
be optionally configured or designed so that they do not impede access
to emergency exits.'' Girardin, a small school bus manufacturer,
stated: ``Anchorages provided in the side wall or in the rear structure
can be achieved without obstructing passenger exit and could also help
to reduce the deflection of the rear seats in the row against the rear
wall.''
Agency Response
We agree not to adopt the requirement for the last row, but since
the commenters have not provided any information on vehicle mounted
belt anchorage designs other than for the last row, we were unable to
assess the safety and effectiveness of bus-mounted anchorage systems in
general. In addition, the commenters did not address our other concern
about whether ``non-integrated'' seat belts could be safety hazards for
unbelted occupants in a crash. Therefore, in this final rule, we will
not reject the requirement in its entirety for all school buses.
Based on comments received on this issue, the last row is excluded
from the requirement because our concern about emergency exit access is
lessened for the last row of seats. The last row of seats in
conventional large school buses and small school buses typically has
two seats with a 610 mm (24 inch) aisle (large buses) or 559 mm (22
inch) aisle (small buses) between them, to provide access to the rear
emergency exit door. FMVSS No. 217 imposes requirements for
unobstructed passage through the door. Thus, at least in the immediate
vicinity of the door, that standard should prevent seat belts from
being installed in such a way that could impede access to the emergency
exit.\50\ We also believe that the location and style of the last row
seats in these buses make it possible to place belt anchorages behind
or to the side of the seat, where the belt webbing would not impede
safe travel in and out of the seat. Thus, if these belts are out of the
way of the students, they are unlikely to pose risks of injury to
unbelted students in a crash (e.g., a student could become entangled in
belt webbing). This is not the case for all bus seats, where belts for
inboard seat positions in particular could be mounted such that the
belt webbing could impede safe passage through the bus interior or pose
an injury risk for unbelted students in a crash.
---------------------------------------------------------------------------
\50\ The requirement for a large school bus emergency exit door
opening is found in 49 CFR 571.217 S5.4.2.1(a)(1).
---------------------------------------------------------------------------
There are rear-engine buses with a rear emergency exit window
instead of a door. Regardless of the type of emergency exit there is in
the bus (door or push-out rear window \51\), we emphasize the
importance of keeping the area of the rear emergency exit free from
seat belt webbing so that emergency egress is not impeded. We will
monitor anchorage designs in this subset of vehicles to ensure that
safety is not compromised. With regard to small school buses, several
commenters (Thomas, Girardin, and NTEA/MCSSB) indicated that in these
vehicles, anchorages could be placed such that they do not interfere
with emergency exits. However, the commenters did not address the other
agency concern with whether ``non-integrated'' seat belts could be
safety hazards for unbelted occupants in a crash. In addition, no data
or specific information about anchorage designs were provided to enable
us to make a determination as to whether the belts could be injurious
to unbelted passengers. Therefore, in this final rule, we will not
exempt small school buses generally from the requirement that seat belt
anchorages be integrated into the seat structure, except for the last
row of seats as discussed in the previous paragraph.
---------------------------------------------------------------------------
\51\ Emergency exit windows in a school bus must provide an
opening large enough to admit unobstructed passage of an ellipsoid
generated by rotating about its minor axis an ellipse with major
axis of 50 cm and minor axis of 33 cm, as given in FMVSS No. 217,
S5.4.2.1(c).
---------------------------------------------------------------------------
5. Minimum Lateral Anchorage Separation
The NPRM proposed to adopt a requirement in FMVSS No. 222 (S5.1.7)
that each passenger seating position with a lap/shoulder restraint
system shall have a minimum seat belt anchor width of 380 mm (15
inches) (and a minimum seating width of 380 mm (15 inches)). At the
same time, the NPRM proposed to amend the application section of FMVSS
No. 210 so that it expressly applied to school buses, and thus proposed
to extend S4.3.1.4 of FMVSS No. 210 to school buses. S4.3.1.4 states:
``Anchorages for an individual seat belt assembly shall be located at
least 165 mm [(6.5 inch)] apart laterally, measured between the
vertical center line of the bolt holes or, for designs using other
means of attachment to the vehicle structure, between the centroid of
such means.''
We have realized that the 380 mm (15 inches) anchorage minimum
lateral spacing requirement proposed for FMVSS No. 222 is inconsistent
with the proposed FMVSS No. 210 requirement that all belts on school
bus seats must be attached to the seat structure. Assuming that the
anchorage lateral spacing is to be measured in a manner consistent with
proposed S4.3.1.4 of
[[Page 62764]]
FMVSS No. 210 and the belted seating position width were 380 mm (15
inches), it would be very difficult to have a 380 mm (15 inches)
anchorage lateral spacing without extending the seat structure beyond
the width of the seat cushion.\52\
---------------------------------------------------------------------------
\52\ The width of each belted seating position is determined as
a multiple of the seat cushion width.
---------------------------------------------------------------------------
Since it seems very unlikely for the anchorage minimum allowed
lateral spacing to be equal to the seating position width for designs
with the minimum allowed seating position width, in this final rule, we
have decided that the seat belt anchorage of school bus seats must be
less than the proposed value. For example, as proposed in the NPRM, a
1,143 mm (45 inch) wide bench seat could have lap/shoulder equipped
seating positions, each with a 380 mm (15 inch) seat width. At the same
time, each lower anchorage for those seating positions would have
needed a 380 mm (15 inch) lateral separation. Therefore, the physical
width of the seat structure makes it difficult to achieve this
anchorage separation. Thus, we will specify spacing of less than 380 mm
(15 inches) that is consistent with the minimum seating position width,
but takes into consideration the physical limitation of the space
available on the seat structure. (As explained below, we are specifying
330 mm (13 inches) for fixed positions or flex-seat position in the
minimum occupancy configuration (both of these must have at least a 380
mm (15 inch) seat widths) and 280 mm (11 inches) for flex-seats in
maximum occupancy configuration (this must have at least a 330 mm (13
inch) seat width).) This value must be achieved at all seating
positions simultaneously, which is important for flex-seat designs that
have a sliding anchorage, like the IMMI design. The specification for
``simultaneous'' specification is important for sliding anchorages to
assure that when multiple occupants are seated on the bench, each
occupant's belt has an acceptable separation.
We continue to believe that a minimum anchorage lateral spacing
should be specified to provide better pelvic load distribution for
frontal impacts than narrow spacing. If anchorages are narrower than
the occupant pelvis, the belts can wrap around the iliac crests and
cause compressive loading. This may be even more undesirable when the
lap portion of the belt is poorly positioned such that it loads the
abdominal region.
To determine the appropriate value for lateral anchorage
separation, we measured the lower anchorage space of several flex-seats
with nominal total bench widths of 990 mm (39 inches).53 54
Based on these data, we believe that flexible occupancy seat designs in
a maximum occupancy configuration (Y + 1 seating positions with lap/
shoulder belts) should be able to achieve a lateral separation of the
lower anchorages of no less than 280 mm (11.0 inches) simultaneously in
any seating position. We found that the IMMI seat is well above this
value. We believe the Takata seat can be easily altered to meet this
requirement. Similarly, any non-flex-seat or a flex-seat in a minimum
occupancy configuration (Y seating positions with lap/shoulder belts)
should be able to achieve a lateral separation of the lower anchorages
of no less than 330 mm (13.0 inches) simultaneously in any seating
position.
---------------------------------------------------------------------------
\53\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for
Various School Bus Seats Equipped with Type 2 Seat Belts, Test
Procedure Development Testing,'' General Testing Laboratories, Inc.,
August 2008.
\54\ ``NHTSA Technical Analysis to Support the Final Rule
Upgrading Passenger Crash Protection in School Buses,'' September
2008.
---------------------------------------------------------------------------
Since this lateral separation need only be achievable, it is
acceptable that the sliding buckle anchorage for the IMMI flex-seat
allows the left or center seat anchorage separation to be independently
less than 280 mm (11.0 inches). One reason we are not unduly concerned
with sliding anchorages as they relate to the issue of the lateral
distance between anchorages is because we believe that such a design
will be self-centering. In other words, the only time the anchorage
separation would likely to be less than 280 mm (11.0 inches) would be
when an occupant with hips narrower than this dimension would be seated
in this position. In that case, the anchor width would tend to match
the occupants' hip width, which would not be problematic in terms of
belt loading on the occupant. Nevertheless, to ensure that sliding or
otherwise movable anchorages cannot be adjusted so close together such
that they could be positioned narrower than a child occupant's pelvis
in a crash, we have also retained the current FMVSS No. 210 requirement
of 165 mm (6.5 inches) minimum spacing for the anchorages. Thus,
movable anchorages for an occupant seating position cannot be capable
of being closer than 165 mm (6.5 inches).
To summarize, this final rule reduces the lower anchorage minimum
lateral spacing from the 380 mm (15 inches) value to 280 mm (11.0
inches) for flexible occupancy seats with the maximum number of
occupants and 330 mm (13 inches) for all other seating positions with
lap/shoulder belts. We note that these must be minimum distances
simultaneously achievable by all seating positions. This is necessary
because it would be very difficult to have a 380 mm (15 inches)
anchorage lateral spacing without extending the seat structure beyond
the width of the seat cushion. The value selected is practicable, based
on measurements of existing designs. Further, under FMVSS No. 210,
movable (e.g., sliding) anchorages for an occupant seating position
cannot be capable of being closer than 165 mm (6.5 inches).
Given space is available, we continue to believe there is merit to
requiring a wide anchorage separation in school buses so as to obtain
good load distributions.
6. Anchorage Strength
The agency proposed that for large school buses with voluntarily
installed lap belts or lap/shoulder seat belts, the FMVSS No. 210
anchorage strength requirement be identical to the requirements for
passenger seat belt anchorages in smaller vehicles, i.e., 22,240 N
(5,000 pounds) applied to the pelvic body block for Type 1 belts and
13,334 N (3,000 pounds) applied to the torso and pelvic body blocks for
Type 2 belts. We stated our recognition that anchorages in large school
buses would be likely exposed to lower crash forces than would small
school buses. We used measurements of seat-to-sled attachment forces in
the deceleration direction to estimate that the total peak dynamic
loading sustained by the seat belts in a large school bus crash pulse
is about 2/3 of that applied in FMVSS No. 210.
We also requested comment on the appropriateness of the strength
levels being proposed for large school buses in FMVSS No. 210. We asked
how much the load could be reduced and still provide an appropriate
safety margin in a variety of crash scenarios. We also sought
information about the cost and weight savings associated with a lesser
requirement.
There was no consensus on this issue in the comments. Many
commenters supported a single FMVSS No. 210 body block load for both
large and small school buses. Takata stated that ``NHTSA sled testing
confirmed that current FMVSS 210 loads are not excessive when the seat
is occupied by two 95th percentile males (such as high school football
players).'' To illustrate this, they calculated that ``[e]ach 95th
percentile male would impart approximately 5,114 pounds/seating
position.'' M2K addressed the issue of practicability and stated that
``at least
[[Page 62765]]
two school bus seat manufacturers seem to be fulfilling current
strength requirements; and reducing these strength requirements would
seem counter-productive to stated goals of the NPRM.'' Concepts stated
that it was logical to apply the current FMVSS No. 210 loads to all
school bus seats since it applies to all other vehicle types. Concepts
also stated: ``We must question the need for, and express strong
opposition to, any proposed reductions in strength required for seat
backs, seat belt anchorages, or seat-to-floor attachment points.'' CEW
stated that they actually test beyond the FMVSS No. 210 limit; in some
cases as high as 32,000 N (7,200 pounds) per seating position. CEW
stated its belief that ``any cost saving by lowering the large bus
FMVSS No. 210 strength levels would most likely be off-set by a
corresponding cost increase by having two different seats, one for the
small bus and one for the large bus.''
IMMI proposed a reduction for the center seating position of
flexible occupancy seats. IMMI recommended that for the center seating
position, a loading of 8,896 N (2,000 pounds) through the torso and
pelvic blocks be applied, rather than 13,345 N (3,000 pounds). IMMI
stated its belief that its suggestion was ``consistent with NHTSA's
rationale for varying the loads in the quasi-static test procedure
depending on whether a seat will accommodate three small or two large
children.''
Blue Bird stated that it would be appropriate to reduce the load on
lap/shoulder belts of large school buses by \1/3\ (apply 8,896 N (2000
pounds) each on the torso and lap body blocks). They also recommended a
lap body block value of 17,500 N (3,934 pounds) for lap belt only
systems, taken directly from NHTSA calculations of per seating position
loading. IC stated that the belt load should--
be changed to \2/3\ of the small bus requirement for both Type 1
and Type 2 restraint systems. While it may be desirable and cost
effective in some cases to use the same design for both small and
large school buses, that certainly is not always the case and that
should not dictate establishing the performance requirement for
large buses at a level higher than necessary * * * * In essence,
setting the performance requirement at a level higher than necessary
could ultimately reduce the number of children riding on school
buses.
NYAPT stated that ``[a]bsent any bona fide testing results and
research-based data to the contrary, we would recommend against
establishing any differential standards among school buses.''
