Document ID: NHTSA-2008-0163-0003
Agency: nhtsa
Document Type: Rule
Title: Federal Motor Vehicle Safety Standards; Seating Systems, Occupant Crash Protection, Seat Belt Assembly Anchorages, School Bus Passenger Seating and Crash Protection
Posted Date: 2008-10-21T04:00Z

[Federal Register: October 21, 2008 (Volume 73, Number 204)]
[Rules and Regulations]               
[Page 62743-62786]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21oc08-7]                         

[[Page 62743]]

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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

[[Page 62744]]

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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: 202-366-0247) 
(fax: 202-366-4921), NVS-113. For legal issues, Ms. Dorothy Nakama, 
Office of the Chief Counsel (telephone: 202-366-2992) (fax: 202-366-
3820), NCC-112. These officials can be reached at the National Highway 
Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington, 
DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction
II. Background
III. Studies
IV. Guiding Principles
    a. Comments in Favor of a Federal Requirement for Belts on Large 
School Buses
    b. Other Issues Concerning Belts on Large School Buses
    c. Comments in Favor of a Federal Ban of Lap Belts in Large 
School Buses
    d. Comments on Use of Section 402 Highway Safety Grant Funds
    1. Use of Existing Federal Grant Funds to Purchase Seat Belts
    2. Additional Federal Grant Funds to Purchase Seat Belts
V. Overview of Upgrades to Occupant Crash Protection Standards
    a. Summary of the NPRM Proposed Upgrades
    b. Overview of Comments
    c. How This Final Rule Differs From the NPRM
    d. Post-NPRM Testing
    e. Organization of Discussion
VI. Upgrades for All School Buses
    a. Seat Back Height
    b. Seat Cushion Latches
VII. Upgrades for Small School Buses
    a. Requiring Lap/Shoulder Belts
    b. Raising the Weight Limit for Small School Buses
    c. FMVSS No. 207, Seating Systems
VIII. Upgrades for Large School Buses
    Requiring Voluntarily Installed Belts to Meet Performance 
Requirements
IX. Performance and Other Requirements for Vehicle Belt Systems
    a. Minimum Seat Width Requirements and Calculating W and Y
    1. Flex-Seats
    2. Using W and Rounding Up
    3. Definitions
    b. FMVSS No. 210, Seat Belt Anchorages
    1. Height of the Torso Belt Anchorage
    2. Anchorage Adjustability
    3. Clarifications of Torso Anchorage Location
    4. Integration of the Seat Belt Anchorages Into the Seat 
Structure
    5. Minimum Lateral Anchorage Separation
    6. Anchorage Strength
    c. Quasi-Static Test for Lap/Shoulder Belts on All School Buses
    1. Background
    2. Comments and Agency Responses
    d. Belt Length
X. Lead Time
XI. Rulemaking Analyses and Notices

I. Introduction

    This final rule upgrades the school bus occupant protection 
requirements of the Federal motor vehicle safety standards, primarily 
by amendments to FMVSS No. 222, ``School bus passenger seating and 
crash protection'' (49 CFR 571.222), and also by amendments to FMVSS 
Nos. 207, 208, and 210 relating to the strength of the seating system 
and seat belt anchorages. The notice of proposed rulemaking (NPRM) 
preceding this final rule was published on November 21, 2007 (72 FR 
65509; Docket No. NHTSA-2007-0014). This final rule also provides 
information to state and local jurisdictions for them to consider when 
deciding whether they should order seat belts on large school buses 
(school buses with a GVWR greater than 4,536 kilograms (kg) (10,000 
pounds (lb)), and responds to comments on the agency's discussion in 
the NPRM of recommended ``best practices'' concerning the belts on the 
large buses.\1\
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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

[[Page 62745]]

     Requiring all school buses with seat bottom cushions that 
are designed to flip up or be removable, typically for easy cleaning, 
to have a self-latching mechanism.
    The first three upgrades are based on the findings of NHTSA's 
school bus research program, discussed in detail later in this 
preamble, which the agency conducted in response to the Transportation 
Equity Act for the 21st Century (TEA-21).\2\ Requiring small school 
buses to have lap/shoulder belts for all passengers and raising the 
seat back height on all school buses to 610 mm (24 inches) makes the 
highly protective interior of the school bus even safer. Further, as 
new designs of lap/shoulder belts intended for large school buses are 
emerging in the marketplace, the third initiative will require lap/
shoulder belts to be complementary with compartmentalization, ensuring 
that the high level of passenger crash protection is enhanced and not 
degraded by any seat belt system.
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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

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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

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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.

[[Page 62748]]

IV. Guiding Principles

    School buses are one of the safest forms of transportation in the 
U.S. Every year, approximately 474,000 public school buses, 
transporting 25.1 million children to and from school and school-
related activities,\9\ travel an estimated 4.8 billion route miles.\10\ 
Over the 11 years ending in 2005, there was an annual average of 26 
school transportation related fatalities (11 school bus occupants 
(including drivers and passengers) and 15 pedestrians).\11\ Six of the 
bus occupant fatalities were school-age children, with the remaining 
fatalities being adult drivers and passengers.\12\ On average, there 
were 9 crashes per year in which an occupant was killed. The school bus 
occupant fatality rate of 0.23 fatalities per 100 million vehicle miles 
traveled (VMT) is more than six times lower than the overall rate for 
motor vehicles of 1.5 per 100 million VMT.\13\
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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.
---------------------------------------------------------------------------

    \14\ NHTSA's Preliminary Regulatory Evaluation accompanying the 
NPRM included the benefits of seat belts in rollover crashes and the 
Final Regulatory Evaluation accompanying this final rule will 
include the benefits of seat belts in side impacts.
    \15\ The tests were in a controlled laboratory investigation so 
assumptions are made about how representative the laboratory tests 
were of the real world, e.g., how representative the test dummies 
were of children, the sled test of an actual vehicle crash, the 
magnitude of the crash replicated as compared to real-world school 
bus crashes, and the ability of purchasers to purchase the belts 
without incurring an unreasonable trade-off in pupil transportation 
safety elsewhere.
---------------------------------------------------------------------------

    Funds provided for pupil transportation are limited, and monies 
spent on lap/shoulder belts on large school buses usually draw from the 
monies spent on other crucial aspects of school transportation. Other 
pupil transportation expenses include purchases of new school buses to 
ensure that as many children as possible are provided school bus 
transportation, driver and pupil training on safe loading practices 
(most of the school bus-related fatalities occur outside the bus while 
children are being loaded or unloaded), on operational costs, such as 
fuel costs, and on upkeep and maintenance of school buses and school 
bus equipment. Given the tradeoff between installing seat belts on 
large school buses and implementing other safety measures that could 
benefit pupil transportation or other social welfare initiatives, and 
given that large school buses are already very safe, we believed that 
States should be permitted the choice of deciding whether belts should 
be part of their large school bus purchases.
    Bearing in mind the already excellent safety record of large school 
buses and the real-world demands on pupil transportation providers, we 
did not believe that the available information indicated that seat 
belts on large school buses would address an unreasonable risk of 
injury or fatality, and so we did not propose in the NPRM that they be 
required by the FMVSS to be installed on these vehicles. However, we 
did want to provide the public the information we obtained from the 
school bus research program about the enhancements that lap/shoulder 
belts achieved in the sled test program. Further, in the NPRM, we 
wanted to inform transportation providers of the concern that 
purchasers should consider lap/shoulder belts on large school buses 
only if there would be no reduction in the number of children that are 
transported to or from school or related events on large school buses. 
We believed that reducing bus ridership would likely result in more 
student fatalities, since walking and private vehicles are less safe 
than riding a large school bus without seat belts.
    We sought in the NPRM to articulate a best practices approach. We 
thought that the best practice would be for local decision-makers to 
consider the already excellent safety record of school buses, the 
economic impact on school systems incurred by the costs of seat belts 
and the impact that lap/shoulder belts have on the seating capacity of 
large school buses. We indicated that, if ample funds were available 
for pupil transportation, and pupil transportation providers could 
order and purchase a sufficient number of school buses needed to 
provide school bus transportation to all children, pupil transportation 
providers should consider installing lap/shoulder belts on large school 
buses. If a State were to determine that lap/shoulder belts were in its 
best interest, we encouraged the State to install those systems.

a. Comments in Favor of a Federal Requirement for Belts on Large School 
Buses

    Widely divergent views were expressed in the comments to the NPRM 
as to whether seat belts should be required or permitted to be 
optional. Many commenters, including State and local jurisdictions, 
supported the approach of allowing purchasers the choice of deciding 
whether to include seat belts on their large school buses rather than 
of mandating the belts. The National School Transportation Association 
(NSTA) \16\ stated that States and local districts should be given the 
option of whether to require seat belts on their school buses because 
States and local districts are in the best position to determine the 
most effective use of their limited resources, and because NSTA 
believed that entities that affirmatively choose to equip their buses 
with lap/shoulder belts are more likely to provide the necessary 
support to ensure that the belts are worn. However, several State 
groups were concerned that the NPRM's reference to the availability of 
402 funds for the purchase and installation of seat belts on school 
buses could result in the states funding less-essential highway safety 
activities to the detriment of potentially more effective and 
worthwhile highway safety programs, such as buckle-up programs and 
those combating drunk or aggressive driving. There was widespread 
support of NHTSA's view that bus occupancy must

[[Page 62749]]

not be reduced due to installation of belt systems. Many comments 
wanted to make sure that the final rule would permit new flexible 
school bus seat designs that have emerged in the marketplace (lap/
shoulder belts on these bench seats can be adjusted to provide two lap/
shoulder belts for two average-size high school students or three lap/
shoulder belts for three elementary school students). Some advocacy 
groups embraced the NPRM as facilitating their efforts to get seat 
belts installed on large school buses.
---------------------------------------------------------------------------

    \16\ NSTA states that it is an association of private businesses 
providing transportation services to public school districts and 
private schools across the country.
---------------------------------------------------------------------------

    However, several commenters (e.g., the National Association for 
Pupil Transportation (NAPT) and the New York Association for Pupil 
Transportation (NYAPT)) \17\ expressed concern that not enough is known 
about belt systems to proceed with the rulemaking. These commenters 
were concerned whether seat belts could reduce the overall safety of 
school buses. NAPT believed that NHTSA should ensure that lap/belt 
systems do not negatively affect compartmentalization in any respect, 
and should quantify ``the marginal safety benefits (if any)'' that lap/
shoulder belts provide beyond compartmentalization. The commenter 
stated that NHTSA should consider whether the belts could reduce safety 
through incorrect use, by impeding emergency evacuation, and by 
reducing safety in side impacts and rollovers (the commenter did not 
explain the concerns it had with the belts affecting side impact and 
rollover performance). NAPT believed that on-going agency research 
(discussed in the 2002 Report to Congress) should be completed before 
further action on this rulemaking is taken by NHTSA.
---------------------------------------------------------------------------

    \17\ The NAPT describes itself as a nonprofit organization that 
supports people who transport children to and from school. Its 
membership organizations include professional school transportation 
personnel in both the public and private sector, school bus 
manufacturers, and aftermarket service and product suppliers. The 
NYAPT represents supervisors and managers of both public school and 
private operators employed in local schools in New York State.
---------------------------------------------------------------------------

    Similarly, the NTSB expressed concern that lap/shoulder belts have 
not been sufficiently researched in non-frontal crash modes, e.g., 
side, oblique and rollover crashes.
    In contrast, notwithstanding the discussion in the NPRM that the 
agency was not proposing a requirement for belts in large school buses, 
many commenters urged the agency to go beyond what was proposed in the 
NPRM and require lap/shoulder belts on large school buses.\18\ The 
National Coalition for School Bus Safety (NCSBS) stated that if lap/
shoulder belts coupled with compartmentalization affords ``optimum 
protection'' as stated in the NPRM, lap/shoulder belts should be 
required on large school buses to provide occupants side and rollover 
crash protection. The commenter indicated that even though ``there has 
been no documentation of mortality or morbidity due to the 20 inch seat 
back height or failure of cushion retention,'' NHTSA proposed to 
increase seat back height and require self-latching cushions. The 
commenter believed that ``[t]his stands in sharp contrast with scores 
of documented fatalities and severe injuries proven to result'' in side 
and rollover crashes due to the absence of seat belts on large school 
buses.\19\
---------------------------------------------------------------------------

    \18\ As noted earlier, many other commenters opposed the idea of 
a requirement for belts on large school buses.
    \19\ No data was provided by the commenter explaining or 
supporting its reference to those fatalities and injuries; we know 
of no such data and cannot substantiate this statement.
---------------------------------------------------------------------------

    Similarly, the West Brook Bus Crash Families (WBBCF) \20\ believed 
that the use of seat belts, in any vehicle, saves lives and reduces 
injuries and urged the agency to require seat belts on large school 
buses. The commenter believed that ``many `real world' considerations 
are conspicuously absent from consideration without explanation'' and 
that the agency's ``cost/benefit `balance' is arbitrary and 
capricious.'' WBBCF stated that speculation based on reductions in 
``manufacturer capacity'' of bus seating ``are confined to a few 
elementary school routes and often resolved though [sic] better route 
scheduling.'' The commenter believed that ``[t]here is a complete 
absence of any real world evidence causally linking reduction in school 
bus seating capacity to increased risk of death or injury of 
alternative forms of travel.'' In addition, the commenter stated that 
``NHTSA should clearly state the proven increases in occupant 
protection resulting from lap/shoulder belts use: 45-60% in frontal 
collision, 70% in rollover and lateral collisions for which 
compartmentalization alone is `incomplete' and ineffective.'' The 
commenter believed that this effective rate would result in ``predicted 
life-saving and injury-reducing benefits of lap-shoulder belts using 
real world data (5-8 lives saved each year; 3,000-5,000 injuries 
reduced annually.'' The commenter questioned why the agency did not 
research whether belts could enhance compartmentalization in side 
crashes and rollovers in the 2002 School Bus Safety Study. In addition, 
the commenter believed that NHTSA should calculate the associated 
reductions in personal and societal costs due to lap/shoulder belts in 
terms of medical, insurance and liability expense, physical disability 
and trauma, emotional trauma, and lost education days. Further, the 
commenter also believed that NHTSA should have acknowledged a finding 
of the American Academy of Pediatrics that between 6,000 and 10,000 
children per year are injured in school bus accidents, and that, the 
commenter believed, many of these injuries could be reduced by a lap/
shoulder belt requirement.
---------------------------------------------------------------------------

    \20\ WBBCF states that it is a parent advocacy organization 
comprised of parents and family members of the 2006 West Brook High 
School girls' varsity soccer team, Beaumont, Texas. It states that 
in March 2006, a motor coach bus transporting the team to a playoff 
game overturned, killing two teammates and injuring others. The 
comment states that WBBCF was formed to advocate safer bus travel 
for school children, including the addition of lap/shoulder seat 
belts in school buses and motor coaches.
---------------------------------------------------------------------------

    Some commenters (e.g., the NCSBS and WBBCF) believed that lap/
shoulder belts on large school buses should also be required to 
reinforce the message to children that they should ``buckle-up'' while 
riding in passenger cars and other private vehicles. NCSBS also stated 
that lap/shoulder belts would reduce driver distraction by improving 
student behavior, which in turn will help reduce driver distraction and 
the frequency of school bus crashes due to driver distraction.
    Adding another facet to the comments were responses from school bus 
drivers and other school bus personnel. School bus drivers were 
universally opposed to having belts on the buses, believing that the 
belts were unnecessary, that they would impede emergency egress, and 
that drivers have limited means to get students to buckle up. George 
Davis of the Fayette County Schools bus shop expressed concern about 
the agency's calling lap/shoulder belts coupled with 
compartmentalization ``optimum crash protection.'' He was concerned 
that there was an implication that those who might choose to spend 
their resources on safety-related items other than belts would be going 
against the ``best practices'' discussed in the NPRM. He stated that it 
should be up to each purchaser to determine whether to purchase seat 
belts on large school buses, and that if a purchaser decides not to 
purchase the belts, then they are also determining what is the ``best 
practice'' for their needs.
Agency Response
    After reviewing all the data, including the comments on the NPRM, 
NHTSA again concludes that large school buses

[[Page 62750]]

that meet our school bus safety standards without seat belts do not 
pose an unreasonable risk of death or injury in an accident. Thus, we 
do not find a safety need for a Federal mandate for seat belts on large 
school buses. However, our statutory authority expressly permits State 
or local jurisdictions to prescribe safety standards that impose higher 
performance requirements than the Federal safety standards for vehicles 
that are for the State's own use, such as school buses. Accordingly, we 
affirm that States and local jurisdictions should continue to be 
offered the choice of whether to order seat belts on their large school 
buses since the belts could provide enhancements to 
compartmentalization. We agree with NSTA that entities that 
affirmatively choose to equip their buses with lap/shoulder belts are 
more likely to provide the necessary support to ensure that the belts 
are worn properly. They are also more likely to be willing and able to 
instruct their students and drivers on emergency egress procedures 
affected by the belts. States and local districts need to examine the 
safest means of transport for their children, and this approach lets 
them decide how to spend their funds. Further, the performance 
requirements of this final rule for voluntarily-installed belts will 
help ensure that the belts enhance and do not degrade 
compartmentalization.
    However, we are not able to concur with those commenters suggesting 
that lap/shoulder belts should be required on large school buses. The 
agency had to balance several compelling principles in this rulemaking. 
First, the agency considered the safety risks to which children on 
large school buses are exposed (how are children being injured or 
killed in school bus-related crashes) and whether seat belts would 
reduce that risk. Data indicate that children who are killed in school 
bus-related crashes are typically killed outside of the school bus as 
they are being loaded or unloaded onto the vehicle, by motorists 
passing the bus or by the school bus itself.\21\ Inside the bus, the 
children are typically killed when they are in the direct zone of 
intrusion of the impacting vehicle or object. In the loading zone 
event, seat belts will not have an effect on preventing the fatality. 
In the intrusion zone, seat belts will similarly be unlikely to be 
effective in preventing the fatality, even in side impacts. In a 
rollover situation where there is ejection, the belts would have a 
beneficial effect, but the incidence of fatal ejections in rollover 
accidents occurring from a large school bus is rare.
---------------------------------------------------------------------------

    \21\ ``Traffic Safety Facts 2006: School Transportation-Related 
Crashes,'' DOT HS 810 813.
---------------------------------------------------------------------------

    WBBCF believed that ``NHTSA should clearly state the proven 
increases in occupant protection resulting from lap/shoulder belt use: 
45-60 percent in frontal collisions, 70 percent in rollover and lateral 
collisions for which compartmentalization alone is `incomplete' and 
ineffective.'' The effectiveness statistics to which WBBCF refers \22\ 
are those that have been determined based on the crash experience of 
passenger cars and other light duty vehicles, although the 
effectiveness in passenger vehicles is much less than 70 percent in 
side impacts. These vehicles' crash experiences are different from that 
of large school buses. As noted earlier in this preamble, fatalities in 
frontal crashes of high severity are infrequent. In school bus side 
crashes, fatalities usually occur only in the area of intrusion from a 
heavy truck. Seat belts provide no benefit for an occupant sitting in 
an intrusion zone when struck by a large intruding object, but can 
provide benefits for those away from the intrusion zone. Although belts 
are effective in reducing the risk of fatality in rollovers due to 
ejection, there are very few fatal ejections in large school bus 
rollover crashes.
---------------------------------------------------------------------------

    \22\ The correct effectiveness estimates in fatality reduction 
for passenger cars is 50 percent for frontal impacts, 74 percent for 
rollover crashes and 21 percent in side impacts.
---------------------------------------------------------------------------

    Nonetheless, seat belts may have some effect on reducing the risk 
of harm in frontal, side and rollover crashes, as they can help 
restrain occupants within the seat and not move about in the vehicle 
interior toward injurious surfaces.\23\ For this final rule we have 
estimated the benefits that would accrue from the addition and correct 
use of lap/shoulder belts on large and small school buses in these 
crashes. For frontal crashes, we have estimated the benefits of the 
belts by using the sled test data obtained from the 2002 School Bus 
Safety Study, comparing dummy injury values with lap/shoulder belts 
versus injury values with compartmentalization. This analysis is 
explained in detail in the FRE accompanying this final rule. With 
regard to the estimated effectiveness of seat belts in large school bus 
side and rollover crashes, we have used the effectiveness statistics of 
74 percent for rollover crashes and 21 percent for side impacts 
attributed to seat belts in passenger cars because no other information 
about the possible effect of belts in buses is available. With those 
data, we have estimated the benefits associated with the addition and 
correct use of lap/shoulder belts on large and small school buses.
---------------------------------------------------------------------------

    \23\ It is noted that raising the seat back height on school 
buses as required by this rule achieves a portion of that risk 
reduction for unbelted passengers on school buses. In the agency's 
2002 School Bus Research Program, with compartmentalization, low 
head injury values were observed for all dummy sizes, except when 
override occurred. High-back seats were shown to prevent override.
---------------------------------------------------------------------------

    The 2002 NAS study indicated that approximately 800 school aged-
children are killed annually in motor vehicle crashes during normal 
school travel hours, among which only 0.5 percent were passengers on 
school buses and 1.5 percent were pedestrians involved in school bus 
related crashes. Seventy-five percent of the annual fatalities were to 
occupants in passenger vehicles and 24 percent were to those walking or 
riding a bicycle. Based on this study, the agency concluded that by far 
the safest means for students to get to school is by a school bus, and 
all efforts should be made to get as many students as possible onto 
school buses.
    When making regulatory decisions on possible enhancements, the 
agency must bear in mind how improvements in one area might have an 
adverse effect on programs in other areas. The net effect on safety 
could be negative if the costs of purchasing and maintaining the seat 
belts and ensuring their correct use results in non-implementation or 
reduced efficacy of other pupil transportation programs that affect 
child safety. For example, some schools are currently eliminating 
school bus service for extracurricular activities or shrinking areas of 
school bus service due to high fuel prices.\24\ Given that very few 
school bus-related serious injuries and fatalities would be prevented 
by a requirement mandating seat belts on large school buses, we could 
not assure that overall safety would not be adversely affected, 
particularly given the many competing demands on school resources and 
the widely varying and unique circumstances associated with 
transporting children in each of these districts. Nonetheless, this 
final rule does not prevent the installation of seat belts on school 
buses and provides appropriate performance requirements for these 
systems when they are installed.
---------------------------------------------------------------------------

    \24\ http://www.usatoday.com/news/education/2008-07-09-
schoolbuses_N.htm.
---------------------------------------------------------------------------

    It is worth noting, however, that our analysis of the data 
indicates that installing lap/shoulder seat belts on all large school 
buses would cost between

[[Page 62751]]

$183 and $252 million.\25\ Those belts would save about 2 lives per 
year if every child wore them on every trip. This estimate reflects the 
potential benefits of lap/shoulder belts in frontal, side, and rollover 
crashes. In addition, correctly worn lap/shoulder belts could prevent 
about 1,900 crash injuries each year if every child wore them on every 
trip. These benefits would be achieved at a cost of between $23 and $36 
million per equivalent life saved. However, to achieve these benefits, 
school districts that choose to install belts on large school buses 
must have a program to ensure that belts are worn and worn correctly by 
the school bus passengers. If belts are not worn, they will offer no 
benefits to the passengers. If belts are worn incorrectly, e.g., 
shoulder belt tucked behind the passenger's back, they will not only 
not provide the desired additional protection, but may cause injuries. 
Absent a program to ensure belts are worn and worn correctly, the 
benefits of seat belts on large school buses will be lower than the 
numbers shown in our analysis, which assumes 100% belt use and all 
belts used correctly.\26\
---------------------------------------------------------------------------

    \25\ The range in costs includes both 55 passenger buses (with 
loss of seating capacity) and 66 passenger buses with flexible 
seating (with no loss of seating capacity). However, they do not 
include the costs of a program to ensure correct belt usage.
    \26\ If, for example, only 50 percent of passengers were to wear 
seat belts, the benefits estimated above would be halved and the 
cost per equivalent life saved would rise to between $46 and $72 
million.
---------------------------------------------------------------------------

    In the NPRM, the agency emphasized its concern that installing lap/
shoulder seat belts on large school buses would reduce the passenger 
capacity of the buses. After NHTSA completed its NPRM but before it 
published the NPRM in the Federal Register, seating system 
manufacturers Takata Corp. (Takata)/M2KLLC(M2K) \27\ and the Safeguard 
Division of Indiana Mills Manufacturing Inc. (IMMI) separately 
approached the agency to introduce their ``flexible seating systems'' 
(or ``flex-seats.'') (As noted earlier in this preamble, these seating 
systems have lap/shoulder belts and are reconfigurable to accommodate 
either three smaller students or two larger students.) Many of the 
commenters referred to these systems with approval and asked NHTSA to 
ensure that the FMVSS No. 222 requirements under consideration would 
not prohibit flex-seat technology.
---------------------------------------------------------------------------

    \27\ Takata (also known as TK Holdings) and M2K jointly 
developed a flexible occupancy seat.
---------------------------------------------------------------------------

