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

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URL: https://www.frixlaw.com/law-library/documents/fr%3AE8-24755

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** October 21, 2008
- **Citation:** 73 FR 62744

## Text

DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2008-0163]
RIN 2127-AK09
Federal Motor Vehicle Safety Standards; Seating Systems, Occupant Crash Protection, Seat Belt Assembly Anchorages, School Bus Passenger Seating and Crash Protection

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

This final rule upgrades the school bus passenger crash protection requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 222. This final rule requires new school buses of 4,536 kilograms (10,000 pounds) or less gross vehicle weight rating (GVWR) (“small school buses”) to have lap/shoulder belts in lieu of the lap belts currently required. This final rule also sets performance standards for seat belts voluntarily installed on school buses with a GVWR greater than 4,536 kilograms (10,000 pounds) (“large school buses”). Each State or local jurisdiction may decide whether to install seat belts on these large school buses. Other changes to school bus safety requirements include raising the height of seat backs from 508 mm (20 inches) to 610 mm (24 inches) on all new school buses and requiring a self-latching mechanism on seat bottom cushions that are designed to flip up or be removable without tools.

DATES:

The effective date of this final rule is April 20, 2009. The requirement for lap/shoulder belts on small school buses applies to small school buses manufactured on or after October 21, 2011. Likewise, the requirement that voluntarily-installed seat belts in large school buses must meet the performance and other requirements specified by this final rule applies to large school buses manufactured on or after October 21, 2011. The requirement for the 24-inch seat backs and the self-latching seat bottom cushions apply to school buses manufactured on or after October 21, 2009.

Petitions for reconsideration:
Petitions for reconsideration of this final rule must be received not later than December 5, 2008.

ADDRESSES:

Petitions for reconsideration of this final rule must refer to the docket and notice number set forth above and be submitted to the Administrator, National Highway Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. Background

III. Studies

IV. Guiding Principles

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

b. Other Issues Concerning Belts on Large School Buses

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

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

1. Use of Existing Federal Grant Funds to Purchase Seat Belts

2. Additional Federal Grant Funds to Purchase Seat Belts

V. Overview of Upgrades to Occupant Crash Protection Standards

a. Summary of the NPRM Proposed Upgrades

b. Overview of Comments

c. How This Final Rule Differs From the NPRM

d. Post-NPRM Testing

e. Organization of Discussion

VI. Upgrades for All School Buses

a. Seat Back Height

b. Seat Cushion Latches

VII. Upgrades for Small School Buses

a. Requiring Lap/Shoulder Belts

b. Raising the Weight Limit for Small School Buses

c. FMVSS No. 207, Seating Systems

VIII. Upgrades for Large School Buses

Requiring Voluntarily Installed Belts to Meet Performance Requirements

IX. Performance and Other Requirements for Vehicle Belt Systems

a. Minimum Seat Width Requirements and Calculating W and Y

1. Flex-Seats

2. Using W and Rounding Up

3. Definitions

b. FMVSS No. 210, Seat Belt Anchorages

1. Height of the Torso Belt Anchorage

2. Anchorage Adjustability

3. Clarifications of Torso Anchorage Location

4. Integration of the Seat Belt Anchorages Into the Seat Structure

5. Minimum Lateral Anchorage Separation

6. Anchorage Strength

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

1. Background

2. Comments and Agency Responses

d. Belt Length

X. Lead Time

XI. Rulemaking Analyses and Notices

I. Introduction

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

This final rule's most significant changes to FMVSS No. 222 involve:

• Requiring small school buses to have a Type 2 seat belt assembly (a combination of pelvic and upper torso restraints (see FMVSS No. 209, S3), referred to in this document as a “lap/shoulder belt”) at each passenger seating position (these buses are currently required to have lap belts);

• Increasing the minimum seat back height requirement from 508 millimeters (mm) (20 inches) from the seating reference point (SgRP) to 610 mm (24 inches) for all school buses;

• Incorporating test procedures into the standard to test lap/shoulder belts in small school buses and voluntarily-installed lap and lap/shoulder belts in large school buses to ensure both the strength of the anchorages and the compatibility of the seat with compartmentalization; and

• Requiring all school buses with seat bottom cushions that are designed to flip up or be removable, typically for easy cleaning, to have a self-latching mechanism.

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

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

This rulemaking engaged the agency and public in a new dialogue on the merits of seat belts on large school buses. It also provided a forum for a fresh look at divergent positions on the belt issue and an opportunity to explore the implications of the school bus research results, the innovation of new technologies, and the realities of current pupil transportation needs. About 127 individuals and organizations commented on the NPRM, with many taking the position that lap/shoulder belts should be required on large school buses and with many opposed to that idea. Some individuals further sought to have the agency prohibit the installation of lap belts on large school buses. Many commenters focused on the emerging seat belt technology that would enable school bus manufacturers to install lap/shoulder belts on large school buses without reducing passenger capacity, and asked NHTSA to ensure that the performance requirements under consideration would not prohibit that technology. Others did not believe any type of belt system should be encouraged for large school buses.

After consideration of the comments, we make final most of the technical changes to the FMVSSs proposed in the NPRM, but have adjusted test procedures and some performance requirements to accommodate the emerging seating design technologies. We have also listened to each of the comments in support of and in opposition to the various issues involved in this rulemaking and have adjusted some of our views, while affirming others.

However, this final rule cannot and does not definitively conclude the debate as to whether a State or local jurisdiction should require seat belts on its large school buses. Under the National Traffic and Motor Vehicle Safety Act (“Safety Act”) (49 U.S.C. 30101
et seq.
) the agency is to prescribe motor vehicle safety standards that are practicable, meet the need for motor vehicle safety, and that are stated in objective terms. Under the Safety Act, “motor vehicle safety” means the performance of a motor vehicle or motor vehicle equipment in a way that protects the public against unreasonable risk of accidents occurring because of the design, construction, or performance of a motor vehicle, and against unreasonable risk of death or injury in an accident * * *.” 49 U.S.C. 30102(a)(8). After considering all available information, including the comments to the NPRM, we cannot conclude that a requirement for seat belts on large school buses will protect against an unreasonable risk of accidents or an unreasonable risk of death or injury in an accident. That is, based on available information, a science-based, data-driven determination that there should be a Federal requirement for the belts cannot be supported at this time. Whether the same conclusion can be made by a State or local jurisdiction is a matter for local decision-makers and we encourage them to make the decisions most appropriate for their individual needs to most safely transport their students to and from school.