Agency Response
In this final rule we will not reduce the loading for either large
school buses or for any seating position of a flexible occupancy seat,
including the small occupant seating position (center position with a
reduced anchor point height). We specify one anchorage strength
requirement (i.e., 13,334 N (3,000 pounds) applied to the torso and
pelvic body blocks) for both large and small school buses with Type 2
seat belts. Based on data from the post-NPRM testing,55 56
the assumption that the large school bus pulse generates about 67
percent of the FMVSS No. 210 force still appears to be valid, assuming
two belted seating positions. Assuming three belted positions, the same
peak dynamic load generates 44 percent of the FMVSS No. 210 force.\57\
---------------------------------------------------------------------------
\55\ ``NHTSA Technical Analysis to Support the Final Rule
Upgrading Passenger Crash Protection in School Buses,'' September
2008.
\56\ ``NHTSA Vehicle Research and Test Center's Technical Report
on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School
Buses,'' September 2008.
\57\ This calculation assumes a bench seat with three fixed or
flex-seating positions and that three 5th percentile female
occupants would be generating the dynamic loading.
---------------------------------------------------------------------------
As discussed elsewhere in this preamble, the agency has chosen a
tiered approach to the quasi-static loading as an acknowledgement that
large and small school buses have different crash characteristics.
Nevertheless, in this final rule, we are keeping a single requirement
in FMVSS No. 210, equal to the more severe small school bus case. One
of the main reasons is a unified FMVSS No. 210 requirement provides a
safety margin and facilitates better efficiency in the testing.
NHTSA's testing and the comments from school bus seat manufacturers
lead us to believe that it is not difficult to sustain the loads
traditionally required by FMVSS No. 210, given that there is no
displacement limit in FMVSS No. 210. This is not true of the quasi-
static test, where we do recognize the multiple force/displacement and
energy criteria that school bus seats must meet supports our decision
not to require a single quasi-static requirement for all school bus
seats. With the FMVSS No. 210 loading, one requirement for all school
bus seats meets the need for safety without being unduly burdensome.
Another fundamental difference between the tiered loading level
approach the agency has taken in the quasi-static test and a single
level of stringency we are specifying to meet FMVSS No. 210
requirements is that the anchorage strength provides the foundation
upon which the restraint system is built. There is a more vital safety
need to require the anchorages to meet the more stringent FMVSS No. 210
requirement. In addition, having the safety margin better ensures that
the anchorages will be strong enough to deal with loading in excess of
what is anticipated, either because of use or misuse by larger
occupants, the stiffness and mass of the vehicle (e.g., vehicles closer
in mass to a small bus than the large school bus will experience a more
severe crash pulse), or because of the nature of the particular school
bus crash. Further, commenters did not provide cost and weight data
showing as to the cost savings, if any, that would result from a
reduced loading for a larger class of school buses. Accordingly, a
13,334 N (3,000 pounds) load will be applied to the torso and pelvic
body blocks for both large and small school buses with Type 2 seat
belts. Similarly, we continue to specify a pelvic body block force of
22,240 N (5,000 pounds) for optionally provided Type 1 seat belts on
large school buses.
c. Quasi-Static Test for Lap/Shoulder Belts on All School Buses
I. Quasi-Static Test Requirement
The agency proposed school buses with lap/shoulder belts must meet
a quasi-static test procedure that was developed by NHTSA to address
possible safety problems caused by having both belted and unbelted
passengers on the same school bus. (The quasi-static test requirements
would be in addition to existing compartmentalization requirements for
seat performance). (72 FR at 65521)
School bus seats designed to provide compartmentalized protection
must contain the child between well-padded seat backs that provide
controlled ride-down in a crash. A school bus seat with a lap/shoulder
belt would have the torso (shoulder) belt attached to the seat back. In
a crash involving a belted child and an unbelted child aft of the
belted occupant, the seat back would be subject to consecutive force
applications from the belted occupant's torso loading the seat back and
the force generated by impact of the unbelted passenger. The quasi-
static test replicates this double-loading scenario and specifies
limits on how far forward the seat back may displace. The test helps
ensure that the top of a seat back does not pull too far forward and
jeopardize the protection of compartmentalized passengers to the rear
of the belted occupants, or diminish the torso restraint effectiveness
for lap/shoulder belted occupants.
[[Page 62766]]
a. Background
The agency developed the quasi-static test by performing a sled
test using the same large school bus crash pulse that was used in the
school bus research program. We measured the loads on the shoulder
belts and both lower parts of the lap belt. Two unbelted 50th
percentile male dummies were positioned behind the seat that contained
two restrained 50th percentile male dummies. Visual observation of seat
kinematics and load cell data produced by the shoulder belts from this
test revealed the following sequence of events:
1. The knees of the unbelted dummy to the rear struck the back of
the forward seat, causing some seat back deflection.
2. The seat back was loaded by the shoulder belt of the restrained
dummy in the forward seat.
3. The shoulder belt load was reduced as the seat back to which it
was attached deflected forward.
4. The shoulder belt loads reduced to approximately zero when the
unbelted dummies' chests struck the forward seat back.
5. The forward seat back deflected further forward as the energy
from the unbelted dummies was absorbed.
This crash scenario is replicated in the quasi-static test. The
load requirement for the quasi-static test is dependant upon the number
of seating positions and also the likely seat capacity. A seat that has
the minimal allowed overall seat width for either a two or three
occupant seat will have a reduced loading requirement from other
seats.\58\
---------------------------------------------------------------------------
\58\ A school bus bench seat has the minimum allowed overall
width if the total seat width in millimeters minus 380Y is 25 mm (1
inch) or less.
---------------------------------------------------------------------------
Stage 1: Torso Belt Anchorage Displacement
The first part of the quasi-static test replicates steps 1 and 2 of
the crash scenario above. The procedure uses the knee and top loading
bars that are currently specified in S5.1.3 of FMVSS No. 222 (seat back
strength), which replicate a passenger's knee and torso loading the
forward seat back \59\ and the FMVSS No. 210 upper torso body
block.\60\ The test procedure uses the bottom loading bar to replicate
the knee loading by the unbelted rear passengers (based on W), then
specifies a pull test on the shoulder belts at each seating position in
the seat to replicate loading of the shoulder belt by the belted
passengers (based on Y). The large school bus shoulder belts are pulled
using the upper torso body block specified in Figure 3 of FMVSS No. 210
with a specified force. The NPRM proposed a force of 5,000 N (1,124
pounds) at each seating position for large school buses, and a force of
7,500 N (1,686 pounds) for small school buses.\61\
---------------------------------------------------------------------------
\59\ The current knee loading test procedure requires that
initially a force of 3,114 N (700 pounds) times the number of
seating positions in the test seat (W) be applied to the seat back
within 5 and not more than 30 seconds, and then the force is reduced
to 1,557 N (350 pounds) times W. The knee loading bar is locked in
this position for the remainder of the test. The current top loading
test procedure requires an additional force through the top loading
bar until 452 joules (4,000 inch-pounds) times W of energy is
absorbed by the seat back.
\60\ The agency is considering a rulemaking that would replace
the torso body block in FMVSS No. 210 with an updated force
application device. If the upper torso body block in FMVSS No. 210
is changed, the body block discussed in this quasi-static procedure
proposed today may be changed to the new force application device as
well.
\61\ As discussed earlier in this section, these 5,000 N (1,124
pounds) and 7,500 N (1,686 pounds) values would be reduced depending
on the width of the seat.
---------------------------------------------------------------------------
We explained in the NPRM that an applied load of 5,000 N (1,124
pounds) for large school buses appeared to be necessary to replicate
the torso belt loading from the sled test and to get the similar seat
response observed from high speed video. For small school buses, a
higher force was proposed because the small school bus crash pulse has
twice the peak acceleration of the large school bus, i.e.,
approximately 25 g's.\62\
---------------------------------------------------------------------------
\62\ The rationale for the load application is explained in the
agency's 2007 Technical Analysis. We have verified the
appropriateness of this load value through additional dynamic
testing performed after the NPRM was published.
---------------------------------------------------------------------------
At this mid-point of the quasi-static test when the torso block
force is being applied, NHTSA measures whether the seat back has pulled
too far forward and jeopardized the protection of compartmentalized
passengers to the rear of the belted occupants or diminished the torso
restraint effectiveness for the lap/shoulder belted occupant. In the
NPRM, the proposed criterion for passing this part of the test was a
specified limit on the forward displacement of the torso belt
anchorage. The specified value was a function of the vertical location
of the anchorage (AH) and the initial angle ([Phi]) \63\ of the seat
back surface that compartmentalizes the occupants rearward of the seat
being tested, i.e., the posterior surface of the seat back. Basically,
for large school buses, the proposed allowable displacement was
equivalent to the amount of displacement that would result from the
seat back deflecting forward 10 degrees past a vertical plane.\64\ For
large school buses, this is represented in the equation below by sin(10
deg.) = 0.174. Thus, the total allowable forward horizontal
displacement for large school buses was proposed to be:
---------------------------------------------------------------------------
\63\ We note that in the preamble of the NPRM, the initial seat
back angle was mistakenly represented by [thetas] in the
displacement limit equation. However, the proposed regulatory text
and the 2007 Technical Analysis correctly identified the initial
seat back angle as [Phi] in the displacement limit equation.
\64\ The derivation of the equation defining this displacement
limit was explained in the agency's 2007 Technical Analysis.
---------------------------------------------------------------------------
Large School Bus Displacement Limit = (AH + 100)(tan[Phi] + 0.174sin(10
deg.)/cos[Phi]) mm.
For small school buses, the displacement limit was proposed to be
equivalent to the amount of displacement resulting from a seat back
deflecting forward 15 degrees past a vertical plane (sin(15 deg.) =
0.259). The displacement limit would be determined using the equation:
Small School Bus Displacement Limit = (AH + 100)(tan[Phi] + 0.259sin(15
deg.)/cos[Phi]) mm.
The proposed allowed displacement for small school buses would be
greater than the limit for large school buses to account for agency
concerns about practicability of small school buses meeting the
displacement criterion.
As noted above, the goal of the proposed torso belt anchorage
displacement criterion was two-fold. The first goal was to assure that
the seat back to which the torso belt is anchored has sufficient
strength to restrain and protect the belted occupant in a frontal
crash. The second goal was to assure that the seat back is still in a
sufficiently upright position to compartmentalize unbelted occupants to
the rear. Thus, we believed that the displacement limit should be
narrow, to ensure that seat backs deviate as little as possible from
the initial upright position.
Stage 2: Energy Absorption Capability of the Seat Back
The quasi-static test continues with procedures to replicate steps
3, 4 and 5 of the crash scenario above. After the torso anchorage
displacement is measured, the torso body block load is released.
Immediately after this load is released, forward load is applied to the
seat back through the top loading bar. It was proposed that the seat
back must be able to absorb the same amount of energy per seating
position (452 joules (4,000 in-pounds)) as is required of a seat back
under the compartmentalization requirement. However, it was proposed
that for this quasi-static test, the seat back need not perform such
that the top loading bar force must stay in the force/deflection
corridor specified for the
[[Page 62767]]
compartmentalization requirement.\65\ We were concerned about the
practicability of meeting the force/deflection corridor, since the
torso body block load may have generated stresses in the seat frame
that exceed the elastic limit of the material and result in residual
strain.
---------------------------------------------------------------------------
\65\ A separate FMVSS No. 222 forward loading test is still
performed on a different test specimen, one that was not subjected
to the quasi-static test, to assure that in a crash, if the seat
were not occupied by a belted passenger and it were impacted by an
unbelted rearward passenger, the seat would meet the force/
deflection corridor.
---------------------------------------------------------------------------
b. Comments and Agency Responses
School bus seat and restraint manufacturers and school bus
manufacturers commented on the quasi-static test. The commenters
generally concurred with the need for a test to assure the
compatibility of belts and compartmentalization, and most suggested
technical changes to the test. IMMI and Takata raised issues concerning
implications of the proposed requirements on their seat designs.
The comments are addressed below, with the agency's responses.
i. IMMI's comments supported the agency's proposal to add the
quasi-static test to assure that compartmentalization is maintained for
seats with lap/shoulder belts, but was concerned that an aspect of the
test procedure would ``disfavor'' its dual frame seat design. It
indicated that using the torso anchor point as the reference for
measuring the displacement ``is not relevant to the ability of certain
school bus seating designs to provide such compartmentalization.'' This
is because with IMMI's design, the outer seat back frame providing
compartmentalization is not attached to the inner frame where the
anchor point is located, so the seat would not meet the proposed
displacement requirement. They urged the agency to change the test
procedure to avoid limiting their dual frame design, which they believe
to have good dynamic performance. IMMI asked that the test measure
``the rear surface of the seat back--rather than measuring the
displacement of the torso anchorage, which is irrelevant to
compartmentalization in this innovative seat design.''