    We have accommodated flexible seating systems (hereafter referred 
to as flexible occupancy seats or flex-seats), as requested, to 
facilitate the use of these new belt systems. However, although flex-
seats may provide a way of offering lap/shoulder belts without 
lessening capacity on an individual given bus, there will still be a 
cost premium for outfitting school buses with the lap/shoulder belts, 
maintaining the seats, and training students and drivers on their use. 
The emergence of flex-seats on the market does not change our position 
concerning a Federal need to require lap/shoulder belts on large school 
buses.
    On the capacity issue, WBBCF stated that it perceived the agency as 
speculating on its concerns about reduced seating capacity due to 
installation of lap/shoulder belts. The commenter stated that 
reductions in ``manufacturer capacity'' of bus seating ``are confined 
to a few elementary school routes and often resolved though [sic] 
better route scheduling.'' The commenter believed that ``[t]here is a 
complete absence of any real world evidence causally linking reduction 
in school bus seating capacity to increased risk of death or injury of 
alternative forms of travel.''
    The agency believes that to some extent, the new flexible occupancy 
seats may have resolved some of the capacity reduction issues 
associated with the earlier versions of lap/shoulder belt seats in 
school buses. However, to the extent that transportation providers 
decide to use the older lap/shoulder belt equipped school bus seats, 
the extent of capacity reduction would depend on each route and may not 
always be resolved through better routing. In response to the WBBCF 
concern that there is an absence of any real world date linking 
reduction in school bus capacity to increased risk of death or injury, 
we disagree. The 2002 NAS study clearly shows that a reduction in 
school bus ridership would lead to children seeking a less safe form of 
transportation to and from school, leading to an increased risk of 
serious/fatal injury. The capacity of school buses, along with other 
characteristics such as bus length and overall weight, is often 
considered by transportation providers when determining which buses can 
be used for each route. To the extent that the same size bus could have 
less seating capacity and the transportation provider would not have 
sufficient resources to add additional buses and drivers, it could 
impact the level of school transportation service provided.
    Some commenters advocating a requirement for belts on buses 
believed that NHTSA did not correctly analyze the pros and cons of a 
requirement for lap/shoulder belts on large school buses. The NCSBS 
thought it was inconsistent for NHTSA to not propose to require seat 
belts on large school buses even though it proposed to require higher 
seat backs and self-latching seat cushions, especially when, the 
commenter stated, ``there has been no documentation of mortality or 
morbidity due to the 20 inch seat back height or failure of cushion 
retention.'' In response, as part of good governance, NHTSA has the 
responsibility to assess whether each of its initiatives would be cost 
effective and propose those that are. The requirements on manufacturers 
and purchasers must involve the best use of its resources. The 
proposals for the higher seat backs was found to be effective and would 
not lead to reduced seating capacity or other negative consequences. We 
could not make the same determination about a Federal mandate to 
require lap/shoulder seat belts on all large school buses. The 
potential impact on pupil transportation resources from a Federal 
mandate may lead to higher overall risk.
    WBBCF stated its belief that NHTSA should have acknowledged a 
finding of the American Academy of Pediatrics (AAP) that between 6,000 
and 10,000 children per year are injured in school bus accidents, and 
that, the commenter believed, many of these injuries could be reduced 
by a lap/shoulder belt requirement. The AAP study referenced by WBBCF 
indicated that there are approximately 17,000 school bus related 
nonfatal injuries annually. Ninety-seven percent of those injured in 
the AAP study were treated and released from the hospital. The study 
used a sample of students treated in hospital emergency rooms for 
injuries which had the word ``school bus'' in the case description to 
generate an estimated nationwide total number of people injured. These 
numbers include injuries that are not traffic related such as slip and 
falls while boarding/alighting (injuries that cannot be prevented by 
any occupant protection system.) The study indicated that the school 
bus injuries were from the following causes:
     Crash Related--7,206
     Boarding/Alighting--84,056
     Slip/Fall--1,162
     Traffic, noncrash--860
     Other/unknown--3,749
    In contrast to the AAP study, to determine the number of school bus 
crash related injuries, NHTSA used real world data where the injury 
resulted from a crash involving a vehicle in transport and on a public 
road. The number of crash related injuries reported in the AAP study 
correlates closely with our estimates of child passengers in school 
buses injured in school bus-related crashes

[[Page 62752]]

(approximately 7,300 injuries annually.) Of these 7,300 injuries, NHTSA 
estimated that 94 percent were minor and non-incapacitating injuries. 
Based on this analysis, we believe that the 97 percent injured in the 
AAP study that were treated and released from the hospital only 
sustained minor injuries.
    Regarding WBBCF's comment that NHTSA should calculate the 
associated reductions in personal and societal costs due to lap/
shoulder belts in terms of medical, insurance and liability expense, 
physical disability and trauma, emotional trauma, and lost education 
days, the Preliminary Regulatory Evaluation (PRE) for the NPRM included 
such factors in its estimates. Likewise, the Final Regulatory 
Evaluation for this final rule also takes into account the 
comprehensive value of an injury and statistical life, which includes 
all of those factors relating to medical, insurance, pain and suffering 
and lost work days.
    Finally, regarding Mr. Davis's comment, we agree that the best 
practice is for each purchaser to determine whether to purchase seat 
belts on large school buses and that part of such a decision is the 
thorough assessment of how the school's resources should be spent. We 
agree that if after weighing all the considerations a purchaser decides 
not to purchase the belts, then it is also determining what is best for 
its needs.

b. Other Issues Concerning Belts on Large School Buses

    NHTSA does not agree that this rulemaking should be delayed until 
completion of the side impact research mentioned in the 2002 Report to 
Congress. In response to NYAPT, our side impact protection 
countermeasure research is still ongoing. We have been actively 
pursuing this research and expect to complete it soon. However, 
completion of this research is not critical to implementing regulations 
specific to the areas discussed in the NPRM or this final rule, such as 
seat belts, raising the seat back height, or requiring seat bottom 
cushions to be self-latching. The research in those areas has been 
completed. The ongoing research with respect to side impact 
improvements will in no way affect the outcome of the previous 
research, or the policies, performance and decisions related to this 
final rule.
    Further, we do not believe that additional research is necessary to 
show ``that the newly developed systems adequately protect children of 
all sizes in severe side impacts'' as suggested by the NTSB. For near 
side impact, the agency's 2002 testing and the NTSB studies have well 
documented that seat belts will provide very limited occupant 
protection for those in direct line with the impact force. This is 
similar to near side occupants in passenger vehicles and the current 
agency school bus side impact research is geared to address this 
condition.
    With regard to the belief that seat belts on large school buses 
should also be required to reinforce the message to children that they 
should wear belts in passenger vehicles, NHTSA studied the issue in 
1985. The agency found that children were able to understand that the 
bus environment was different than that of a passenger car, and that 
not having belts on school buses did not dilute the buckle up message 
for family vehicles.\28\ NHTSA did a follow-up literature review in 
2007 and determined that the results of the 1985 study are likely 
unchanged. See, ``School Bus Seat Belts and Carryover Effects in 
Elementary School-Aged Children'', which we have placed in the docket 
for this final rule.
---------------------------------------------------------------------------

    \28\ Gardner, A. M., Plitt, W., & Goldhammer, M. (1986). 
``School bus safety belts: Their use, carryover effects and 
administrative issues,'' (Final Report No. DOT HS 806 965). 
Washington, DC: National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

c. Comments in Favor of a Federal Ban of Lap Belts in Large School 
Buses

    In the NPRM, we decided against prohibiting lap belts on large 
school buses. Although we acknowledged that laboratory research, 
including our own on lap belted dummies, showed relatively poor 
performance of lap belts in large school buses, we could not conclude 
that the addition of lap belts in large school buses reduced overall 
occupant protection such that they should be banned. We noted that lap 
belts were required in three states (New York (NY) (1987), New Jersey 
(1994), Florida (2001)), in many other school districts, and in 
special-needs equipped school buses. We stated that our examination of 
NY State school bus crash data for lap belt equipped and non-belt 
equipped buses could not conclude that lap belts either helped or hurt 
occupant injury outcomes.
    A number of commenters to the NPRM wanted NHTSA to ban lap belts. 
The NTSB believed that NHTSA's 2002 school bus test program showed that 
lap belts ``afford occupants little if any safety benefit above that 
achieved by compartmentalization alone and may cause additional neck 
and abdominal injury.'' The NTSB and the National Association of State 
Directors of Pupil Transportation Services (NASDPTS) \29\ believed that 
since lap belts are not an acceptable means of occupant protection in 
passenger cars, light trucks, or small school buses, lap-only belts 
should not be installed on large school buses. Similarly, NYAPT 
believed that NHTSA should prohibit the installation of lap belts on 
school buses and clearly state what the commenter believed were the 
inherent risks associated with their use. In addition, the commenter 
stated that few NY school districts require the use of lap belts by 
student passengers. Accordingly, it believed that the agency's 
statements in the NPRM relating to the evaluation of New York crash 
data should be corrected. The commenter stated that the agency should 
not have determined that the data from New York is inconclusive, but 
rather that seat belt usage in school buses is so minimal and 
inconsistent that there is no relevant data to analyze and compare.
---------------------------------------------------------------------------

    \29\ The NASDPTS states that it represents State directors 
responsible for school transportation in each state, school bus 
manufacturers and other industry suppliers, school transportation 
contractors, and associations with memberships that include 
transportation officials, drivers, trainers and technicians.
---------------------------------------------------------------------------

Agency Response
    In response to NYAPT's comment, we stand by our statement in the 
NPRM that we cannot conclude that lap belts either helped or hurt 
occupant injury outcomes. It was not possible to estimate lap belt 
performance or effectiveness.
    Crash data have consistently shown that lap belts are a good safety 
device in passenger vehicles, even though lap/shoulder belts are more 
effective when worn properly. We currently allow a lap belt in the 
front center seat of a passenger vehicle, and we allow lap belts in 
medium to heavy vehicles over 4,536 kg (10,000 pounds) GVWR. Lap belts 
have been shown to be almost as effective as lap/shoulder belts in 
rollover crashes, and benefit far side occupants in side impacts 
involving these vehicles.
    The NPRM did not propose to ban lap belts on large school buses and 
we decline to concur at this time that lap belts should be prohibited 
on large school buses. The large school bus environment is different 
from that of small school buses, passenger cars, and small trucks and 
vans, and experiences less severe crash forces. Thus, the type of 
restraint that is appropriate for each may differ. A state might want 
to install seat belts on their school buses to supplement 
compartmentalization in side or rollover crashes, and we are unable to 
conclude that if they do, they must install lap/shoulder belts, given

[[Page 62753]]

the additional cost and potential reduced capacity associated with such 
Type 2 restraints over lap belts and the absence of real-world injury 
data.

d. Comments on Use of Section 402 Highway Safety Grant Funds

    In the NPRM, we noted that certain highway safety grant funds may 
continue to be used to fund the purchase and installation of seat belts 
(lap or lap/shoulder) on school buses. Annually, all States, the 
District of Columbia, Puerto Rico, the Bureau of Indian Affairs, and 
the U.S. territories receive NHTSA section 402 State and Community 
Highway Safety Formula Grant Funds. A wide range of behavioral highway 
safety activities that help reduce crashes, deaths, and injuries, 
including seat belt-related activities, qualify as eligible costs under 
the section 402 program. Each State determines how to allocate its 
funds based on its own priorities and identified highway safety 
problems as described in an annual Highway Safety Plan (HSP). We stated 
that, as with all proposed expenditures of section 402 funds, the 
purchase and installation of seat belts on school buses must be 
identified as a need in the State's HSP and comply with all 
requirements under 23 U.S.C. Part 1200. Section 402 funds may not be 
used to purchase the school bus in its entirety, but may fund only the 
incremental portion of the bus cost directly related to the purchase 
and installation of seat belts.
1. Use of Existing Federal Grant Funds To Purchase Seat Belts
    In response to the NPRM, the Governors Highway Safety Association 
(GHSA), Georgia Governor's Office of Highway Safety (GOHS), and 
Maryland Department of Transportation wrote that although lap/shoulder 
belts on large school buses is an important safety issue, the biggest 
danger to children, as evidenced by years of data, is in the area 
around school buses and on the way to and from school. The commenters 
stated that emphasizing the use of Federal 402 funds for school bus 
safety represents a significant shift in Federal policy, but there is 
no evidence to support such a shift. They expressed concern that the 
impact on the 402 program is potentially enormous and devastating to a 
State's highway safety program, could eliminate a State's entire 
apportionment and still barely pay for the costs of the improvement. 
They believe that from a cost/benefit perspective, this solution 
threatens many other higher priority objectives, including impaired 
driving prevention, child passenger safety, and aggressive driving. For 
example, Maryland stated that in the past 10 years, there has been one 
school bus occupant-related fatality in the State of Maryland. In 
contrast, the commenter stated, in 2006 in Maryland there were 199 
fatal crashes involving alcohol, 79 fatal crashes involving aggressive 
drivers, 95 fatal crashes involving pedestrians, 83 fatal crashes 
involving motorcycles, and 102 fatal crashes involving young drivers. 
Maryland expressed the view that because of media coverage of recent 
school bus crashes, ``states may be pressured to spend federal highway 
safety money for this purpose [seat belts on large school buses], at 
the expense of many competing highway safety needs.''
    The GOHS stated that in the NPRM, NHTSA chose not to calculate the 
costs of installing seat belts on large school buses, because 
installation is voluntary. It stated its belief that local school 
districts that wish to install safety belts on large school buses would 
incur sizable costs. The GOHS also stated that most school districts 
identify the specifications for new school buses and then they put the 
specifications out to bid. They further stated that costs of 
improvements are not individualized, but are part of the overall cost 
of the new bus design. It would therefore be difficult for school 
districts to determine the incremental cost of a single improvement and 
then invoice the state highway safety office just for the improvement.
Agency Response
    NHTSA does not agree that using Federal safety grant money to 
install safety equipment on school buses represents a significant shift 
in Federal policy. For example, when we issued final rules in the early 
1990s requiring stop arms and upgraded mirror systems on school buses 
as a means to provide enhanced protection for children who ride school 
buses, we specifically allowed Federal safety grant funds to be used to 
purchase the newly specified school bus safety equipment.
    Nothing in this final rule changes the fact that deciding how to 
use section 402 grant funds is at the discretion of each State. If a 
State should decide that lap/shoulder belts on large school buses is a 
safety priority, NHTSA is simply stating that the Federal safety grant 
funds may be used to purchase the belts. If a State should choose to 
purchase seat belts, its decision must be based on the State's own 
priorities identified in its Annual Highway Safety Plan and comply with 
all requirements under 23 CFR Part 1200. Section 402 funds may not be 
used to purchase the entire school bus, but may fund only the 
incremental portion of the bus' cost that is directly related to the 
purchase and installation of seat belts. NHTSA has also determined that 
in addition to using section 402 funds, 23 U.S.C. section 406 Safety 
Belt Performance Grant Funds can be used to fund the incremental 
portion directly related to the purchase and installation of seat belts 
on school buses.
    NHTSA is aware that many important safety issues compete for 
funding from each State's Federal safety grant funds. Therefore, it is 
imperative that each State base its selection for fundable projects on 
its highway safety priorities. For States considering the installation 
of seat belts on large school buses, NHTSA has provided estimates of 
the cost to install seat belts in large school buses in the Preliminary 
Regulatory Evaluation that was available in the docket (NHTSA-2007-
0014-0005.1) for the NPRM. NHTSA believes that in order to determine 
the incremental cost of seat belts on large school buses, when it 
orders the school buses, it would be a simple matter for the State to 
ask the school bus manufacturer for an itemized list of options, 
including seat belts.
2. Additional Federal Grant Funds To Purchase Seat Belts
    The GOHS, North Carolina Dept. of Public Instruction, the National 
Association of State Directors of Pupil Transportation Services 
(NASDPTS), and the Texas Department of Transportation all sought 
additional funding for school bus improvements in NHTSA's next 
reauthorization. The commenters believe that additional funding is 
needed in order to make a change in school bus seating viable on a 
widespread basis. They asked NHTSA to establish a ``separate designated 
federal fund source'' (using NASDPTS' words) to offset the additional 
cost of lap/shoulder belts on school buses, either within section 402 
or apart from it. The commenters stated that existing funds are 
insufficient to implement lap/shoulder belts without significant 
cutbacks in other highway safety initiatives. NADSPTS commented: ``When 
this NPRM was introduced, the general public was given the impression 
through the media and news releases that school bus lap/shoulder belt 
funding would be made available, not that we would have to compete for 
existing section 402 funds.''
NHTSA Response
    NHTSA has not identified any additional funds that can be used as a 
separate set-aside for the purchase of seat belts on school buses. 
NHTSA emphasizes that it makes available

[[Page 62754]]

existing Federal safety grant funds only if a State, in its Annual 
Highway Safety Plan, includes school bus safety initiatives related to 
improving the protection of children that ride in school buses.

V. Overview of Upgrades to Occupant Crash Protection Standards

a. Summary of the NPRM Proposed Upgrades

    After considering the findings of NHTSA's 2002 School Bus Safety 
Study, the NPRM proposed several sets of upgrades to the school bus 
safety requirements. The first set of upgrades involved improving the 
compartmentalized school bus interior for all school buses. Seat back 
height was proposed to be increased from 508 mm (20 inches) to 610 mm 
(24 inches) to reduce the potential for passenger override in a crash. 
We also proposed to require self-latching mechanisms for school buses 
with seat bottom cushions that are designed to flip up or be removable 
without tools.
    The second set of upgrades proposed to require small school buses 
to have lap/shoulder belts instead of just lap belts. The lap/shoulder 
belt systems were to fit all passengers from ages 6 through adult, to 
be equipped with retractors, to meet the existing anchorage strength 
requirements for lap/shoulder belts in FMVSS No. 210, and to meet new 
requirements for belt anchor location and torso belt adjustability. The 
seat belts were to meet a ``quasi-static'' test requirement to help 
ensure that seat backs incorporating lap/shoulder belts are strong 
enough to withstand the forward pull of the torso belts in a crash and 
the forces imposed on the seat from unbelted passengers to the rear of 
the belted occupants. A minimum seat belt width of 380 mm (15 inches) 
was proposed for belted occupants. In addition, the vehicles had to 
meet FMVSS No. 207 because the load in some seating configurations 
imposed by FMVSS No. 207 is greater than the load that would be imposed 
by FMVSS No. 222's seat performance requirements.
    The third set of upgrades involved requirements for voluntarily-
installed seat belts on large school buses. For large school buses with 
voluntarily-installed lap/shoulder belts, it was proposed that the 
vehicle meet the requirements described above for lap/shoulder belts on 
small school buses, except the quasi-static test would be slightly 
revised for the large school buses to account for crash characteristic 
differences between the vehicles. (Due to the mass and other 
characteristics of the vehicles, in crashes typically small school 
buses are subject to higher severity crash forces than are large school 
buses.) Further, we did not propose to apply FMVSS No. 207 to large 
school buses.

b. Overview of Comments

    Commenters \30\ generally supported the proposed increase in seat 
back height, citing the increased compartmentalization and safety 
benefits that higher seat backs would provide. Some seat manufacturers 
and members of the general public asked that seat backs be made even 
higher than the proposed 610 mm (24 inches), to protect against 
whiplash or to meet Federal head restraint standards. On the other 
hand, most school bus drivers and some members of the general public 
opposed raising the seat back height, mainly due to concerns about 
decreased driver visibility of students and potential discipline 
problems. Similarly, most comments also acknowledged the safety benefit 
of self-latching mechanisms for seat cushions. However, the NTSB 
commented that the weight required to activate the latching mechanism 
(that of a 6-year-old child) did not guarantee attachment of the 
cushion.
---------------------------------------------------------------------------

    \30\ The commenters included school bus seat and restraint 
manufacturers or consultants (AmSafe Commercial Products (AmSafe), 
C.W. White Company (CEW), Concepts Analysis Corp., Freedman Seating 
Company, IMMI, M2K, Takata, school bus manufacturers and their 
professional associations (Blue Bird Corp., Girardin Minibus Inc., 
IC Corp. (IC), National Truck Equipment Association/Manufacturers 
Council of Small School Buses (MCSSB), and Thomas Built Buses, Inc., 
the NTSB, the National Association of State Directors of Pupil 
Transportation Services (NASDPTS), numerous other organizations, and 
the general public.
---------------------------------------------------------------------------

    There was widespread support for the proposed requirement for lap/
shoulder belts on all small school buses from the commenters (school 
bus seat and restraint manufacturers, transportation providers and 
other organizations). A number of commenters asked that ``small school 
bus'' be redefined to include similarly built buses that have a GVWR of 
over 4,536 kg (10,000 pounds). In addition, the National Child Care 
Association was concerned that the NPRM, if made final, would result in 
increased costs for the multifunction school activity bus.
    Commenters generally supported the proposed performance standards 
for school buses, with bus, seat, and restraint manufacturers providing 
detailed comments on technical aspects of the test procedures and 
performance requirements. Many commenters asked NHTSA to ensure that 
the proposed seat width minimum of 380 millimeters (mm) (15 inches) did 
not prohibit flex-seats.

c. Post-NPRM Testing

    To support this final rule, NHTSA performed additional research 
after the NPRM was published. The testing was done to verify analyses 
used to derive NPRM test values and to address questions raised by 
comments to the NPRM. Below, we provide a brief description of the 
post-NPRM testing and how some of the results affected this final rule. 
A more complete discussion of the post-NPRM testing can be found in the 
technical document supporting this final rule (2008 Technical 
Analysis).\31\
---------------------------------------------------------------------------

    \31\ ``NHTSA Technical Analysis to Support the Final Rule 
Upgrading Passenger Crash Protection in School Buses,'' September 
2008.
---------------------------------------------------------------------------

    Both dynamic and static testing was performed. The tested seats 
were lap/shoulder equipped and manufactured by CEW, IMMI and Takata. 
The CEW seat is a unified frame seat back design with two fixed lap/
shoulder belts. The IMMI and Takata seats are flex-seat designs with 
configurations of 3 and 2 occupants per bench. The IMMI design has a 
dual-frame seat back, with the outer frame providing 
compartmentalization of the rearward occupants and the inner frame 
anchoring the lap/shoulder belt for the occupant of the seat.
    Sled testing of school bus seats was performed in a manner similar 
to the 2002 School Bus Safety Study.\32\ However, testing was performed 
using both the large and small school bus crash pulse, rather than just 
the large school bus pulse use in previous testing. This testing helped 
the agency gain general insight into the dynamic performance of flex-
seat designs.
---------------------------------------------------------------------------

    \32\ ``NHTSA Vehicle Research and Test Center's Technical Report 
on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School 
Buses,'' September 2008. See docket for this final rule.
---------------------------------------------------------------------------

    The small school bus sled testing was also specifically performed 
to verify the proposed torso body block pull force applied in the 
quasi-static test. The proposed value had been derived through 
mathematical calculation using Newtonian mechanics and measurements 
made in large school bus pulse sled testing. The results of the new 
testing confirm that the proposed small school bus torso body block 
pull force is appropriate.
    The small school bus sled testing was also useful in verifying the 
peak dynamic loading on the entire seat structure. These data were used 
in our analysis of the need for implementing

[[Page 62755]]

the FMVSS No. 207 requirements to the seats during the FMVSS No. 210 
testing.
    The agency performed extensive testing to address comments related 
to the proposed quasi-static test.33 34 A particular focus 
of this testing was the many issues raised by potential allowance of 
flex-seats in the final rule. Through this test work, the agency 
determined that it would be appropriate to increase the preload and the 
zone where the torso body blocks are initially placed.\35\ We also 
determined that the quasi-static test could be applied to flex-seats in 
all potential seating configurations. A similar determination was made 
when flex-seats were tested to the FMVSS No. 210 requirements for seat 
belt anchorages. The FMVSS No. 210 testing can be performed on flex-
seats in all potential seating configurations.
---------------------------------------------------------------------------

    \33\ Id.
    \34\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for 
Various School Bus Seats Equipped with Type 2 Seat Belts, Test 
Procedure Development Testing,'' General Testing Laboratories, Inc., 
August 2008. See docket for this final rule.
    \35\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for 
Various School Bus Seats Equipped With Type 2 Seat Belts, Torso 
Block Preload and Positioning,'' General Testing Laboratories, Inc., 
July 2008. See docket for this final rule.
---------------------------------------------------------------------------

    To address comments specific to dual-frame seats, the agency also 
verified the ability to measure seat back displacement in the quasi-
static test in addition to, and separate from, anchor point 
displacement.

d. How This Final Rule Differs From the NPRM

    The following are the most important differences between the final 
rule and the NPRM:
    1. The minimum seat width requirement is revised to accommodate 
flexible occupancy seats (flex-seats). Further, quasi-static loading 
requirements appropriate for flexible occupancy seats are adopted.
    2. The quasi-static test at S5.1.5 of FMVSS No. 222 will limit the 
displacement of the torso belt anchor point and the seat back, rather 
than just the anchor point. This change was made to make the 
requirement more performance oriented, and not unnecessarily restrict 
seat designs that incorporate other than unified frame design. Further, 
to address practicability concerns, the performance limit on anchor 
point displacement is revised to allow the equivalent of four degrees 
of additional rotation.
    3. In the quasi-static test, the energy absorption requirement will 
specify that the seat back force-deflection signature must stay below 
the upper bounds of existing force/deflection zone upper boundary of 
FMVSS No. 222. In addition, the torso belt adjustment must be 
maintained during the test.
    4. To accommodate flex-seats, the torso anchor point minimum height 
requirement of FMVSS No. 210 will allow, but not require, the center 
seating positions in flex-seats to only accommodate an occupant as 
large as an average 10-year-old child, rather than an adult male. Such 
a center seating position is defined as a ``small occupant seating 
position'' (SOSP) and will be marked as such by way of a label on the 
seat belt for that seating position. In addition, the minimum lateral 
anchorage separation requirement is modified to allow a reasonable 
accommodation of existing designs of flex-seats and non-flex-seats.\36\
---------------------------------------------------------------------------

    \36\ To address small occupant seating positions, in FMVSS No. 
208, ``Occupant crash protection,'' dimensions of a 10-year-old 
child are added to the provisions (at S7.1.5) that specify 
dimensions of the occupant that must be restrained by a seat.
---------------------------------------------------------------------------

e. Organization of Discussion

    The discussion of the amendments made by this final rule are 
organized as follows: Upgrades for all school buses (seat back height; 
cushion latches); upgrades for small school buses (requiring lap/
shoulder belts; FMVSS No. 207; other issues); upgrades for large school 
buses (requiring voluntarily installed belts to meet performance 
requirement,); performance requirements for vehicles with seat belt 
systems (seat width requirements; seat belt anchorage requirements 
(FMVSS No. 210); quasi-static test; other issues).
    For the NPRM, NHTSA prepared a 2007 Technical Analysis that, among 
other things, presented a detailed analysis of data, engineering 
studies, and other information supporting these amendments. A copy of 
the document was placed in Docket NHTSA-2007-0014. As indicated above, 
an updated 2008 Technical Analysis has also been prepared and placed in 
the docket for this final rule. In addition, several other technical 
reports supporting this final rule have also been placed in the docket. 
The agency refers to these documents from time to time in this 
preamble.