This final rule provides the most up-to-date information known to the agency on seat belts on large school buses. It discusses principles that the agency has weighed about belts on large buses and attempts to clear up some misunderstanding expressed in some of the comments about the benefits of belts in school bus side impacts and rollover crashes. It affirms that States should have the choice of ordering seat belts on their large school buses since the belts could enhance the already very safe passenger protection afforded by large school buses, and makes sure that these voluntarily-installed belts will not degrade compartmentalization.

II. Background

The Motor Vehicle and Schoolbus Safety Amendments of 1974 directed NHTSA to issue motor vehicle safety standards applicable to school buses and school bus equipment. In response to this legislation, NHTSA revised several of its safety standards to improve existing requirements for school buses, extended ones for other vehicle classes to those buses, and issued new safety standards exclusively for school buses. FMVSS No. 222, one of a set of new standards for school buses, improves protection to school bus passengers during crashes and sudden driving maneuvers.

Effective since 1977, FMVSS No. 222 contains occupant protection requirements for school bus seating positions and restraining barriers. Its requirements for school buses with GVWR's of 4,536 kg (10,000 pounds) or less (small school buses) differ from those for school buses with GVWR's greater than 4,536 kg (10,000 pounds) (large school buses), because the “crash pulse” or deceleration experienced by the small school buses is typically more severe than that of the large buses in similar collisions. For the small school buses, the standard includes requirements that all seating positions must be equipped with lap (Type 1) or lap/shoulder (Type 2) seat belt assemblies and anchorages for passengers.
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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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Lap/shoulder belts and appropriate anchorages for the driver and front passenger (if provided) seating position, lap belts or lap/shoulder and appropriate anchorages for all other passenger seating positions.

Compartmentalization ensures that passengers are cushioned and contained by the seats in the event of a school bus crash by requiring school bus seats to be positioned in a manner that provides a compact, protected area surrounding each seat. If a seat is not compartmentalized by a seat back in front of it, compartmentalization must be provided by a padded and protective restraining barrier. The seats and restraining barriers must be strong enough to maintain their integrity in a crash, yet flexible enough to be capable

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.
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The issue has been closely analyzed by other parties as well, such as the National Transportation Safety Board, and the National Academy of Sciences. Various reports have been issued, the most significant of which are described below.

4
Through the years, NHTSA has been petitioned about seat belts on large school buses. (See, e.g., denials of petitions to require seat belt anchorages, 41 FR 28506 (July 12, 1976), 48 FR 47032 (October 17, 1983); response to petition for rulemaking to prohibit the installation of lap belts on large school buses, 71 FR 40057 (July 14, 2006).)

III. Studies

• National Transportation Safety Board, 1987

In 1987, the National Transportation Safety Board (NTSB) reported on a study of forty-three post-standard school bus crashes investigated by the Safety Board. NTSB concluded that most fatalities and injuries in school bus crashes occurred because the occupant seating positions were directly in line with the crash forces, and that seat belts would not have prevented those injuries and fatalities. (NTSB/SS-87/01, Safety Study, Crashworthiness of Large Post-standard School Buses, March 1987, National Transportation Safety Board.)

• National Academy of Sciences, 1989

A 1989 National Academy of Sciences (NAS) study concluded that the overall potential benefits of requiring seat belts on large school buses were insufficient to justify a Federal mandate for installation. The NAS also stated that funds used to purchase and maintain seat belts might be better spent on other school bus safety programs with the potential to save more lives and reduce more injuries. (Special Report 222, Improving School Bus Safety, National Academy of Sciences, Transportation Research Board, Washington, DC, 1989)

• National Transportation Safety Board, 1999

In 1999, the NTSB reported on six school bus crashes it investigated in which passenger fatalities or serious injuries occurred away from the area of vehicle impact. The NTSB found compartmentalization to be an effective means of protecting passengers in school bus crashes. However, because many of those passengers injured in the six crashes were believed to have been thrown from their compartments, NTSB believed other means of occupant protection should be examined. (NTSB/SIR-99/04, Highway Safety Report, Bus Crashworthiness Issues, September 1999, National Transportation Safety Board)

• National Academy of Sciences, 2002

In 2002, the NAS published a study that analyzed the safety of various transportation modes used by school children to get to and from school and school-related activities. The report concluded that each year there are approximately 815 school transportation fatal injuries per year. Two percent were school bus-related, compared to 22 percent due to walking/bicycling, and 75 percent from passenger car crashes, especially those with teen drivers. The report stated that changes in any one characteristic of school travel can lead to dramatic changes in the overall risk to the student population. Thus, the NAS concluded, it is important for school transportation decisions to take into account all potential aspects of changes to requirements to school transportation. (Special Report 269, “The Relative Risks of School Travel: A National Perspective and Guidance for Local Community Risk Assessment,” Transportation Research Board of the National Academies, 2002)

• National Highway Traffic Safety Administration, 2002

In 2002, NHTSA studied school bus safety (2002 School Bus Safety Study). Based on this research, the agency issued a Congressional Report that detailed occupant safety on school buses and analyzed options for improving occupant safety. (“Report to Congress, School Bus Safety: Crashworthiness Research, April 2002,”
http://www-nrd.nhtsa.dot.gov/departments/nrd-11/SchoolBus/SBReportFINAL.pdf
) (hereinafter “2002 Report to Congress”). The agency provided additional analysis of these data in a Technical Analysis supporting the NPRM (“2007 Technical Analysis”).
5

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

TEA-21 directed NHTSA to study and assess school bus occupant safety and analyze options for improvement. In response, the agency developed a research program to determine the real-world effectiveness of FMVSS No. 222 requirements for school bus passenger crash protection, evaluate alternative passenger crash protection systems in controlled laboratory tests, and provide findings to support rulemaking activities to upgrade the passenger crash protection for school bus passengers.

The research program consisted of NHTSA first conducting a full-scale school bus crash test to determine a representative crash pulse. The crash

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),
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as specified in FMVSS No. 208 “Occupant crash protection.”