Agency Response
NHTSA does not agree that it is a simple matter to change from the
restriction on the horizontal displacement of the torso anchor point to
the rear surface of the seat back. Simply placing a rotation or
displacement limit on the compartmentalizing seat back would provide no
limit on the forward displacement of the torso anchorage of a dual
frame design such as IMMI's. If the agency were to just limit the seat
back displacement/rotation, the dual frame design could offer very
little resistance to forward excursion of the belted occupant while
still meeting the requirement, which could in some designs provide no
better protection than just a lap belt. Thus, just measuring the
displacement/rotation of the seat back would not achieve our goals of
protecting both the belted and rearward unbelted occupants.
However, in recognition of the merits of making our requirements as
performance-oriented as possible, we have decided to limit the
horizontal displacement of both the anchor point and seat back to avoid
unnecessary design restrictions. As discussed in the 2008 Technical
Analysis, in consideration of comments to the NPRM, the agency believes
there is sufficient justification to limit the displacement of torso
anchor point as well as the seat back in the final rule. This will have
no substantial effect on unified frame seat designs in that the seat
back displacement limit will be identical to the anchor point
displacement limit in the NPRM.
Thus, the quasi-static displacement measurement will include both a
seat back and a torso anchor point displacement. We have decided that
the best way to do this is to measure the displacement of a point on
the rear surface of the seat back, rearward of the anchor point. This
seat back displacement point is found by passing a horizontal
longitudinal line through the torso anchor point and determining where
it intersects the seat back surface. With the seat back displacement
point defined in this way, the displacement limits can be calculated.
We selected this approach for determining the seat back displacement
point because of its simplicity. While we acknowledge that a point on
the surface of the seat back may be prone to displacement as a result
of deformation of non-structural elements such as upholstery, our
testing has indicated that such movement is not significant in
comparison to the structural deformation of the seat back caused by
torso belt loading.
We also considered measuring the displacement of other points on
the seat back structure. For example, we considered removing a section
of upholstery in the vicinity of the seat back displacement point
described above, in order to expose a portion of the seat back frame
that could be tracked. However, our examination of the structure of
lap/shoulder belt equipped seat backs showed a great deal of variation
in the internal structure. We felt this might lead to substantial
variability in objectively identifying a point on the internal
structure to track.
ii. IMMI requested that NHTSA allow additional torso anchor point
displacement equivalent to 4 degrees of additional seat back rotation
for both the large and small school bus requirements to accommodate its
design. The commenter provided data in support of its request.
Agency Response
We have decided to grant IMMI's request. The commenter asked for
torso anchor point displacement equivalent to 4 degrees of additional
seat back rotation for both the large and small school bus
requirements. We estimate that this will result in approximately a 40
mm increase in allowable anchor point displacement.
As explained in the 2008 Technical Analysis, IMMI presented
comparative dynamic testing data in its supplemental comments on the
NPRM that showed the results of tests of prototype designs of flex-
seats under consideration by IMMI with 5th percentile female dummies
and with the two 50th percentile male dummies. The dummies measured
injury levels under the IARVs even though the seat was not capable of
achieving the displacement limit with the added approximately 40 mm of
displacement. IMMI informed NHTSA that it was going to redesign the
flex-seat's inner frame to provide additional torso belt support. We
would expect that a redesign of the dual frame seat to meet the final
rule anchor point limit would have equal or better dynamic performance.
In addition, our analysis indicates that anchor point displacement of a
dual frame seat design will still be bound by the energy absorption
phase of the quasi-static test even as greater anchor point
displacement is allowed during the torso belt pull phase of the test.
Also, the seat will still need to meet the energy absorption of 452 J
(4,000 inch-pounds) per occupant seating position specified in S5.1.3.
These parameters will still limit the reduction in strength/energy
absorption capability of the inner frame.
iii. Freedman commented: ``If a seat assembly includes more than
one torso belt anchor point how should the displacement be measured?
Should the average or the worst case displacement be used for
evaluation? FSTL recommends that NHTSA clarify the procedure to address
the possibility of multiple torso belt anchor points on one seat.''
[[Page 62768]]
Agency Response
The agency will use the displacement of any of the torso belt
anchorage points to determine if a seat meets the performance criteria.
iv. Freedman tested its double occupant 3PT Family Seat ``according
to the parameters proposed for small school buses.'' As a result,
Freedman suggested one change to proposed S5.1.6.5.7.; that ``the
forward and rearward travel distance of the upper loading bar pivot
attachment point measured from the position at which the initial
application of 44 N of force is attained'' be changed to ``the forward
and rearward travel distance of the upper loading bar pivot attachment
point measured from the position at which an application of 44 N of
force is attained.''
Agency Response
The agency has adjusted the performance criteria in such a way that
the measurement for forward travel will start after the 44 N force is
obtained.
v. CEW asked NHTSA to remove the requirement to measure the initial
seat back angle. CEW believes this would be time-consuming and
unnecessary if an angular rotation limit were used. CEW proposed that
``the criteria for both large and small school buses could be: Shoulder
anchor displacement must be < 10 degrees forward of vertical per above
quote or a linear equivalent.'' Takata also suggested the agency
consider different displacement measurement methodology and limits when
assessing the performance of the seat back in various stages of the
quasi-static test. They specified that a displacement plane should
establish the limit on seat back rotation. The primary context of this
seemed to be the energy absorption criteria of the quasi-static test.
However, this would also seem to limit the seat back rotation during
the torso belt loading portion of the test.
Agency Response
We decline to accept the CEW or Takata suggestions. The final rule
will continue to use a horizontal displacement limit for anchor point
motion. The final rule will also use a horizontal displacement limit
for seat back motion.
As explained in the 2007 Technical Analysis, the agency derived the
torso anchor point displacement assuming rigid body rotation of the
seat back about a point 100 mm below the SgRP. We understood that the
actual anchor point displacement is dependent upon the seat back
design. Although specific points on the seat back may rotate and
translate, the seat back may actually bend like a cantilever beam under
load. As CEW and Takata suggest, certainly this bending motion can be
described as a change in angle of a line passing through the anchor
point or upper part of the seat back and some other reference point
near the seat base. However, we continue to believe that the forward
displacement of the anchor point is more relevant to occupant restraint
than rotation of a line passing through it. That is because a
rotational measurement would not take into consideration the absolute
displacement of the anchor point. While the Takata suggestion provides
a displacement limiting plane in space and thus restricts absolute
translation of the anchor point, we do not regard this method to be
superior to the agency's proposal.
We disagree with the CEW comment that measurement of the initial
seat back angle, which is necessary to calculate the displacement
limit, is complicated and time consuming. We believe this to be a
relatively simple measurement to make. We also do not agree with Blue
Bird's suggestion to place Figure 9 from the 2007 Technical Analysis in
the regulatory text, since this may imply that only rigid body rotation
is occurring.
Finally, while the idea to use a rotational limit to control the
seat back motion as opposed to a displacement limit has merit, we do
not believe it is more merited than the displacement value of the
anchor point as proposed by the agency. We also believe it would be
challenging to find an objective method of measuring the seat back
angle at multiple locations along the seat back as it is being deformed
in a non-uniform way due to non-symmetric loading from multiple torso
belts.
vi. Takata believed that the final rule should limit the
displacement of the ``effective point'' or ``effective anchorage.''
This would differ from the anchor point in that it would include where
the torso belt interacts with the torso belt adjustment device. Takata
was concerned that the adjustment device might slip during the torso
body block loading. This slippage would result in additional belt
spool-out. Thus, the displacement of the anchor point would not be
representative of the actual occupant displacement. Takata was also
concerned that movement of the adjustment device could cause the torso
belt angle to change and cause the load path to move off the shoulder.
They suggested that the quasi-static procedure mark the belt webbing
and limit slippage to no more than 25 mm (1.0 inch), after accounting
for webbing stretch. In an ex parte meeting with the agency they
explained that the distance between the effective point and latch plate
should not increase by more than 25 mm (1.0 inch).
Agency Response
Both quasi-static and dynamic testing of seat belt designs with
torso belt adjustment devices showed that the devices tended to slip
when loading was applied to the torso belts. Thus, we believe that
Takata's suggestion of limiting the adjuster slippage to 25 mm (1.0
inch) or less is reasonable. However, we believe that this value should
be relative to the initial position on the fixed webbing upon which the
adjuster travels. This avoids having to deal with or compensate for
stretch in the torso restraint webbing, which would be necessary if we
were to use the test method suggested by Takata.
Finally, to implement this change, the initial position of the
torso belt adjustment device must be such that slippage will be
possible. For example, if the starting position for the adjuster is
fully up, there is nowhere for it to go, and the test will not discern
the sufficiency of adjuster's capability of remaining in position. To
verify that the adjuster does not slip more than 25 mm (1.0) under
load, the final rule will require it to be placed 38 mm (1.5 inches)
below its highest position of adjustment.
vii. The proposed quasi-static procedure applied no load through
the pelvic body block. A pelvic body block was not included because the
focus of the test is to assure that the top of the seat back does not
pull too far forward, reducing compartmentalization, and because a
visual assessment showed that the desired seat response could be
achieved with only the torso body block load. However, the agency
requested comments on whether the quasi-static test should apply a
pelvic block loading. IMMI, CEW and Blue Bird agreed with the NPRM as
it relates to not applying pelvic block loading during the quasi-static
test as it would not make a significant contribution to the seat back
loading/displacement. Blue Bird argued it would be an unnecessary
complication.
Takata was the sole commenter indicating a preference for the
pelvic loading. Takata also indicated that there should be limits
placed on the lateral displacement of lap belt anchorages, consistent
with ECE R14, to reduce the likelihood of occupants loading each other.
It requested that after the belt loading sequence in the quasi-static
test, the anchorage spacing of a 330 or 380 mm (13 or 15 inches)
seating position
[[Page 62769]]
should be not less than 305 or 350 mm (12 or 13.77 inches),
respectively.
Agency Response
We agree with the majority of commenters and continue to believe
that pelvic block loading would be of no consequence to the outcome of
the quasi-static test. Therefore, the only reason to apply the pelvic
load would be to implement the Takata recommendation to restrict the
change in lateral anchorage spacing after belt loading in the quasi-
static test, consistent with ECE R14. We are not convinced that the
quasi-static test as currently written would be appropriate to
ascertain the tendency for anchorages to displace in the real world.
The quasi-static test pulls only on the torso belt. The pelvic belt
portion of the restraint is not pulled. To implement the ECE R14
requirement according to the Takata suggestion, the test would need to
pull on the pelvic belt portion, which is not done in the test. In
addition, the ECE R14 requirements are applicable to general passenger
vehicles and are not specifically tailored to school buses. In Europe,
non-school buses, and not buses designed to meet the
compartmentalization requirements in FMVSS No. 222, are used.
ECE R14 is essentially the analogous regulation to FMVSS No. 210.
After application of loading to the anchorages, the minimum allowed
anchorage spacing cannot be violated. We note that FMVSS No. 210 has no
equivalent requirement to limit lateral anchorage spacing after
anchorage loading. The agency has never found that a safety need exists
for such a requirement in any vehicle to which FMVSS No. 210 applies.
In addition, application of the suggested provision would be design
restrictive, effectively eliminating flex-seat designs with sliding
lower anchorages. As we expressed in section IX.b.5., we see no safety
need to disallow such designs. Moreover, the commenter did not provide
any test data to support the contention that performance would be
compromised by allowing anchors to slide.
viii. In the NPRM, we proposed that any seating position that has
greater than a 380 mm (15 inches) seat width would be exposed to a body
block load based on a 50th percentile male occupant (5,000 N (1,124
pounds) and 7,500 N (1,686 pounds) for large and small school buses,
respectively). Any seating position that has the minimum seating width
of 380 mm (15 inches) would be exposed to a torso body block load based
on a 5th percentile female occupant (3,300 N (742 pounds) and 5,000 N
(1,124 pounds) for large and small school buses, respectively).\66\
Thus, a bench seat having a width between 1,140 mm (44.9 inches) and
1,165 mm (45.9 inches) could have three belted positions that need to
meet the 5th percentile female loading.
---------------------------------------------------------------------------
\66\ S5.1.6.5.5 specified that 5,000 N is applied to the torso
belts if the bench width is no more than 25 mm greater than the
number of belted positions (Y) times 380 mm (15 inches). A wider
bench indicates that there is nominally more than 380 mm (15 inches)
per belted seating positions and the load applied to the torso belts
must be 7,500 N.
---------------------------------------------------------------------------
Takata suggested that if the minimum seat width for a lap/shoulder
belt seating position is maintained at 380 mm (15 inches), all seating
positions should be loaded assuming 50th percentile male occupants
rather than the 5th percentile female occupants. Takata argued that the
reduced load is not representative of potential worst case usage.
Agency Response
There is a potential that three 50th percentile (or larger) males
may try to sit in a 1,143 mm (45 inch) wide seat with three lap/
shoulder belts. However, data submitted by Takata indicates the
shoulder width of a 50th percentile male is 465 mm (18.3 inches),
substantially larger than the 380 mm (15 inch) seat spacing. In making
a determination of appropriate loading, the agency must consider the
probability of a loading situation occurring. We are not convinced that
the likelihood of this misuse condition is high, and Takata has not
provided the agency any information as to the likelihood of the loading
scenario they described.