VI. Upgrades for All School Buses

a. Seat Back Height

    In the NPRM, we proposed that the minimum seat back height for 
school bus seats (specified in FMVSS No. 222) be raised from a minimum 
508 mm (20 inches) to 610 mm (24 inches). This increase in minimum seat 
back height was supported by agency-conducted sled tests that assessed 
the compartmentalization performance of 508 mm (20 inch) and 610 mm (24 
inch) seat backs for large (50th percentile male) occupants. The 
results of these tests indicated that 610 mm (24 inch) seat backs would 
provide more effective compartmentalization for larger occupants than 
508 mm (20 inch) seat backs. In tests with the higher seat back, the 
extent to which the dummies overrode the seats in front of them was 
lessened. The higher seat back was also effective in reducing head 
contact with test dummies that were placed in seats forward of the 
dummies. In tests using the 508 mm (20 inch) seat backs where dummy 
head contact did occur because of override, the HIC15 values tended to 
be well above the established IARVs.
    In general, the commenters supported the proposal for the increase 
in seat back height to 24 inches. Three school bus seat and restraint 
manufacturers (Concepts Analysis Corp. (Concepts), CEW, and Takata) 
supported an increase in seat back height, with CEW agreeing with the 
proposed seat back height and barrier area and both Concepts and Takata 
recommending that the minimum seat back be increased as set forth in 
FMVSS No. 202a. Three school bus manufacturers and associations (Thomas 
Built Buses, Inc. (Thomas), National Truck Equipment Association/
Manufacturers Council of Small School Buses (NTEA/MCSSB), and Girardin 
Minibus, Inc. (Girardin)) agreed with the proposed increase in seat 
back height. However, Thomas, NTEA/MCSSB, and Girardin requested that 
this requirement not apply to the last row of seats because it was 
believed that there is no rearward occupant to compartmentalize, driver 
visibility through the rear window would be better, and a lower seat 
back would allow for more knee room in the last row. Those opposing the 
proposal expressed concern about reduced driver visibility of students.
Agency Response
    This final rule increases the minimum seat back height for school 
bus seats to 610 mm (24 in), as proposed in the NPRM.
    1. In response to Takata et al., when FMVSS No. 202a begins to 
phase-in for rear seats in the 2011 model year, it will require that 
any head restraints provided in the rear outboard seats (they are 
optional) must have a minimum height of 750 mm (29.5 inches) above the 
H-point.\37\ This requirement will be applicable to passenger vehicles, 
trucks

[[Page 62756]]

and buses, including school buses, with a GVWR of 4,536 kg (10,000 
pounds) or less. Under FMVSS No. 202a, rear seats are not required to 
have a head restraint but if the seat back is above 700 mm above the H-
point, it is considered a ``head restraint'' and must meet the 
requirements of the standard. Outboard school bus seats meeting the 610 
mm (24 inch) requirement will not have to meet the rear seat provisions 
of FMVSS No. 202a unless they are over 700 mm above the H-point, or 90 
mm (3.5 inches) in excess of the 610 mm (24 inch) limit. We will not 
raise school bus seat back heights above 24 inches in this final rule 
because the greater mass of large school buses reduces the potential 
risk of whiplash for their occupants (the harm addressed by FMVSS No. 
202a) in comparison to other vehicles on the road and a seat back 
height of 610 mm (24 inches) will offer better whiplash protection to a 
broader spectrum of school-aged children than would a height of 508 mm 
(20 inches).
---------------------------------------------------------------------------

    \37\ For illustration purposes, the H-point is similar to the 
actual SgRP of the seat as opposed to the design SgRP. It is found 
by placing the SAE J826 manikin in the seat.
---------------------------------------------------------------------------

    It should be noted that this final rule only requires that seat 
backs be a minimum of 610 mm (24 inches). If individual states, 
counties, or school districts wish to specify a seat back higher than 
610 mm (24 inches), they are free to do so. As noted above, FMVSS No. 
202a would apply to small school buses with seat backs above 700 mm.
    2. We are denying the request that the minimum seat back height 
requirement not be applied to the last row of seats. There is no 
current exemption for the seat back height of the last row of seats. 
Given that there are rigid structures in a school bus rearward of the 
last row, this additional seat back height will provide added potential 
protection to the occupants of the last row in the event of a rear 
impact. Further, the occupants of the last row should be afforded the 
better whiplash protection offered by the 610 mm (24 inch) seat back.
    The argument that the height should be reduced to improve driver 
visibility is not persuasive. Since the row directly forward of the 
last row would not be exempted from the seat back height requirement, 
any decrease in driver visibility due to the seat back of the rearmost 
row would be minimal. (Further discussion of the driver visibility 
issue is provided below.)
    Finally, it was stated that additional knee space would be 
available if the last row did not have to be 610 mm (24 inches) high. 
If we assume a seat back with a 12 degree angle from the vertical, the 
higher seat back height would necessitate the rear seat row to move 
forward approximately 21 mm (0.84 inches) [100 mm x tan(12deg.)]. This 
change could be spread evenly over the entire length of the vehicle, 
resulting in a negligible difference in leg room for each row of seats.
    3. With regard to reduced driver visibility of the students, as 
discussed in the NPRM preamble and in comments from school 
transportation providers, a number of states, including Illinois, New 
Jersey, New York, Ohio, North Carolina and Washington, already require 
seat back heights of 610 mm (24 inches) in their school buses. We are 
not aware of reports of visibility problems or insufficient discipline 
of students on the buses. In fact, the Monroe-Woodbury Central School 
District indicated that the 24-in seat back improved student behavior 
as students were unable to easily hang over the tops of the seat backs 
to interact with friends in distant rows, but instead had to converse 
with passengers around him or her while staying seated. Additionally, 
as pointed out by some commenters, increasing the minimum seat back 
height to 610 mm (24 inches) would make the minimum seat back height 
the same as the industry designations from the 2005 edition of the 
National School Transportation Specification and Procedures (NSTSP) for 
minimum seat back height.
    4. Mr. James Hofferberth stated that NHTSA ``has failed to consider 
alternative [compartmentalization] strategies, such as a reduction of 
seat height to reduce cost, coupled with the provision of a vertical 
transverse containment panel from the top of the seat to the ceiling of 
the bus.'' To our knowledge, there is no compartmentalization strategy 
such as that discussed by the commenter that has been tested and proven 
in both effectiveness and feasibility as compartmentalization. 
Therefore, at this time, such alternatives are not viable alternatives 
to the heightened seat back approach.

b. Seat Cushion Latches

    NHTSA proposed to amend S5.1.5 of FMVSS No. 222 to require latching 
devices for school bus seats that have latches that allow them to flip 
up or be removed for easy cleaning. We also proposed a test procedure 
that would require the latch to activate when a 22 kg (48 pounds) mass 
is placed on top of the seat at the seat cushion's center. The 22 kg 
(48 pounds) mass is that of an average 6-year-old child. The test was 
to ensure that any unlatched seat cushion would latch when a child 
occupant sits on the seat.
    In general, comments addressing this issue supported the proposal. 
The NSTA noted that New York and Connecticut already require self-
latching mechanisms for seat cushions in their buses, and NCDPI stated 
that they now require positive locking devices on their school bus 
seats. They did not provide any details on the specifications they 
require. CEW noted that currently, manually operated seat cushion 
latches can inadvertently be left unlatched after cleaning, and that 
the proposed self-latching mechanisms could ``benefit safety in a crash 
situation.'' Concepts believed that this requirement ``should add only 
pennies to the cost of [a] school bus seat.''
    While NTSB supported a requirement for self-latching mechanisms for 
school bus seat cushions, it had concerns about the proposed test 
requirements regarding the mass required to activate the latch. It 
stated that its concern that ``some designs of flip-up or removable 
seats that comply with this standard may allow the seat to come loose 
during a crash or rollover if a sufficient weight is not applied to the 
seat cushion for the self-latch to activate.'' NTSB stated that the 
load requirement should be removed from the proposed seat cushion 
retention standard unless NHTSA can verify that all seats with this 
design are hinged and cannot fully separate from the seat frame when 
the latch is not activated.
Agency Response
    This final rule adopts the requirement that self-latching 
mechanisms be installed on school bus seat cushions that flip up or are 
removable. We acknowledge that, under the requirement, some cushions 
could still come loose during a crash because the latch would only be 
required to activate under a 22 kg (48 pounds) mass. While latching 
devices which activate under the weight of the seat cushion alone (as 
NTSB suggested) would be preferred, at this time we have not received 
any data indicating the minimum loads that are required to activate 
latches of this type. We specify 22 kg (48 pounds) because that is the 
mass of the 50th percentile 6-year-old child, i.e., a child in 
kindergarten or first grade. The cushion will thus latch when a child 
sits on it. We received no data in response to the NPRM that indicate 
alternative loads. Therefore, we do not have the information necessary 
to support removing or reducing this load requirement.
    One commenter described the currently-used seat cushion latches as 
``primitive'' and ``hard to open,'' and state that ``they are not 
always secured fully when [they] get the seat back down.'' We believe 
that such problems

[[Page 62757]]

may be the main reason why school bus seat cushions are not always 
secured to the seats in current school buses. With self-latching 
devices that meet the proposed requirements, a bus driver would only 
have to firmly push down on the top of the seat cushion to re-attach it 
after cleaning. This greatly simplifies the process of latching the 
seat cushions, making it much more likely that they will be properly 
attached to the seats.
    Finally, regarding a comment from the National Child Care 
Association, we do not require that seat cushions flip up, but rather 
have adopted a requirement for self-latching mechanisms that would be 
installed on seat cushions that do flip up or are removable.

VII. Upgrades for Small School Buses

a. Requiring Lap/Shoulder Belts

    The agency proposed that small school buses be required to have 
lap/shoulder belts at all passenger seating positions. Since the FMVSSs 
were first promulgated, small school bus passenger seats have been 
required to have passenger lap belts (defined as Type 1 belts in FMVSS 
No. 209) as specified in FMVSS No. 208, belts that meet the lap belt 
strength requirements specified in FMVSS No. 210. Lap/shoulder belts 
provide an increased level of protection from lap belts in small school 
buses by reducing the potential of head and neck injuries in frontal 
impacts.
    All commenters supported the proposal. Accordingly, this final rule 
adopts the requirement for the reasons stated in the NPRM. The seat 
belt systems are required to meet the performance requirements of FMVSS 
Nos. 208, 210, and 222 as discussed in the NPRM and this final rule. 
(Under current requirements, the seat belts already must meet FMVSS No. 
209, ``Seat belt assemblies.'')

b. Raising the Weight Limit for Small School Buses

    Historically the dividing line between what is considered a 
``large'' and a ``small'' school bus is the GVWR delineation. School 
buses with a GVWR above 4,536 kg (10,000 pounds) are large school 
buses, while school buses with a GVWR of 4,536 kg (10,000 pounds) or 
less are small school buses.
    In response to the NPRM, several commenters suggested raising the 
weight limit for small school buses from 4,536 kg (10,000 pounds) to 
6,576 kg (14,500 pounds). IMMI stated that the small school bus 
requirement that lap/shoulder belts be installed at all seating 
positions should apply to all school buses that are built on a van 
chassis, which are known in the industry as type ``A'' school buses. 
The commenter stated that these consist of type ``A-1'' school buses, 
which have a GVWR of 4,536 kg (10,000 pounds) or less, and type ``A-2'' 
school buses, which have a GVWR that can range up to 6,576 kg (14,500 
pounds). IMMI explained that both the type A-1 and the type A-2 buses 
are built on similar van chassis, and so they are both exposed to 
similar operating and crash environments. Another commenter stated that 
the National School Transportation Specifications and Procedures 
(NSTSP) for school bus types defines Type A-1 school buses as having an 
upper weight limit of 6,576 kg.\38\ Thus, this comment suggested, it 
would be easier to determine which school buses must comply with the 
lap/shoulder belt requirement if NHTSA's definition of small school 
buses followed the NSTSP recommendation.
---------------------------------------------------------------------------

    \38\ This information is different than that provided by IMMI, 
but the difference is inconsequential to the commenters' arguments.
---------------------------------------------------------------------------

Agency Response
    The suggestion to raise the weight cut-off for small school buses 
to include Type A-1 buses with a GVWR below 6,576 kg (14,500 pounds) 
may have, but it is beyond the scope of this rulemaking. We also note 
that the suggested change in weight limit is not trivial. Expanding the 
small school bus category as suggested would result in a substantial 
increase in the fleet percentage of small school buses, i.e., from 7.2 
to 24 percent.

c. FMVSS No. 207, Seating Systems

    In the NPRM, we proposed to apply FMVSS No. 207 to small school 
buses with lap/shoulder belts because the load imposed by FMVSS No. 207 
appears to be greater than the load that would be imposed by FMVSS No. 
222's seat performance requirements at S5.1.3.
    There was no consensus between commenters. CEW disagreed with the 
proposal to apply the FMVSS No. 207 loading to small school buses. It 
explained that ``[m]any of our customers request that we pull the FMVSS 
No. 210 test to higher forces than those required by NHTSA to insure 
that they have a `safety margin' above NHTSA's requirement * * * Most 
of our customers ask us to pass FMVSS No. 210 by 110% or 120% * * * If 
FMVSS No. 207 and FMVSS No. 210 are added and customers still want 110% 
and 120%, we would be adding safety factors to safety factors, as well 
as undue additional costs.'' In contrast, IMMI agreed that FMVSS No. 
207 should apply to all small schools buses and ``all van-based, A type 
school buses, regardless of their GVWR.''
    Blue Bird Corp. (Blue Bird) disagreed with the proposal. Using the 
data the agency provided in the NPRM, it provided an extensive analysis 
showing that for a seat bench with three lap/shoulder belts, the FMVSS 
No. 210 load is 130 percent [18,000 pounds/(11,802 + 2,040) pounds] of 
the total dynamic load on the seat, plus the load that would be imposed 
by FMVSS No. 207.
    If the final rule makes FMVSS No. 207 applicable to small school 
buses with lap/shoulder belts, Blue Bird requested an exemption for a 
``davenport'' mounted seat which ``consists of separate seat cushion 
and seat back assemblies of wood or plastic, foam, and upholstery 
fastened to the bus body structure forming the front and top of the 
engine compartment.'' However, Blue Bird stated that it was unaware of 
such rear engine configurations for small school buses.
Agency Response
    With respect to Blue Bird's analysis, the commenter used the peak 
total force on the seat in the large bus sled tests performed by the 
agency (35,000 N (7,869 pounds)).\39\ Using an assumption expressed in 
the NPRM (regarding the quasi-static test) that belt loads for the 
small school bus situation would be 1.5 times that of the large school 
bus, the commenter estimated that the total seat force for a small 
school bus seat occupied by two persons would be 52,000 N (11,803 
pounds).\40\
---------------------------------------------------------------------------

    \39\ These seats were occupied by two 50 percentile male Hybrid 
III dummies.
    \40\ Rather than the value used by Blue Bird, however, the 
agency actually derived a range of potential ratios for the small to 
large school bus belt loads from 1.1 to 2.4 times. We choose 1.5 in 
the NPRM out of a concern for practicability in the quasi-static 
test.
---------------------------------------------------------------------------

    The agency now has actual measurements of total seat load in a 
small school bus crash pulse, and has found that the ratio of large to 
small school bus forces is about 58 percent.41 42 Using this 
actual small school bus total seat loading, we have estimated the 
extent to which the FMVSS No. 210 load combined with the FMVSS No. 207 
load exceeds the actual measured total load on the seat.
---------------------------------------------------------------------------

    \41\ ``NHTSA Technical Analysis to Support the Final Rule 
Upgrading Passenger Crash Protection in School Buses,'' September 
2008.
    \42\ ``NHTSA Vehicle Research and Test Center's Technical Report 
on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School 
Buses,'' September 2008.
---------------------------------------------------------------------------

    By first assuming the seat in question has three lap/shoulder belt 
positions,

[[Page 62758]]

we calculate that the total FMVSS No. 210 loading is 80,064 N (18,000 
pounds) [3 x 26,669 N]. This assumes that the total dynamic load on the 
seat from the three occupants (for the purposes of this analysis, we 
assumed the occupants were three 5th percentile females) is as we 
measured in the sled testing with two 50th percentile dummies (we 
assumed for this analysis that the loading from three 5th percentile 
females would be about the same as the loading from the two adult 
dummies). Assuming this three positions seat weighs 46.3 kg (102 
pounds),\43\ the combined FMVSS Nos. 207 and 210 loading will be 146 
percent of the dynamic load [(80,064 N + 46.3 kg x 20 g x 9.81)/(2 x 
30,574 N)].
---------------------------------------------------------------------------

    \43\ This is the value Blue Bird used in its comments for a 
1,143 mm (45 inch) wide seat bench.
---------------------------------------------------------------------------

    Second, by assuming a 990 mm (39 inch) wide seat with two fixed 
lap/shoulder belts and a seat mass of 34.5 kg (76 pounds), we calculate 
that the combined FMVSS Nos. 207 and 210 loading is 98.4 percent of the 
dynamic load [(53,376 N + 34.5 kg x 20 g x 9.81)/(2 x 30,574 N)].
    As these calculations have shown, depending on the number of lap/
shoulder belts on the bench and the assumed occupant sizes, the 
addition of the FMVSS No. 207 loading to the FMVSS No. 210 loading 
creates a condition where the total seat loading is even higher than 
what might be expected to occur dynamically (as in the situation with 
the three small occupants) or the total seat loading matches the 
dynamic loading level fairly closely (latter situation with two adult 
occupants). Accordingly, the data indicate that the FMVSS No. 207 load 
is not redundant to the FMVSS No. 222 loads.
    We note that, as explained below in section IX.b.6, flex-seats 
would tend to be in the category of bench seats that would be 
overloaded (first situation) since all three belted positions in the 
maximum occupant configuration will receive the same FMVSS No. 210 belt 
loading. The agency considered whether to develop a scheme by which 
some small school bus seats (those with 2 fixed seating positions) 
would be subject to the FMVSS No. 207 loading and some (those 
configurable to 3 seating positions) would not. We decided against this 
approach because it seemed to be an unnecessary complication not based 
on any need to assure practicability.
    Finally, we have decided against Blue Bird's recommendation to 
exempt seats that might be mounted on the cover of a rear engine bus 
(davenport seats). First, we note that Blue Bird stated they were not 
aware such a design currently exists in small school buses. Second, the 
final rule will require such a seat to have lap/shoulder belt 
anchorages mounted on it, unless the seat satisfies the last row seat 
exemption discussed later in this preamble. We seek to ensure that a 
seat with belt anchorages attached be sufficiently robust to sustain 
the additional FMVSS No. 207 seat inertial loading and that a last row 
seat that does not have belt anchorages still be mounted to the vehicle 
firmly enough to stay attached under its own inertial loading.

VIII. Upgrades for Large School Buses

    This final rule requires voluntarily installed seat belts on large 
school buses to meet performance requirements of FMVSS Nos. 208, 210, 
and 222 as discussed in the NPRM and this final rule. (Under current 
requirements, the seat belts already must meet FMVSS No. 209, ``Seat 
belt assemblies.'') Comments to the NPRM were overwhelmingly supportive 
of the objective to require voluntarily installed seat belts to meet 
performance requirements.

IX. Performance and Other Requirements for Vehicle Belt Systems

a. Minimum Seat Width Requirements and Calculating W and Y

    In S4.1 of FMVSS No. 222, NHTSA currently considers the number of 
seating positions (W) on a bench seat to be the width of the bench seat 
in millimeters, divided by 381 and rounded to the nearest whole number. 
This W value is used to calculate the compartmentalization requirements 
for seats on all school buses and the number of lap belt only seating 
positions on small school buses that must meet the provisions of FMVSS 
Nos. 208 and 210. In the NPRM, we proposed to continue to consider W to 
be the number of seating positions per bench seat with optionally 
provided lap belts on large school buses as well as the 
compartmentalization requirements for all school buses, except that the 
divisor was proposed to be 380 (for simplicity) rather than 381.
    However, for the seating positions on small school buses with 
required lap/shoulder belts and on large school buses with optional 
lap/shoulder belts, we proposed to define the number of seating 
positions (using ``Y'') in a slightly different way. Y is the total 
seat width in millimeters divided by 380, rounded down to the nearest 
whole number. Under the definitions of W and the proposed definition of 
Y, a 1,118 mm (44 inch) wide seat would have W = 3 seating positions 
for the purposes of calculating the magnitude of the 
compartmentalization requirements to apply to the seat back, but only Y 
= 2 seating positions for determining the lap/shoulder belts installed 
on the seat.\44\ The result of this ``Y'' calculation would be that 
each passenger seating position in a school bus seat with a lap/
shoulder belt would have a minimum seating width of 380 mm (15 inches). 
In addition, the NPRM also proposed to adopt a requirement in FMVSS No. 
222 (at S5.1.7) that each passenger seating position with a Type 2 
(lap/shoulder) restraint system shall have a minimum seating width of 
380 mm (15 inches). We proposed a minimum seating position width of 380 
mm (15 inches) for seats with lap/shoulder belts because we sought to 
ensure that lap/shoulder belt anchorages are not installed so narrowly 
spaced that they would only fit the smallest occupants.
---------------------------------------------------------------------------

    \44\ ``Y'' would also be used to determine the loads to be 
applied to the shoulder belts for the quasi-static test, discussed 
below in this preamble. See also paragraphs S5.1.6.5.5(a) and (b) of 
the proposed regulatory text.
---------------------------------------------------------------------------

    A new school bus seat belt technology has emerged in the 
marketplace involving 990 mm (39 inch) bench school bus seats with lap/
shoulder belts that have flexible configurations (flex-seats). These 
flex-seats have lap/shoulder belts that can be adjusted to provide two 
lap/shoulder belts for two full average-size high school students or 
three lap/shoulder belts for three elementary school students. Takata 
and its partner, M2K LLC (M2K), and IMMI both produce these bench seats 
with flexible occupancy seat designs. In its minimum occupancy 
configurations, two 50th percentile male occupants can be accommodated 
per bench. In its maximum occupancy configuration, three 6- to 10-year-
old children can be accommodated per bench. In comments to the NPRM, 
many commenters (pupil transportation providers, state and local 
districts, schools, individuals, advocacy groups) urged NHTSA to permit 
these flexible occupancy seats in the final rule.
    In comments, IMMI, Takata, M2K, and Concepts stated that while they 
supported the NPRM, the provision that each seating position with a 
lap/shoulder belt have a minimum width of 15 inches is design 
restrictive, would reduce bus capacity, and would discourage 
installation of lap/shoulder belts. IMMI, Takata, and Concepts 
specifically recommended a minimum seat width of 330 mm (13 inches). 
The 330 mm (13 inch) minimum seat will permit the flexible occupancy 
seats that

[[Page 62759]]