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The injury assessment reference values (IARVs) for these measurements are the thresholds used to assess new motor vehicles with regard to frontal occupant protection as specified in FMVSS No. 208. HIC15 is a measure of the risk of head injury, Chest G is a measure of chest injury risk, and Nij is a measure of neck injury risk. For HIC15, a score of 700 is equivalent to a 30 percent risk of a serious head injury (skull fracture and concussion onset). In a similar fashion, Chest G of 60 equates to a 60 percent risk of a serious chest injury and Nij of 1 equates to a 22 percent risk of a serious neck injury. For all these measurements, higher scores indicate a higher likelihood of risk. For example, a Nij of 2 equates to a 67 percent risk of serious neck injury while a Nij of 4 equates to a 99 percent risk. More information regarding these injury measures can be found at NHTSA's Web site (
http://www-nrd.nhtsa.dot.gov/pdf/nrd-11/airbags/rev_criteria.pdf
).

NHTSA then ran frontal crash test simulations at the agency's Vehicle Research and Test Center (VRTC), using a test sled to evaluate passenger protection systems. Twenty-five sled tests using 96 test dummies of various sizes utilizing different restraint strategies were conducted that replicated the acceleration time history of the school bus full-scale frontal impact test. The goal of the laboratory tests was to analyze the dummy injury measures to gain a better understanding of the effectiveness of the occupant crash protection countermeasures. In addition to injury measures, dummy kinematics and interaction with restraints (i.e., seat backs and seat belts, as well as each other) were also analyzed to provide a fuller understanding of the important factors contributing to the type, mechanism, and potential severity of any resulting injury.

NHTSA studied three different restraint strategies: (a) Compartmentalization; (b) lap belt (with compartmentalization); and (c) lap/shoulder belt (with compartmentalization).

Within the context of these restraint strategies, various boundary conditions were evaluated: (a) Seat spacing—483 mm (19 inches), 559 mm (22 inches) and 610 mm (24 inches); (b) seat back height—nominally 508 mm (20 inches) and 610 mm (24 inches); and (c) fore/aft seat occupant loading.
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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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Unbelted occupants in the aft seat will affect the kinematics of belted occupants in the fore seat due to seat back deformation. Similarly, belted occupant loading of the fore seat back through the torso belt will affect the compartmentalization for unbelted occupants in the aft seat.

The agency found the following with regard to compartmentalization:

• Head injury measures were low for all dummy sizes, except when override
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occurred.

8
Override means an occupant's head or torso translates forward beyond the forward seat back providing compartmentalization.

• High head injury values (greater than the IARV) or dummy-to-dummy contacts beyond the biofidelic range of the test dummy were produced when the large male dummy overrode the seat in front of it, while the high-back seats lessened the override.

• Low chest injury measures were observed for all dummy sizes.

• Two 50th percentile male dummies in a seat were not well compartmentalized, as evidenced by head and neck injury measures being greater than the IARVs, due to large forward seat back deformation.

• Based on dummy motion and interaction with each other, compartmentalization was sensitive to seat back height for the 50th percentile male dummy.

• Compartmentalization of 6YO and 5th percentile female dummies did not appear to be sensitive to rear loading conditions.

• Compartmentalization of the 50th percentile male dummy did not appear to be sensitive to seat spacing for the 50th percentile male dummy.

• The average neck injury values for the 6YO and 5th percentile female dummy tests were above the IARV.

The agency found the following with regard to lap belts:

• Head and chest injury values were low for all dummy sizes.

• The average neck injury value was greater than the IARV for all test dummies, and was 70 percent above for the 5th percentile female dummy.

• Neck injury values increased for the 5th percentile female dummy when the seat spacing was increased from 483 mm (19 inches) to 559 mm (22 inches).

The agency found the following with regard to properly worn lap/shoulder belts:

• Head, chest and neck injury values were low for all size dummies and below those seen in the compartmentalization and lap belt results.

• Average head injury values were, at most, about half those seen in the compartmentalization and lap belt results.

• Neck injury values increased with application of rear loading for the 6YO and 5th percentile female dummies.

• Lap/shoulder belt systems would require approximately 380 mm (15 inches) of seat width per passenger seating position. The standard school bus bench seat is 990 mm (39 inches) wide, and is considered a three-passenger seat. If the width of the seat bench were increased to 1,143 mm (45 inches) for both seats on the left and right side of the school bus, the aisle width would be reduced to an unacceptable level.

NHTSA found that, for improperly worn lap/shoulder belts:

• Placing the shoulder belt behind the dummy's back resulted in dummy motion and average dummy injury values similar to lap belt restraint.

• Placing the shoulder belt under the dummy's arm provided more restraint on dummy torso motions than when the belt is placed behind the back. Average dummy injury values for the 6YO were about the same as seen with lap/shoulder belts and 5th percentile female dummy injury values were between those seen in lap/shoulder belts and lap belts.

It is important to note that these sled tests simulated only a severe, 30 mph (48.3 km/h) frontal crash condition. Therefore, the agency was not able to conclude that the higher neck injury measures associated with the lap belt in these tests would translate to an overall greater safety risk. Lap belts could retain the occupants in side impact, rollover, or lower speed frontal crashes, which occur with a greater frequency.

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,
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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.
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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.

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.
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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.
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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)
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stated that States and local districts should be given the option of whether to require seat belts on their school buses because States and local districts are in the best position to determine the most effective use of their limited resources, and because NSTA believed that entities that affirmatively choose to equip their buses with lap/shoulder belts are more likely to provide the necessary support to ensure that the belts are worn. However, several State groups were concerned that the NPRM's reference to the availability of 402 funds for the purchase and installation of seat belts on school buses could result in the states funding less-essential highway safety activities to the detriment of potentially more effective and worthwhile highway safety programs, such as buckle-up programs and those combating drunk or aggressive driving. There was widespread support of NHTSA's view that bus occupancy must

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

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

However, several commenters (e.g., the National Association for Pupil Transportation (NAPT) and the New York Association for Pupil Transportation (NYAPT))
17

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

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

Similarly, the NTSB expressed concern that lap/shoulder belts have not been sufficiently researched in non-frontal crash modes, e.g., side, oblique and rollover crashes.