Further, there is an issue of the practicability of requiring seats
to meet the quasi-static requirements assuming three 50th percentile
males are occupying all three lap/shoulder belt positions. The agency
has no quasi-static testing or sled testing in this configuration. This
would represent a 50 percent increase in stringency for total torso
body block loading for seats that would fall in this category. We
estimated the torso body block load normalized to the upper loading
bar. Increasing the total torso body block loading by adding an
additional torso load (50 percent increase) would result in a load of
13,770 N (3,096 pounds) and 9,180 N (2,064 pounds) for the small and
large school bus cases, respectively.
The small school bus load would clearly exceed the upper limit of
the force-deflection zone required by S5.1.3 of FMVSS No. 222. In the
2007 Technical Analysis we discussed the implications of requiring a
normalized torso body block load that was at or above the upper limit
of the force-deflection zone. We stated that such a requirement might
necessitate novel designs that have an energy absorbing phase during
seat back contact with unbelted occupants and a stiff phase when the
belted occupant is loading the seat back through the anchorage. These
designs will take time and resources to develop.
Ultimately, the agency must establish a reasonable limit to the
seating position width that should be expected to accommodate a 50th
percentile male and the associated belt loading. This is particularly
true given our new minimum width of 330 mm (13 inches) for the ``small
occupant seating position'' of flex-seats. Given the available
information, we see no sufficient reason to change the load requirement
from what was proposed.
The question arises as to what should be the appropriate torso body
block loading for a flex-seat at its maximum occupant capacity. NHTSA
believes that it is reasonable to assume that the outside seating
positions of a flex-seat, in a maximum occupancy configuration, could
be loaded to levels consistent with occupancy by adult 5th percentile
adult females and so is adopting that load requirement. Certainly,
larger occupants could be present in these outside seats, but this
would result in the center seating position accommodating
correspondingly smaller occupants. Assuming the outside seats are
occupied by 5th percentile adult females (a 12-year-old child is
approximately the size of a 5th percentile adult female), the center
seat could be occupied by an occupant about the size of a 10-year-old.
This is consistent with our allowance for a lower anchor height for the
center seat of flex-seats. Nonetheless, we believe that it is in the
best interest of safety to maintain the loading of this position to the
same level as the other positions on a flexible occupancy seat, i.e.,
equivalent to that of a 5th percentile adult female.
There is not much of a difference between the associated loads of a
5th percentile adult female and a 10-year-old child. Our latest data on
the mass of a 10-year-old is 37.2 kg (82 pounds). The total percentage
increase in applied torso load between assuming three 5th percentile
females or two 5th percentile females and one 10-year-old would be 9%
[((3 x 49) - ((2 x 49) + 37.2)/((2 x 49) + 37.2)]. We have no
practicability concerns with the three-across 5th percentile female
loading on a flexible occupancy seat. Moreover, the approach is
consistent with the load level that the
[[Page 62770]]
agency is establishing for other three-seating position bench seats
with fixed lap/shoulder belts.
Accordingly, the agency has concluded that flex-seats in a maximum
occupancy configuration must be loaded in the quasi-static test to a
level consistent with all seat positions being occupied by 5th
percentile female occupants, that is to say, a torso body block load of
3,300 N (742 pounds) and 5,000 N (1,124 pounds) for large and small
school buses, respectively. This would include flexible occupancy
seating positions down to a 330 mm (13 inch) width, up to a fixed seat
width of nominally 380 mm (15 inches). As was proposed, seating
positions with widths of 380 mm (15 inches) or larger are load values
consistent with occupancy of a 50th percentile male occupant.
ix. CEW asked that the agency to modify the quasi-static energy
absorption requirement such that the upper loading bar load remains in
the present FMVSS No. 222 force-deflection corridor. They argued that
the compartmentalized occupant behind a belted occupant should be
offered the full protection of a seat back that can stay within the
force-deflection corridor and not just that of a seat back that meets
the reduced performance level proposed in the NPRM.
Agency Response
We believe there is merit to the CEW request. In the preamble of
the NPRM, we contrasted the energy absorption for an occupant behind
belted and unbelted occupants. We stated that for unbelted occupants
behind belted occupants, ``the manner of absorbing energy would not be
as controlled as when impacting a seat back that had not been subjected
to the previous loading from the seat belts.'' An altered performance
level as specified in the force-deflection corridor would no longer be
applied. However, the required amount of energy absorption remained the
same as specified by S5.1.3. We believed that this was necessary
because the torso belt pull would have loaded the seat back into
plastic deformation and it was unclear how well controlled the force/
deflection curve of subsequent loading with the upper loading bar could
be.
According to CEW, at least for their design, this subsequent
loading is sufficiently controllable. In fact, the agency's own data is
verification of CEW's position. Figures 2 and 3 below entitled, ``CEW
with three fixed width seating positions'' and ``CEW with two fixed
width seating positions,'' respectively, show the force-deflection
curves of the upper loading bar in the quasi-static test for a CEW
unified frame design.\67\
---------------------------------------------------------------------------
\67\ NHTSA-2007-0014-0016.
[GRAPHIC] [TIFF OMITTED] TR21OC08.054
[[Page 62771]]
[GRAPHIC] [TIFF OMITTED] TR21OC08.055
However, we are concerned that adopting the entire corridor may
unnecessarily restrict the design of seat backs other than that of
conventional unified frame seats. Figures 4 and 5 below, ``IMMI-V1 with
three fixed width seating positions'' and ``IMMM-V1 two fixed width
seating positions,'' respectively, show the results of agency testing
for the IMMI-V1 dual frame design. Note that the force/deflection curve
exits the lower boundary at the location of the upward slope and
reenters at the flat portion of the boundary. However, this design
still achieved the necessary amount of energy absorption prior to 356
mm of displacement in the case of the two-position seat and prior to
exiting the upper bound of the corridor in the case of the three-
position seat. We note that testing with a prototype considered by IMMI
showed a force-deflection signature that remained within the required
corridor.\68\
---------------------------------------------------------------------------
\68\ ``NHTSA Technical Analysis to Support the Final Rule
Upgrading Passenger Crash Protection in School Buses,'' September
2008.
---------------------------------------------------------------------------
Our concern about being design restrictive relates to imposing the
lower bound of the corridor. For the dual frame design in the quasi-
static test, the inner frame will have been initially pulled away from
the rest of the seat back. As the upper loading bar initially loaded
the outer seat back frame, for this particular version of the IMMI
design (IMMI-V1) this outer frame did not offer sufficient resistance
to stay in the corridor and neither did it meet the proposed anchorage
displacement requirement.\69\ If the manufacturer were to modify the
design so as to meet the new torso anchor point displacement limit, the
seat will have a stronger inner frame. We are concerned that
strengthening of the inner frame would make it problematic to
strengthen the outer frame such that it could stay above the lower
bound of the force deflection curve.\70\ The result of the prototype
IMMI design staying within the corridor does not change this conclusion
since that design also did not meet the new torso anchor point
displacement limit.
---------------------------------------------------------------------------
\69\ This version of the IMMI seat is no longer manufactured.
\70\ This is because the combined frame still needs to stay in
the corridor for the S5.1.3 energy requirement.
---------------------------------------------------------------------------
However, we do believe it is reasonable to expect a compliant dual
frame design to stay below the upper bound of the corridor.
Accordingly, we are adopting the upper boundary of the corridor, so the
seat back must perform such that the top loading bar force must stay
within the top of the force/deflection corridor specified for the
compartmentalization requirement. This requirement helps ensure that
the seat back will not be too stiff in containing the unbelted
passenger in a crash.
BILLING CODE 4910-59-P
[[Page 62772]]
[GRAPHIC] [TIFF OMITTED] TR21OC08.056
x. CEW and Girardin requested that lap/shoulder belt equipped seats
not have to independently meet the energy absorption requirement of
S5.1.3 since the quasi-static test addresses this separately. Takata
asked that the energy quasi-static energy absorption requirement be met
prior to the seat back going beyond a specified displacement plane.
Agency Response
We do not agree with this request. We still believe it is important
that the seat back meet the compartmentalization requirement as it
currently exists, i.e., prior to the seat being deformed or stressed by
belt loading. Even when there are lap/shoulder belts on school buses,
some occupants may not use them. In that case,
[[Page 62773]]
compartmentalization is the only restraint method. We have no
guarantee, nor have we been shown any data indicating, that a seat back
remaining in the corridor after belt loading will always be in the
corridor prior to belt loading. In addition, to implement the CEW and
Girardin recommendation the quasi-static test would have to impose
compliance with the entire force-deflection corridor. As we explained
above, we are not imposing the lower bound at this time.
xi. Both Freedman and Blue Bird requested that the displacement
limit in the energy absorption phase of the quasi-static test begin
when the 44 N (10 pounds) is obtained as a result of upper loading bar
in S5.1.6.5.7 as opposed to when the 44 N (10 pounds) is applied when
the seat back position is determined in S5.1.6.3.
Agency Response
The comments indicate confusion as to where the calculation of
displacement for the energy calculation in S5.1.6.5.7 should begin. It
is to begin when 44 N of force is achieved in the upper loading bar
during the load application specified in S5.1.6.5.7. Changes have been
made to the regulatory text to make this clear.
xii. We also sought comment on the proposed procedure (see
S5.1.6.5.4 of the proposed rule) for positioning the torso block used
in the quasi-static test. We also asked whether the proposed procedure
was sufficiently clear and whether there are ways to improve the
clarity of the test procedure.
Several commenters addressed the proposed 300 N (67 pounds) preload
used in the test. CEW stated testing indicated that the 300 N (67
pounds) preload is not sufficient to hold the torso body block in place
until the full load is applied. They recommended that the preload be
increased to 896 N (200 pounds). Freedman stated that it was difficult
to position the torso body blocks as described in S5.1.6.5.4 and the
300 N (67 pound) preload seemed inadequate to position the torso body
block in the prescribed zone. Freedman recommended that the preload be
increased to a load between 890 to 1,334 N (200 to 300 pounds).
Freedman indicated that the torso body block was also difficult to
position without any support beneath it. They requested clarification
on whether the use of supports to help position the body block within
the required zone was permissible.
Blue Bird stated that their experience has been that a 300 N (67
pounds) preload applied slightly upward (5-15 degrees) is not
sufficient to counteract the body block weight and hold it such that
the applied load remains at the desired angle. They did not suggest a
specific load, but stated their belief it would be several hundred
pounds. They stated that at such a weight, the seat belt webbing
stretches and seat back displacement becomes a concern. They suggested
the use of a spacer on top of the seat cushion as a superior
alternative method to achieve the desired initial body block position
until the applied load negates the gravitational pull on the body
block.
Agency Response
After considering the comments, the agency is revising the applied
preload and positioning zone for the torso body block. We found that a
preload of 600 N (135 pounds) will position the torso body block in a
repeatable manner without the use of any support under the block.\71\
---------------------------------------------------------------------------
\71\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for
Various School Bus Seats Equipped with Type 2 Seat Belts, Torso
Block Preload and Positioning,'' General Testing Laboratories, Inc.,
July 2008.
---------------------------------------------------------------------------
In addition, the agency has found that the zone for locating the
origin of the torso body block radius must be referenced to the
adjusted height of the torso belt to address flex-seat designs. As
earlier discussed in this preamble, this final rule specifies that the
torso belt adjusted height will be 38 mm (1.5 inches) below its highest
position of adjustment to account for slippage. In addition, for small
occupant seating positions of a flex-seat, this adjusted position may
be well below 400 mm above the SgRP.
The agency evaluated the sensitivity and repeatability of the torso
body block position to preload values and torso belt adjusted height.
Our analysis showed that a preload of 600 N (135 pounds) was sufficient
to position the torso body block in a repeatable manner without the use
of any support under the block. The origin of the torso block will
still be located no more than 100 mm forward of the SgRP. However, the
vertical zone is now referenced to the torso belt adjusted height. This
zone is established by locating a horizontal plane that has a vertical
position halfway between the torso belt adjusted height and 100 mm
below the SgRP. The origin of the torso body block radius must be
within 75 mm (3.0 inches) of this plane. Mathematically, the vertical
location of the upper and lower plane is as follows:
Upper Plane = (TBAH - 100)/2 + 75 = (TBAH)/2 + 25 mm
Lower Plane = (TBAH - 100)/2-75 = (TBAH)/2-125 mm
Where TBAH is the torso belt adjusted height above the SgRP.
Figure 6 below shows the newly defined zone. The new torso block
zone now ``floats'' with the torso belt adjusted height, which allows a
reasonable and achievable zone that can be used with the large
potential range of belt heights on school bus seats. This is
particularly important when the center position is a flexible occupancy
seat that potentially has a lower torso anchor point height.
[[Page 62774]]
[GRAPHIC] [TIFF OMITTED] TR21OC08.057
xiii. IMMI, Takata and Concepts all asked that the agency allow
dynamic certification of lap/shoulder belt equipped school bus seats as
an alternative to the quasi-static test. These tests would use
instrumented dummies and IARVs. They stated that sled or full-vehicle
crash testing more accurately represents ``real world'' performance.