IMMI and Takata manufacture. Other commenters, including Thomas, NTEA/
MCSSB, and IC Corp. (IC) also asked that the value be reduced to 330 mm 
(13 inches). Thomas and NTEA/MCSSB also asked that W be used for lap/
shoulder seating positions rather than Y. They also suggested that the 
divisor be 380 rather than 381 and that the result be rounded up 
instead of down.
    Other commenters wrote in favor of the 380 mm (15 inch) (or wider) 
seat. Blue Bird, CEW and AmSafe Commercial Products (AmSafe) agreed 
that 380 mm (15 inches) is the appropriate seat width value. Blue Bird 
believed that since children are getting larger, smaller minimum 
spacing is not in their best interest. Freedman Seating Company 
(Freedman) stated that the minimum seat width should be increased to 16 
inches. AmSafe stated that if three 330 mm (13 inch) positions were 
allowed on a 990 mm (39 inch) bench seat, three average adult males 
could attempt to use the seat, resulting in a dangerous situation if 
there were a crash.
Agency Response
    When we proposed that each seating position with a lap/shoulder 
belt have a minimum width of 380 mm (15 inches), our stated concern was 
that manufacturers not be allowed to install lap/shoulder belts in such 
a narrow space that only the smallest occupants would fit. We also 
acknowledged that a bench seat with 380 mm (15 inches) of width per 
lap/shoulder belt position would not accommodate occupants larger than 
a 5th percentile female simultaneously in every position. When 
developing the NPRM, the flex-seat designs had not yet reached the 
marketplace so the design restrictiveness of an absolute 380 mm (15 
inch) seat width requirement was not fully recognized by the agency 
during the NPRM stage.
1. Flex-Seats
    The comments and presentations to the agency since the NPRM have 
had us reconsider the proposed requirement for a 380 mm (15 inch) 
minimum seat width and whether design flexibility could be accommodated 
while assuring that seats will be wide enough for real world use by 
full size high school students. We agree with the majority of those 
commenting on the issue that flex-seats should be permitted as an 
option for school transportation providers wishing to implement lap/
shoulder belts. Depending on the size mix of occupants being 
transported, flex-seats could be helpful in maximizing the occupancy 
rate of school buses.
    The commenters opposing the reduction of the 380 mm (15 inches) 
minimum width per lap/shoulder belted position indicated that 330 mm 
(13 inches) is too small even for smaller children. They also indicated 
their concern that if narrower positions were allowed, adult size 
occupants might try to fit in them, potentially resulting in dangerous 
situations.
    It may be true that today's children are larger than children in 
the past, and that would argue against reducing the 380 mm (15 inches) 
specification for fixed width lap/shoulder belted positions. However, 
we do not believe it justifies prohibiting flex-seats since they are 
designed to accommodate occupants needing seat widths from 330 to 495 
mm (13 to 19.5 inches). We agree that there is a risk that a 330 mm (13 
inches) seating position on a flex-seat in a maximum occupancy 
configuration may be misused by a person too large for the seat (one 
who should have sat in a flex-seat in a minimum occupancy 
configuration), but such misuse could be reduced through student 
training.
    To provide more design flexibility in FMVSS No. 222 and to 
accommodate flex-seats, this final rule specifies that one lap/shoulder 
belt may be installed for every 330 (13 inches) of seat bench width, 
provided that the lap/shoulder belt seat can be reconfigured to have 
seating positions for every 380 mm (15 inches) of seat bench width. 
This ability for the seat bench width to be adjusted is specified 
because, as stated in the preamble of the NPRM, we continue to believe 
there is merit in limiting a manufacturer's ability to install too many 
fixed position lap/shoulder seat belts on a bench seat that 
accommodates only the smallest occupants.
2. Using W and Rounding Up
    Both Thomas and NTEA/MCSSB indicated that the number of lap/
shoulder belt seating positions should be W instead of Y. They also 
commented that after dividing the bench width by 380, the result should 
be rounded up to the next integer. NHTSA disagrees with these comments. 
Under the commenters' suggested methodology, a 759 mm (29.9 inches) 
wide bench seat could have 3 lap/shoulder belts, with each position 
providing 253 mm (10 inches) of seat width. We decline to adopt this 
suggestion for the same reason we reject the idea of a fixed 330 mm (13 
inches) seat, i.e., manufacturers should not be permitted to install 
fixed position lap/shoulder seat belts on a bench seat that 
accommodates only the smallest occupants. In addition, a bench with 253 
mm (10 inches) wide seating positions cannot accommodate 6-year-old 
occupants in every seating position.
3. Definitions
    In this final rule, we are changing the seat width specification 
and making other necessary changes to the regulatory text modifications 
to permit flex-seats. To clarify the reduction in seat width and its 
restriction to flex-seats, we are adding new definitions to FMVSS No. 
222, as follows:
    Fixed occupancy seat means a bench seat equipped with Type 2 seat 
belts that has a permanent configuration regarding the number of 
seating positions on the seat. The number of seating positions on the 
bench seat cannot be increased or decreased.
    Flexible occupancy seat means a bench seat equipped with Type 2 
seat belts that can be reconfigured so that the number of seating 
positions on the seat varies based on occupant size. The seat has a 
minimum occupancy configuration for larger occupants and maximum 
occupancy configuration for smaller occupants, and the number of 
passengers capable of being carried in the minimum occupancy 
configuration must differ from the number of passengers capable of 
being carried in the maximum occupancy configuration.
    Maximum occupancy configuration means, on a bench seat equipped 
with Type 2 seat belts, an arrangement whereby the lap belt portion of 
the Type 2 seat belts is such that the maximum number of occupants can 
be belted.
    Minimum occupancy configuration means, on a bench seat equipped 
with Type 2 seat belts, an arrangement whereby the lap belt portion of 
the Type 2 seat belts is such that the minimum number of occupants can 
be belted.
    Under these definitions, a traditional bench seat is a ``fixed 
occupancy seat.'' Flex-seats (which are flexible occupancy seats) must 
have both a maximum and minimum occupancy configuration. These 
definitions by themselves do not detail the numbers of occupants (W or 
Y) allowed in these configurations. Instead, that specification is 
conveyed in S4.1(c) and (d) of FMVSS No. 222, specified by this final 
rule.
    Section S4.1(c) states that the number of fixed lap/shoulder seat 
belt positions per bench must be Y, essentially the same as that 
proposed in the NPRM. S4.1(c) also states that a flexible occupancy 
seat configured to hold the minimum number of occupants must also have 
Y lap/shoulder belt positions. Therefore, a 39-inch wide bench seat 
will either have 2 [rounded down from (990/380)] lap/shoulder belts or 
will be configurable to have 2. This assures that a seat belt equipped 
bench provides a

[[Page 62760]]

sufficient number of seating positions (Y) to accommodate the number of 
larger students that might be seated there.
    Section S4.1(d) requires that when a flexible occupancy seat is 
configured to hold the maximum number of occupants, it must have Y + 1 
lap/shoulder belted positions. However, the minimum allowed bench seat 
width must be no less than (Y + 1) x 330 mm (13 inches). As an example, 
a 990 mm (39 inches) flexible occupancy seat may have 3 lap/shoulder 
belts, of seat widths of 330 mm (13 inches), as long as the seat can be 
reconfigured to have 2 lap/shoulder belts of seat widths of at least 
380 mm (15 inches). For this example, the 2 lap/shoulder belt seating 
positions would each be 445 mm (19.5 inches) wide.
    Since proposed S5.1.7 is no longer needed because the minimum seat 
belt width requirement for older children is now specified in S4.1(c) 
and (d), proposed S5.1.7 is not adopted by this final rule.

b. Seat Belt Anchorages (FMVSS No. 210)

    NHTSA proposed that requirements be added to FMVSS No. 210 that 
would ensure that the seat belt anchorages on school bus seats be 
designed so that the belt system will properly fit the range of 
children on a school bus: the average 6-year-old (represented by the 
Hybrid III 6-year-old child dummy (45 inches tall/52 pounds)); the 
average 12-year-old (represented by the Hybrid III 5th percentile 
female dummy (59 inches/108 pounds)); and the large high school student 
(represented by the 50th percentile adult male dummy (69 inches/172 
pounds)). Proper seat belt fit prevents injury and helps ensure that 
the system performs properly in a crash. If the lap/shoulder seat belts 
did not fit the child occupant properly, there is an increased 
likelihood that the child would misuse the lap/shoulder belt system by 
placing the shoulder portion under the arm or behind the back. NHTSA's 
school bus research results showed that when the shoulder belt was 
placed behind the back, the restraint system functioned like a lap 
belt. Lap belts produced a higher risk of neck injury in the testing 
program when evaluated in a simulated severe frontal crash. Further, a 
torso belt anchorage located below the top of the shoulder may increase 
the spinal compression loading in a crash, increase the risk of the 
occupant sliding under the belt in a crash, and increase the risk of 
spinal and abdominal injuries.
1. Height of the Torso Belt Anchorage
    We proposed that school bus seats with lap/shoulder belts have a 
minimum shoulder belt adjustment range between 280 mm (11 inches) and 
520 mm (20.5 inches) above the SgRP (which was the location of the 
school bus torso belt anchor point), to ensure that the shoulder belt 
will fit passengers ranging in size from a 6-year-old child to a 50th 
percentile adult male. We proposed a definition of ``school bus torso 
belt adjusted height'' in FMVSS No. 210 as an objective means of 
determining the adjustment height. We also proposed regulatory text for 
FMVSS No. 208 to specify belt fit and performance characteristics for 
lap/shoulder belts on school bus bench seats. Specifically, we proposed 
to amend S7.1.5 \45\ to assure that the belts fit a 50th percentile 6-
year-old to a 50th percentile male.
---------------------------------------------------------------------------

    \45\ The NPRM at S7.1.5 of the proposed regulatory text for 
FMVSS No. 208 (72 FR at 65527) proposed that the seat belt assembly 
has to operate by means of an emergency-locking retractor (ELR) or 
an automatic-locking retractor (ALR). In this final rule, we have 
removed the allowance for ALRs. No current lap/shoulder seat belts 
on school bus seats utilize ALRs and there is no clear indication 
that ALRs would provide any performance or comfort benefits compared 
to emergency locking retractor (ELR) equipped lap/shoulder belts. 
This will not preclude manufacturers from providing convertible 
ELRs, i.e., ALR/ELR type belts, just those that function solely as 
ALRs. In addition, any lap/shoulder belts in large or small school 
buses must still have to meet S7.1.1.5 of FMVSS No. 208, which 
specifies the lockability of belts. (The lockability feature 
facilitates the installation of child restraints using the belt 
system.) This is currently the situation for small school buses with 
lap/shoulder belts, and was proposed and now made final by this 
rulemaking for large school buses.
---------------------------------------------------------------------------

    Five commenters (AmSafe, Blue Bird, CEW, IMMI and Takata) addressed 
the minimum distance above the SgRP for the torso belt anchor point, 
520 mm (20.5 inches), and the distance above the SgRP for the lowest 
point on the adjustment range of the torso belt, 280 mm (11 inches). 
CEW, AmSafe and Blue Bird supported the proposed minimum torso anchor 
point height proposal. AmSafe expressed concern that a lower torso 
anchor point could be dangerous to the average adult male because of 
potential spinal compression during a crash.
    IMMI commented that in order to allow the flexible occupancy seats, 
changes would be necessary to FMVSS Nos. 208, 209, and 210. It stated 
that the 520 mm (20.5 inches) minimum anchor point height in FMVSS No. 
210 would need to be reduced to 394 mm (15.5 inches) so that the 
``flexible configuration cannot be used by three large students.'' It 
believed 394 mm (15.5 inches) would accommodate a 10-year-old child. 
IMMI suggested that the minimum torso anchor point for the center 
seating position of a flex-seat be located in a range between 387 and 
400 mm (15.2 to 15.7 inches) above the SgRP.
    Takata's comments suggested several alternatives to the torso belt 
adjustment range and the torso anchor point minimum height. One Takata-
suggested alternative was to place various anthropomorphic test dummies 
(ATDs) (6-year-old, 10-year-old, 5th percentile female and 50th 
percentile male) in belted seating positions and then determine whether 
proper belt fit could be achieved. Takata also made proposals specific 
to flex-seats. One of these was to specifically not require a 330 mm 
(13 inches) wide seating position to accommodate a 50th percentile 
male. Another was to specifically allow the torso belt anchor point to 
be a minimum of 380 mm (15 inches) from the SgRP for the center seating 
position of a flex-seat, rather than 520 mm (20.5 inches) proposed in 
the NPRM.

Agency Response

    The Takata seat design described in comments to the NPRM (hereafter 
referred to as the original Takata design or seat) differs from the 
IMMI and CEW designs in that the torso anchor point itself is 
adjustable rather than just the torso belt.\46\ Therefore, the proposed 
language in S4.1.3.2 of FMVSS No. 210 would effectively disallow these 
designs because the minimum anchor point is much less than 520 mm, even 
for the outside seating positions.
---------------------------------------------------------------------------

    \46\ A more recent Takata design, tested after the NPRM was 
published, had fixed torso belt anchorages in all three seating 
positions. Torso belt adjustment was achieved by an adjustment 
device sliding on a separate length of webbing.
---------------------------------------------------------------------------

    Since the original Takata design was not known to the agency until 
after the NPRM was drafted, we did not consider in the NPRM stage the 
use of adjustable anchorages to achieve the desired torso belt 
adjustment range. After considering the comments to the NPRM, we 
believe it would be appropriate to have a minimum anchorage height 
specification for a fixed anchorage and an achievable position for an 
adjustable anchorage. For the reasons discussed in the NPRM, for fixed 
anchorages, the anchorage must be a minimum of 520 mm (20.5 in) above 
the SgRP. A fixed point above 520 mm (20.5 inches) would be acceptable. 
An adjustable anchorage may have a lower position of adjustment as long 
as this minimum distance from the SgRP (520 mm) can be achieved.
    We are adopting a different requirement for the torso anchor for 
the

[[Page 62761]]

center seating position of flex-seats that is designed for elementary 
school passengers only. (Elsewhere in this preamble we explain that the 
standard will refer to this position as a ``small occupant seating 
position'' and will define the term.) IMMI stated that the torso anchor 
for this small occupant seating position was lowered in their design to 
reduce the likelihood that large occupants would sit there. The lowered 
torso anchor would act as a disincentive to overcrowd the flex-seat. We 
agree that design disincentives to overcrowding the flex-seat are 
desirable. A lower anchor point for the center seat of a flex-seat in 
its maximum occupancy (3-seating position) configuration may serve as a 
visual cue that only a small occupant should be located in the center 
position. (In addition, as also discussed later in this preamble, we 
are requiring the torso belt of a small occupant seating position to be 
labeled: ``Do Not Sit In Middle Seat If Over Age 10.'' This label is to 
further discourage full size occupants from using the center seating 
position if it has a lower torso anchorage point.)
    As to what the minimum height should be for that position, IMMI 
suggested that the minimum torso anchor point height should be lowered 
to a range between 387 and 400 mm (15.2 and 15.7 inches) above the 
SgRP. Takata requested a minimum torso anchor point of 380 mm (15 
inches). We have decided to reduce the value for the minimum allowable 
anchor point height for the center seating position in a flexible 
occupancy seat to 400 mm (15.7 inches), which was the upper limit of 
IMMI's suggestion. We have chosen 400 mm (15.7 inches) over 380 mm (15 
inches) because the higher value places the anchorage higher on the 
seat vis-[agrave]-vis the child's shoulder, thus reducing the 
likelihood of spinal compression loading in a crash. According to the 
anthropometric data submitted by Takata, the anchor point will be above 
the shoulder of an average 10-year-old occupant by at least 37 mm (1.5 
inches).\47\ Since the required labeling suggests that a 10-year-old 
can be accommodated by such a seating position, we believe it is 
reasonable to exceed the 10-year-old shoulder height by this value to 
assure the vast majority of 10-year-olds would be accommodated.
---------------------------------------------------------------------------

    \47\ It was necessary to add specifications in FMVSS No. 208 
that provides the weight and dimensions for a 10-year-old occupant. 
In addition, this final rule specifies that lap/shoulder belts at a 
SOSP need only restrain an occupant up to the size of an average 10-
year-old child.
---------------------------------------------------------------------------

2. Anchorage Adjustability
    CEW, AmSafe, and Blue Bird supported the torso belt adjustment 
range to ensure that lap/shoulder belts fit all passengers from an 
adult.
    IMMI believed that a center seating position in a flexible 
occupancy seat that adjusts from 280 to 394 mm (11 to 15.5 inches) 
above the SgRP would accommodate occupants from a 6-year-old to a 10-
year-old and be configured so that larger occupants would not use it. 
Takata suggested that instead of the adjustment range proposed in the 
NPRM, NHTSA could place various anthropomorphic test dummies (ATDs) (6-
year-old, 10-year-old, 5th percentile female and 50th percentile male) 
in belted seating positions to determination whether proper belt fit 
could be achieved. Alternatively, the commenter suggested, NHTSA could 
specifically not require a 330 mm (13 inch) wide seating position to 
accommodate a 50th percentile male.

Agency Response

    For the reasons provided in the NPRM, we have decided to maintain 
the adjustment range proposed for torso belts in the NPRM.
    Takata's comments indicate that they believe their original design 
would properly fit occupants down to the size of a 6-year-old child 
even though it does not adjust down to 280 mm (11 inches) above the 
SgRP. We believe that maintaining torso belt adjustability is an 
objective way of ensuring that lap/shoulder belts will fit even the 
smallest school bus riders. In the past, the agency has reviewed belt 
fit devices in order to determine an objective fit criterion for 
children riding in child restraint systems and booster seats in 
automobiles, but has been unsuccessful.\48\ Therefore, we have produced 
guidelines for caregivers to use to keep the torso belt off the neck 
and upper abdomen.\49\ We believe that the minimum seat width and 
anchor spacing, along with the general design constraints, will provide 
sufficient belt fit without establishing additional ``belt fit'' 
requirements with test dummies. The adjustment range proposed for torso 
belts is practicable, objective and clear, and all other commenters on 
this issue agreed that adjustment to the 280 mm (11 inches) level is 
appropriate to address the full range of potential occupants.
---------------------------------------------------------------------------

    \48\ 70 FR 51720, 51722-51728 (August 31, 2005; Docket No. 
NHTSA-2005-21245). See also 69 FR 13503, (March 23, 2004; Docket 
NHTSA-99-5100).
    \49\ See, e.g., tip 3 of Transportation Safety Tips for 
Children http://www.nhtsa.dot.gov/people/injury/childps/newtips/
index.htm. ``The lap belt must fit low and tight across the upper 
thighs. The shoulder belt should rest over the center of the 
shoulder and across the chest.''
---------------------------------------------------------------------------

    The location of the anchorage is shown below in Figure 1.
BILLING CODE 4910-59-P

[[Page 62762]]

[GRAPHIC] [TIFF OMITTED] TR21OC08.053

3. Clarifications of Torso Anchorage Location
    i. Blue Bird asked if the reference to ``more than 10 degrees from 
the horizontal plane'' in the proposed definition of ``school bus torso 
belt adjusted height'' in S3 of FMVSS No. 210 was meant to state ``from 
the vertical plane.'' The answer is no. We believe that the commenter 
may have misunderstood the definition and the concept behind it. This 
definition was added to FMVSS No. 210 to provide an objective means of 
determining the height position of the torso belt. Fundamental to the 
concept of correct positioning of a torso belt is that the anchorage 
not be below the shoulder, which could result in compressive loads on 
the spine in a frontal crash. The horizontal plane is relevant to see 
where the torso belt anchorage is located relative to the top of the 
shoulder.
    However, because the definition was unclear to the commenter, we 
have decided to add a small clarification to the definition to specify 
that the height is measured from the SgRP.
    ii. Takata also stated that in addition to vertical position, the 
lateral position of the torso belt relative to the midsagittal plane is 
also important. We agree with Takata that lateral position of the torso 
anchor point will also influence belt fit. However, the agency will 
leave this parameter to the discretion of the manufacturer so it might 
be optimized in the context of the required vertical adjustment range.

[[Page 62763]]

4. Integration of the Seat Belt Anchorages Into the Seat Structure
    The NPRM proposed that the seat belt anchorages, both torso and 
lap, be required to be integrated into the seat structure. This 
proposal was made because we were concerned that if we did not, some 
manufacturers could incorporate seat belt anchorages into other 
structures in the school bus, potentially injuring unbelted school bus 
passengers in a crash, or obstructing passengers during emergency 
egress. We also requested comment on whether there were anchorage 
designs, other than those integrated into the seat back, that would not 
impede emergency evacuation or potentially cause injury to unbelted 
passengers.
    In its comments, CEW stated that it was ``not aware of a seat belt 
anchor design (other than being integrated into the structure of the 
seat) that would not impede access/egress to an emergency exit or 
become a source of injury or hazard.'' IMMI agreed with the requirement 
proposed in the NPRM that seat belt anchors be integrated into the seat 
structure for most seats, but requested an exception for the last row 
of ``Type D'' school buses. Their rationale for the exemption was:

    The seats in such a row are integral with the vehicle body 
structure and most commonly, the torso restraint retractors at such 
seats are mounted into the bus body structure, and the shoulder 
belts are routed over the upper edge or through the seat back. The 
lap belt anchorages are also incorporated into the lower structure 
of the davenport. This design helps bus manufacturers minimize seat 
back thickness in order to optimize seat spacing for maximizing 
capacity. And restraints mounted in this manner can not impede 
access to emergency exits or become an injury hazard to unbelted 
passengers.

    In opposition to the proposal were Thomas, IC, NTEA/MCSSB, and 
Girardin, which stated that seat belt anchorages, at least for certain 
bus types or seat positions, do not need to be integrated into the seat 
structure. Alternatively, Thomas requested that ``anchorages integrated 
into the bus body structure be permitted in the last seating row'' for 
all bus sizes.
    Thomas and NTEA/MCSSB both commented that seat belts should not be 
required to be integrated into the seat structure for small school 
buses. They stated that some anchorages could be installed on the bus 
floor, sidewall, or roof, and stated that ``[t]hese installations could 
be optionally configured or designed so that they do not impede access 
to emergency exits.'' Girardin, a small school bus manufacturer, 
stated: ``Anchorages provided in the side wall or in the rear structure 
can be achieved without obstructing passenger exit and could also help 
to reduce the deflection of the rear seats in the row against the rear 
wall.''
Agency Response
    We agree not to adopt the requirement for the last row, but since 
the commenters have not provided any information on vehicle mounted 
belt anchorage designs other than for the last row, we were unable to 
assess the safety and effectiveness of bus-mounted anchorage systems in 
general. In addition, the commenters did not address our other concern 
about whether ``non-integrated'' seat belts could be safety hazards for 
unbelted occupants in a crash. Therefore, in this final rule, we will 
not reject the requirement in its entirety for all school buses.
    Based on comments received on this issue, the last row is excluded 
from the requirement because our concern about emergency exit access is 
lessened for the last row of seats. The last row of seats in 
conventional large school buses and small school buses typically has 
two seats with a 610 mm (24 inch) aisle (large buses) or 559 mm (22 
inch) aisle (small buses) between them, to provide access to the rear 
emergency exit door. FMVSS No. 217 imposes requirements for 
unobstructed passage through the door. Thus, at least in the immediate 
vicinity of the door, that standard should prevent seat belts from 
being installed in such a way that could impede access to the emergency 
exit.\50\ We also believe that the location and style of the last row 
seats in these buses make it possible to place belt anchorages behind 
or to the side of the seat, where the belt webbing would not impede 
safe travel in and out of the seat. Thus, if these belts are out of the 
way of the students, they are unlikely to pose risks of injury to 
unbelted students in a crash (e.g., a student could become entangled in 
belt webbing). This is not the case for all bus seats, where belts for 
inboard seat positions in particular could be mounted such that the 
belt webbing could impede safe passage through the bus interior or pose 
an injury risk for unbelted students in a crash.
---------------------------------------------------------------------------

    \50\ The requirement for a large school bus emergency exit door 
opening is found in 49 CFR 571.217 S5.4.2.1(a)(1).
---------------------------------------------------------------------------

    There are rear-engine buses with a rear emergency exit window 
instead of a door. Regardless of the type of emergency exit there is in 
the bus (door or push-out rear window \51\), we emphasize the 
importance of keeping the area of the rear emergency exit free from 
seat belt webbing so that emergency egress is not impeded. We will 
monitor anchorage designs in this subset of vehicles to ensure that 
safety is not compromised. With regard to small school buses, several 
commenters (Thomas, Girardin, and NTEA/MCSSB) indicated that in these 
vehicles, anchorages could be placed such that they do not interfere 
with emergency exits. However, the commenters did not address the other 
agency concern with whether ``non-integrated'' seat belts could be 
safety hazards for unbelted occupants in a crash. In addition, no data 
or specific information about anchorage designs were provided to enable 
us to make a determination as to whether the belts could be injurious 
to unbelted passengers. Therefore, in this final rule, we will not 
exempt small school buses generally from the requirement that seat belt 
anchorages be integrated into the seat structure, except for the last 
row of seats as discussed in the previous paragraph.
---------------------------------------------------------------------------

    \51\ Emergency exit windows in a school bus must provide an 
opening large enough to admit unobstructed passage of an ellipsoid 
generated by rotating about its minor axis an ellipse with major 
axis of 50 cm and minor axis of 33 cm, as given in FMVSS No. 217, 
S5.4.2.1(c).
---------------------------------------------------------------------------

5. Minimum Lateral Anchorage Separation
    The NPRM proposed to adopt a requirement in FMVSS No. 222 (S5.1.7) 
that each passenger seating position with a lap/shoulder restraint 
system shall have a minimum seat belt anchor width of 380 mm (15 
inches) (and a minimum seating width of 380 mm (15 inches)). At the 
same time, the NPRM proposed to amend the application section of FMVSS 
No. 210 so that it expressly applied to school buses, and thus proposed 
to extend S4.3.1.4 of FMVSS No. 210 to school buses. S4.3.1.4 states: 
``Anchorages for an individual seat belt assembly shall be located at 
least 165 mm [(6.5 inch)] apart laterally, measured between the 
vertical center line of the bolt holes or, for designs using other 
means of attachment to the vehicle structure, between the centroid of 
such means.''
    We have realized that the 380 mm (15 inches) anchorage minimum 
lateral spacing requirement proposed for FMVSS No. 222 is inconsistent 
with the proposed FMVSS No. 210 requirement that all belts on school 
bus seats must be attached to the seat structure. Assuming that the 
anchorage lateral spacing is to be measured in a manner consistent with 
proposed S4.3.1.4 of

[[Page 62764]]

FMVSS No. 210 and the belted seating position width were 380 mm (15 
inches), it would be very difficult to have a 380 mm (15 inches) 
anchorage lateral spacing without extending the seat structure beyond 
the width of the seat cushion.\52\
---------------------------------------------------------------------------

    \52\ The width of each belted seating position is determined as 
a multiple of the seat cushion width.
---------------------------------------------------------------------------

    Since it seems very unlikely for the anchorage minimum allowed 
lateral spacing to be equal to the seating position width for designs 
with the minimum allowed seating position width, in this final rule, we 
have decided that the seat belt anchorage of school bus seats must be 
less than the proposed value. For example, as proposed in the NPRM, a 
1,143 mm (45 inch) wide bench seat could have lap/shoulder equipped 
seating positions, each with a 380 mm (15 inch) seat width. At the same 
time, each lower anchorage for those seating positions would have 
needed a 380 mm (15 inch) lateral separation. Therefore, the physical 
width of the seat structure makes it difficult to achieve this 
anchorage separation. Thus, we will specify spacing of less than 380 mm 
(15 inches) that is consistent with the minimum seating position width, 
but takes into consideration the physical limitation of the space 
available on the seat structure. (As explained below, we are specifying 
330 mm (13 inches) for fixed positions or flex-seat position in the 
minimum occupancy configuration (both of these must have at least a 380 
mm (15 inch) seat widths) and 280 mm (11 inches) for flex-seats in 
maximum occupancy configuration (this must have at least a 330 mm (13 
inch) seat width).) This value must be achieved at all seating 
positions simultaneously, which is important for flex-seat designs that 
have a sliding anchorage, like the IMMI design. The specification for 
``simultaneous'' specification is important for sliding anchorages to 
assure that when multiple occupants are seated on the bench, each 
occupant's belt has an acceptable separation.
    We continue to believe that a minimum anchorage lateral spacing 
should be specified to provide better pelvic load distribution for 
frontal impacts than narrow spacing. If anchorages are narrower than 
the occupant pelvis, the belts can wrap around the iliac crests and 
cause compressive loading. This may be even more undesirable when the 
lap portion of the belt is poorly positioned such that it loads the 
abdominal region.
    To determine the appropriate value for lateral anchorage 
separation, we measured the lower anchorage space of several flex-seats 
with nominal total bench widths of 990 mm (39 inches).53 54 
Based on these data, we believe that flexible occupancy seat designs in 
a maximum occupancy configuration (Y + 1 seating positions with lap/
shoulder belts) should be able to achieve a lateral separation of the 
lower anchorages of no less than 280 mm (11.0 inches) simultaneously in 
any seating position. We found that the IMMI seat is well above this 
value. We believe the Takata seat can be easily altered to meet this 
requirement. Similarly, any non-flex-seat or a flex-seat in a minimum 
occupancy configuration (Y seating positions with lap/shoulder belts) 
should be able to achieve a lateral separation of the lower anchorages 
of no less than 330 mm (13.0 inches) simultaneously in any seating 
position.
---------------------------------------------------------------------------