In contrast, notwithstanding the discussion in the NPRM that the agency was not proposing a requirement for belts in large school buses, many commenters urged the agency to go beyond what was proposed in the NPRM and require lap/shoulder belts on large school buses.
18

The National Coalition for School Bus Safety (NCSBS) stated that if lap/shoulder belts coupled with compartmentalization affords “optimum protection” as stated in the NPRM, lap/shoulder belts should be required on large school buses to provide occupants side and rollover crash protection. The commenter indicated that even though “there has been no documentation of mortality or morbidity due to the 20 inch seat back height or failure of cushion retention,” NHTSA proposed to increase seat back height and require self-latching cushions. The commenter believed that “[t]his stands in sharp contrast with scores of documented fatalities and severe injuries proven to result” in side and rollover crashes due to the absence of seat belts on large school buses.
19

18
As noted earlier, many other commenters opposed the idea of a requirement for belts on large school buses.

19
No data was provided by the commenter explaining or supporting its reference to those fatalities and injuries; we know of no such data and cannot substantiate this statement.

Similarly, the West Brook Bus Crash Families (WBBCF)
20

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

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

Some commenters (e.g., the NCSBS and WBBCF) believed that lap/shoulder belts on large school buses should also be required to reinforce the message to children that they should “buckle-up” while riding in passenger cars and other private vehicles. NCSBS also stated that lap/shoulder belts would reduce driver distraction by improving student behavior, which in turn will help reduce driver distraction and the frequency of school bus crashes due to driver distraction.

Adding another facet to the comments were responses from school bus drivers and other school bus personnel. School bus drivers were universally opposed to having belts on the buses, believing that the belts were unnecessary, that they would impede emergency egress, and that drivers have limited means to get students to buckle up. George Davis of the Fayette County Schools bus shop expressed concern about the agency's calling lap/shoulder belts coupled with compartmentalization “optimum crash protection.” He was concerned that there was an implication that those who might choose to spend their resources on safety-related items other than belts would be going against the “best practices” discussed in the NPRM. He stated that it should be up to each purchaser to determine whether to purchase seat belts on large school buses, and that if a purchaser decides not to purchase the belts, then they are also determining what is the “best practice” for their needs.

Agency Response

After reviewing all the data, including the comments on the NPRM, NHTSA again concludes that large school buses

that meet our school bus safety standards without seat belts do not pose an unreasonable risk of death or injury in an accident. Thus, we do not find a safety need for a Federal mandate for seat belts on large school buses. However, our statutory authority expressly permits State or local jurisdictions to prescribe safety standards that impose higher performance requirements than the Federal safety standards for vehicles that are for the State's own use, such as school buses. Accordingly, we affirm that States and local jurisdictions should continue to be offered the choice of whether to order seat belts on their large school buses since the belts could provide enhancements to compartmentalization. We agree with NSTA that entities that affirmatively choose to equip their buses with lap/shoulder belts are more likely to provide the necessary support to ensure that the belts are worn properly. They are also more likely to be willing and able to instruct their students and drivers on emergency egress procedures affected by the belts. States and local districts need to examine the safest means of transport for their children, and this approach lets them decide how to spend their funds. Further, the performance requirements of this final rule for voluntarily-installed belts will help ensure that the belts enhance and do not degrade compartmentalization.

However, we are not able to concur with those commenters suggesting that lap/shoulder belts should be required on large school buses. The agency had to balance several compelling principles in this rulemaking. First, the agency considered the safety risks to which children on large school buses are exposed (how are children being injured or killed in school bus-related crashes) and whether seat belts would reduce that risk. Data indicate that children who are killed in school bus-related crashes are typically killed outside of the school bus as they are being loaded or unloaded onto the vehicle, by motorists passing the bus or by the school bus itself.
21

Inside the bus, the children are typically killed when they are in the direct zone of intrusion of the impacting vehicle or object. In the loading zone event, seat belts will not have an effect on preventing the fatality. In the intrusion zone, seat belts will similarly be unlikely to be effective in preventing the fatality, even in side impacts. In a rollover situation where there is ejection, the belts would have a beneficial effect, but the incidence of fatal ejections in rollover accidents occurring from a large school bus is rare.

21
“Traffic Safety Facts 2006: School Transportation-Related Crashes,” DOT HS 810 813.

WBBCF believed that “NHTSA should clearly state the proven increases in occupant protection resulting from lap/shoulder belt use: 45-60 percent in frontal collisions, 70 percent in rollover and lateral collisions for which compartmentalization alone is ‘incomplete’ and ineffective.” The effectiveness statistics to which WBBCF refers
22

are those that have been determined based on the crash experience of passenger cars and other light duty vehicles, although the effectiveness in passenger vehicles is much less than 70 percent in side impacts. These vehicles' crash experiences are different from that of large school buses. As noted earlier in this preamble, fatalities in frontal crashes of high severity are infrequent. In school bus side crashes, fatalities usually occur only in the area of intrusion from a heavy truck. Seat belts provide no benefit for an occupant sitting in an intrusion zone when struck by a large intruding object, but can provide benefits for those away from the intrusion zone. Although belts are effective in reducing the risk of fatality in rollovers due to ejection, there are very few fatal ejections in large school bus rollover crashes.

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

Nonetheless, seat belts may have some effect on reducing the risk of harm in frontal, side and rollover crashes, as they can help restrain occupants within the seat and not move about in the vehicle interior toward injurious surfaces.
23

For this final rule we have estimated the benefits that would accrue from the addition and correct use of lap/shoulder belts on large and small school buses in these crashes. For frontal crashes, we have estimated the benefits of the belts by using the sled test data obtained from the 2002 School Bus Safety Study, comparing dummy injury values with lap/shoulder belts versus injury values with compartmentalization. This analysis is explained in detail in the FRE accompanying this final rule. With regard to the estimated effectiveness of seat belts in large school bus side and rollover crashes, we have used the effectiveness statistics of 74 percent for rollover crashes and 21 percent for side impacts attributed to seat belts in passenger cars because no other information about the possible effect of belts in buses is available. With those data, we have estimated the benefits associated with the addition and correct use of lap/shoulder belts on large and small school buses.

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

The 2002 NAS study indicated that approximately 800 school aged-children are killed annually in motor vehicle crashes during normal school travel hours, among which only 0.5 percent were passengers on school buses and 1.5 percent were pedestrians involved in school bus related crashes. Seventy-five percent of the annual fatalities were to occupants in passenger vehicles and 24 percent were to those walking or riding a bicycle. Based on this study, the agency concluded that by far the safest means for students to get to school is by a school bus, and all efforts should be made to get as many students as possible onto school buses.