Agency Response
These commenters are addressing an issue (dynamic testing) that is
outside the scope of this rulemaking since a dynamic test component was
expressly not proposed by NHTSA. Nonetheless, the agency wishes to take
this opportunity to provide some views on the issue.
In the preamble to the NPRM, the agency stated it was proposing the
quasi-static test instead of a dynamic test because ``manufacturers are
familiar with quasi-static testing * * * [M]anufacturers would be able
to test a large number of seats and a variety of design configurations
without incurring the delay and additional cost of sending each
configuration to an outside testing facility.'' In terms of testing
cost, we continue to believe it is less expensive to certify compliance
by the quasi-static test than it would be to perform a dynamic
equivalent. Now, with the advent of flex-seats that must be tested in
several occupant configurations, this cost differential may be even
larger. Because the quasi-static test is less costly than sled testing,
the quasi-static test allows testing of more seating systems on a
school bus and/or more school buses than 5 if a sled test were
specified.
In addition, a quasi-static test is currently specified in FMVSS
No. 222 to test the performance characteristics of
compartmentalization. The test has been successful in ensuring the
integrity of the compartmentalized passenger compartment since the
inception of FMVSS No. 222. A quasi-static test to assess the effect
that lap/shoulder belts have on the compartmentalized seating systems
thus is a rational aspect of this rulemaking, as it broadens the
current successful framework used to assess school bus seating systems
and extends it to assess the effect that equipment (lap/shoulder belts)
added to the systems affect the seating systems. Developing a dynamic
test for lap/shoulder belts in FMVSS No. 222 would
[[Page 62775]]
take further study and investment of agency resources that the agency
believes is more appropriately directed to other priorities at this
time.
xiv. This final rule excludes the last row of seats from the
portion of the quasi-static test where the rear loading bar load is
applied to simulate the force imposed by compartmentalized occupants
seated in a more rearward seat row. However, the torso body block
loading will still be applied and the anchor point displacement limit
must still be met. The reason for this exclusion is that there will be
no occupants rearward of the last row of occupants. However, the
standard will ensure that the lap/shoulder belts are capable of
adequately restraining the occupants in the last row in a frontal
impact.
This exclusion is consistent with other exclusions of FMVSS No. 222
applied to the last seat row that were adopted based on the
appropriateness of the requirement as applied to the last row. In this
rulemaking, we have excluded from the FMVSS No. 210 requirement, that
last row seat belt anchorages be integrated in the seat structure.
Similarly, the last row is currently excluded from the
compartmentalization energy absorption requirement of FMVSS No. 223 at
S5.1.3.
d. Lap Belt Buckle Belt Length
In the NPRM, we noted that for a proper fit, the lap belt or lap
belt portion of a lap/shoulder belt must fit low across the occupant's
hips so that the crash loads are distributed across the pelvis and not
the abdominal area. Loading of the abdomen rather than the pelvis
increases the risk of internal injuries caused by the seat belt
penetration into the soft tissue of the abdomen. We stated that we were
aware that lap belts supplied to some states have long buckle stalks or
long belt lengths between the ``seat bight'' (approximately the
intersection of the seat cushion and seat back) and buckle that cause
the lap belt to not fit low across the hips of the passengers. We asked
for comment on whether such designs should be retained because of
privacy issues, even if the long buckle stalks may result in
misplacement of the lap belt across the child's abdomen and difficulty
in child restraint attachment.
Most commenters responding to this issue supported the short buckle
stalks. CEW agreed that a longer buckle stalk can allow the seat belt
to engage in the abdominal area, whereas a shorter buckle stalk forces
the belt engagement lower in the pelvic area. However, they stated they
respected the privacy considerations and that they let the end user
decide whether to use longer buckle stalks. IMMI stated belt buckles
should not be permitted to ride across the abdomen and recommended that
NHTSA establish a maximum length limit for the distance between the
buckle tip and the seat bight. SafeRide News stated that a much shorter
buckle stalk should be used, similar to that found in most private
passenger vehicles, with which children are familiar from buckling
themselves up. On the other hand, NYAPT stated its belief that the
longer stalks can make the seat belt system more conducive to emergency
evacuations of children, particularly children with special needs.
Agency Response
In this final rule, to optimize crash protection on school buses,
we are limiting the location of the distance between the buckle end and
associated latch plate to within 65 mm (2.6 inches) of the SgRP (FMVSS
No. 222, S5.1.7). We agree with the commenters that privacy concerns
are somewhat allayed by having the seat belt buckles located at the
children's sides and not in the middle of the seating position. In
response to NYAPT, we understand its concern but believe that the pros
of the belt positioned in the pelvic area outweigh the concerns about
emergency evacuation. Further, emergency evacuation could be
facilitated by the similarity of the short buckle stalks with the
family vehicle and the familiarity of the short buckle stalk to the
children, as stated by SafeRide News. Driver and student training in
emergency evacuation procedures should also help in timely egress from
the vehicle.
The measurement is taken by pulling the lap portion of the belt
webbing on the latchplate side with a 20 N force applied in the
vertical longitudinal plane. (The seat belt assembly is buckled during
the test.) The load is applied through a range of angles and the end of
the buckle/latchplate assembly must not go beyond a defined limit
plane. The limit plane is 40 degrees from the horizontal, transverse
with respect to the vehicle and is 65 mm from the SgRP. We have chosen
the SgRP as the reference point for measurement since it is more
objective than trying to use the seat bight. The 65 mm (2.6 inch) value
is based on measurements from seats manufactured by IMMI and Takata.
(See discussion in the 2008 Technical Assessment.) All the measured
seats would meet the proposal. We also placed a 6YO test dummy in these
seats to get an indication of the buckle location with respect to the
dummy abdomen and found the location to be acceptable, i.e., the belt
was placed nearer to the hip area and not high on the abdominal region.
XI. Lead Time
The NPRM proposed a one year lead time for school bus manufacturers
to meet the new requirements for a 24-in minimum seat back and seat
cushion retention, since there is limited or no development necessary
for these changes. We also proposed a one-year lead time for meeting
requirements for voluntarily installed seat belts in large school buses
and a three year lead time for meeting mandatory installation in small
school buses. We stated our belief that three years are necessary for
small school buses since some design, testing, and development will be
necessary to certify compliance to the new requirements. We also
proposed that optional early compliance be permitted.
IC Corporation requested that NHTSA allow the same lead time for
large buses as for small buses, three years, to allow for ``adequate
time to properly engineer, tool and validate the designs.'' The
commenter stated that the rulemaking establishes new design and
performance standards for lap/shoulder belts on large school buses and
that time is needed to design, develop and test the systems.
In response, NHTSA agrees with the comment. There is good cause for
the lead time because school bus manufacturers need time to design and
manufacture school buses that meet the performance requirements adopted
by this final rule. We have thus provided a one year lead time for
compliance with the requirement to install higher seat backs and
restraining barriers on all school buses and to meet the seat cushion
retention test. A three year lead time is provided for meeting
requirements for voluntarily installed seat belts (lap belts and lap/
shoulder belts) in large school buses and for mandatory lap/shoulder
belts in small school buses. Optional early compliance is available for
all of these amendments, as of the date of publication of this final
rule.
XII. Rulemaking Analyses and Notices
Executive Order 12866 and DOT Regulatory Policies and Procedures
This rulemaking document was not reviewed by the Office of
Management and Budget under E.O. 12866 and is not considered to be
significant under E.O. 12866 or the Department's Regulatory Policies
and Procedures (44 FR 11034; February 26, 1979). NHTSA has
[[Page 62776]]
prepared a final regulatory evaluation (FRE) for this final rule.\72\
---------------------------------------------------------------------------
\72\ NHTSA's 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 also be
obtained by contacting http://www.regulations.gov or by contacting
DOT's Docket Management Facility, M-30, U.S. Department of
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, telephone 202-366-9324.
---------------------------------------------------------------------------
This final rule requires: (a) For all school buses to increase seat
back height from 508 mm (20 inches) to 610 mm (24 inches), and to
require a self-latching mechanism for seat bottom cushions that are
designed to flip up; \73\ and (b) for small school buses (GVWR of 4,536
kg (10,000 pounds) or less, passenger seat lap/shoulder belts in lieu
of the currently-required lap belts. School bus manufacturers will be
required to certify that the belt systems meet specifications for
retractors, strength, location and adjustability. Under the
requirements, seat backs with lap/shoulder belts are subject to a
quasi-static test to assure that the seat backs are strong enough to
withstand the forces from a belted passenger and that of an unbelted
passenger seated behind the belted occupant. This final rule also
requires: Performance requirements for voluntarily-installed seat belts
on large (over 4,536 kg (10,000 pounds)) school buses. For large school
buses with voluntarily-installed lap/shoulder belts, the vehicle would
be subject to the requirements described above for lap/shoulder belts
on small school buses, except that applied test forces and performance
limits would be adjusted so as to be representative of those imposed on
large school buses. Large school buses with voluntarily-installed lap
belts would be required to meet anchorage strength requirements. This
final rule does not require seat belts to be installed on large school
buses. The performance requirements for seat belts on large school
buses affect large school buses only if purchasers choose to order seat
belts on their vehicles.
---------------------------------------------------------------------------
\73\ The agency estimates that a self-latching mechanism on
flip-up seat bottoms will cost less than $3 per seat, or $66 per
bus. This cost was not included in the estimates given below.
---------------------------------------------------------------------------
The School Bus Fleet 2007 Fact Book on U.S. school bus sales for
the sales years 2001-2005 reports that for each of these years on
average, approximately 40,000 school buses were sold. NHTSA estimates
that of the 40,000 school buses sold per year, 2,500 of them were
10,000 pounds GVWR or under. The other 37,500 school buses were over
10,000 pounds GVWR. Four states currently require high back seats
(Illinois, New Jersey, New York, and Ohio). These states have 21.7
percent of the sales. Thus, the high back seat incremental costs apply
to 78.3 percent of these sales or 1,958 buses that are 10,000 pounds
GVWR or under and 29,362 buses that are over 10,000 pounds GVWR.
Small School Buses
NHTSA estimates that the costs of this rulemaking are the
incremental cost of the higher (24 inch) seat back ($45 to $64 per
small school bus for 78.3 percent of the fleet) plus the incremental
cost for lap/shoulder belts over lap belts of $1,121 to $2,417. This
amounts to a total incremental cost per school bus of $1,166 to $2,481
per bus for those states without high back seats. If it is assumed that
in a given year, 2,500 small school buses are sold, for all small
school buses, the total incremental costs of this rulemaking are
estimated to be from $2,889,000 ($45 x 1,958 + $1,121 x 2,500 small
school buses) to $6,167,000 ($64 x 1,958 + $2,417 x 2,500 small school
buses).
The estimated benefits resulting from the higher seat backs and
lap/shoulder belts on small school buses is, per year, 43 fewer
injuries, and 0.8 fewer fatalities.
Large School Buses
Costs of Higher Seat Backs on Large School Buses--In this final
rule, all large school buses must have the higher seat backs of 24
inches. NHTSA estimates the cost per large school bus of the higher
seat back to be $125. NHTSA estimates that the total costs of the
higher seat backs on large school buses to be $3,680,000 (29,362 large
school buses times $125.40).
Benefits of Higher Seat Backs on Large School Buses--The benefits
from higher seat backs on large school buses is estimated to be 23
fewer injuries per year, and 0.14 fewer fatalities per year.
Costs and Benefits of Performance Requirements for Voluntarily-
Installed Belts on Large School Buses--As earlier noted, nothing in
this rulemaking requires any party to install lap or lap/shoulder belts
at passenger seating positions in large school buses. Instead, this
rulemaking specifies performance requirements that voluntarily-
installed lap or lap/shoulder belts at passenger seating positions must
meet. Lap or lap/shoulder belts that are now installed in large school
buses are affected by this rulemaking, in that the voluntarily-
installed belt systems would be subject to the performance requirements
set forth in this final rule whereas currently the systems are not
subject to any Federal standard. The agency is unable to estimate the
costs and benefits of this part because not enough is known about the
requirements that state and local authorities now specify for the
performance of seat belt systems on large school buses.
Overview of Costs and Benefits
Costs of High Back Seats and Lap/Shoulder Belts for Small School Buses,
and of High Back Seats for Large School Buses
Small School Buses: Adding together the high back seat incremental
cost of $45 to $64 to the incremental cost for lap/shoulder belts over
lap belts of $1,121 to $2,417, results in a total incremental cost of
$1,166 to $2,481 per bus.
Large School Buses: The incremental cost for high back seat is
estimated to be $125 per bus.
Table 1--Total Costs (Per Bus and for the Fleet)
[$2006]
----------------------------------------------------------------------------------------------------------------
Large buses 66 Small buses 14 Small buses 20
passenger passenger passenger
----------------------------------------------------------------------------------------------------------------
Per Bus Costs........................ $125................... $1,166................. $2,481.