    \53\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for 
Various School Bus Seats Equipped with Type 2 Seat Belts, Test 
Procedure Development Testing,'' General Testing Laboratories, Inc., 
August 2008.
    \54\ ``NHTSA Technical Analysis to Support the Final Rule 
Upgrading Passenger Crash Protection in School Buses,'' September 
2008.
---------------------------------------------------------------------------

    Since this lateral separation need only be achievable, it is 
acceptable that the sliding buckle anchorage for the IMMI flex-seat 
allows the left or center seat anchorage separation to be independently 
less than 280 mm (11.0 inches). One reason we are not unduly concerned 
with sliding anchorages as they relate to the issue of the lateral 
distance between anchorages is because we believe that such a design 
will be self-centering. In other words, the only time the anchorage 
separation would likely to be less than 280 mm (11.0 inches) would be 
when an occupant with hips narrower than this dimension would be seated 
in this position. In that case, the anchor width would tend to match 
the occupants' hip width, which would not be problematic in terms of 
belt loading on the occupant. Nevertheless, to ensure that sliding or 
otherwise movable anchorages cannot be adjusted so close together such 
that they could be positioned narrower than a child occupant's pelvis 
in a crash, we have also retained the current FMVSS No. 210 requirement 
of 165 mm (6.5 inches) minimum spacing for the anchorages. Thus, 
movable anchorages for an occupant seating position cannot be capable 
of being closer than 165 mm (6.5 inches).
    To summarize, this final rule reduces the lower anchorage minimum 
lateral spacing from the 380 mm (15 inches) value to 280 mm (11.0 
inches) for flexible occupancy seats with the maximum number of 
occupants and 330 mm (13 inches) for all other seating positions with 
lap/shoulder belts. We note that these must be minimum distances 
simultaneously achievable by all seating positions. This is necessary 
because it would be very difficult to have a 380 mm (15 inches) 
anchorage lateral spacing without extending the seat structure beyond 
the width of the seat cushion. The value selected is practicable, based 
on measurements of existing designs. Further, under FMVSS No. 210, 
movable (e.g., sliding) anchorages for an occupant seating position 
cannot be capable of being closer than 165 mm (6.5 inches).
    Given space is available, we continue to believe there is merit to 
requiring a wide anchorage separation in school buses so as to obtain 
good load distributions.
6. Anchorage Strength
    The agency proposed that for large school buses with voluntarily 
installed lap belts or lap/shoulder seat belts, the FMVSS No. 210 
anchorage strength requirement be identical to the requirements for 
passenger seat belt anchorages in smaller vehicles, i.e., 22,240 N 
(5,000 pounds) applied to the pelvic body block for Type 1 belts and 
13,334 N (3,000 pounds) applied to the torso and pelvic body blocks for 
Type 2 belts. We stated our recognition that anchorages in large school 
buses would be likely exposed to lower crash forces than would small 
school buses. We used measurements of seat-to-sled attachment forces in 
the deceleration direction to estimate that the total peak dynamic 
loading sustained by the seat belts in a large school bus crash pulse 
is about 2/3 of that applied in FMVSS No. 210.
    We also requested comment on the appropriateness of the strength 
levels being proposed for large school buses in FMVSS No. 210. We asked 
how much the load could be reduced and still provide an appropriate 
safety margin in a variety of crash scenarios. We also sought 
information about the cost and weight savings associated with a lesser 
requirement.
    There was no consensus on this issue in the comments. Many 
commenters supported a single FMVSS No. 210 body block load for both 
large and small school buses. Takata stated that ``NHTSA sled testing 
confirmed that current FMVSS 210 loads are not excessive when the seat 
is occupied by two 95th percentile males (such as high school football 
players).'' To illustrate this, they calculated that ``[e]ach 95th 
percentile male would impart approximately 5,114 pounds/seating 
position.'' M2K addressed the issue of practicability and stated that 
``at least

[[Page 62765]]

two school bus seat manufacturers seem to be fulfilling current 
strength requirements; and reducing these strength requirements would 
seem counter-productive to stated goals of the NPRM.'' Concepts stated 
that it was logical to apply the current FMVSS No. 210 loads to all 
school bus seats since it applies to all other vehicle types. Concepts 
also stated: ``We must question the need for, and express strong 
opposition to, any proposed reductions in strength required for seat 
backs, seat belt anchorages, or seat-to-floor attachment points.'' CEW 
stated that they actually test beyond the FMVSS No. 210 limit; in some 
cases as high as 32,000 N (7,200 pounds) per seating position. CEW 
stated its belief that ``any cost saving by lowering the large bus 
FMVSS No. 210 strength levels would most likely be off-set by a 
corresponding cost increase by having two different seats, one for the 
small bus and one for the large bus.''
    IMMI proposed a reduction for the center seating position of 
flexible occupancy seats. IMMI recommended that for the center seating 
position, a loading of 8,896 N (2,000 pounds) through the torso and 
pelvic blocks be applied, rather than 13,345 N (3,000 pounds). IMMI 
stated its belief that its suggestion was ``consistent with NHTSA's 
rationale for varying the loads in the quasi-static test procedure 
depending on whether a seat will accommodate three small or two large 
children.''
    Blue Bird stated that it would be appropriate to reduce the load on 
lap/shoulder belts of large school buses by \1/3\ (apply 8,896 N (2000 
pounds) each on the torso and lap body blocks). They also recommended a 
lap body block value of 17,500 N (3,934 pounds) for lap belt only 
systems, taken directly from NHTSA calculations of per seating position 
loading. IC stated that the belt load should--

    be changed to \2/3\ of the small bus requirement for both Type 1 
and Type 2 restraint systems. While it may be desirable and cost 
effective in some cases to use the same design for both small and 
large school buses, that certainly is not always the case and that 
should not dictate establishing the performance requirement for 
large buses at a level higher than necessary * * * * In essence, 
setting the performance requirement at a level higher than necessary 
could ultimately reduce the number of children riding on school 
buses.

    NYAPT stated that ``[a]bsent any bona fide testing results and 
research-based data to the contrary, we would recommend against 
establishing any differential standards among school buses.''
Agency Response
    In this final rule we will not reduce the loading for either large 
school buses or for any seating position of a flexible occupancy seat, 
including the small occupant seating position (center position with a 
reduced anchor point height). We specify one anchorage strength 
requirement (i.e., 13,334 N (3,000 pounds) applied to the torso and 
pelvic body blocks) for both large and small school buses with Type 2 
seat belts. Based on data from the post-NPRM testing,55 56 
the assumption that the large school bus pulse generates about 67 
percent of the FMVSS No. 210 force still appears to be valid, assuming 
two belted seating positions. Assuming three belted positions, the same 
peak dynamic load generates 44 percent of the FMVSS No. 210 force.\57\
---------------------------------------------------------------------------

    \55\ ``NHTSA Technical Analysis to Support the Final Rule 
Upgrading Passenger Crash Protection in School Buses,'' September 
2008.
    \56\ ``NHTSA Vehicle Research and Test Center's Technical Report 
on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School 
Buses,'' September 2008.
    \57\ This calculation assumes a bench seat with three fixed or 
flex-seating positions and that three 5th percentile female 
occupants would be generating the dynamic loading.
---------------------------------------------------------------------------

    As discussed elsewhere in this preamble, the agency has chosen a 
tiered approach to the quasi-static loading as an acknowledgement that 
large and small school buses have different crash characteristics. 
Nevertheless, in this final rule, we are keeping a single requirement 
in FMVSS No. 210, equal to the more severe small school bus case. One 
of the main reasons is a unified FMVSS No. 210 requirement provides a 
safety margin and facilitates better efficiency in the testing.
    NHTSA's testing and the comments from school bus seat manufacturers 
lead us to believe that it is not difficult to sustain the loads 
traditionally required by FMVSS No. 210, given that there is no 
displacement limit in FMVSS No. 210. This is not true of the quasi-
static test, where we do recognize the multiple force/displacement and 
energy criteria that school bus seats must meet supports our decision 
not to require a single quasi-static requirement for all school bus 
seats. With the FMVSS No. 210 loading, one requirement for all school 
bus seats meets the need for safety without being unduly burdensome.
    Another fundamental difference between the tiered loading level 
approach the agency has taken in the quasi-static test and a single 
level of stringency we are specifying to meet FMVSS No. 210 
requirements is that the anchorage strength provides the foundation 
upon which the restraint system is built. There is a more vital safety 
need to require the anchorages to meet the more stringent FMVSS No. 210 
requirement. In addition, having the safety margin better ensures that 
the anchorages will be strong enough to deal with loading in excess of 
what is anticipated, either because of use or misuse by larger 
occupants, the stiffness and mass of the vehicle (e.g., vehicles closer 
in mass to a small bus than the large school bus will experience a more 
severe crash pulse), or because of the nature of the particular school 
bus crash. Further, commenters did not provide cost and weight data 
showing as to the cost savings, if any, that would result from a 
reduced loading for a larger class of school buses. Accordingly, a 
13,334 N (3,000 pounds) load will be applied to the torso and pelvic 
body blocks for both large and small school buses with Type 2 seat 
belts. Similarly, we continue to specify a pelvic body block force of 
22,240 N (5,000 pounds) for optionally provided Type 1 seat belts on 
large school buses.

c. Quasi-Static Test for Lap/Shoulder Belts on All School Buses

I. Quasi-Static Test Requirement
    The agency proposed school buses with lap/shoulder belts must meet 
a quasi-static test procedure that was developed by NHTSA to address 
possible safety problems caused by having both belted and unbelted 
passengers on the same school bus. (The quasi-static test requirements 
would be in addition to existing compartmentalization requirements for 
seat performance). (72 FR at 65521)
    School bus seats designed to provide compartmentalized protection 
must contain the child between well-padded seat backs that provide 
controlled ride-down in a crash. A school bus seat with a lap/shoulder 
belt would have the torso (shoulder) belt attached to the seat back. In 
a crash involving a belted child and an unbelted child aft of the 
belted occupant, the seat back would be subject to consecutive force 
applications from the belted occupant's torso loading the seat back and 
the force generated by impact of the unbelted passenger. The quasi-
static test replicates this double-loading scenario and specifies 
limits on how far forward the seat back may displace. The test helps 
ensure that the top of a seat back does not pull too far forward and 
jeopardize the protection of compartmentalized passengers to the rear 
of the belted occupants, or diminish the torso restraint effectiveness 
for lap/shoulder belted occupants.

[[Page 62766]]

a. Background
    The agency developed the quasi-static test by performing a sled 
test using the same large school bus crash pulse that was used in the 
school bus research program. We measured the loads on the shoulder 
belts and both lower parts of the lap belt. Two unbelted 50th 
percentile male dummies were positioned behind the seat that contained 
two restrained 50th percentile male dummies. Visual observation of seat 
kinematics and load cell data produced by the shoulder belts from this 
test revealed the following sequence of events:
    1. The knees of the unbelted dummy to the rear struck the back of 
the forward seat, causing some seat back deflection.
    2. The seat back was loaded by the shoulder belt of the restrained 
dummy in the forward seat.
    3. The shoulder belt load was reduced as the seat back to which it 
was attached deflected forward.
    4. The shoulder belt loads reduced to approximately zero when the 
unbelted dummies' chests struck the forward seat back.
    5. The forward seat back deflected further forward as the energy 
from the unbelted dummies was absorbed.
    This crash scenario is replicated in the quasi-static test. The 
load requirement for the quasi-static test is dependant upon the number 
of seating positions and also the likely seat capacity. A seat that has 
the minimal allowed overall seat width for either a two or three 
occupant seat will have a reduced loading requirement from other 
seats.\58\
---------------------------------------------------------------------------

    \58\ A school bus bench seat has the minimum allowed overall 
width if the total seat width in millimeters minus 380Y is 25 mm (1 
inch) or less.
---------------------------------------------------------------------------

Stage 1: Torso Belt Anchorage Displacement
    The first part of the quasi-static test replicates steps 1 and 2 of 
the crash scenario above. The procedure uses the knee and top loading 
bars that are currently specified in S5.1.3 of FMVSS No. 222 (seat back 
strength), which replicate a passenger's knee and torso loading the 
forward seat back \59\ and the FMVSS No. 210 upper torso body 
block.\60\ The test procedure uses the bottom loading bar to replicate 
the knee loading by the unbelted rear passengers (based on W), then 
specifies a pull test on the shoulder belts at each seating position in 
the seat to replicate loading of the shoulder belt by the belted 
passengers (based on Y). The large school bus shoulder belts are pulled 
using the upper torso body block specified in Figure 3 of FMVSS No. 210 
with a specified force. The NPRM proposed a force of 5,000 N (1,124 
pounds) at each seating position for large school buses, and a force of 
7,500 N (1,686 pounds) for small school buses.\61\
---------------------------------------------------------------------------

    \59\ The current knee loading test procedure requires that 
initially a force of 3,114 N (700 pounds) times the number of 
seating positions in the test seat (W) be applied to the seat back 
within 5 and not more than 30 seconds, and then the force is reduced 
to 1,557 N (350 pounds) times W. The knee loading bar is locked in 
this position for the remainder of the test. The current top loading 
test procedure requires an additional force through the top loading 
bar until 452 joules (4,000 inch-pounds) times W of energy is 
absorbed by the seat back.
    \60\ The agency is considering a rulemaking that would replace 
the torso body block in FMVSS No. 210 with an updated force 
application device. If the upper torso body block in FMVSS No. 210 
is changed, the body block discussed in this quasi-static procedure 
proposed today may be changed to the new force application device as 
well.
    \61\ As discussed earlier in this section, these 5,000 N (1,124 
pounds) and 7,500 N (1,686 pounds) values would be reduced depending 
on the width of the seat.
---------------------------------------------------------------------------

    We explained in the NPRM that an applied load of 5,000 N (1,124 
pounds) for large school buses appeared to be necessary to replicate 
the torso belt loading from the sled test and to get the similar seat 
response observed from high speed video. For small school buses, a 
higher force was proposed because the small school bus crash pulse has 
twice the peak acceleration of the large school bus, i.e., 
approximately 25 g's.\62\
---------------------------------------------------------------------------

    \62\ The rationale for the load application is explained in the 
agency's 2007 Technical Analysis. We have verified the 
appropriateness of this load value through additional dynamic 
testing performed after the NPRM was published.
---------------------------------------------------------------------------

    At this mid-point of the quasi-static test when the torso block 
force is being applied, NHTSA measures whether the seat back has pulled 
too far forward and jeopardized the protection of compartmentalized 
passengers to the rear of the belted occupants or diminished the torso 
restraint effectiveness for the lap/shoulder belted occupant. In the 
NPRM, the proposed criterion for passing this part of the test was a 
specified limit on the forward displacement of the torso belt 
anchorage. The specified value was a function of the vertical location 
of the anchorage (AH) and the initial angle ([Phi]) \63\ of the seat 
back surface that compartmentalizes the occupants rearward of the seat 
being tested, i.e., the posterior surface of the seat back. Basically, 
for large school buses, the proposed allowable displacement was 
equivalent to the amount of displacement that would result from the 
seat back deflecting forward 10 degrees past a vertical plane.\64\ For 
large school buses, this is represented in the equation below by sin(10 
deg.) = 0.174. Thus, the total allowable forward horizontal 
displacement for large school buses was proposed to be:
---------------------------------------------------------------------------

    \63\ We note that in the preamble of the NPRM, the initial seat 
back angle was mistakenly represented by [thetas] in the 
displacement limit equation. However, the proposed regulatory text 
and the 2007 Technical Analysis correctly identified the initial 
seat back angle as [Phi] in the displacement limit equation.
    \64\ The derivation of the equation defining this displacement 
limit was explained in the agency's 2007 Technical Analysis.
---------------------------------------------------------------------------

Large School Bus Displacement Limit = (AH + 100)(tan[Phi] + 0.174sin(10 
deg.)/cos[Phi]) mm.
    For small school buses, the displacement limit was proposed to be 
equivalent to the amount of displacement resulting from a seat back 
deflecting forward 15 degrees past a vertical plane (sin(15 deg.) = 
0.259). The displacement limit would be determined using the equation:
Small School Bus Displacement Limit = (AH + 100)(tan[Phi] + 0.259sin(15 
deg.)/cos[Phi]) mm.
    The proposed allowed displacement for small school buses would be 
greater than the limit for large school buses to account for agency 
concerns about practicability of small school buses meeting the 
displacement criterion.
    As noted above, the goal of the proposed torso belt anchorage 
displacement criterion was two-fold. The first goal was to assure that 
the seat back to which the torso belt is anchored has sufficient 
strength to restrain and protect the belted occupant in a frontal 
crash. The second goal was to assure that the seat back is still in a 
sufficiently upright position to compartmentalize unbelted occupants to 
the rear. Thus, we believed that the displacement limit should be 
narrow, to ensure that seat backs deviate as little as possible from 
the initial upright position.
Stage 2: Energy Absorption Capability of the Seat Back
    The quasi-static test continues with procedures to replicate steps 
3, 4 and 5 of the crash scenario above. After the torso anchorage 
displacement is measured, the torso body block load is released. 
Immediately after this load is released, forward load is applied to the 
seat back through the top loading bar. It was proposed that the seat 
back must be able to absorb the same amount of energy per seating 
position (452 joules (4,000 in-pounds)) as is required of a seat back 
under the compartmentalization requirement. However, it was proposed 
that for this quasi-static test, the seat back need not perform such 
that the top loading bar force must stay in the force/deflection 
corridor specified for the

[[Page 62767]]

compartmentalization requirement.\65\ We were concerned about the 
practicability of meeting the force/deflection corridor, since the 
torso body block load may have generated stresses in the seat frame 
that exceed the elastic limit of the material and result in residual 
strain.
---------------------------------------------------------------------------

    \65\ A separate FMVSS No. 222 forward loading test is still 
performed on a different test specimen, one that was not subjected 
to the quasi-static test, to assure that in a crash, if the seat 
were not occupied by a belted passenger and it were impacted by an 
unbelted rearward passenger, the seat would meet the force/
deflection corridor.
---------------------------------------------------------------------------

b. Comments and Agency Responses
    School bus seat and restraint manufacturers and school bus 
manufacturers commented on the quasi-static test. The commenters 
generally concurred with the need for a test to assure the 
compatibility of belts and compartmentalization, and most suggested 
technical changes to the test. IMMI and Takata raised issues concerning 
implications of the proposed requirements on their seat designs.
    The comments are addressed below, with the agency's responses.
    i. IMMI's comments supported the agency's proposal to add the 
quasi-static test to assure that compartmentalization is maintained for 
seats with lap/shoulder belts, but was concerned that an aspect of the 
test procedure would ``disfavor'' its dual frame seat design. It 
indicated that using the torso anchor point as the reference for 
measuring the displacement ``is not relevant to the ability of certain 
school bus seating designs to provide such compartmentalization.'' This 
is because with IMMI's design, the outer seat back frame providing 
compartmentalization is not attached to the inner frame where the 
anchor point is located, so the seat would not meet the proposed 
displacement requirement. They urged the agency to change the test 
procedure to avoid limiting their dual frame design, which they believe 
to have good dynamic performance. IMMI asked that the test measure 
``the rear surface of the seat back--rather than measuring the 
displacement of the torso anchorage, which is irrelevant to 
compartmentalization in this innovative seat design.''
Agency Response
    NHTSA does not agree that it is a simple matter to change from the 
restriction on the horizontal displacement of the torso anchor point to 
the rear surface of the seat back. Simply placing a rotation or 
displacement limit on the compartmentalizing seat back would provide no 
limit on the forward displacement of the torso anchorage of a dual 
frame design such as IMMI's. If the agency were to just limit the seat 
back displacement/rotation, the dual frame design could offer very 
little resistance to forward excursion of the belted occupant while 
still meeting the requirement, which could in some designs provide no 
better protection than just a lap belt. Thus, just measuring the 
displacement/rotation of the seat back would not achieve our goals of 
protecting both the belted and rearward unbelted occupants.
    However, in recognition of the merits of making our requirements as 
performance-oriented as possible, we have decided to limit the 
horizontal displacement of both the anchor point and seat back to avoid 
unnecessary design restrictions. As discussed in the 2008 Technical 
Analysis, in consideration of comments to the NPRM, the agency believes 
there is sufficient justification to limit the displacement of torso 
anchor point as well as the seat back in the final rule. This will have 
no substantial effect on unified frame seat designs in that the seat 
back displacement limit will be identical to the anchor point 
displacement limit in the NPRM.
    Thus, the quasi-static displacement measurement will include both a 
seat back and a torso anchor point displacement. We have decided that 
the best way to do this is to measure the displacement of a point on 
the rear surface of the seat back, rearward of the anchor point. This 
seat back displacement point is found by passing a horizontal 
longitudinal line through the torso anchor point and determining where 
it intersects the seat back surface. With the seat back displacement 
point defined in this way, the displacement limits can be calculated. 
We selected this approach for determining the seat back displacement 
point because of its simplicity. While we acknowledge that a point on 
the surface of the seat back may be prone to displacement as a result 
of deformation of non-structural elements such as upholstery, our 
testing has indicated that such movement is not significant in 
comparison to the structural deformation of the seat back caused by 
torso belt loading.
    We also considered measuring the displacement of other points on 
the seat back structure. For example, we considered removing a section 
of upholstery in the vicinity of the seat back displacement point 
described above, in order to expose a portion of the seat back frame 
that could be tracked. However, our examination of the structure of 
lap/shoulder belt equipped seat backs showed a great deal of variation 
in the internal structure. We felt this might lead to substantial 
variability in objectively identifying a point on the internal 
structure to track.
    ii. IMMI requested that NHTSA allow additional torso anchor point 
displacement equivalent to 4 degrees of additional seat back rotation 
for both the large and small school bus requirements to accommodate its 
design. The commenter provided data in support of its request.
Agency Response
    We have decided to grant IMMI's request. The commenter asked for 
torso anchor point displacement equivalent to 4 degrees of additional 
seat back rotation for both the large and small school bus 
requirements. We estimate that this will result in approximately a 40 
mm increase in allowable anchor point displacement.
    As explained in the 2008 Technical Analysis, IMMI presented 
comparative dynamic testing data in its supplemental comments on the 
NPRM that showed the results of tests of prototype designs of flex-
seats under consideration by IMMI with 5th percentile female dummies 
and with the two 50th percentile male dummies. The dummies measured 
injury levels under the IARVs even though the seat was not capable of 
achieving the displacement limit with the added approximately 40 mm of 
displacement. IMMI informed NHTSA that it was going to redesign the 
flex-seat's inner frame to provide additional torso belt support. We 
would expect that a redesign of the dual frame seat to meet the final 
rule anchor point limit would have equal or better dynamic performance. 
In addition, our analysis indicates that anchor point displacement of a 
dual frame seat design will still be bound by the energy absorption 
phase of the quasi-static test even as greater anchor point 
displacement is allowed during the torso belt pull phase of the test. 
Also, the seat will still need to meet the energy absorption of 452 J 
(4,000 inch-pounds) per occupant seating position specified in S5.1.3. 
These parameters will still limit the reduction in strength/energy 
absorption capability of the inner frame.
    iii. Freedman commented: ``If a seat assembly includes more than 
one torso belt anchor point how should the displacement be measured? 
Should the average or the worst case displacement be used for 
evaluation? FSTL recommends that NHTSA clarify the procedure to address 
the possibility of multiple torso belt anchor points on one seat.''