When making regulatory decisions on possible enhancements, the agency must bear in mind how improvements in one area might have an adverse effect on programs in other areas. The net effect on safety could be negative if the costs of purchasing and maintaining the seat belts and ensuring their correct use results in non-implementation or reduced efficacy of other pupil transportation programs that affect child safety. For example, some schools are currently eliminating school bus service for extracurricular activities or shrinking areas of school bus service due to high fuel prices.
24

Given that very few school bus-related serious injuries and fatalities would be prevented by a requirement mandating seat belts on large school buses, we could not assure that overall safety would not be adversely affected, particularly given the many competing demands on school resources and the widely varying and unique circumstances associated with transporting children in each of these districts. Nonetheless, this final rule does not prevent the installation of seat belts on school buses and provides appropriate performance requirements for these systems when they are installed.

24

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

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

$183 and $252 million.
25

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

25
The range in costs includes both 55 passenger buses (with loss of seating capacity) and 66 passenger buses with flexible seating (with no loss of seating capacity). However, they do not include the costs of a program to ensure correct belt usage.

26
If, for example, only 50 percent of passengers were to wear seat belts, the benefits estimated above would be halved and the cost per equivalent life saved would rise to between $46 and $72 million.

In the NPRM, the agency emphasized its concern that installing lap/shoulder seat belts on large school buses would reduce the passenger capacity of the buses. After NHTSA completed its NPRM but before it published the NPRM in the
Federal Register
, seating system manufacturers Takata Corp. (Takata)/M2KLLC(M2K)
27

and the Safeguard Division of Indiana Mills Manufacturing Inc. (IMMI) separately approached the agency to introduce their “flexible seating systems” (or “flex-seats.”) (As noted earlier in this preamble, these seating systems have lap/shoulder belts and are reconfigurable to accommodate either three smaller students or two larger students.) Many of the commenters referred to these systems with approval and asked NHTSA to ensure that the FMVSS No. 222 requirements under consideration would not prohibit flex-seat technology.

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

We have accommodated flexible seating systems (hereafter referred to as flexible occupancy seats or flex-seats), as requested, to facilitate the use of these new belt systems. However, although flex-seats may provide a way of offering lap/shoulder belts without lessening capacity on an individual given bus, there will still be a cost premium for outfitting school buses with the lap/shoulder belts, maintaining the seats, and training students and drivers on their use. The emergence of flex-seats on the market does not change our position concerning a Federal need to require lap/shoulder belts on large school buses.

On the capacity issue, WBBCF stated that it perceived the agency as speculating on its concerns about reduced seating capacity due to installation of lap/shoulder belts. The commenter stated that reductions in “manufacturer capacity” of bus seating “are confined to a few elementary school routes and often resolved though [sic] better route scheduling.” The commenter believed that “[t]here is a complete absence of any real world evidence causally linking reduction in school bus seating capacity to increased risk of death or injury of alternative forms of travel.”

The agency believes that to some extent, the new flexible occupancy seats may have resolved some of the capacity reduction issues associated with the earlier versions of lap/shoulder belt seats in school buses. However, to the extent that transportation providers decide to use the older lap/shoulder belt equipped school bus seats, the extent of capacity reduction would depend on each route and may not always be resolved through better routing. In response to the WBBCF concern that there is an absence of any real world date linking reduction in school bus capacity to increased risk of death or injury, we disagree. The 2002 NAS study clearly shows that a reduction in school bus ridership would lead to children seeking a less safe form of transportation to and from school, leading to an increased risk of serious/fatal injury. The capacity of school buses, along with other characteristics such as bus length and overall weight, is often considered by transportation providers when determining which buses can be used for each route. To the extent that the same size bus could have less seating capacity and the transportation provider would not have sufficient resources to add additional buses and drivers, it could impact the level of school transportation service provided.

Some commenters advocating a requirement for belts on buses believed that NHTSA did not correctly analyze the pros and cons of a requirement for lap/shoulder belts on large school buses. The NCSBS thought it was inconsistent for NHTSA to not propose to require seat belts on large school buses even though it proposed to require higher seat backs and self-latching seat cushions, especially when, the commenter stated, “there has been no documentation of mortality or morbidity due to the 20 inch seat back height or failure of cushion retention.” In response, as part of good governance, NHTSA has the responsibility to assess whether each of its initiatives would be cost effective and propose those that are. The requirements on manufacturers and purchasers must involve the best use of its resources. The proposals for the higher seat backs was found to be effective and would not lead to reduced seating capacity or other negative consequences. We could not make the same determination about a Federal mandate to require lap/shoulder seat belts on all large school buses. The potential impact on pupil transportation resources from a Federal mandate may lead to higher overall risk.

WBBCF stated its belief that NHTSA should have acknowledged a finding of the American Academy of Pediatrics (AAP) that between 6,000 and 10,000 children per year are injured in school bus accidents, and that, the commenter believed, many of these injuries could be reduced by a lap/shoulder belt requirement. The AAP study referenced by WBBCF indicated that there are approximately 17,000 school bus related nonfatal injuries annually. Ninety-seven percent of those injured in the AAP study were treated and released from the hospital. The study used a sample of students treated in hospital emergency rooms for injuries which had the word “school bus” in the case description to generate an estimated nationwide total number of people injured. These numbers include injuries that are not traffic related such as slip and falls while boarding/alighting (injuries that cannot be prevented by any occupant protection system.) The study indicated that the school bus injuries were from the following causes:

• Crash Related—7,206

• Boarding/Alighting—84,056

• Slip/Fall—1,162

• Traffic, noncrash—860

• Other/unknown—3,749

In contrast to the AAP study, to determine the number of school bus crash related injuries, NHTSA used real world data where the injury resulted from a crash involving a vehicle in transport and on a public road. The number of crash related injuries reported in the AAP study correlates closely with our estimates of child passengers in school buses injured in school bus-related crashes

(approximately 7,300 injuries annually.) Of these 7,300 injuries, NHTSA estimated that 94 percent were minor and non-incapacitating injuries. Based on this analysis, we believe that the 97 percent injured in the AAP study that were treated and released from the hospital only sustained minor injuries.