Annual Fleet Costs................... $3.7 million........... $2.9 million........... $6.2 million.
Combined Annual Fleet Costs.......... $6.6 to $9.9 million...
----------------------------------------------------------------------------------------------------------------
[[Page 62777]]
Benefits of High Back Seats and Lap/Shoulder Belts for Small School
Buses, and of High Back Seats for Large School Buses
The benefits for small school buses and large school buses are
estimated as shown below in Table 2:
Table 2--Total Benefits
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small school bus Large school bus Total
-----------------------------------------------------------------------------------------------
Injuries Fatalities Injuries Fatalities Injuries Fatalities
--------------------------------------------------------------------------------------------------------------------------------------------------------
High Back Seat.......................................... Combined below \1\ 23 0.14 23 0.14
Lap/Shoulder Belts...................................... 43 0.08 n.a. n.a. 43 0.08
-----------------------------------------------------------------------------------------------
Total............................................... 43 0.08 23 0.14 66 0.22
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ We did not have test data to allow us to separate out the high back seats from lap/shoulder belts for small school buses; thus, these data have been
combined.
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 proposed rulemaking 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. According to 13 CFR section 121.201,
the Small Business Administration's size standards regulations used to
define small business concerns, school bus manufacturers would fall
under North American Industry Classification System (NAICS) No. 336111,
Automobile Manufacturing, which has a size standard of 1,000 employees
or fewer. Using the size standard of 1,000 employees or fewer, NHTSA
estimates that there are two small school bus manufacturers in the
United States (U.S. Bus Corp. and Van-Con). NHTSA believes that both
U.S. Bus Corp and Van-Con manufacture small school buses and large
school buses.
I hereby certify that this final rule will not have a significant
economic impact on a substantial number of small entities. In this
final rule, the small businesses manufacturing small buses will incur
incremental costs ranging from a low of $1,166 to $2,481 per small
school bus, out of a total cost of $40,000 to $50,000 per small school
bus. The small businesses manufacturing large school buses will incur
incremental costs of $125 per school bus (out of a total of more than
$70,000) for the costs of the higher seat backs. The costs of lap/
shoulder belts on large school buses is not a factor, as nothing in
this final rule requires lap/shoulder belts or lap belts at passenger
seating positions in large school buses.
The relatively minimal additional costs outlined above for large
and small school buses will be passed on to school bus purchasers.
Those purchasers are required to be sold school buses if they purchase
a new bus, and to use school buses. Thus, small school bus
manufacturers will not lose market share as a result of the changes in
this final rule. While small organizations and governmental
jurisdictions procuring school buses will be affected by this
rulemaking in that the cost of school buses will increase, the agency
believes the cost increases will be small compared to the cost of the
vehicles and that the impacts on these entities will not be
significant.
Executive Order 13132
NHTSA has examined today's final rule pursuant to Executive Order
13132 (64 FR 43255, August 10, 1999). On July 11, 2007, NHTSA held a
public meeting bringing together a roundtable of state and local
government policymakers, school bus manufacturers, pupil transportation
associations and consumer groups to discuss the safety, policy and
economic issues related to seat belts on school buses (see NHTSA Docket
28103). No additional consultation with States, local governments or
their representatives is contemplated beyond the rulemaking process.
Further, the agency has concluded that the rulemaking will not have
federalism implications because it will not have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.'' This final
rule specifies performance requirements for seat belts voluntarily
installed on large school buses, but does not require the belts on the
large buses.
Further, no consultation is needed to discuss the preemptive effect
of today's rulemaking. NHTSA rules can have preemptive effect in at
least two ways. First, the National Traffic and Motor Vehicle Safety
Act contains an express preemptive provision: ``When a motor vehicle
safety standard is in effect under this chapter, a State or a political
subdivision of a State may prescribe or continue in effect a standard
applicable to the same aspect of performance of a motor vehicle or
motor vehicle equipment only if the standard is identical to the
standard prescribed under this chapter.'' 49 U.S.C. 30103(b)(1). It is
this statutory command that preempts State law, not today's rulemaking,
so consultation would be inappropriate.
Second, in addition to the express preemption noted above, the
Supreme Court has also recognized that State requirements imposed on
motor vehicle
[[Page 62778]]
manufacturers, including sanctions imposed by State tort law, can stand
as an obstacle to the accomplishment and execution of a NHTSA safety
standard. When such a conflict is discerned, the Supremacy Clause of
the Constitution makes their State requirements unenforceable. See
Geier v. American Honda Motor Co., 529 U.S. 861 (2000). NHTSA has not
discerned any potential State requirements that might conflict with the
final rule, however, in part because such conflicts can arise in varied
contexts. We cannot completely rule out the possibility that such a
conflict might become apparent in the future through subsequent
experience with the standard. NHTSA may opine on such conflicts in the
future, if warranted.
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 would 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
OMB control number. Today's final rule does 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.'' OMB Circular A-119 ``Federal Participation in the
Development and Use of Voluntary Consensus Standards and in Conformity
Assessment Activities'' (February 10, 1998) establishes policies to
implement the NTAA throughout Federal executive agencies. In section
4.a. of OMB Circular A-119, ``voluntary consensus standards'' are
defined as standards developed or adopted by voluntary consensus
standards bodies, both domestic and international. After carefully
reviewing the available information, NHTSA has determined that there
are no voluntary consensus standards relevant to this rulemaking.
In its comments to the November 21, 2007 NPRM, the National
Association of State Directors of Pupil Transportation Services
(NASDPTS) suggested that ``NHTSA strongly consider the national
consensus recommendations contained within the NSTSP [National School
Transportation Specifications and Procedures] whenever they are
relevant to the current NPRM.'' Our response to this comment is to
explain that we had reviewed the NSTSP recommendations but did not find
them applicable to this rulemaking. Those recommendations are developed
by school bus purchasers and users; NHTSA's FMVSSs apply to school bus
and equipment manufacture and these manufacturers are not directly
involved in the development of the recommendations. Today's final rule
do not apply to purchasers and users, but instead sets performance
standards for school buses to which school bus manufacturers must
certify compliance.
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 (7) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
The preemptive effect of this final rule has been discussed above.
NHTSA notes further that there is no requirement that individuals
submit a petition for reconsideration or pursue other administrative
proceeding before they may file suit in court.
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 $100 million annually
(adjusted for inflation 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 $100 million
annually.
Executive Order 13045
Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any
rule that: (1) Is determined to be ``economically significant'' as
defined under E.O. 12866, and (2) concerns an environmental, health, or
safety risk that NHTSA has reason to believe may have a
disproportionate effect on children. This rulemaking is not subject to
the Executive Order because it is not economically significant as
defined in E.O. 12866.
Executive Order 13211
Executive Order 13211 (66 FR 28355, May 18, 2001) applies to any
rulemaking that: (1) Is determined to be economically significant as
defined under E.O. 12866, and is likely to have a significantly adverse
effect on the supply of, distribution of, or use of energy; or (2) that
is designated by the Administrator of the Office of Information and
Regulatory Affairs as a significant energy action. This rulemaking is
not subject to E.O. 13211.
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 (Volume 65, Number 70; Pages 19477-78).
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles, and Tires.
0
In consideration of the foregoing, NHTSA amends 49 CFR Part 571 as set
forth below.
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
0
1. The authority citation for Part 571 continues to read as follows:
[[Page 62779]]
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50.
0
2. Section 571.207 is amended by revising the introductory text of
S4.2, to read as follows:
Sec. 571.207 Standard No. 207, Seating systems.
* * * * *
S4.2. General performance requirements. When tested in accordance
with S5, each occupant seat shall withstand the following forces, in
newtons, except for: a side-facing seat; a passenger seat on a bus
other than a school bus; a passenger seat on a school bus with a GVWR
greater than 4,536 kilograms (10,000 pounds); and, a passenger seat on
a school bus with a GVWR less than or equal to 4,536 kg manufactured
before October 21, 2011.
* * * * *
0
3. Section 571.208 is amended by revising S4.4.3.3, revising the
heading of S4.4.5 and revising S4.4.5.1, revising the table in S7.1.4,
and adding S7.1.5, to read as follows:
Sec. 571.208 Standard No. 208, Occupant crash protection.
* * * * *
S4.4.3.3 School buses with a gross vehicle weight rating of 4,536
kg (10,000 pounds) or less.
(a) Each school bus with a gross vehicle weight rating of 4,536 kg
(10,000 pounds) or less manufactured before October 21, 2011 must be
equipped with an integral Type 2 seat belt assembly at the driver's
designated seating position and at the right front passenger's
designated seating position (if any), and with a Type 1 or Type 2 seat
belt assembly at all other seating positions. Type 2 seat belt
assemblies installed in compliance with this requirement must comply
with Standard No. 209 (49 CFR 571.209) and with S7.1 and S7.2 of this
standard. The lap belt portion of a Type 2 seat belt assembly installed
at the driver's designated seating position and at the right front
passenger's designated seating position (if any) must meet the
requirements specified in S4.4.3.3(c).
(b) Each school bus with a gross vehicle weight rating of 4,536 kg
(10,000 pounds) or less manufactured on or after October 21, 2011 must
be equipped with an integral Type 2 seat belt assembly at all seating
positions. The seat belt assembly at the driver's designated seating
position and at the right front passenger's designated seating position
(if any) shall comply with Standard No. 209 (49 CFR 571.209) and with
S7.1 and S7.2 of this standard. The lap belt portion of a Type 2 seat
belt assembly installed at the driver's designated seating position and
at the right front passenger's designated seating position (if any)
shall meet the requirements specified in S4.4.3.3(c). Type 2 seat belt
assemblies installed on the rear seats of school buses must meet the
requirements of S7.1.1.5, S7.1.5 and S7.2 of this standard.
(c) The lap belt portion of a Type 2 seat belt assembly installed
at the driver's designated seating position and at the right front
passenger's designated seating position (if any) shall include either
an emergency locking retractor or an automatic locking retractor, which
retractor shall not retract webbing to the next locking position until
at least \3/4\ inch of webbing has moved into the retractor. In
determining whether an automatic locking retractor complies with this
requirement, the webbing is extended to 75 percent of its length and
the retractor is locked after the initial adjustment. If a Type 2 seat
belt assembly installed in compliance with this requirement
incorporates any webbing tension-relieving device, the vehicle owner's
manual shall include the information specified in S7.4.2(b) of this
standard for the tension-relieving device, and the vehicle shall comply
with S7.4.2(c) of this standard.
* * * * *
S4.4.5 Buses with a GVWR of 10,000 lb (4,536 kg) or less, except
school buses, manufactured on or after September 1, 2007.
S4.4.5.1 Except as provided in S4.4.5.2, S4.4.5.3, S4.4.5.4,
S4.4.5.5 and S4.4.5.6, each bus with a gross vehicle weight rating of
10,000 lb (4,536 kg) or less, except school buses, shall be equipped
with a Type 2 seat belt assembly at every designated seating position
other than a side-facing position. Type 2 seat belt assemblies
installed in compliance with this requirement shall conform to Standard
No. 209 (49 CFR 571.209) and with S7.1 and S7.2 of this standard. If a
Type 2 seat belt assembly installed in compliance with this requirement
incorporates a webbing tension relieving device, the vehicle owner's
manual shall include the information specified in S7.4.2(b) of this
standard for the tension relieving device, and the vehicle shall
conform to S7.4.2(c) of this standard. Side-facing designated seating
positions shall be equipped, at the manufacturer's option, with a Type
1 or Type 2 seat belt assembly.
* * * * *
S7.1.4 * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
50th-percentile 6- 50th-percentile 10- 5th-percentile adult 50th-percentile adult 95th-percentile adult
year-old child year-old child female male male
--------------------------------------------------------------------------------------------------------------------------------------------------------
Weight............................. 47.3 pounds........... 82.1 pounds........... 102 pounds........... 164 pounds 3.
Erect sitting height............... 25.4 inches........... 28.9 inches........... 30.9 inches.......... 35.7 inches .1.
Hip breadth (sitting).............. 8.4 inches............ 10.1 inches........... 12.8 inches.......... 14.7 inches .7.
Hip circumference (sitting)........ 23.9 inches........... 27.4 inches (standing) 36.4 inches.......... 42 inches............ 47.2 inches.
Waist circumference (sitting)...... 20.8 inches........... 25.7 inches (standing) 23.6 inches.......... 32 inches .6.
Chest depth........................ ...................... 6.0 inches............ 7.5 inches........... 9.3 inches .2.
Chest circumference:
(nipple)....................... ...................... ...................... 30.5 inches..........
(upper)........................ ...................... 26.3 inches........... 29.8 inches.......... 37.4 inches .6.
(lower)........................ ...................... ...................... 26.6 inches..........
--------------------------------------------------------------------------------------------------------------------------------------------------------
S7.1.5 School bus bench seats. The seat belt assemblies on school
bus bench seats will operate by means of any emergency-locking
retractor that conforms to 49 CFR 571.209 to restrain persons whose
dimensions range from those of a 50th percentile 6-year-old child to
those of a 50th percentile 10-year-old, for small occupant seating
positions, as defined in 49 CFR 571.222, and to those of a 50th
percentile adult male for all other seating positions. The seat back
may be in any position.