[[Page 62768]]

Agency Response
    The agency will use the displacement of any of the torso belt 
anchorage points to determine if a seat meets the performance criteria.
    iv. Freedman tested its double occupant 3PT Family Seat ``according 
to the parameters proposed for small school buses.'' As a result, 
Freedman suggested one change to proposed S5.1.6.5.7.; that ``the 
forward and rearward travel distance of the upper loading bar pivot 
attachment point measured from the position at which the initial 
application of 44 N of force is attained'' be changed to ``the forward 
and rearward travel distance of the upper loading bar pivot attachment 
point measured from the position at which an application of 44 N of 
force is attained.''
Agency Response
    The agency has adjusted the performance criteria in such a way that 
the measurement for forward travel will start after the 44 N force is 
obtained.
    v. CEW asked NHTSA to remove the requirement to measure the initial 
seat back angle. CEW believes this would be time-consuming and 
unnecessary if an angular rotation limit were used. CEW proposed that 
``the criteria for both large and small school buses could be: Shoulder 
anchor displacement must be < 10 degrees forward of vertical per above 
quote or a linear equivalent.'' Takata also suggested the agency 
consider different displacement measurement methodology and limits when 
assessing the performance of the seat back in various stages of the 
quasi-static test. They specified that a displacement plane should 
establish the limit on seat back rotation. The primary context of this 
seemed to be the energy absorption criteria of the quasi-static test. 
However, this would also seem to limit the seat back rotation during 
the torso belt loading portion of the test.
Agency Response
    We decline to accept the CEW or Takata suggestions. The final rule 
will continue to use a horizontal displacement limit for anchor point 
motion. The final rule will also use a horizontal displacement limit 
for seat back motion.
    As explained in the 2007 Technical Analysis, the agency derived the 
torso anchor point displacement assuming rigid body rotation of the 
seat back about a point 100 mm below the SgRP. We understood that the 
actual anchor point displacement is dependent upon the seat back 
design. Although specific points on the seat back may rotate and 
translate, the seat back may actually bend like a cantilever beam under 
load. As CEW and Takata suggest, certainly this bending motion can be 
described as a change in angle of a line passing through the anchor 
point or upper part of the seat back and some other reference point 
near the seat base. However, we continue to believe that the forward 
displacement of the anchor point is more relevant to occupant restraint 
than rotation of a line passing through it. That is because a 
rotational measurement would not take into consideration the absolute 
displacement of the anchor point. While the Takata suggestion provides 
a displacement limiting plane in space and thus restricts absolute 
translation of the anchor point, we do not regard this method to be 
superior to the agency's proposal.
    We disagree with the CEW comment that measurement of the initial 
seat back angle, which is necessary to calculate the displacement 
limit, is complicated and time consuming. We believe this to be a 
relatively simple measurement to make. We also do not agree with Blue 
Bird's suggestion to place Figure 9 from the 2007 Technical Analysis in 
the regulatory text, since this may imply that only rigid body rotation 
is occurring.
    Finally, while the idea to use a rotational limit to control the 
seat back motion as opposed to a displacement limit has merit, we do 
not believe it is more merited than the displacement value of the 
anchor point as proposed by the agency. We also believe it would be 
challenging to find an objective method of measuring the seat back 
angle at multiple locations along the seat back as it is being deformed 
in a non-uniform way due to non-symmetric loading from multiple torso 
belts.
    vi. Takata believed that the final rule should limit the 
displacement of the ``effective point'' or ``effective anchorage.'' 
This would differ from the anchor point in that it would include where 
the torso belt interacts with the torso belt adjustment device. Takata 
was concerned that the adjustment device might slip during the torso 
body block loading. This slippage would result in additional belt 
spool-out. Thus, the displacement of the anchor point would not be 
representative of the actual occupant displacement. Takata was also 
concerned that movement of the adjustment device could cause the torso 
belt angle to change and cause the load path to move off the shoulder. 
They suggested that the quasi-static procedure mark the belt webbing 
and limit slippage to no more than 25 mm (1.0 inch), after accounting 
for webbing stretch. In an ex parte meeting with the agency they 
explained that the distance between the effective point and latch plate 
should not increase by more than 25 mm (1.0 inch).
Agency Response
    Both quasi-static and dynamic testing of seat belt designs with 
torso belt adjustment devices showed that the devices tended to slip 
when loading was applied to the torso belts. Thus, we believe that 
Takata's suggestion of limiting the adjuster slippage to 25 mm (1.0 
inch) or less is reasonable. However, we believe that this value should 
be relative to the initial position on the fixed webbing upon which the 
adjuster travels. This avoids having to deal with or compensate for 
stretch in the torso restraint webbing, which would be necessary if we 
were to use the test method suggested by Takata.
    Finally, to implement this change, the initial position of the 
torso belt adjustment device must be such that slippage will be 
possible. For example, if the starting position for the adjuster is 
fully up, there is nowhere for it to go, and the test will not discern 
the sufficiency of adjuster's capability of remaining in position. To 
verify that the adjuster does not slip more than 25 mm (1.0) under 
load, the final rule will require it to be placed 38 mm (1.5 inches) 
below its highest position of adjustment.
    vii. The proposed quasi-static procedure applied no load through 
the pelvic body block. A pelvic body block was not included because the 
focus of the test is to assure that the top of the seat back does not 
pull too far forward, reducing compartmentalization, and because a 
visual assessment showed that the desired seat response could be 
achieved with only the torso body block load. However, the agency 
requested comments on whether the quasi-static test should apply a 
pelvic block loading. IMMI, CEW and Blue Bird agreed with the NPRM as 
it relates to not applying pelvic block loading during the quasi-static 
test as it would not make a significant contribution to the seat back 
loading/displacement. Blue Bird argued it would be an unnecessary 
complication.
    Takata was the sole commenter indicating a preference for the 
pelvic loading. Takata also indicated that there should be limits 
placed on the lateral displacement of lap belt anchorages, consistent 
with ECE R14, to reduce the likelihood of occupants loading each other. 
It requested that after the belt loading sequence in the quasi-static 
test, the anchorage spacing of a 330 or 380 mm (13 or 15 inches) 
seating position

[[Page 62769]]

should be not less than 305 or 350 mm (12 or 13.77 inches), 
respectively.
Agency Response
    We agree with the majority of commenters and continue to believe 
that pelvic block loading would be of no consequence to the outcome of 
the quasi-static test. Therefore, the only reason to apply the pelvic 
load would be to implement the Takata recommendation to restrict the 
change in lateral anchorage spacing after belt loading in the quasi-
static test, consistent with ECE R14. We are not convinced that the 
quasi-static test as currently written would be appropriate to 
ascertain the tendency for anchorages to displace in the real world. 
The quasi-static test pulls only on the torso belt. The pelvic belt 
portion of the restraint is not pulled. To implement the ECE R14 
requirement according to the Takata suggestion, the test would need to 
pull on the pelvic belt portion, which is not done in the test. In 
addition, the ECE R14 requirements are applicable to general passenger 
vehicles and are not specifically tailored to school buses. In Europe, 
non-school buses, and not buses designed to meet the 
compartmentalization requirements in FMVSS No. 222, are used.
    ECE R14 is essentially the analogous regulation to FMVSS No. 210. 
After application of loading to the anchorages, the minimum allowed 
anchorage spacing cannot be violated. We note that FMVSS No. 210 has no 
equivalent requirement to limit lateral anchorage spacing after 
anchorage loading. The agency has never found that a safety need exists 
for such a requirement in any vehicle to which FMVSS No. 210 applies. 
In addition, application of the suggested provision would be design 
restrictive, effectively eliminating flex-seat designs with sliding 
lower anchorages. As we expressed in section IX.b.5., we see no safety 
need to disallow such designs. Moreover, the commenter did not provide 
any test data to support the contention that performance would be 
compromised by allowing anchors to slide.
    viii. In the NPRM, we proposed that any seating position that has 
greater than a 380 mm (15 inches) seat width would be exposed to a body 
block load based on a 50th percentile male occupant (5,000 N (1,124 
pounds) and 7,500 N (1,686 pounds) for large and small school buses, 
respectively). Any seating position that has the minimum seating width 
of 380 mm (15 inches) would be exposed to a torso body block load based 
on a 5th percentile female occupant (3,300 N (742 pounds) and 5,000 N 
(1,124 pounds) for large and small school buses, respectively).\66\ 
Thus, a bench seat having a width between 1,140 mm (44.9 inches) and 
1,165 mm (45.9 inches) could have three belted positions that need to 
meet the 5th percentile female loading.
---------------------------------------------------------------------------

    \66\ S5.1.6.5.5 specified that 5,000 N is applied to the torso 
belts if the bench width is no more than 25 mm greater than the 
number of belted positions (Y) times 380 mm (15 inches). A wider 
bench indicates that there is nominally more than 380 mm (15 inches) 
per belted seating positions and the load applied to the torso belts 
must be 7,500 N.
---------------------------------------------------------------------------

    Takata suggested that if the minimum seat width for a lap/shoulder 
belt seating position is maintained at 380 mm (15 inches), all seating 
positions should be loaded assuming 50th percentile male occupants 
rather than the 5th percentile female occupants. Takata argued that the 
reduced load is not representative of potential worst case usage.
Agency Response
    There is a potential that three 50th percentile (or larger) males 
may try to sit in a 1,143 mm (45 inch) wide seat with three lap/
shoulder belts. However, data submitted by Takata indicates the 
shoulder width of a 50th percentile male is 465 mm (18.3 inches), 
substantially larger than the 380 mm (15 inch) seat spacing. In making 
a determination of appropriate loading, the agency must consider the 
probability of a loading situation occurring. We are not convinced that 
the likelihood of this misuse condition is high, and Takata has not 
provided the agency any information as to the likelihood of the loading 
scenario they described.
    Further, there is an issue of the practicability of requiring seats 
to meet the quasi-static requirements assuming three 50th percentile 
males are occupying all three lap/shoulder belt positions. The agency 
has no quasi-static testing or sled testing in this configuration. This 
would represent a 50 percent increase in stringency for total torso 
body block loading for seats that would fall in this category. We 
estimated the torso body block load normalized to the upper loading 
bar. Increasing the total torso body block loading by adding an 
additional torso load (50 percent increase) would result in a load of 
13,770 N (3,096 pounds) and 9,180 N (2,064 pounds) for the small and 
large school bus cases, respectively.
    The small school bus load would clearly exceed the upper limit of 
the force-deflection zone required by S5.1.3 of FMVSS No. 222. In the 
2007 Technical Analysis we discussed the implications of requiring a 
normalized torso body block load that was at or above the upper limit 
of the force-deflection zone. We stated that such a requirement might 
necessitate novel designs that have an energy absorbing phase during 
seat back contact with unbelted occupants and a stiff phase when the 
belted occupant is loading the seat back through the anchorage. These 
designs will take time and resources to develop.
    Ultimately, the agency must establish a reasonable limit to the 
seating position width that should be expected to accommodate a 50th 
percentile male and the associated belt loading. This is particularly 
true given our new minimum width of 330 mm (13 inches) for the ``small 
occupant seating position'' of flex-seats. Given the available 
information, we see no sufficient reason to change the load requirement 
from what was proposed.
    The question arises as to what should be the appropriate torso body 
block loading for a flex-seat at its maximum occupant capacity. NHTSA 
believes that it is reasonable to assume that the outside seating 
positions of a flex-seat, in a maximum occupancy configuration, could 
be loaded to levels consistent with occupancy by adult 5th percentile 
adult females and so is adopting that load requirement. Certainly, 
larger occupants could be present in these outside seats, but this 
would result in the center seating position accommodating 
correspondingly smaller occupants. Assuming the outside seats are 
occupied by 5th percentile adult females (a 12-year-old child is 
approximately the size of a 5th percentile adult female), the center 
seat could be occupied by an occupant about the size of a 10-year-old. 
This is consistent with our allowance for a lower anchor height for the 
center seat of flex-seats. Nonetheless, we believe that it is in the 
best interest of safety to maintain the loading of this position to the 
same level as the other positions on a flexible occupancy seat, i.e., 
equivalent to that of a 5th percentile adult female.
    There is not much of a difference between the associated loads of a 
5th percentile adult female and a 10-year-old child. Our latest data on 
the mass of a 10-year-old is 37.2 kg (82 pounds). The total percentage 
increase in applied torso load between assuming three 5th percentile 
females or two 5th percentile females and one 10-year-old would be 9% 
[((3 x 49) - ((2 x 49) + 37.2)/((2 x 49) + 37.2)]. We have no 
practicability concerns with the three-across 5th percentile female 
loading on a flexible occupancy seat. Moreover, the approach is 
consistent with the load level that the

[[Page 62770]]

agency is establishing for other three-seating position bench seats 
with fixed lap/shoulder belts.
    Accordingly, the agency has concluded that flex-seats in a maximum 
occupancy configuration must be loaded in the quasi-static test to a 
level consistent with all seat positions being occupied by 5th 
percentile female occupants, that is to say, a torso body block load of 
3,300 N (742 pounds) and 5,000 N (1,124 pounds) for large and small 
school buses, respectively. This would include flexible occupancy 
seating positions down to a 330 mm (13 inch) width, up to a fixed seat 
width of nominally 380 mm (15 inches). As was proposed, seating 
positions with widths of 380 mm (15 inches) or larger are load values 
consistent with occupancy of a 50th percentile male occupant.
    ix. CEW asked that the agency to modify the quasi-static energy 
absorption requirement such that the upper loading bar load remains in 
the present FMVSS No. 222 force-deflection corridor. They argued that 
the compartmentalized occupant behind a belted occupant should be 
offered the full protection of a seat back that can stay within the 
force-deflection corridor and not just that of a seat back that meets 
the reduced performance level proposed in the NPRM.
Agency Response
    We believe there is merit to the CEW request. In the preamble of 
the NPRM, we contrasted the energy absorption for an occupant behind 
belted and unbelted occupants. We stated that for unbelted occupants 
behind belted occupants, ``the manner of absorbing energy would not be 
as controlled as when impacting a seat back that had not been subjected 
to the previous loading from the seat belts.'' An altered performance 
level as specified in the force-deflection corridor would no longer be 
applied. However, the required amount of energy absorption remained the 
same as specified by S5.1.3. We believed that this was necessary 
because the torso belt pull would have loaded the seat back into 
plastic deformation and it was unclear how well controlled the force/
deflection curve of subsequent loading with the upper loading bar could 
be.
    According to CEW, at least for their design, this subsequent 
loading is sufficiently controllable. In fact, the agency's own data is 
verification of CEW's position. Figures 2 and 3 below entitled, ``CEW 
with three fixed width seating positions'' and ``CEW with two fixed 
width seating positions,'' respectively, show the force-deflection 
curves of the upper loading bar in the quasi-static test for a CEW 
unified frame design.\67\
---------------------------------------------------------------------------

    \67\ NHTSA-2007-0014-0016.
    [GRAPHIC] [TIFF OMITTED] TR21OC08.054
    

[[Page 62771]]

[GRAPHIC] [TIFF OMITTED] TR21OC08.055

    However, we are concerned that adopting the entire corridor may 
unnecessarily restrict the design of seat backs other than that of 
conventional unified frame seats. Figures 4 and 5 below, ``IMMI-V1 with 
three fixed width seating positions'' and ``IMMM-V1 two fixed width 
seating positions,'' respectively, show the results of agency testing 
for the IMMI-V1 dual frame design. Note that the force/deflection curve 
exits the lower boundary at the location of the upward slope and 
reenters at the flat portion of the boundary. However, this design 
still achieved the necessary amount of energy absorption prior to 356 
mm of displacement in the case of the two-position seat and prior to 
exiting the upper bound of the corridor in the case of the three-
position seat. We note that testing with a prototype considered by IMMI 
showed a force-deflection signature that remained within the required 
corridor.\68\
---------------------------------------------------------------------------

    \68\ ``NHTSA Technical Analysis to Support the Final Rule 
Upgrading Passenger Crash Protection in School Buses,'' September 
2008.
---------------------------------------------------------------------------

    Our concern about being design restrictive relates to imposing the 
lower bound of the corridor. For the dual frame design in the quasi-
static test, the inner frame will have been initially pulled away from 
the rest of the seat back. As the upper loading bar initially loaded 
the outer seat back frame, for this particular version of the IMMI 
design (IMMI-V1) this outer frame did not offer sufficient resistance 
to stay in the corridor and neither did it meet the proposed anchorage 
displacement requirement.\69\ If the manufacturer were to modify the 
design so as to meet the new torso anchor point displacement limit, the 
seat will have a stronger inner frame. We are concerned that 
strengthening of the inner frame would make it problematic to 
strengthen the outer frame such that it could stay above the lower 
bound of the force deflection curve.\70\ The result of the prototype 
IMMI design staying within the corridor does not change this conclusion 
since that design also did not meet the new torso anchor point 
displacement limit.
---------------------------------------------------------------------------

    \69\ This version of the IMMI seat is no longer manufactured.
    \70\ This is because the combined frame still needs to stay in 
the corridor for the S5.1.3 energy requirement.
---------------------------------------------------------------------------

    However, we do believe it is reasonable to expect a compliant dual 
frame design to stay below the upper bound of the corridor. 
Accordingly, we are adopting the upper boundary of the corridor, so the 
seat back must perform such that the top loading bar force must stay 
within the top of the force/deflection corridor specified for the 
compartmentalization requirement. This requirement helps ensure that 
the seat back will not be too stiff in containing the unbelted 
passenger in a crash.
BILLING CODE 4910-59-P

[[Page 62772]]

[GRAPHIC] [TIFF OMITTED] TR21OC08.056

    x. CEW and Girardin requested that lap/shoulder belt equipped seats 
not have to independently meet the energy absorption requirement of 
S5.1.3 since the quasi-static test addresses this separately. Takata 
asked that the energy quasi-static energy absorption requirement be met 
prior to the seat back going beyond a specified displacement plane.
Agency Response
    We do not agree with this request. We still believe it is important 
that the seat back meet the compartmentalization requirement as it 
currently exists, i.e., prior to the seat being deformed or stressed by 
belt loading. Even when there are lap/shoulder belts on school buses, 
some occupants may not use them. In that case,

[[Page 62773]]

compartmentalization is the only restraint method. We have no 
guarantee, nor have we been shown any data indicating, that a seat back 
remaining in the corridor after belt loading will always be in the 
corridor prior to belt loading. In addition, to implement the CEW and 
Girardin recommendation the quasi-static test would have to impose 
compliance with the entire force-deflection corridor. As we explained 
above, we are not imposing the lower bound at this time.
    xi. Both Freedman and Blue Bird requested that the displacement 
limit in the energy absorption phase of the quasi-static test begin 
when the 44 N (10 pounds) is obtained as a result of upper loading bar 
in S5.1.6.5.7 as opposed to when the 44 N (10 pounds) is applied when 
the seat back position is determined in S5.1.6.3.
Agency Response
    The comments indicate confusion as to where the calculation of 
displacement for the energy calculation in S5.1.6.5.7 should begin. It 
is to begin when 44 N of force is achieved in the upper loading bar 
during the load application specified in S5.1.6.5.7. Changes have been 
made to the regulatory text to make this clear.
    xii. We also sought comment on the proposed procedure (see 
S5.1.6.5.4 of the proposed rule) for positioning the torso block used 
in the quasi-static test. We also asked whether the proposed procedure 
was sufficiently clear and whether there are ways to improve the 
clarity of the test procedure.
    Several commenters addressed the proposed 300 N (67 pounds) preload 
used in the test. CEW stated testing indicated that the 300 N (67 
pounds) preload is not sufficient to hold the torso body block in place 
until the full load is applied. They recommended that the preload be 
increased to 896 N (200 pounds). Freedman stated that it was difficult 
to position the torso body blocks as described in S5.1.6.5.4 and the 
300 N (67 pound) preload seemed inadequate to position the torso body 
block in the prescribed zone. Freedman recommended that the preload be 
increased to a load between 890 to 1,334 N (200 to 300 pounds). 
Freedman indicated that the torso body block was also difficult to 
position without any support beneath it. They requested clarification 
on whether the use of supports to help position the body block within 
the required zone was permissible.
    Blue Bird stated that their experience has been that a 300 N (67 
pounds) preload applied slightly upward (5-15 degrees) is not 
sufficient to counteract the body block weight and hold it such that 
the applied load remains at the desired angle. They did not suggest a 
specific load, but stated their belief it would be several hundred 
pounds. They stated that at such a weight, the seat belt webbing 
stretches and seat back displacement becomes a concern. They suggested 
the use of a spacer on top of the seat cushion as a superior 
alternative method to achieve the desired initial body block position 
until the applied load negates the gravitational pull on the body 
block.
Agency Response
    After considering the comments, the agency is revising the applied 
preload and positioning zone for the torso body block. We found that a 
preload of 600 N (135 pounds) will position the torso body block in a 
repeatable manner without the use of any support under the block.\71\
---------------------------------------------------------------------------

    \71\ ``FMVSS No. 222 School Bus Seat Quasi-Static Testing for 
Various School Bus Seats Equipped with Type 2 Seat Belts, Torso 
Block Preload and Positioning,'' General Testing Laboratories, Inc., 
July 2008.
---------------------------------------------------------------------------

    In addition, the agency has found that the zone for locating the 
origin of the torso body block radius must be referenced to the 
adjusted height of the torso belt to address flex-seat designs. As 
earlier discussed in this preamble, this final rule specifies that the 
torso belt adjusted height will be 38 mm (1.5 inches) below its highest 
position of adjustment to account for slippage. In addition, for small 
occupant seating positions of a flex-seat, this adjusted position may 
be well below 400 mm above the SgRP.
    The agency evaluated the sensitivity and repeatability of the torso 
body block position to preload values and torso belt adjusted height. 
Our analysis showed that a preload of 600 N (135 pounds) was sufficient 
to position the torso body block in a repeatable manner without the use 
of any support under the block. The origin of the torso block will 
still be located no more than 100 mm forward of the SgRP. However, the 
vertical zone is now referenced to the torso belt adjusted height. This 
zone is established by locating a horizontal plane that has a vertical 
position halfway between the torso belt adjusted height and 100 mm 
below the SgRP. The origin of the torso body block radius must be 
within 75 mm (3.0 inches) of this plane. Mathematically, the vertical 
location of the upper and lower plane is as follows:

Upper Plane = (TBAH - 100)/2 + 75 = (TBAH)/2 + 25 mm
Lower Plane = (TBAH - 100)/2-75 = (TBAH)/2-125 mm

Where TBAH is the torso belt adjusted height above the SgRP.
    Figure 6 below shows the newly defined zone. The new torso block 
zone now ``floats'' with the torso belt adjusted height, which allows a 
reasonable and achievable zone that can be used with the large 
potential range of belt heights on school bus seats. This is 
particularly important when the center position is a flexible occupancy 
seat that potentially has a lower torso anchor point height.

[[Page 62774]]

[GRAPHIC] [TIFF OMITTED] TR21OC08.057

    xiii. IMMI, Takata and Concepts all asked that the agency allow 
dynamic certification of lap/shoulder belt equipped school bus seats as 
an alternative to the quasi-static test. These tests would use 
instrumented dummies and IARVs. They stated that sled or full-vehicle 
crash testing more accurately represents ``real world'' performance.
Agency Response
    These commenters are addressing an issue (dynamic testing) that is 
outside the scope of this rulemaking since a dynamic test component was 
expressly not proposed by NHTSA. Nonetheless, the agency wishes to take 
this opportunity to provide some views on the issue.
    In the preamble to the NPRM, the agency stated it was proposing the 
quasi-static test instead of a dynamic test because ``manufacturers are 
familiar with quasi-static testing * * * [M]anufacturers would be able 
to test a large number of seats and a variety of design configurations 
without incurring the delay and additional cost of sending each 
configuration to an outside testing facility.'' In terms of testing 
cost, we continue to believe it is less expensive to certify compliance 
by the quasi-static test than it would be to perform a dynamic 
equivalent. Now, with the advent of flex-seats that must be tested in 
several occupant configurations, this cost differential may be even 
larger. Because the quasi-static test is less costly than sled testing, 
the quasi-static test allows testing of more seating systems on a 
school bus and/or more school buses than 5 if a sled test were 
specified.
    In addition, a quasi-static test is currently specified in FMVSS 
No. 222 to test the performance characteristics of 
compartmentalization. The test has been successful in ensuring the 
integrity of the compartmentalized passenger compartment since the 
inception of FMVSS No. 222. A quasi-static test to assess the effect 
that lap/shoulder belts have on the compartmentalized seating systems 
thus is a rational aspect of this rulemaking, as it broadens the 
current successful framework used to assess school bus seating systems 
and extends it to assess the effect that equipment (lap/shoulder belts) 
added to the systems affect the seating systems. Developing a dynamic 
test for lap/shoulder belts in FMVSS No. 222 would

[[Page 62775]]

take further study and investment of agency resources that the agency 
believes is more appropriately directed to other priorities at this 
time.
    xiv. This final rule excludes the last row of seats from the 
portion of the quasi-static test where the rear loading bar load is 
applied to simulate the force imposed by compartmentalized occupants 
seated in a more rearward seat row. However, the torso body block 
loading will still be applied and the anchor point displacement limit 
must still be met. The reason for this exclusion is that there will be 
no occupants rearward of the last row of occupants. However, the 
standard will ensure that the lap/shoulder belts are capable of 
adequately restraining the occupants in the last row in a frontal 
impact.
    This exclusion is consistent with other exclusions of FMVSS No. 222 
applied to the last seat row that were adopted based on the 
appropriateness of the requirement as applied to the last row. In this 
rulemaking, we have excluded from the FMVSS No. 210 requirement, that 
last row seat belt anchorages be integrated in the seat structure. 
Similarly, the last row is currently excluded from the 
compartmentalization energy absorption requirement of FMVSS No. 223 at 
S5.1.3.

d. Lap Belt Buckle Belt Length

    In the NPRM, we noted that for a proper fit, the lap belt or lap 
belt portion of a lap/shoulder belt must fit low across the occupant's 
hips so that the crash loads are distributed across the pelvis and not 
the abdominal area. Loading of the abdomen rather than the pelvis 
increases the risk of internal injuries caused by the seat belt 
penetration into the soft tissue of the abdomen. We stated that we were 
aware that lap belts supplied to some states have long buckle stalks or 
long belt lengths between the ``seat bight'' (approximately the 
intersection of the seat cushion and seat back) and buckle that cause 
the lap belt to not fit low across the hips of the passengers. We asked 
for comment on whether such designs should be retained because of 
privacy issues, even if the long buckle stalks may result in 
misplacement of the lap belt across the child's abdomen and difficulty 
in child restraint attachment.
    Most commenters responding to this issue supported the short buckle 
stalks. CEW agreed that a longer buckle stalk can allow the seat belt 
to engage in the abdominal area, whereas a shorter buckle stalk forces 
the belt engagement lower in the pelvic area. However, they stated they 
respected the privacy considerations and that they let the end user 
decide whether to use longer buckle stalks. IMMI stated belt buckles 
should not be permitted to ride across the abdomen and recommended that 
NHTSA establish a maximum length limit for the distance between the 
buckle tip and the seat bight. SafeRide News stated that a much shorter 
buckle stalk should be used, similar to that found in most private 
passenger vehicles, with which children are familiar from buckling 
themselves up. On the other hand, NYAPT stated its belief that the 
longer stalks can make the seat belt system more conducive to emergency 
evacuations of children, particularly children with special needs.
Agency Response
    In this final rule, to optimize crash protection on school buses, 
we are limiting the location of the distance between the buckle end and 
associated latch plate to within 65 mm (2.6 inches) of the SgRP (FMVSS 
No. 222, S5.1.7). We agree with the commenters that privacy concerns 
are somewhat allayed by having the seat belt buckles located at the 
children's sides and not in the middle of the seating position. In 
response to NYAPT, we understand its concern but believe that the pros 
of the belt positioned in the pelvic area outweigh the concerns about 
emergency evacuation. Further, emergency evacuation could be 
facilitated by the similarity of the short buckle stalks with the 
family vehicle and the familiarity of the short buckle stalk to the 
children, as stated by SafeRide News. Driver and student training in 
emergency evacuation procedures should also help in timely egress from 
the vehicle.
    The measurement is taken by pulling the lap portion of the belt 
webbing on the latchplate side with a 20 N force applied in the 
vertical longitudinal plane. (The seat belt assembly is buckled during 
the test.) The load is applied through a range of angles and the end of 
the buckle/latchplate assembly must not go beyond a defined limit 
plane. The limit plane is 40 degrees from the horizontal, transverse 
with respect to the vehicle and is 65 mm from the SgRP. We have chosen 
the SgRP as the reference point for measurement since it is more 
objective than trying to use the seat bight. The 65 mm (2.6 inch) value 
is based on measurements from seats manufactured by IMMI and Takata. 
(See discussion in the 2008 Technical Assessment.) All the measured 
seats would meet the proposal. We also placed a 6YO test dummy in these 
seats to get an indication of the buckle location with respect to the 
dummy abdomen and found the location to be acceptable, i.e., the belt 
was placed nearer to the hip area and not high on the abdominal region.