Regarding WBBCF's comment that NHTSA should calculate the associated reductions in personal and societal costs due to lap/shoulder belts in terms of medical, insurance and liability expense, physical disability and trauma, emotional trauma, and lost education days, the Preliminary Regulatory Evaluation (PRE) for the NPRM included such factors in its estimates. Likewise, the Final Regulatory Evaluation for this final rule also takes into account the comprehensive value of an injury and statistical life, which includes all of those factors relating to medical, insurance, pain and suffering and lost work days.

Finally, regarding Mr. Davis's comment, we agree that the best practice is for each purchaser to determine whether to purchase seat belts on large school buses and that part of such a decision is the thorough assessment of how the school's resources should be spent. We agree that if after weighing all the considerations a purchaser decides not to purchase the belts, then it is also determining what is best for its needs.

b. Other Issues Concerning Belts on Large School Buses

NHTSA does not agree that this rulemaking should be delayed until completion of the side impact research mentioned in the 2002 Report to Congress. In response to NYAPT, our side impact protection countermeasure research is still ongoing. We have been actively pursuing this research and expect to complete it soon. However, completion of this research is not critical to implementing regulations specific to the areas discussed in the NPRM or this final rule, such as seat belts, raising the seat back height, or requiring seat bottom cushions to be self-latching. The research in those areas has been completed. The ongoing research with respect to side impact improvements will in no way affect the outcome of the previous research, or the policies, performance and decisions related to this final rule.

Further, we do not believe that additional research is necessary to show “that the newly developed systems adequately protect children of all sizes in severe side impacts” as suggested by the NTSB. For near side impact, the agency's 2002 testing and the NTSB studies have well documented that seat belts will provide very limited occupant protection for those in direct line with the impact force. This is similar to near side occupants in passenger vehicles and the current agency school bus side impact research is geared to address this condition.

With regard to the belief that seat belts on large school buses should also be required to reinforce the message to children that they should wear belts in passenger vehicles, NHTSA studied the issue in 1985. The agency found that children were able to understand that the bus environment was different than that of a passenger car, and that not having belts on school buses did not dilute the buckle up message for family vehicles.
28

NHTSA did a follow-up literature review in 2007 and determined that the results of the 1985 study are likely unchanged. See, “School Bus Seat Belts and Carryover Effects in Elementary School-Aged Children”, which we have placed in the docket for this final rule.

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

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

In the NPRM, we decided against prohibiting lap belts on large school buses. Although we acknowledged that laboratory research, including our own on lap belted dummies, showed relatively poor performance of lap belts in large school buses, we could not conclude that the addition of lap belts in large school buses reduced overall occupant protection such that they should be banned. We noted that lap belts were required in three states (New York (NY) (1987), New Jersey (1994), Florida (2001)), in many other school districts, and in special-needs equipped school buses. We stated that our examination of NY State school bus crash data for lap belt equipped and non-belt equipped buses could not conclude that lap belts either helped or hurt occupant injury outcomes.

A number of commenters to the NPRM wanted NHTSA to ban lap belts. The NTSB believed that NHTSA's 2002 school bus test program showed that lap belts “afford occupants little if any safety benefit above that achieved by compartmentalization alone and may cause additional neck and abdominal injury.” The NTSB and the National Association of State Directors of Pupil Transportation Services (NASDPTS)
29

believed that since lap belts are not an acceptable means of occupant protection in passenger cars, light trucks, or small school buses, lap-only belts should not be installed on large school buses. Similarly, NYAPT believed that NHTSA should prohibit the installation of lap belts on school buses and clearly state what the commenter believed were the inherent risks associated with their use. In addition, the commenter stated that few NY school districts require the use of lap belts by student passengers. Accordingly, it believed that the agency's statements in the NPRM relating to the evaluation of New York crash data should be corrected. The commenter stated that the agency should not have determined that the data from New York is inconclusive, but rather that seat belt usage in school buses is so minimal and inconsistent that there is no relevant data to analyze and compare.

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

Agency Response

In response to NYAPT's comment, we stand by our statement in the NPRM that we cannot conclude that lap belts either helped or hurt occupant injury outcomes. It was not possible to estimate lap belt performance or effectiveness.

Crash data have consistently shown that lap belts are a good safety device in passenger vehicles, even though lap/shoulder belts are more effective when worn properly. We currently allow a lap belt in the front center seat of a passenger vehicle, and we allow lap belts in medium to heavy vehicles over 4,536 kg (10,000 pounds) GVWR. Lap belts have been shown to be almost as effective as lap/shoulder belts in rollover crashes, and benefit far side occupants in side impacts involving these vehicles.

The NPRM did not propose to ban lap belts on large school buses and we decline to concur at this time that lap belts should be prohibited on large school buses. The large school bus environment is different from that of small school buses, passenger cars, and small trucks and vans, and experiences less severe crash forces. Thus, the type of restraint that is appropriate for each may differ. A state might want to install seat belts on their school buses to supplement compartmentalization in side or rollover crashes, and we are unable to conclude that if they do, they must install lap/shoulder belts, given

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

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

In the NPRM, we noted that certain highway safety grant funds may continue to be used to fund the purchase and installation of seat belts (lap or lap/shoulder) on school buses. Annually, all States, the District of Columbia, Puerto Rico, the Bureau of Indian Affairs, and the U.S. territories receive NHTSA section 402 State and Community Highway Safety Formula Grant Funds. A wide range of behavioral highway safety activities that help reduce crashes, deaths, and injuries, including seat belt-related activities, qualify as eligible costs under the section 402 program. Each State determines how to allocate its funds based on its own priorities and identified highway safety problems as described in an annual Highway Safety Plan (HSP). We stated that, as with all proposed expenditures of section 402 funds, the purchase and installation of seat belts on school buses must be identified as a need in the State's HSP and comply with all requirements under 23 U.S.C. Part 1200. Section 402 funds may not be used to purchase the school bus in its entirety, but may fund only the incremental portion of the bus cost directly related to the purchase and installation of seat belts.

