[Federal Register: October 21, 2008 (Volume 73, Number 204)]
[Rules and Regulations]
[Page 62743-62786]
[DOCID:fr21oc08-7]

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Part III

Department of Transportation

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National Highway Traffic Safety Administration

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49 CFR Part 571

Federal Motor Vehicle Safety Standards; Seating Systems, Occupant Crash
Protection, Seat Belt Assembly Anchorages, School Bus Passenger Seating
and Crash Protection; Final Rule

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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.

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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:<PHONE_NUMBER>)
(fax:<PHONE_NUMBER>), NVS-113. For legal issues, Ms. Dorothy Nakama,
Office of the Chief Counsel (telephone:<PHONE_NUMBER>) (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\
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    \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.
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    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

     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.
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    \2\ The fourth initiative, for self-latching mechanisms,
responds to an NTSB recommendation to NHTSA (H-84-75).
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    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.
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    \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.
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    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

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.
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    \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).)
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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\
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    \5\ ``NHTSA Technical Analysis to Support Upgrading the
Passenger Crash Protection in School Buses (September 2007),''
Docket No. NHTSA-2007-0014.
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    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

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.''
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    \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).
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    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.
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    \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.
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    The agency found the following with regard to compartmentalization:
     Head injury measures were low for all dummy sizes, except
when override \8\ occurred.
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    \8\ Override means an occupant's head or torso translates
forward beyond the forward seat back providing compartmentalization.
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     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.

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\
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    \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.
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    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.
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    \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

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

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

$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

(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

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

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

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

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

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,

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 S<IP_ADDRESS>.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

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