XI. Lead Time

    The NPRM proposed a one year lead time for school bus manufacturers 
to meet the new requirements for a 24-in minimum seat back and seat 
cushion retention, since there is limited or no development necessary 
for these changes. We also proposed a one-year lead time for meeting 
requirements for voluntarily installed seat belts in large school buses 
and a three year lead time for meeting mandatory installation in small 
school buses. We stated our belief that three years are necessary for 
small school buses since some design, testing, and development will be 
necessary to certify compliance to the new requirements. We also 
proposed that optional early compliance be permitted.
    IC Corporation requested that NHTSA allow the same lead time for 
large buses as for small buses, three years, to allow for ``adequate 
time to properly engineer, tool and validate the designs.'' The 
commenter stated that the rulemaking establishes new design and 
performance standards for lap/shoulder belts on large school buses and 
that time is needed to design, develop and test the systems.
    In response, NHTSA agrees with the comment. There is good cause for 
the lead time because school bus manufacturers need time to design and 
manufacture school buses that meet the performance requirements adopted 
by this final rule. We have thus provided a one year lead time for 
compliance with the requirement to install higher seat backs and 
restraining barriers on all school buses and to meet the seat cushion 
retention test. A three year lead time is provided for meeting 
requirements for voluntarily installed seat belts (lap belts and lap/
shoulder belts) in large school buses and for mandatory lap/shoulder 
belts in small school buses. Optional early compliance is available for 
all of these amendments, as of the date of publication of this final 
rule.

XII. Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

    This rulemaking document was not reviewed by the Office of 
Management and Budget under E.O. 12866 and is not considered to be 
significant under E.O. 12866 or the Department's Regulatory Policies 
and Procedures (44 FR 11034; February 26, 1979). NHTSA has

[[Page 62776]]

prepared a final regulatory evaluation (FRE) for this final rule.\72\
---------------------------------------------------------------------------

    \72\ NHTSA's FRE discusses issues relating to the potential 
costs, benefits and other impacts of this regulatory action. The FRE 
is available in the docket for this final rule and may also be 
obtained by contacting http://www.regulations.gov or by contacting 
DOT's Docket Management Facility, M-30, U.S. Department of 
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, telephone 202-366-9324.
---------------------------------------------------------------------------

    This final rule requires: (a) For all school buses to increase seat 
back height from 508 mm (20 inches) to 610 mm (24 inches), and to 
require a self-latching mechanism for seat bottom cushions that are 
designed to flip up; \73\ and (b) for small school buses (GVWR of 4,536 
kg (10,000 pounds) or less, passenger seat lap/shoulder belts in lieu 
of the currently-required lap belts. School bus manufacturers will be 
required to certify that the belt systems meet specifications for 
retractors, strength, location and adjustability. Under the 
requirements, seat backs with lap/shoulder belts are subject to a 
quasi-static test to assure that the seat backs are strong enough to 
withstand the forces from a belted passenger and that of an unbelted 
passenger seated behind the belted occupant. This final rule also 
requires: Performance requirements for voluntarily-installed seat belts 
on large (over 4,536 kg (10,000 pounds)) school buses. For large school 
buses with voluntarily-installed lap/shoulder belts, the vehicle would 
be subject to the requirements described above for lap/shoulder belts 
on small school buses, except that applied test forces and performance 
limits would be adjusted so as to be representative of those imposed on 
large school buses. Large school buses with voluntarily-installed lap 
belts would be required to meet anchorage strength requirements. This 
final rule does not require seat belts to be installed on large school 
buses. The performance requirements for seat belts on large school 
buses affect large school buses only if purchasers choose to order seat 
belts on their vehicles.
---------------------------------------------------------------------------

    \73\ The agency estimates that a self-latching mechanism on 
flip-up seat bottoms will cost less than $3 per seat, or $66 per 
bus. This cost was not included in the estimates given below.
---------------------------------------------------------------------------

    The School Bus Fleet 2007 Fact Book on U.S. school bus sales for 
the sales years 2001-2005 reports that for each of these years on 
average, approximately 40,000 school buses were sold. NHTSA estimates 
that of the 40,000 school buses sold per year, 2,500 of them were 
10,000 pounds GVWR or under. The other 37,500 school buses were over 
10,000 pounds GVWR. Four states currently require high back seats 
(Illinois, New Jersey, New York, and Ohio). These states have 21.7 
percent of the sales. Thus, the high back seat incremental costs apply 
to 78.3 percent of these sales or 1,958 buses that are 10,000 pounds 
GVWR or under and 29,362 buses that are over 10,000 pounds GVWR.

Small School Buses

    NHTSA estimates that the costs of this rulemaking are the 
incremental cost of the higher (24 inch) seat back ($45 to $64 per 
small school bus for 78.3 percent of the fleet) plus the incremental 
cost for lap/shoulder belts over lap belts of $1,121 to $2,417. This 
amounts to a total incremental cost per school bus of $1,166 to $2,481 
per bus for those states without high back seats. If it is assumed that 
in a given year, 2,500 small school buses are sold, for all small 
school buses, the total incremental costs of this rulemaking are 
estimated to be from $2,889,000 ($45 x 1,958 + $1,121 x 2,500 small 
school buses) to $6,167,000 ($64 x 1,958 + $2,417 x 2,500 small school 
buses).
    The estimated benefits resulting from the higher seat backs and 
lap/shoulder belts on small school buses is, per year, 43 fewer 
injuries, and 0.8 fewer fatalities.

Large School Buses

    Costs of Higher Seat Backs on Large School Buses--In this final 
rule, all large school buses must have the higher seat backs of 24 
inches. NHTSA estimates the cost per large school bus of the higher 
seat back to be $125. NHTSA estimates that the total costs of the 
higher seat backs on large school buses to be $3,680,000 (29,362 large 
school buses times $125.40).
    Benefits of Higher Seat Backs on Large School Buses--The benefits 
from higher seat backs on large school buses is estimated to be 23 
fewer injuries per year, and 0.14 fewer fatalities per year.
    Costs and Benefits of Performance Requirements for Voluntarily-
Installed Belts on Large School Buses--As earlier noted, nothing in 
this rulemaking requires any party to install lap or lap/shoulder belts 
at passenger seating positions in large school buses. Instead, this 
rulemaking specifies performance requirements that voluntarily-
installed lap or lap/shoulder belts at passenger seating positions must 
meet. Lap or lap/shoulder belts that are now installed in large school 
buses are affected by this rulemaking, in that the voluntarily-
installed belt systems would be subject to the performance requirements 
set forth in this final rule whereas currently the systems are not 
subject to any Federal standard. The agency is unable to estimate the 
costs and benefits of this part because not enough is known about the 
requirements that state and local authorities now specify for the 
performance of seat belt systems on large school buses.

Overview of Costs and Benefits

Costs of High Back Seats and Lap/Shoulder Belts for Small School Buses, 
and of High Back Seats for Large School Buses

    Small School Buses: Adding together the high back seat incremental 
cost of $45 to $64 to the incremental cost for lap/shoulder belts over 
lap belts of $1,121 to $2,417, results in a total incremental cost of 
$1,166 to $2,481 per bus.
    Large School Buses: The incremental cost for high back seat is 
estimated to be $125 per bus.

                                Table 1--Total Costs (Per Bus and for the Fleet)
                                                     [$2006]
----------------------------------------------------------------------------------------------------------------
                                            Large buses 66           Small buses 14           Small buses 20
                                              passenger                passenger                passenger
----------------------------------------------------------------------------------------------------------------
Per Bus Costs........................  $125...................  $1,166.................  $2,481.
Annual Fleet Costs...................  $3.7 million...........  $2.9 million...........  $6.2 million.
Combined Annual Fleet Costs..........  $6.6 to $9.9 million...
----------------------------------------------------------------------------------------------------------------

[[Page 62777]]

Benefits of High Back Seats and Lap/Shoulder Belts for Small School 
Buses, and of High Back Seats for Large School Buses

    The benefits for small school buses and large school buses are 
estimated as shown below in Table 2:

                                                                 Table 2--Total Benefits
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Small school bus                Large school bus                      Total
                                                         -----------------------------------------------------------------------------------------------
                                                             Injuries       Fatalities       Injuries       Fatalities       Injuries       Fatalities
--------------------------------------------------------------------------------------------------------------------------------------------------------
High Back Seat..........................................        Combined below \1\                    23            0.14              23            0.14
Lap/Shoulder Belts......................................              43            0.08            n.a.            n.a.              43            0.08
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................              43            0.08              23            0.14              66            0.22
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ We did not have test data to allow us to separate out the high back seats from lap/shoulder belts for small school buses; thus, these data have been
  combined.

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of proposed rulemaking or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small governmental jurisdictions). 
The Small Business Administration's regulations at 13 CFR Part 121 
define a small business, in part, as a business entity ``which operates 
primarily within the United States.'' (13 CFR 121.105(a)). No 
regulatory flexibility analysis is required if the head of an agency 
certifies that the rule will not have a significant economic impact on 
a substantial number of small entities. The SBREFA amended the 
Regulatory Flexibility Act to require Federal agencies to provide a 
statement of the factual basis for certifying that a rule will not have 
a significant economic impact on a substantial number of small 
entities.
    NHTSA has considered the effects of this rulemaking action under 
the Regulatory Flexibility Act. According to 13 CFR section 121.201, 
the Small Business Administration's size standards regulations used to 
define small business concerns, school bus manufacturers would fall 
under North American Industry Classification System (NAICS) No. 336111, 
Automobile Manufacturing, which has a size standard of 1,000 employees 
or fewer. Using the size standard of 1,000 employees or fewer, NHTSA 
estimates that there are two small school bus manufacturers in the 
United States (U.S. Bus Corp. and Van-Con). NHTSA believes that both 
U.S. Bus Corp and Van-Con manufacture small school buses and large 
school buses.
    I hereby certify that this final rule will not have a significant 
economic impact on a substantial number of small entities. In this 
final rule, the small businesses manufacturing small buses will incur 
incremental costs ranging from a low of $1,166 to $2,481 per small 
school bus, out of a total cost of $40,000 to $50,000 per small school 
bus. The small businesses manufacturing large school buses will incur 
incremental costs of $125 per school bus (out of a total of more than 
$70,000) for the costs of the higher seat backs. The costs of lap/
shoulder belts on large school buses is not a factor, as nothing in 
this final rule requires lap/shoulder belts or lap belts at passenger 
seating positions in large school buses.
    The relatively minimal additional costs outlined above for large 
and small school buses will be passed on to school bus purchasers. 
Those purchasers are required to be sold school buses if they purchase 
a new bus, and to use school buses. Thus, small school bus 
manufacturers will not lose market share as a result of the changes in 
this final rule. While small organizations and governmental 
jurisdictions procuring school buses will be affected by this 
rulemaking in that the cost of school buses will increase, the agency 
believes the cost increases will be small compared to the cost of the 
vehicles and that the impacts on these entities will not be 
significant.

Executive Order 13132

    NHTSA has examined today's final rule pursuant to Executive Order 
13132 (64 FR 43255, August 10, 1999). On July 11, 2007, NHTSA held a 
public meeting bringing together a roundtable of state and local 
government policymakers, school bus manufacturers, pupil transportation 
associations and consumer groups to discuss the safety, policy and 
economic issues related to seat belts on school buses (see NHTSA Docket 
28103). No additional consultation with States, local governments or 
their representatives is contemplated beyond the rulemaking process. 
Further, the agency has concluded that the rulemaking will not have 
federalism implications because it will not have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.'' This final 
rule specifies performance requirements for seat belts voluntarily 
installed on large school buses, but does not require the belts on the 
large buses.
    Further, no consultation is needed to discuss the preemptive effect 
of today's rulemaking. NHTSA rules can have preemptive effect in at 
least two ways. First, the National Traffic and Motor Vehicle Safety 
Act contains an express preemptive provision: ``When a motor vehicle 
safety standard is in effect under this chapter, a State or a political 
subdivision of a State may prescribe or continue in effect a standard 
applicable to the same aspect of performance of a motor vehicle or 
motor vehicle equipment only if the standard is identical to the 
standard prescribed under this chapter.'' 49 U.S.C. 30103(b)(1). It is 
this statutory command that preempts State law, not today's rulemaking, 
so consultation would be inappropriate.
    Second, in addition to the express preemption noted above, the 
Supreme Court has also recognized that State requirements imposed on 
motor vehicle

[[Page 62778]]

manufacturers, including sanctions imposed by State tort law, can stand 
as an obstacle to the accomplishment and execution of a NHTSA safety 
standard. When such a conflict is discerned, the Supremacy Clause of 
the Constitution makes their State requirements unenforceable. See 
Geier v. American Honda Motor Co., 529 U.S. 861 (2000). NHTSA has not 
discerned any potential State requirements that might conflict with the 
final rule, however, in part because such conflicts can arise in varied 
contexts. We cannot completely rule out the possibility that such a 
conflict might become apparent in the future through subsequent 
experience with the standard. NHTSA may opine on such conflicts in the 
future, if warranted.

National Environmental Policy Act

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

Paperwork Reduction Act

    Under the procedures established by the Paperwork Reduction Act of 
1995, a person is not required to respond to a collection of 
information by a Federal agency unless the collection displays a valid 
OMB control number. Today's final rule does not establish any new 
information collection requirements.

National Technology Transfer and Advancement Act

    Under the National Technology Transfer and Advancement Act of 1995 
(NTTAA) (Pub. L. 104-113), ``all Federal agencies and departments shall 
use technical standards that are developed or adopted by voluntary 
consensus standards bodies, using such technical standards as a means 
to carry out policy objectives or activities determined by the agencies 
and departments.'' OMB Circular A-119 ``Federal Participation in the 
Development and Use of Voluntary Consensus Standards and in Conformity 
Assessment Activities'' (February 10, 1998) establishes policies to 
implement the NTAA throughout Federal executive agencies. In section 
4.a. of OMB Circular A-119, ``voluntary consensus standards'' are 
defined as standards developed or adopted by voluntary consensus 
standards bodies, both domestic and international. After carefully 
reviewing the available information, NHTSA has determined that there 
are no voluntary consensus standards relevant to this rulemaking.
    In its comments to the November 21, 2007 NPRM, the National 
Association of State Directors of Pupil Transportation Services 
(NASDPTS) suggested that ``NHTSA strongly consider the national 
consensus recommendations contained within the NSTSP [National School 
Transportation Specifications and Procedures] whenever they are 
relevant to the current NPRM.'' Our response to this comment is to 
explain that we had reviewed the NSTSP recommendations but did not find 
them applicable to this rulemaking. Those recommendations are developed 
by school bus purchasers and users; NHTSA's FMVSSs apply to school bus 
and equipment manufacture and these manufacturers are not directly 
involved in the development of the recommendations. Today's final rule 
do not apply to purchasers and users, but instead sets performance 
standards for school buses to which school bus manufacturers must 
certify compliance.

Executive Order 12988

    With respect to the review of the promulgation of a new regulation, 
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR 
4729, February 7, 1996) requires that Executive agencies make every 
reasonable effort to ensure that the regulation: (1) Clearly specifies 
the preemptive effect; (2) clearly specifies the effect on existing 
Federal law or regulation; (3) provides a clear legal standard for 
affected conduct, while promoting simplification and burden reduction; 
(4) clearly specifies the retroactive effect, if any; (5) adequately 
defines key terms; and (7) addresses other important issues affecting 
clarity and general draftsmanship under any guidelines issued by the 
Attorney General. This document is consistent with that requirement. 
The preemptive effect of this final rule has been discussed above. 
NHTSA notes further that there is no requirement that individuals 
submit a petition for reconsideration or pursue other administrative 
proceeding before they may file suit in court.

Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 requires agencies to 
prepare a written assessment of the costs, benefits and other effects 
of proposed or final rules that include a Federal mandate likely to 
result in the expenditure by State, local or tribal governments, in the 
aggregate, or by the private sector, of more than $100 million annually 
(adjusted for inflation with base year of 1995). This final rule will 
not result in expenditures by State, local or tribal governments, in 
the aggregate, or by the private sector in excess of $100 million 
annually.

Executive Order 13045

    Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any 
rule that: (1) Is determined to be ``economically significant'' as 
defined under E.O. 12866, and (2) concerns an environmental, health, or 
safety risk that NHTSA has reason to believe may have a 
disproportionate effect on children. This rulemaking is not subject to 
the Executive Order because it is not economically significant as 
defined in E.O. 12866.

Executive Order 13211

    Executive Order 13211 (66 FR 28355, May 18, 2001) applies to any 
rulemaking that: (1) Is determined to be economically significant as 
defined under E.O. 12866, and is likely to have a significantly adverse 
effect on the supply of, distribution of, or use of energy; or (2) that 
is designated by the Administrator of the Office of Information and 
Regulatory Affairs as a significant energy action. This rulemaking is 
not subject to E.O. 13211.

Regulation Identifier Number (RIN)

    The Department of Transportation assigns a regulation identifier 
number (RIN) to each regulatory action listed in the Unified Agenda of 
Federal Regulations. The Regulatory Information Service Center 
publishes the Unified Agenda in April and October of each year. You may 
use the RIN contained in the heading at the beginning of this document 
to find this action in the Unified Agenda.

Privacy Act

    Anyone is able to search the electronic form of all comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (Volume 65, Number 70; Pages 19477-78).

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles, and Tires.

0
In consideration of the foregoing, NHTSA amends 49 CFR Part 571 as set 
forth below.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for Part 571 continues to read as follows:

[[Page 62779]]

    Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166; 
delegation of authority at 49 CFR 1.50.

0
2. Section 571.207 is amended by revising the introductory text of 
S4.2, to read as follows:

Sec.  571.207  Standard No. 207, Seating systems.

* * * * *
    S4.2. General performance requirements. When tested in accordance 
with S5, each occupant seat shall withstand the following forces, in 
newtons, except for: a side-facing seat; a passenger seat on a bus 
other than a school bus; a passenger seat on a school bus with a GVWR 
greater than 4,536 kilograms (10,000 pounds); and, a passenger seat on 
a school bus with a GVWR less than or equal to 4,536 kg manufactured 
before October 21, 2011.
* * * * *

0
3. Section 571.208 is amended by revising S4.4.3.3, revising the 
heading of S4.4.5 and revising S4.4.5.1, revising the table in S7.1.4, 
and adding S7.1.5, to read as follows:

Sec.  571.208  Standard No. 208, Occupant crash protection.

* * * * *
    S4.4.3.3 School buses with a gross vehicle weight rating of 4,536 
kg (10,000 pounds) or less.
    (a) Each school bus with a gross vehicle weight rating of 4,536 kg 
(10,000 pounds) or less manufactured before October 21, 2011 must be 
equipped with an integral Type 2 seat belt assembly at the driver's 
designated seating position and at the right front passenger's 
designated seating position (if any), and with a Type 1 or Type 2 seat 
belt assembly at all other seating positions. Type 2 seat belt 
assemblies installed in compliance with this requirement must comply 
with Standard No. 209 (49 CFR 571.209) and with S7.1 and S7.2 of this 
standard. The lap belt portion of a Type 2 seat belt assembly installed 
at the driver's designated seating position and at the right front 
passenger's designated seating position (if any) must meet the 
requirements specified in S4.4.3.3(c).
    (b) Each school bus with a gross vehicle weight rating of 4,536 kg 
(10,000 pounds) or less manufactured on or after October 21, 2011 must 
be equipped with an integral Type 2 seat belt assembly at all seating 
positions. The seat belt assembly at the driver's designated seating 
position and at the right front passenger's designated seating position 
(if any) shall comply with Standard No. 209 (49 CFR 571.209) and with 
S7.1 and S7.2 of this standard. The lap belt portion of a Type 2 seat 
belt assembly installed at the driver's designated seating position and 
at the right front passenger's designated seating position (if any) 
shall meet the requirements specified in S4.4.3.3(c). Type 2 seat belt 
assemblies installed on the rear seats of school buses must meet the 
requirements of S7.1.1.5, S7.1.5 and S7.2 of this standard.
    (c) The lap belt portion of a Type 2 seat belt assembly installed 
at the driver's designated seating position and at the right front 
passenger's designated seating position (if any) shall include either 
an emergency locking retractor or an automatic locking retractor, which 
retractor shall not retract webbing to the next locking position until 
at least \3/4\ inch of webbing has moved into the retractor. In 
determining whether an automatic locking retractor complies with this 
requirement, the webbing is extended to 75 percent of its length and 
the retractor is locked after the initial adjustment. If a Type 2 seat 
belt assembly installed in compliance with this requirement 
incorporates any webbing tension-relieving device, the vehicle owner's 
manual shall include the information specified in S7.4.2(b) of this 
standard for the tension-relieving device, and the vehicle shall comply 
with S7.4.2(c) of this standard.
* * * * *
    S4.4.5 Buses with a GVWR of 10,000 lb (4,536 kg) or less, except 
school buses, manufactured on or after September 1, 2007.
    S4.4.5.1 Except as provided in S4.4.5.2, S4.4.5.3, S4.4.5.4, 
S4.4.5.5 and S4.4.5.6, each bus with a gross vehicle weight rating of 
10,000 lb (4,536 kg) or less, except school buses, shall be equipped 
with a Type 2 seat belt assembly at every designated seating position 
other than a side-facing position. Type 2 seat belt assemblies 
installed in compliance with this requirement shall conform to Standard 
No. 209 (49 CFR 571.209) and with S7.1 and S7.2 of this standard. If a 
Type 2 seat belt assembly installed in compliance with this requirement 
incorporates a webbing tension relieving device, the vehicle owner's 
manual shall include the information specified in S7.4.2(b) of this 
standard for the tension relieving device, and the vehicle shall 
conform to S7.4.2(c) of this standard. Side-facing designated seating 
positions shall be equipped, at the manufacturer's option, with a Type 
1 or Type 2 seat belt assembly.
* * * * *
    S7.1.4 * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                       50th-percentile  6-    50th-percentile  10-    5th-percentile adult  50th-percentile adult  95th-percentile adult
                                         year-old child          year-old child              female                  male                   male
--------------------------------------------------------------------------------------------------------------------------------------------------------
Weight.............................  47.3 pounds...........  82.1 pounds...........  102 pounds...........  164 pounds 3.
Erect sitting height...............  25.4 inches...........  28.9 inches...........  30.9 inches..........  35.7 inches .1.
Hip breadth (sitting)..............  8.4 inches............  10.1 inches...........  12.8 inches..........  14.7 inches .7.
Hip circumference (sitting)........  23.9 inches...........  27.4 inches (standing)  36.4 inches..........  42 inches............  47.2 inches.
Waist circumference (sitting)......  20.8 inches...........  25.7 inches (standing)  23.6 inches..........  32 inches .6.
Chest depth........................  ......................  6.0 inches............  7.5 inches...........  9.3 inches .2.
Chest circumference:
    (nipple).......................  ......................  ......................  30.5 inches..........
    (upper)........................  ......................  26.3 inches...........  29.8 inches..........  37.4 inches .6.
    (lower)........................  ......................  ......................  26.6 inches..........
--------------------------------------------------------------------------------------------------------------------------------------------------------

    S7.1.5 School bus bench seats. The seat belt assemblies on school 
bus bench seats will operate by means of any emergency-locking 
retractor that conforms to 49 CFR 571.209 to restrain persons whose 
dimensions range from those of a 50th percentile 6-year-old child to 
those of a 50th percentile 10-year-old, for small occupant seating 
positions, as defined in 49 CFR 571.222, and to those of a 50th 
percentile adult male for all other seating positions. The seat back 
may be in any position.
* * * * *

0
4. Section 571.210 is amended by revising S2; amending S3 by revising 
the heading and adding definitions for

[[Page 62780]]

``school bus torso belt adjusted height,'' ``school bus torso belt 
anchor point,'' and ``small occupant seating position,'' in 
alphabetical order; adding S4.1.3 and S4.1.3.1 through S4.1.3.5; by 
revising in the introductory paragraph of S4.3.2, the second sentence; 
revising S4.3.2(b) and by adding Figure 4 to the end of the section, to 
read as follows:

Sec.  571.210  Standard No. 210, Seat belt assembly anchorages.