1. Use of Existing Federal Grant Funds To Purchase Seat Belts

In response to the NPRM, the Governors Highway Safety Association (GHSA), Georgia Governor's Office of Highway Safety (GOHS), and Maryland Department of Transportation wrote that although lap/shoulder belts on large school buses is an important safety issue, the biggest danger to children, as evidenced by years of data, is in the area around school buses and on the way to and from school. The commenters stated that emphasizing the use of Federal 402 funds for school bus safety represents a significant shift in Federal policy, but there is no evidence to support such a shift. They expressed concern that the impact on the 402 program is potentially enormous and devastating to a State's highway safety program, could eliminate a State's entire apportionment and still barely pay for the costs of the improvement. They believe that from a cost/benefit perspective, this solution threatens many other higher priority objectives, including impaired driving prevention, child passenger safety, and aggressive driving. For example, Maryland stated that in the past 10 years, there has been one school bus occupant-related fatality in the State of Maryland. In contrast, the commenter stated, in 2006 in Maryland there were 199 fatal crashes involving alcohol, 79 fatal crashes involving aggressive drivers, 95 fatal crashes involving pedestrians, 83 fatal crashes involving motorcycles, and 102 fatal crashes involving young drivers. Maryland expressed the view that because of media coverage of recent school bus crashes, “states may be pressured to spend federal highway safety money for this purpose [seat belts on large school buses], at the expense of many competing highway safety needs.”

The GOHS stated that in the NPRM, NHTSA chose not to calculate the costs of installing seat belts on large school buses, because installation is voluntary. It stated its belief that local school districts that wish to install safety belts on large school buses would incur sizable costs. The GOHS also stated that most school districts identify the specifications for new school buses and then they put the specifications out to bid. They further stated that costs of improvements are not individualized, but are part of the overall cost of the new bus design. It would therefore be difficult for school districts to determine the incremental cost of a single improvement and then invoice the state highway safety office just for the improvement.

Agency Response

NHTSA does not agree that using Federal safety grant money to install safety equipment on school buses represents a significant shift in Federal policy. For example, when we issued final rules in the early 1990s requiring stop arms and upgraded mirror systems on school buses as a means to provide enhanced protection for children who ride school buses, we specifically allowed Federal safety grant funds to be used to purchase the newly specified school bus safety equipment.

Nothing in this final rule changes the fact that deciding how to use section 402 grant funds is at the discretion of each State. If a State should decide that lap/shoulder belts on large school buses is a safety priority, NHTSA is simply stating that the Federal safety grant funds may be used to purchase the belts. If a State should choose to purchase seat belts, its decision must be based on the State's own priorities identified in its Annual Highway Safety Plan and comply with all requirements under 23 CFR Part 1200. Section 402 funds may not be used to purchase the entire school bus, but may fund only the incremental portion of the bus' cost that is directly related to the purchase and installation of seat belts. NHTSA has also determined that in addition to using section 402 funds, 23 U.S.C. section 406 Safety Belt Performance Grant Funds can be used to fund the incremental portion directly related to the purchase and installation of seat belts on school buses.

NHTSA is aware that many important safety issues compete for funding from each State's Federal safety grant funds. Therefore, it is imperative that each State base its selection for fundable projects on its highway safety priorities. For States considering the installation of seat belts on large school buses, NHTSA has provided estimates of the cost to install seat belts in large school buses in the Preliminary Regulatory Evaluation that was available in the docket (NHTSA-2007-0014-0005.1) for the NPRM. NHTSA believes that in order to determine the incremental cost of seat belts on large school buses, when it orders the school buses, it would be a simple matter for the State to ask the school bus manufacturer for an itemized list of options, including seat belts.

2. Additional Federal Grant Funds To Purchase Seat Belts

The GOHS, North Carolina Dept. of Public Instruction, the National Association of State Directors of Pupil Transportation Services (NASDPTS), and the Texas Department of Transportation all sought additional funding for school bus improvements in NHTSA's next reauthorization. The commenters believe that additional funding is needed in order to make a change in school bus seating viable on a widespread basis. They asked NHTSA to establish a “separate designated federal fund source” (using NASDPTS' words) to offset the additional cost of lap/shoulder belts on school buses, either within section 402 or apart from it. The commenters stated that existing funds are insufficient to implement lap/shoulder belts without significant cutbacks in other highway safety initiatives. NADSPTS commented: “When this NPRM was introduced, the general public was given the impression through the media and news releases that school bus lap/shoulder belt funding would be made available, not that we would have to compete for existing section 402 funds.”

NHTSA Response

NHTSA has not identified any additional funds that can be used as a separate set-aside for the purchase of seat belts on school buses. NHTSA emphasizes that it makes available

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

V. Overview of Upgrades to Occupant Crash Protection Standards

a. Summary of the NPRM Proposed Upgrades

After considering the findings of NHTSA's 2002 School Bus Safety Study, the NPRM proposed several sets of upgrades to the school bus safety requirements. The first set of upgrades involved improving the compartmentalized school bus interior for all school buses. Seat back height was proposed to be increased from 508 mm (20 inches) to 610 mm (24 inches) to reduce the potential for passenger override in a crash. We also proposed to require self-latching mechanisms for school buses with seat bottom cushions that are designed to flip up or be removable without tools.

The second set of upgrades proposed to require small school buses to have lap/shoulder belts instead of just lap belts. The lap/shoulder belt systems were to fit all passengers from ages 6 through adult, to be equipped with retractors, to meet the existing anchorage strength requirements for lap/shoulder belts in FMVSS No. 210, and to meet new requirements for belt anchor location and torso belt adjustability. The seat belts were to meet a “quasi-static” test requirement to help ensure that seat backs incorporating lap/shoulder belts are strong enough to withstand the forward pull of the torso belts in a crash and the forces imposed on the seat from unbelted passengers to the rear of the belted occupants. A minimum seat belt width of 380 mm (15 inches) was proposed for belted occupants. In addition, the vehicles had to meet FMVSS No. 207 because the load in some seating configurations imposed by FMVSS No. 207 is greater than the load that would be imposed by FMVSS No. 222's seat performance requirements.

The third set of upgrades involved requirements for voluntarily-installed seat belts on large school buses. For large school buses with voluntarily-installed lap/shoulder belts, it was proposed that the vehicle meet the requirements described above for lap/shoulder belts on small school buses, except the quasi-static test would be slightly revised for the large school buses to account for crash characteristic differences between the vehicles. (Due to the mass and other characteristics of the vehicles, in crashes typically small school buses are subject to higher severity crash forces than are large school buses.) Further, we did not propose to apply FMVSS No. 207 to large school buses.

b. Overview of Comments

Commenters
30

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

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

There was widespread support for the proposed requirement for lap/shoulder belts on all small school buses from the commenters (school bus seat and restraint manufacturers, transportation providers and other organizations). A number of commenters asked that “small school bus” be redefined to include similarly built buses that have a GVWR of over 4,536 kg (10,000 pounds). In addition, the National Child Care Association was concerned that the NPRM, if made final, would result in increased costs for the multifunction school activity bus.