* * * * *
0
4. Section 571.210 is amended by revising S2; amending S3 by revising
the heading and adding definitions for
[[Page 62780]]
``school bus torso belt adjusted height,'' ``school bus torso belt
anchor point,'' and ``small occupant seating position,'' in
alphabetical order; adding S4.1.3 and S4.1.3.1 through S4.1.3.5; by
revising in the introductory paragraph of S4.3.2, the second sentence;
revising S4.3.2(b) and by adding Figure 4 to the end of the section, to
read as follows:
Sec. 571.210 Standard No. 210, Seat belt assembly anchorages.
* * * * *
S2. Application. This standard applies to passenger cars,
multipurpose passenger vehicles, trucks, buses, and school buses.
S3. Definitions.
School bus torso belt adjusted height means the vertical height
above the SgRP of the point at which the torso belt deviates more than
10 degrees from the horizontal plane when the torso belt is pulled away
from the seat by a 20 N force at a location on the webbing
approximately 100 mm from the adjustment device and the pulled portion
of the webbing is held in a horizontal plane.
School bus torso belt anchor point means the midpoint of the torso
belt width where the torso belt first contacts the uppermost torso belt
anchorage.
* * * * *
Small occupant seating position is as defined in 49 CFR 571.222.
* * * * *
S4.1.3 School bus passenger seats.
S4.1.3.1 Except for seats with no other seats behind them, seat
belt anchorages on school buses manufactured on or after October 21,
2011 must be attached to the school bus seat structure and the seat
belt shall be Type 1 or Type 2 as defined in S3 of FMVSS No. 209 (49
CFR 571.209).
S4.1.3.2 Type 2 seat belt anchorages on school buses manufactured
on or after October 21, 2011 must meet the following location
requirements.
(a) As specified in Figure 4, the vertical distance from the
seating reference point for the school bus torso belt anchor point must
be fixed or adjustable to at least 400 mm for a small occupant seating
position of a flexible occupancy seat, as defined in 49 CFR 571.222,
and at least 520 mm above the SgRP for all other seating positions. The
school bus torso belt adjusted height at each seating position shall,
at a minimum, be adjustable from the torso belt anchor point to within
at least 280 mm vertically above the SgRP to the minimum required
vertical height of the school bus torso belt anchor point for that
seating position.
(b) The minimum lateral distance between the vertical centerline of
the bolt holes or the centroid of any other means of attachment to the
structure specified in 4.1.3.1, simultaneously achievable by all
seating positions, must be:
(i) 280 mm for seating positions in a flexible occupancy seat in a
maximum occupancy configuration, as defined in 49 CFR 571.222; and
(ii) 330 mm for all other seating positions.
S4.1.3.3 School buses with a GVWR less than or equal to 4,536 kg
(10,000 pounds) must meet the requirements of S4.2.2 of this standard.
S4.1.3.4 School buses with a GVWR greater than 4,536 kg (10,000
pounds) manufactured on or after October 21, 2011, with Type 1 seat
belt anchorages, must meet the strength requirements specified in
S4.2.1 of this standard.
S4.1.3.5 School buses with a GVWR greater than 4,536 kg (10,000
pounds) manufactured on or after October 21, 2011, with Type 2 seat
belt anchorages, must meet the strength requirements specified in
S4.2.2 of this standard.
* * * * *
S4.3.2 Seat belt anchorages for the upper torso portion of Type 2
seat belt assemblies. * * * Except a small occupant seating position as
defined in 49 CFR 571.222, with the seat and seat back so positioned,
as specified by subsection (a) or (b) of this section, the upper end of
the upper torso restraint shall be located within the acceptable range
shown in Figure 1, with reference to a two-dimensional drafting
template described in Society of Automotive Engineers (SAE) Standard
J826, revised May 1987, ``Devices for Use in Defining and Measuring
Vehicle Seating Accommodation'' (incorporated by reference, see Sec.
571.5). * * *
* * * * *
(b) Except for seating positions on school bus bench seats,
compliance with this section shall be determined with adjustable
anchorages at the midpoint of the adjustment range of all adjustable
positions. For seating positions on school bus bench seats, place
adjustable anchorages and torso belt height adjusters in their
uppermost position.
* * * * *
BILLING CODE 4910-59-P
[[Page 62781]]
[GRAPHIC] [TIFF OMITTED] TR21OC08.058
0
5. Section 571.222 is amended by:
0
a. Adding to S4, in alphabetical order, definitions of ``fixed
occupancy seat'', ``flexible occupancy seat'', ``maximum occupancy
configuration'', ``minimum occupancy configuration'', ``seat bench
width'' and ``small occupant seating position'';
0
b. Revising S4.1; revising, in S5, paragraphs (a) and (b); revising
S5.1.2; revising S5.1.5; adding S5.1.6, S5.1.6.1 through S5.1.6.5, and
S5.1.6.5.1 through S5.1.6.5.7; adding S5.1.7 through S5.1.7.2; revising
S5.2.2; adding S5.5; and adding Figures 8 and 9 following Figure 7 at
the end of the section.
The revisions and additions read as follows:
Sec. 571.222 Standard No. 222; School bus passenger seating and crash
protection.
* * * * *
S4. Definitions.
* * * * *
Fixed occupancy seat means a bench seat equipped with Type 2 seat
belts that has a permanent configuration regarding the number of
seating positions on the seat. The number of seating positions on the
bench seat cannot be increased or decreased.
Flexible occupancy seat means a bench seat equipped with Type 2
seat belts that can be reconfigured so that the number of seating
positions on the seat can change. The seat has a minimum occupancy
configuration and maximum occupancy configuration, and the number of
passengers capable of being carried in the minimum occupancy
configuration must differ from the number of passengers capable of
being carried in the maximum occupancy configuration.
Maximum occupancy configuration means, on a bench seat equipped
with Type 2 seat belts, an arrangement whereby the lap belt portion of
the Type 2 seat belts is such that the maximum number of occupants can
be belted.
Minimum occupancy configuration means, on a bench seat equipped
with Type 2 seat belts, an arrangement whereby the lap belt portion of
the Type 2 seat belts is such that the minimum number of occupants can
be belted.
* * * * *
[[Page 62782]]
Seat bench width means the maximum transverse width of the bench
seat cushion.
Small occupant seating position means the center seating position
on a flexible occupancy seat in a maximum occupancy configuration, if
the torso belt portion of the Type 2 seat belt is intended to restrain
occupants whose dimensions range from those of a 50th percentile 6
year-old child only to those of a 50th percentile 10 year-old child and
the torso belt anchor point cannot achieve a minimum height of 520 mm
above the seating reference point, as specified by S4.1.3.2(a) of 49
CFR 571.210.
* * * * *
S4.1 Determination of the number of seating positions and seat belt
positions
(a) The number of seating positions considered to be in a bench
seat for vehicles manufactured before October 21, 2011 is expressed by
the symbol W, and calculated as the seat bench width in millimeters
divided by 381 and rounded to the nearest whole number.
(b) The number of seating positions and the number of Type 1 seat
belt positions considered to be in a bench seat for vehicles
manufactured on or after October 21, 2011 is expressed by the symbol W,
and calculated as the seat bench width in millimeters divided by 380
and rounded to the nearest whole number.
(c) Except as provided in S4.1(d), the number of Type 2 seat belt
positions on a flexible occupancy seat in a minimum occupancy
configuration or a fixed occupancy seat for vehicles manufactured on or
after October 21, 2011 is expressed by the symbol Y, and calculated as
the seat bench width in millimeters divided by 380 and rounded to the
next lowest whole number. The minimum seat bench width for a seat
equipped with a Type 2 seat belt is 380 mm. See Table 1 for an
illustration.
(d) A flexible occupancy seat meeting the requirements of S4.1(c)
may also have a maximum occupancy configuration with Y +1 Type 2 seat
belt positions, if the minimum seat bench width for this configuration
is Y +1 times 330 mm. See Table 1 for an illustration.
(e) A flexible occupancy seat equipped with Type 2 seat belts in a
maximum occupancy configuration may have up to one single small
occupant seating position.
Table 1--Number of Seating Positions as a Function of Seat Bench Width
----------------------------------------------------------------------------------------------------------------
Seat bench width (mm)
Seating configuration ---------------------------------------------------------------------
380-659 660-759 760-989 990-1139 1140-1319
----------------------------------------------------------------------------------------------------------------
Minimum or Fixed Occupancy................ 1 1 2 2 3
Maximum Occupancy......................... 1 2 2 3 3
----------------------------------------------------------------------------------------------------------------
S5. Requirements.
(a) Large school buses.
(1) Each school bus manufactured before October 21, 2011 with a
gross vehicle weight rating of more than 4,536 kg (10,000 pounds) shall
be capable of meeting any of the requirements set forth under this
heading when tested under the conditions of S6. However, a particular
school bus passenger seat (i.e., a test specimen) in that weight class
need not meet further requirements after having met S5.1.2 and S5.1.5,
or having been subjected to either S5.1.3, S5.1.4, or S5.3.
(2) Each school bus manufactured on or after October 21, 2011 with
a gross vehicle weight rating of more than 4,536 kg (10,000 pounds)
shall be capable of meeting any of the requirements set forth under
this heading when tested under the conditions of S6 of this standard or
Sec. 571.210. However, a particular school bus passenger seat (i.e., a
test specimen) in that weight class need not meet further requirements
after having met S5.1.2 and S5.1.5, or having been subjected to either
S5.1.3, S5.1.4, S5.1.6 (if applicable), or S5.3. If S5.1.6.5.5(b) is
applicable, a particular test specimen need only meet S5.1.6.5.5(b)(1)
or (2) as part of meeting S5.1.6 in its entirety. Each vehicle with
voluntarily installed Type 1 seat belts and seat belt anchorages at W
seating positions in a bench seat, voluntarily installed Type 2 seat
belts and seat belt anchorages at Y seat belt positions in a fixed
occupancy seat, or voluntarily installed Type 2 seat belts and seat
belt anchorages at Y and Y + 1 seat belt positions in a flexible
occupancy seat, shall also meet the requirements of:
(i) S4.4.3.3 of Standard No. 208 (49 CFR 571.208);
(ii) Standard No. 209 (49 CFR 571.209), as they apply to school
buses; and,
(iii) Standard No. 210 (49 CFR 571.210) as it applies to school
buses with a gross vehicle weight rating greater than 10,000 pounds.
(b) Small school buses. Each vehicle with a gross vehicle weight
rating of 4,536 kg (10,000 pounds) or less shall be capable of meeting
the following requirements at all seating positions:
(1)(i) In the case of vehicles manufactured before September 1,
1991, the requirements of Sec. Sec. 571.208, 571.209, and 571.210 as
they apply to multipurpose passenger vehicles;
(ii) In the case of vehicles manufactured on or after September 1,
1991, the requirements of S4.4.3.3 of Sec. 571.208 and the
requirements of Sec. Sec. 571.209 and 571.210 as they apply to school
buses with a gross vehicle weight rating of 4,536 kg or less;
(iii) In the case of vehicles manufactured on or after October 21,
2011 the requirements of S4.4.3.3(b) of Sec. 571.208 and the
requirements of Sec. Sec. 571.207, 571.209 and 571.210 as they apply
to school buses with a gross vehicle weight rating of 4,536 kg or less;
and,
(2) The requirements of S5.1.2, S5.1.3, S5.1.4, S5.1.5, S5.1.6,
S5.1.7, S5.3, S5.4 and S5.5 of this standard. However, the requirements
of Sec. Sec. 571.208 and 571.210 shall be met at Y seat belt positions
in a fixed occupancy seat, and at Y and Y + 1 seat belt positions for a
flexible occupancy seat. A particular school bus passenger seat (i.e. a
test specimen) in that weight class need not meet further requirements
after having met S5.1.2 and S5.1.5, or after having been subjected to
either S5.1.3, S5.1.4, S5.1.6, or S5.3 of this standard or Sec.
571.207, Sec. 571.210 or Sec. 571.225.
* * * * *
S5.1.2 Seat back height, position, and surface area.
(a) For school buses manufactured before October 21, 2009, each
school bus passenger seat must be equipped with a seat back that has a
vertical height of at least 508 mm (20 inches) above the seating
reference point. Each school bus passenger seat must be equipped with a
seat back that, in the front projected view, has front surface area
above the horizontal plane that passes through the seating reference
point, and below the horizontal plane 508 mm (20 inches) above the
seating reference point, of not less than 90
[[Page 62783]]
percent of the seat bench width in millimeters multiplied by 508.
(b) For school buses manufactured on or after October 21, 2009,
each school bus passenger seat must be equipped with a seat back that
has a vertical height of at least 610 mm (24 inches) above the seating
reference point. The minimum total width of the seat back at 610 mm (24
inches) above the seating reference point shall be 75 percent of the
maximum width of the seat bench. Each school bus passenger seat must be
equipped with a seat back that, in the front projected view, has front
surface area above the horizontal plane that passes through the seating
reference point, and below the horizontal plane 610 mm (24 inches)
above the seating reference point, of not less than 90 percent of the
seat bench width in millimeters multiplied by 610.