* * * * *
    S2. Application. This standard applies to passenger cars, 
multipurpose passenger vehicles, trucks, buses, and school buses.
    S3. Definitions.
    School bus torso belt adjusted height means the vertical height 
above the SgRP of the point at which the torso belt deviates more than 
10 degrees from the horizontal plane when the torso belt is pulled away 
from the seat by a 20 N force at a location on the webbing 
approximately 100 mm from the adjustment device and the pulled portion 
of the webbing is held in a horizontal plane.
    School bus torso belt anchor point means the midpoint of the torso 
belt width where the torso belt first contacts the uppermost torso belt 
anchorage.
* * * * *
    Small occupant seating position is as defined in 49 CFR 571.222.
* * * * *
    S4.1.3 School bus passenger seats.
    S4.1.3.1 Except for seats with no other seats behind them, seat 
belt anchorages on school buses manufactured on or after October 21, 
2011 must be attached to the school bus seat structure and the seat 
belt shall be Type 1 or Type 2 as defined in S3 of FMVSS No. 209 (49 
CFR 571.209).
    S4.1.3.2 Type 2 seat belt anchorages on school buses manufactured 
on or after October 21, 2011 must meet the following location 
requirements.
    (a) As specified in Figure 4, the vertical distance from the 
seating reference point for the school bus torso belt anchor point must 
be fixed or adjustable to at least 400 mm for a small occupant seating 
position of a flexible occupancy seat, as defined in 49 CFR 571.222, 
and at least 520 mm above the SgRP for all other seating positions. The 
school bus torso belt adjusted height at each seating position shall, 
at a minimum, be adjustable from the torso belt anchor point to within 
at least 280 mm vertically above the SgRP to the minimum required 
vertical height of the school bus torso belt anchor point for that 
seating position.
    (b) The minimum lateral distance between the vertical centerline of 
the bolt holes or the centroid of any other means of attachment to the 
structure specified in 4.1.3.1, simultaneously achievable by all 
seating positions, must be:
    (i) 280 mm for seating positions in a flexible occupancy seat in a 
maximum occupancy configuration, as defined in 49 CFR 571.222; and
    (ii) 330 mm for all other seating positions.
    S4.1.3.3 School buses with a GVWR less than or equal to 4,536 kg 
(10,000 pounds) must meet the requirements of S4.2.2 of this standard.
    S4.1.3.4 School buses with a GVWR greater than 4,536 kg (10,000 
pounds) manufactured on or after October 21, 2011, with Type 1 seat 
belt anchorages, must meet the strength requirements specified in 
S4.2.1 of this standard.
    S4.1.3.5 School buses with a GVWR greater than 4,536 kg (10,000 
pounds) manufactured on or after October 21, 2011, with Type 2 seat 
belt anchorages, must meet the strength requirements specified in 
S4.2.2 of this standard.
* * * * *
    S4.3.2 Seat belt anchorages for the upper torso portion of Type 2 
seat belt assemblies. * * * Except a small occupant seating position as 
defined in 49 CFR 571.222, with the seat and seat back so positioned, 
as specified by subsection (a) or (b) of this section, the upper end of 
the upper torso restraint shall be located within the acceptable range 
shown in Figure 1, with reference to a two-dimensional drafting 
template described in Society of Automotive Engineers (SAE) Standard 
J826, revised May 1987, ``Devices for Use in Defining and Measuring 
Vehicle Seating Accommodation'' (incorporated by reference, see Sec.  
571.5). * * *
* * * * *
    (b) Except for seating positions on school bus bench seats, 
compliance with this section shall be determined with adjustable 
anchorages at the midpoint of the adjustment range of all adjustable 
positions. For seating positions on school bus bench seats, place 
adjustable anchorages and torso belt height adjusters in their 
uppermost position.
* * * * *
BILLING CODE 4910-59-P

[[Page 62781]]

[GRAPHIC] [TIFF OMITTED] TR21OC08.058

0
5. Section 571.222 is amended by:
0
a. Adding to S4, in alphabetical order, definitions of ``fixed 
occupancy seat'', ``flexible occupancy seat'', ``maximum occupancy 
configuration'', ``minimum occupancy configuration'', ``seat bench 
width'' and ``small occupant seating position'';
0
b. Revising S4.1; revising, in S5, paragraphs (a) and (b); revising 
S5.1.2; revising S5.1.5; adding S5.1.6, S5.1.6.1 through S5.1.6.5, and 
S5.1.6.5.1 through S5.1.6.5.7; adding S5.1.7 through S5.1.7.2; revising 
S5.2.2; adding S5.5; and adding Figures 8 and 9 following Figure 7 at 
the end of the section.
    The revisions and additions read as follows:

Sec.  571.222  Standard No. 222; School bus passenger seating and crash 
protection.

* * * * *
    S4. Definitions.
* * * * *
    Fixed occupancy seat means a bench seat equipped with Type 2 seat 
belts that has a permanent configuration regarding the number of 
seating positions on the seat. The number of seating positions on the 
bench seat cannot be increased or decreased.
    Flexible occupancy seat means a bench seat equipped with Type 2 
seat belts that can be reconfigured so that the number of seating 
positions on the seat can change. The seat has a minimum occupancy 
configuration and maximum occupancy configuration, and the number of 
passengers capable of being carried in the minimum occupancy 
configuration must differ from the number of passengers capable of 
being carried in the maximum occupancy configuration.
    Maximum occupancy configuration means, on a bench seat equipped 
with Type 2 seat belts, an arrangement whereby the lap belt portion of 
the Type 2 seat belts is such that the maximum number of occupants can 
be belted.
    Minimum occupancy configuration means, on a bench seat equipped 
with Type 2 seat belts, an arrangement whereby the lap belt portion of 
the Type 2 seat belts is such that the minimum number of occupants can 
be belted.
* * * * *

[[Page 62782]]

    Seat bench width means the maximum transverse width of the bench 
seat cushion.
    Small occupant seating position means the center seating position 
on a flexible occupancy seat in a maximum occupancy configuration, if 
the torso belt portion of the Type 2 seat belt is intended to restrain 
occupants whose dimensions range from those of a 50th percentile 6 
year-old child only to those of a 50th percentile 10 year-old child and 
the torso belt anchor point cannot achieve a minimum height of 520 mm 
above the seating reference point, as specified by S4.1.3.2(a) of 49 
CFR 571.210.
* * * * *
    S4.1 Determination of the number of seating positions and seat belt 
positions
    (a) The number of seating positions considered to be in a bench 
seat for vehicles manufactured before October 21, 2011 is expressed by 
the symbol W, and calculated as the seat bench width in millimeters 
divided by 381 and rounded to the nearest whole number.
    (b) The number of seating positions and the number of Type 1 seat 
belt positions considered to be in a bench seat for vehicles 
manufactured on or after October 21, 2011 is expressed by the symbol W, 
and calculated as the seat bench width in millimeters divided by 380 
and rounded to the nearest whole number.
    (c) Except as provided in S4.1(d), the number of Type 2 seat belt 
positions on a flexible occupancy seat in a minimum occupancy 
configuration or a fixed occupancy seat for vehicles manufactured on or 
after October 21, 2011 is expressed by the symbol Y, and calculated as 
the seat bench width in millimeters divided by 380 and rounded to the 
next lowest whole number. The minimum seat bench width for a seat 
equipped with a Type 2 seat belt is 380 mm. See Table 1 for an 
illustration.
    (d) A flexible occupancy seat meeting the requirements of S4.1(c) 
may also have a maximum occupancy configuration with Y +1 Type 2 seat 
belt positions, if the minimum seat bench width for this configuration 
is Y +1 times 330 mm. See Table 1 for an illustration.
    (e) A flexible occupancy seat equipped with Type 2 seat belts in a 
maximum occupancy configuration may have up to one single small 
occupant seating position.

                     Table 1--Number of Seating Positions as a Function of Seat Bench Width
----------------------------------------------------------------------------------------------------------------
                                                                    Seat bench width (mm)
           Seating configuration           ---------------------------------------------------------------------
                                               380-659       660-759       760-989      990-1139      1140-1319
----------------------------------------------------------------------------------------------------------------
Minimum or Fixed Occupancy................            1             1             2             2             3
Maximum Occupancy.........................            1             2             2             3             3
----------------------------------------------------------------------------------------------------------------

    S5. Requirements.
    (a) Large school buses.
    (1) Each school bus manufactured before October 21, 2011 with a 
gross vehicle weight rating of more than 4,536 kg (10,000 pounds) shall 
be capable of meeting any of the requirements set forth under this 
heading when tested under the conditions of S6. However, a particular 
school bus passenger seat (i.e., a test specimen) in that weight class 
need not meet further requirements after having met S5.1.2 and S5.1.5, 
or having been subjected to either S5.1.3, S5.1.4, or S5.3.
    (2) Each school bus manufactured on or after October 21, 2011 with 
a gross vehicle weight rating of more than 4,536 kg (10,000 pounds) 
shall be capable of meeting any of the requirements set forth under 
this heading when tested under the conditions of S6 of this standard or 
Sec.  571.210. However, a particular school bus passenger seat (i.e., a 
test specimen) in that weight class need not meet further requirements 
after having met S5.1.2 and S5.1.5, or having been subjected to either 
S5.1.3, S5.1.4, S5.1.6 (if applicable), or S5.3. If S5.1.6.5.5(b) is 
applicable, a particular test specimen need only meet S5.1.6.5.5(b)(1) 
or (2) as part of meeting S5.1.6 in its entirety. Each vehicle with 
voluntarily installed Type 1 seat belts and seat belt anchorages at W 
seating positions in a bench seat, voluntarily installed Type 2 seat 
belts and seat belt anchorages at Y seat belt positions in a fixed 
occupancy seat, or voluntarily installed Type 2 seat belts and seat 
belt anchorages at Y and Y + 1 seat belt positions in a flexible 
occupancy seat, shall also meet the requirements of:
    (i) S4.4.3.3 of Standard No. 208 (49 CFR 571.208);
    (ii) Standard No. 209 (49 CFR 571.209), as they apply to school 
buses; and,
    (iii) Standard No. 210 (49 CFR 571.210) as it applies to school 
buses with a gross vehicle weight rating greater than 10,000 pounds.
    (b) Small school buses. Each vehicle with a gross vehicle weight 
rating of 4,536 kg (10,000 pounds) or less shall be capable of meeting 
the following requirements at all seating positions:
    (1)(i) In the case of vehicles manufactured before September 1, 
1991, the requirements of Sec. Sec.  571.208, 571.209, and 571.210 as 
they apply to multipurpose passenger vehicles;
    (ii) In the case of vehicles manufactured on or after September 1, 
1991, the requirements of S4.4.3.3 of Sec.  571.208 and the 
requirements of Sec. Sec.  571.209 and 571.210 as they apply to school 
buses with a gross vehicle weight rating of 4,536 kg or less;
    (iii) In the case of vehicles manufactured on or after October 21, 
2011 the requirements of S4.4.3.3(b) of Sec.  571.208 and the 
requirements of Sec. Sec.  571.207, 571.209 and 571.210 as they apply 
to school buses with a gross vehicle weight rating of 4,536 kg or less; 
and,
    (2) The requirements of S5.1.2, S5.1.3, S5.1.4, S5.1.5, S5.1.6, 
S5.1.7, S5.3, S5.4 and S5.5 of this standard. However, the requirements 
of Sec. Sec.  571.208 and 571.210 shall be met at Y seat belt positions 
in a fixed occupancy seat, and at Y and Y + 1 seat belt positions for a 
flexible occupancy seat. A particular school bus passenger seat (i.e. a 
test specimen) in that weight class need not meet further requirements 
after having met S5.1.2 and S5.1.5, or after having been subjected to 
either S5.1.3, S5.1.4, S5.1.6, or S5.3 of this standard or Sec.  
571.207, Sec.  571.210 or Sec.  571.225.
* * * * *
    S5.1.2 Seat back height, position, and surface area.
    (a) For school buses manufactured before October 21, 2009, each 
school bus passenger seat must be equipped with a seat back that has a 
vertical height of at least 508 mm (20 inches) above the seating 
reference point. Each school bus passenger seat must be equipped with a 
seat back that, in the front projected view, has front surface area 
above the horizontal plane that passes through the seating reference 
point, and below the horizontal plane 508 mm (20 inches) above the 
seating reference point, of not less than 90

[[Page 62783]]

percent of the seat bench width in millimeters multiplied by 508.
    (b) For school buses manufactured on or after October 21, 2009, 
each school bus passenger seat must be equipped with a seat back that 
has a vertical height of at least 610 mm (24 inches) above the seating 
reference point. The minimum total width of the seat back at 610 mm (24 
inches) above the seating reference point shall be 75 percent of the 
maximum width of the seat bench. Each school bus passenger seat must be 
equipped with a seat back that, in the front projected view, has front 
surface area above the horizontal plane that passes through the seating 
reference point, and below the horizontal plane 610 mm (24 inches) 
above the seating reference point, of not less than 90 percent of the 
seat bench width in millimeters multiplied by 610.
* * * * *
    S5.1.5 Seat cushion retention.
    (a) Seat cushion latching. For school buses manufactured on or 
after October 21, 2009, school bus passenger seat cushions equipped 
with attachment devices that allow for the seat cushion to be removable 
without tools or to flip up must have a self-latching mechanism that is 
activated when a 22-kg (48.4-pound) mass is placed on the center of the 
seat cushion with the seat cushion in the down position.
    (b) Seat cushion retention. In the case of school bus passenger 
seats equipped with seat cushions, with all manual attachment devices 
between the seat and the seat cushion in the manufacturer's designated 
position for attachment, the seat cushion shall not separate from the 
seat at any attachment point when subjected to an upward force in 
newtons of 5 times the mass of the seat cushion in kilograms and 
multiplied by 9.8 m/s\2\, applied in any period of not less than 1 nor 
more than 5 seconds, and maintained for 5 seconds.
    S5.1.6 Quasi-static test of compartmentalization and Type 2 seat 
belt performance. This section applies to school buses manufactured on 
or after October 21, 2011 with a gross vehicle weight rating expressed 
in the first column of Tables 2 through 4, and that are equipped with 
Type 2 seat belt assemblies.
    (a) Except as provided in S5.1.6(b), when tested under the 
conditions of S5.1.6.5.1 through S5.1.6.5.6, the criteria specified in 
S5.1.6.1 and S5.1.6.2 must be met.
    (b) A school bus passenger seat that does not have another seat 
behind it is not loaded with the upper and lower loading bars as 
specified in S5.1.6.5.2, S5.1.6.5.3, and S5.1.6.5.7 and is excluded 
from the requirements of S5.1.6.1(b).
    S5.1.6.1 Displacement limits. In Tables 2 and 3, AH is the height 
in millimeters of the school bus torso belt anchor point specified by 
S4.1.3.2(a) of Standard No. 210 (49 CFR 571.210) and [Phi] is the angle 
of the posterior surface of the seat back defined in S5.1.6.3 of this 
standard.
    (a) Any school bus torso belt anchor point, as defined in S3 of 
Standard No. 210, must not displace horizontally forward from its 
initial position (when [Phi] was determined) more than the value in 
millimeters calculated from the following expression in the second 
column of Table 2:

           Table 2--Torso Belt Anchor Point Displacement Limit
------------------------------------------------------------------------
                                                Displacement limit in
        Gross vehicle weight rating                  millimeters
------------------------------------------------------------------------
More than 4,536 kg (10,000 pounds)........  (AH + 100) (tan[Phi] + 0.242/
                                             cos[Phi])
Less than or equal to 4,536 kg (10,000      (AH + 100) (tan[Phi] + 0.356/
 pounds).                                    cos[Phi])
------------------------------------------------------------------------

    (b) A point directly rearward of any school bus torso belt anchor 
point, as defined in S3 of Standard No. 210 (49 CFR 571.210) on the 
rear facing surface of the seat back, must not displace horizontally 
forward from its initial position (when [Phi] was determined) more than 
the value in millimeters calculated from the following expression in 
the second column of Table 3:

               Table 3--Seat Back Point Displacement Limit
------------------------------------------------------------------------
                                                Displacement limit in
        Gross vehicle weight rating                  millimeters
------------------------------------------------------------------------
More than 4,536 kg (10,000 pounds)........  (AH + 100) (tan[Phi] + 0.174/
                                             cos[Phi])
Less than or equal to 4,536 kg (10,000      (AH + 100) (tan[Phi] + 0.259/
 pounds).                                    cos[Phi])
------------------------------------------------------------------------

    S5.1.6.2 Slippage of device used to achieve torso belt adjusted 
height. If the torso belt adjusted height, as defined in S3 of Standard 
No. 210 (49 CFR 571.210), is achieved without the use of an adjustable 
torso belt anchorage, the adjustment device must not slip more than 25 
mm (1.0 inches) along the webbing or guide material upon which it moves 
for the purpose of adjusting the torso belt height.
    S5.1.6.3 Angle of the posterior surface of a seat back. If the seat 
back inclination is adjustable, the seat back is placed in the 
manufacturer's normal design riding position. If such a position is not 
specified, the seat back is positioned so it is in the most upright 
position. Position the loading bar specified in S6.5 of this standard 
so that it is laterally centered behind the seat back with the bar's 
longitudinal axis in a transverse plane of the vehicle in a horizontal 
plane within  6 mm (0.25 inches) of the horizontal plane 
passing through the seating reference point and move the bar forward 
against the seat back until a force of 44 N (10 pounds) has been 
applied. Position a second loading bar as described in S6.5 of this 
standard so that it is laterally centered behind the seat back with the 
bar's longitudinal axis in a transverse plane of the vehicle and in the 
horizontal plane 406  6 mm (16  0.25 inches) 
above the seating reference point, and move the bar forward against the 
seat back until a force of 44 N (10 pounds) has been applied. Determine 
the angle from vertical of a line in the longitudinal vehicle plane 
that passes through the geometric center of the cross-section of each 
cylinder, as shown in Figure 8. That angle is the angle of the 
posterior surface of the seat back.
    S5.1.6.4 The seat back must absorb 452W joules of energy when 
subjected to the force specified in S5.1.6.5.7.
    S5.1.6.5 Quasi-static test procedure.
    S5.1.6.5.1 Adjust the seat back as specified in S5.1.6.3. Place all 
torso anchor points in their highest position of adjustment. If the 
torso belt adjusted height, as defined in S3 of FMVSS No. 210, is 
achieved by a method other than an adjustable anchor point, initially 
place the torso belt adjusted height at its highest position. Then move 
the adjustment device 38 mm (1.5 inches) downward with respect to its 
webbing or guide material.
    S5.1.6.5.2 Position the lower loading bar specified in S6.5 of this 
standard so that it is laterally centered behind the seat back with the 
bar's longitudinal axis in a transverse plane of the vehicle and in any 
horizontal plane between 102 mm (4 inches) above and 102 mm (4 inches) 
below the seating reference point of the school bus passenger seat 
behind the test specimen. Position the upper loading bar described in 
S6.5 so that it is laterally centered behind the seat back with the 
bar's longitudinal axis in a transverse plane of the vehicle and in the 
horizontal plane 406 mm (16 inches) above the seating reference point 
of the school bus passenger seat behind the test specimen.
    S5.1.6.5.3 Apply a force of 3,114W N (700W pounds) horizontally in 
the forward direction through the lower loading bar specified at S6.5 
at the pivot attachment point. Reach the specified

[[Page 62784]]

load in not less than 5 and not more than 30 seconds. No sooner than 
1.0 second after attaining the required force, reduce that force to 
1,557W N (350W pounds) and maintain the pivot point position of the 
loading bar at the position where the 1,557W N (350W pounds) is 
attained until the completion of S5.1.6.5.7 of this standard.
    S5.1.6.5.4 Position the body block specified in Figure 3 of FMVSS 
No. 210 (49 CFR 571.210) under each torso belt (between the torso belt 
and the seat back) in the passenger seat and apply a preload force of 
600  50 N (135  11 pounds) on each body block 
in a forward direction parallel to the longitudinal centerline of the 
vehicle pursuant to the specifications of Standard No. 210 (49 CFR 
571.210). After preload application is complete, the origin of the 203 
mm body block radius at any point across the 102 mm body block 
thickness shall lie within the zone defined by S5.1.6.5.4(a) and 
S5.1.6.5.4(b) as shown in Figure 9:
    (a) At or rearward of a transverse vertical plane of the vehicle 
located 100 mm longitudinally forward of the seating reference point.
    (b) Within 75 mm of the horizontal plane located midway between the 
horizontal plane passing through the school bus torso belt adjusted 
height, specified in S3 of Standard No. 210 (49 CFR 571.210), and the 
horizontal plane 100 mm below the seating reference point.
    S5.1.6.5.5 Load application.
    (a) Fixed Occupancy Seat. For school buses with the gross vehicle 
weight rating listed in the first column of Table 4, if the expression 
in the second column is true, simultaneously apply the force listed in 
the third column to each body block.

       Table 4--Torso Body Block Forces for Fixed Occupancy Seats
------------------------------------------------------------------------
   Gross vehicle weight rating      True expression      Applied force
------------------------------------------------------------------------
More than 4,536 kg (10,000        ((seat bench width  3,300 N (742
 pounds).                          in mm)--(380Y))     pounds).
                                   <= 25 mm (1 inch).
More than 4,536 kg (10,000        ((seat bench width  5,000 N (1,124
 pounds).                          in mm)--(380Y)) >   pounds).
                                   25 mm (1 inch).
Less than or equal to 4,536 kg    ((seat bench width  5,000 N (1,124
 (10,000 pounds).                  in mm)--(380Y))     pounds).
                                   <= 25 mm (1 inch).
Less than or equal to 4,536 kg    ((seat bench width  7,500 N (1,686
 (10,000 pounds).                  in mm)--(380Y)) >   pounds).
                                   25 mm (1 inch).
------------------------------------------------------------------------

    (b) Flexible Occupancy Seat.
    (1) For school buses with the gross vehicle weight rating listed in 
the first column of Table 5 and a bench seat in the maximum occupancy 
configuration for a flexible occupancy seat of Y+1 seat belt positions 
as specified in S4.1(d), simultaneously apply the force listed in the 
second column of Table 5 to each body block.

   Table 5--Torso Body Block Forces in Maximum Occupancy Configuration
------------------------------------------------------------------------
        Gross vehicle weight rating                 Applied force
------------------------------------------------------------------------
More than 4,536 kg (10,000 pounds)........  3,300 N (742 pounds).
Less than or equal to 4,536 kg (10,000      5,000 N (1,124 pounds).
 pounds).
------------------------------------------------------------------------

    (2) For a flexible occupancy seat in the minimum occupant 
configuration, apply the forces to each body block as specified in 
S5.1.6.5.5(a).
    S5.1.6.5.6 Reach the specified load in not less than 5 and not more 
than 30 seconds. While maintaining the load, measure the school bus 
torso belt anchor point and seat back point horizontal displacement and 
then remove the body block.
    S5.1.6.5.7 Move the upper bar forward against the seat back until a 
force of 44 N has been applied. Apply an additional force horizontally 
in the forward direction through the upper bar until 452W joules of 
energy have been absorbed in deflecting the seat back. The maximum 
travel of the pivot attachment point for the upper loading bar shall 
not exceed 356 mm as measured from the position at which the initial 
application of 44 N of force is attained and the maximum load must stay 
below the upper boundary of the force/deflection zone in Figure 1. 
Apply the additional load in not less than 5 seconds and not more than 
30 seconds. Maintain the pivot attachment point at the maximum forward 
travel position for not less than 5 seconds, and not more than 10 
seconds and release the load in not less than 5 seconds and not more 
than 30 seconds. (For the determination of S5.1.6.5.7, the energy 
calculation describes only the force applied through the upper loading 
bar, and the forward and rearward travel distance of the upper loading 
bar pivot attachment point measured from the position at which the 
application in this section of 44 N of force is attained.)
    S5.1.7 Buckle side length limit. This section applies to rear 
passenger seats on school buses manufactured on or after October 21, 
2011 that are equipped with Type 1 or Type 2 seat belt assemblies. All 
portions of the buckle/latchplate assembly must remain rearward of the 
limit plane defined in S5.1.7.1 when tested under the conditions of 
S5.1.7.2.
    S5.1.7.1 Buckle/latchplate limit plane. Establish a transverse 
limit plane 65 mm from the SgRP that is perpendicular to a transverse 
plane that passes through the SgRP at an angle of 50 degrees to the 
horizontal.
    S5.1.7.2 Load application. Insert the seat belt latchplate into the 
seat belt buckle. Apply a 20 N load to the buckle/latchplate assembly 
whose vector is in a vertical longitudinal plane. Apply the load along 
the centerline of the webbing attached to the latchplate at least 100mm 
from the nearest point on the latchplate. The load may be applied at 
any angle in the range of 30 to 75 degrees from horizontal.
* * * * *
    S5.2.2 Barrier height, position, and rear surface area. The 
position and rear surface area of the restraining barrier shall be such 
that, in a front projected view of the bus, each point of the barrier's 
perimeter coincides with or lies outside of the perimeter of the 
minimum seat back area required by S5.1.2 for the seat immediately 
rearward of the restraining barrier.
* * * * *
    S5.5 Labeling.
    (a) A small occupant seating position must be permanently and 
legibly marked or labeled with the phrase: ``Do Not Sit In Middle Seat 
If Over Age 10''. The phrase must be comprised of no more than two 
lines of text. The label must be placed on the torso belt portion of 
the Type 2 seat belt. It must be plainly visible and easily readable 
when the seat belt is in a stored position. The

[[Page 62785]]

distance from the top edge of the top line of text to the bottom edge 
of the bottom line of text must be at least 35 mm. If the label is sewn 
on, it must be stitched around its entire perimeter.
    (b) [Reserved]
* * * * *
BILLING CODE 4910-59-P
[GRAPHIC] [TIFF OMITTED] TR21OC08.059

[[Page 62786]]

[GRAPHIC] [TIFF OMITTED] TR21OC08.060

    Issued on: October 14, 2008.
David Kelly,
Acting Administrator.
[FR Doc. E8-24755 Filed 10-15-08; 4:15 pm]

BILLING CODE 4910-59-C