* * * * *
S5.1.5 Seat cushion retention.
(a) Seat cushion latching. For school buses manufactured on or
after October 21, 2009, school bus passenger seat cushions equipped
with attachment devices that allow for the seat cushion to be removable
without tools or to flip up must have a self-latching mechanism that is
activated when a 22-kg (48.4-pound) mass is placed on the center of the
seat cushion with the seat cushion in the down position.
(b) Seat cushion retention. In the case of school bus passenger
seats equipped with seat cushions, with all manual attachment devices
between the seat and the seat cushion in the manufacturer's designated
position for attachment, the seat cushion shall not separate from the
seat at any attachment point when subjected to an upward force in
newtons of 5 times the mass of the seat cushion in kilograms and
multiplied by 9.8 m/s\2\, applied in any period of not less than 1 nor
more than 5 seconds, and maintained for 5 seconds.
S5.1.6 Quasi-static test of compartmentalization and Type 2 seat
belt performance. This section applies to school buses manufactured on
or after October 21, 2011 with a gross vehicle weight rating expressed
in the first column of Tables 2 through 4, and that are equipped with
Type 2 seat belt assemblies.
(a) Except as provided in S5.1.6(b), when tested under the
conditions of S5.1.6.5.1 through S5.1.6.5.6, the criteria specified in
S5.1.6.1 and S5.1.6.2 must be met.
(b) A school bus passenger seat that does not have another seat
behind it is not loaded with the upper and lower loading bars as
specified in S5.1.6.5.2, S5.1.6.5.3, and S5.1.6.5.7 and is excluded
from the requirements of S5.1.6.1(b).
S5.1.6.1 Displacement limits. In Tables 2 and 3, AH is the height
in millimeters of the school bus torso belt anchor point specified by
S4.1.3.2(a) of Standard No. 210 (49 CFR 571.210) and [Phi] is the angle
of the posterior surface of the seat back defined in S5.1.6.3 of this
standard.
(a) Any school bus torso belt anchor point, as defined in S3 of
Standard No. 210, must not displace horizontally forward from its
initial position (when [Phi] was determined) more than the value in
millimeters calculated from the following expression in the second
column of Table 2:
Table 2--Torso Belt Anchor Point Displacement Limit
------------------------------------------------------------------------
Displacement limit in
Gross vehicle weight rating millimeters
------------------------------------------------------------------------
More than 4,536 kg (10,000 pounds)........ (AH + 100) (tan[Phi] + 0.242/
cos[Phi])
Less than or equal to 4,536 kg (10,000 (AH + 100) (tan[Phi] + 0.356/
pounds). cos[Phi])
------------------------------------------------------------------------
(b) A point directly rearward of any school bus torso belt anchor
point, as defined in S3 of Standard No. 210 (49 CFR 571.210) on the
rear facing surface of the seat back, must not displace horizontally
forward from its initial position (when [Phi] was determined) more than
the value in millimeters calculated from the following expression in
the second column of Table 3:
Table 3--Seat Back Point Displacement Limit
------------------------------------------------------------------------
Displacement limit in
Gross vehicle weight rating millimeters
------------------------------------------------------------------------
More than 4,536 kg (10,000 pounds)........ (AH + 100) (tan[Phi] + 0.174/
cos[Phi])
Less than or equal to 4,536 kg (10,000 (AH + 100) (tan[Phi] + 0.259/
pounds). cos[Phi])
------------------------------------------------------------------------
S5.1.6.2 Slippage of device used to achieve torso belt adjusted
height. If the torso belt adjusted height, as defined in S3 of Standard
No. 210 (49 CFR 571.210), is achieved without the use of an adjustable
torso belt anchorage, the adjustment device must not slip more than 25
mm (1.0 inches) along the webbing or guide material upon which it moves
for the purpose of adjusting the torso belt height.
S5.1.6.3 Angle of the posterior surface of a seat back. If the seat
back inclination is adjustable, the seat back is placed in the
manufacturer's normal design riding position. If such a position is not
specified, the seat back is positioned so it is in the most upright
position. Position the loading bar specified in S6.5 of this standard
so that it is laterally centered behind the seat back with the bar's
longitudinal axis in a transverse plane of the vehicle in a horizontal
plane within 6 mm (0.25 inches) of the horizontal plane
passing through the seating reference point and move the bar forward
against the seat back until a force of 44 N (10 pounds) has been
applied. Position a second loading bar as described in S6.5 of this
standard so that it is laterally centered behind the seat back with the
bar's longitudinal axis in a transverse plane of the vehicle and in the
horizontal plane 406 6 mm (16 0.25 inches)
above the seating reference point, and move the bar forward against the
seat back until a force of 44 N (10 pounds) has been applied. Determine
the angle from vertical of a line in the longitudinal vehicle plane
that passes through the geometric center of the cross-section of each
cylinder, as shown in Figure 8. That angle is the angle of the
posterior surface of the seat back.
S5.1.6.4 The seat back must absorb 452W joules of energy when
subjected to the force specified in S5.1.6.5.7.
S5.1.6.5 Quasi-static test procedure.
S5.1.6.5.1 Adjust the seat back as specified in S5.1.6.3. Place all
torso anchor points in their highest position of adjustment. If the
torso belt adjusted height, as defined in S3 of FMVSS No. 210, is
achieved by a method other than an adjustable anchor point, initially
place the torso belt adjusted height at its highest position. Then move
the adjustment device 38 mm (1.5 inches) downward with respect to its
webbing or guide material.
S5.1.6.5.2 Position the lower loading bar specified in S6.5 of this
standard so that it is laterally centered behind the seat back with the
bar's longitudinal axis in a transverse plane of the vehicle and in any
horizontal plane between 102 mm (4 inches) above and 102 mm (4 inches)
below the seating reference point of the school bus passenger seat
behind the test specimen. Position the upper loading bar described in
S6.5 so that it is laterally centered behind the seat back with the
bar's longitudinal axis in a transverse plane of the vehicle and in the
horizontal plane 406 mm (16 inches) above the seating reference point
of the school bus passenger seat behind the test specimen.
S5.1.6.5.3 Apply a force of 3,114W N (700W pounds) horizontally in
the forward direction through the lower loading bar specified at S6.5
at the pivot attachment point. Reach the specified
[[Page 62784]]
load in not less than 5 and not more than 30 seconds. No sooner than
1.0 second after attaining the required force, reduce that force to
1,557W N (350W pounds) and maintain the pivot point position of the
loading bar at the position where the 1,557W N (350W pounds) is
attained until the completion of S5.1.6.5.7 of this standard.
S5.1.6.5.4 Position the body block specified in Figure 3 of FMVSS
No. 210 (49 CFR 571.210) under each torso belt (between the torso belt
and the seat back) in the passenger seat and apply a preload force of
600 50 N (135 11 pounds) on each body block
in a forward direction parallel to the longitudinal centerline of the
vehicle pursuant to the specifications of Standard No. 210 (49 CFR
571.210). After preload application is complete, the origin of the 203
mm body block radius at any point across the 102 mm body block
thickness shall lie within the zone defined by S5.1.6.5.4(a) and
S5.1.6.5.4(b) as shown in Figure 9:
(a) At or rearward of a transverse vertical plane of the vehicle
located 100 mm longitudinally forward of the seating reference point.
(b) Within 75 mm of the horizontal plane located midway between the
horizontal plane passing through the school bus torso belt adjusted
height, specified in S3 of Standard No. 210 (49 CFR 571.210), and the
horizontal plane 100 mm below the seating reference point.
S5.1.6.5.5 Load application.
(a) Fixed Occupancy Seat. For school buses with the gross vehicle
weight rating listed in the first column of Table 4, if the expression
in the second column is true, simultaneously apply the force listed in
the third column to each body block.
Table 4--Torso Body Block Forces for Fixed Occupancy Seats
------------------------------------------------------------------------
Gross vehicle weight rating True expression Applied force
------------------------------------------------------------------------
More than 4,536 kg (10,000 ((seat bench width 3,300 N (742
pounds). in mm)--(380Y)) pounds).
<= 25 mm (1 inch).
More than 4,536 kg (10,000 ((seat bench width 5,000 N (1,124
pounds). in mm)--(380Y)) > pounds).
25 mm (1 inch).
Less than or equal to 4,536 kg ((seat bench width 5,000 N (1,124
(10,000 pounds). in mm)--(380Y)) pounds).
<= 25 mm (1 inch).
Less than or equal to 4,536 kg ((seat bench width 7,500 N (1,686
(10,000 pounds). in mm)--(380Y)) > pounds).
25 mm (1 inch).
------------------------------------------------------------------------
(b) Flexible Occupancy Seat.
(1) For school buses with the gross vehicle weight rating listed in
the first column of Table 5 and a bench seat in the maximum occupancy
configuration for a flexible occupancy seat of Y+1 seat belt positions
as specified in S4.1(d), simultaneously apply the force listed in the
second column of Table 5 to each body block.
Table 5--Torso Body Block Forces in Maximum Occupancy Configuration
------------------------------------------------------------------------
Gross vehicle weight rating Applied force
------------------------------------------------------------------------
More than 4,536 kg (10,000 pounds)........ 3,300 N (742 pounds).
Less than or equal to 4,536 kg (10,000 5,000 N (1,124 pounds).
pounds).
------------------------------------------------------------------------
(2) For a flexible occupancy seat in the minimum occupant
configuration, apply the forces to each body block as specified in
S5.1.6.5.5(a).
S5.1.6.5.6 Reach the specified load in not less than 5 and not more
than 30 seconds. While maintaining the load, measure the school bus
torso belt anchor point and seat back point horizontal displacement and
then remove the body block.
S5.1.6.5.7 Move the upper bar forward against the seat back until a
force of 44 N has been applied. Apply an additional force horizontally
in the forward direction through the upper bar until 452W joules of
energy have been absorbed in deflecting the seat back. The maximum
travel of the pivot attachment point for the upper loading bar shall
not exceed 356 mm as measured from the position at which the initial
application of 44 N of force is attained and the maximum load must stay
below the upper boundary of the force/deflection zone in Figure 1.
Apply the additional load in not less than 5 seconds and not more than
30 seconds. Maintain the pivot attachment point at the maximum forward
travel position for not less than 5 seconds, and not more than 10
seconds and release the load in not less than 5 seconds and not more
than 30 seconds. (For the determination of S5.1.6.5.7, the energy
calculation describes only the force applied through the upper loading
bar, and the forward and rearward travel distance of the upper loading
bar pivot attachment point measured from the position at which the
application in this section of 44 N of force is attained.)
S5.1.7 Buckle side length limit. This section applies to rear
passenger seats on school buses manufactured on or after October 21,
2011 that are equipped with Type 1 or Type 2 seat belt assemblies. All
portions of the buckle/latchplate assembly must remain rearward of the
limit plane defined in S5.1.7.1 when tested under the conditions of
S5.1.7.2.
S5.1.7.1 Buckle/latchplate limit plane. Establish a transverse
limit plane 65 mm from the SgRP that is perpendicular to a transverse
plane that passes through the SgRP at an angle of 50 degrees to the
horizontal.
S5.1.7.2 Load application. Insert the seat belt latchplate into the
seat belt buckle. Apply a 20 N load to the buckle/latchplate assembly
whose vector is in a vertical longitudinal plane. Apply the load along
the centerline of the webbing attached to the latchplate at least 100mm
from the nearest point on the latchplate. The load may be applied at
any angle in the range of 30 to 75 degrees from horizontal.
* * * * *
S5.2.2 Barrier height, position, and rear surface area. The
position and rear surface area of the restraining barrier shall be such
that, in a front projected view of the bus, each point of the barrier's
perimeter coincides with or lies outside of the perimeter of the
minimum seat back area required by S5.1.2 for the seat immediately
rearward of the restraining barrier.
* * * * *
S5.5 Labeling.
(a) A small occupant seating position must be permanently and
legibly marked or labeled with the phrase: ``Do Not Sit In Middle Seat
If Over Age 10''. The phrase must be comprised of no more than two
lines of text. The label must be placed on the torso belt portion of
the Type 2 seat belt. It must be plainly visible and easily readable
when the seat belt is in a stored position. The
[[Page 62785]]
distance from the top edge of the top line of text to the bottom edge
of the bottom line of text must be at least 35 mm. If the label is sewn
on, it must be stitched around its entire perimeter.
(b) [Reserved]
* * * * *
BILLING CODE 4910-59-P
[GRAPHIC] [TIFF OMITTED] TR21OC08.059
[[Page 62786]]
[GRAPHIC] [TIFF OMITTED] TR21OC08.060
Issued on: October 14, 2008.
David Kelly,
Acting Administrator.
[FR Doc. E8-24755 Filed 10-15-08; 4:15 pm]
BILLING CODE 4910-59-C