Commenters generally supported the proposed performance standards for school buses, with bus, seat, and restraint manufacturers providing detailed comments on technical aspects of the test procedures and performance requirements. Many commenters asked NHTSA to ensure that the proposed seat width minimum of 380 millimeters (mm) (15 inches) did not prohibit flex-seats.

c. Post-NPRM Testing

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

31
“NHTSA Technical Analysis to Support the Final Rule Upgrading Passenger Crash Protection in School Buses,” September 2008.

Both dynamic and static testing was performed. The tested seats were lap/shoulder equipped and manufactured by CEW, IMMI and Takata. The CEW seat is a unified frame seat back design with two fixed lap/shoulder belts. The IMMI and Takata seats are flex-seat designs with configurations of 3 and 2 occupants per bench. The IMMI design has a dual-frame seat back, with the outer frame providing compartmentalization of the rearward occupants and the inner frame anchoring the lap/shoulder belt for the occupant of the seat.

Sled testing of school bus seats was performed in a manner similar to the 2002 School Bus Safety Study.
32

However, testing was performed using both the large and small school bus crash pulse, rather than just the large school bus pulse use in previous testing. This testing helped the agency gain general insight into the dynamic performance of flex-seat designs.

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

The small school bus sled testing was also specifically performed to verify the proposed torso body block pull force applied in the quasi-static test. The proposed value had been derived through mathematical calculation using Newtonian mechanics and measurements made in large school bus pulse sled testing. The results of the new testing confirm that the proposed small school bus torso body block pull force is appropriate.

The small school bus sled testing was also useful in verifying the peak dynamic loading on the entire seat structure. These data were used in our analysis of the need for implementing

the FMVSS No. 207 requirements to the seats during the FMVSS No. 210 testing.

The agency performed extensive testing to address comments related to the proposed quasi-static test.
33 34

A particular focus of this testing was the many issues raised by potential allowance of flex-seats in the final rule. Through this test work, the agency determined that it would be appropriate to increase the preload and the zone where the torso body blocks are initially placed.
35

We also determined that the quasi-static test could be applied to flex-seats in all potential seating configurations. A similar determination was made when flex-seats were tested to the FMVSS No. 210 requirements for seat belt anchorages. The FMVSS No. 210 testing can be performed on flex-seats in all potential seating configurations.

33

Id
.

34
“FMVSS No. 222 School Bus Seat Quasi-Static Testing for Various School Bus Seats Equipped with Type 2 Seat Belts, Test Procedure Development Testing,” General Testing Laboratories, Inc., August 2008. See docket for this final rule.

35
“FMVSS No. 222 School Bus Seat Quasi-Static Testing for Various School Bus Seats Equipped With Type 2 Seat Belts, Torso Block Preload and Positioning,” General Testing Laboratories, Inc., July 2008. See docket for this final rule.

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

d. How This Final Rule Differs From the NPRM

The following are the most important differences between the final rule and the NPRM:

1. The minimum seat width requirement is revised to accommodate flexible occupancy seats (flex-seats). Further, quasi-static loading requirements appropriate for flexible occupancy seats are adopted.

2. The quasi-static test at S5.1.5 of FMVSS No. 222 will limit the displacement of the torso belt anchor point
and
the seat back, rather than just the anchor point. This change was made to make the requirement more performance oriented, and not unnecessarily restrict seat designs that incorporate other than unified frame design. Further, to address practicability concerns, the performance limit on anchor point displacement is revised to allow the equivalent of four degrees of additional rotation.

3. In the quasi-static test, the energy absorption requirement will specify that the seat back force-deflection signature must stay below the upper bounds of existing force/deflection zone upper boundary of FMVSS No. 222. In addition, the torso belt adjustment must be maintained during the test.

4. To accommodate flex-seats, the torso anchor point minimum height requirement of FMVSS No. 210 will allow, but not require, the center seating positions in flex-seats to only accommodate an occupant as large as an average 10-year-old child, rather than an adult male. Such a center seating position is defined as a “small occupant seating position” (SOSP) and will be marked as such by way of a label on the seat belt for that seating position. In addition, the minimum lateral anchorage separation requirement is modified to allow a reasonable accommodation of existing designs of flex-seats and non-flex-seats.
36

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

e. Organization of Discussion

The discussion of the amendments made by this final rule are organized as follows: Upgrades for all school buses (seat back height; cushion latches); upgrades for small school buses (requiring lap/shoulder belts; FMVSS No. 207; other issues); upgrades for large school buses (requiring voluntarily installed belts to meet performance requirement,); performance requirements for vehicles with seat belt systems (seat width requirements; seat belt anchorage requirements (FMVSS No. 210); quasi-static test; other issues).

For the NPRM, NHTSA prepared a 2007 Technical Analysis that, among other things, presented a detailed analysis of data, engineering studies, and other information supporting these amendments. A copy of the document was placed in Docket NHTSA-2007-0014. As indicated above, an updated 2008 Technical Analysis has also been prepared and placed in the docket for this final rule. In addition, several other technical reports supporting this final rule have also been placed in the docket. The agency refers to these documents from time to time in this preamble.

VI. Upgrades for All School Buses

a. Seat Back Height

In the NPRM, we proposed that the minimum seat back height for school bus seats (specified in FMVSS No. 222) be raised from a minimum 508 mm (20 inches) to 610 mm (24 inches). This increase in minimum seat back height was supported by agency-conducted sled tests that assessed the compartmentalization performance of 508 mm (20 inch) and 610 mm (24 inch) seat backs for large (50th percentile male) occupants. The results of these tests indicated that 610 mm (24 inch) seat backs would provide more effective compartmentalization for larger occupants than 508 mm (20 inch) seat backs. In tests with the higher seat back, the extent to which the dummies overrode the seats in front of them was lessened. The higher seat back was also effective in reducing head contact with test dummies that were placed in seats forward of the dummies. In tests using the 508 mm (20 inch) seat backs where dummy head contact did occur because of override, the HIC15 values tended to be well above the established IARVs.

In general, the commenters supported the proposal for the increase in seat back height to 24 inches. Three school bus seat and restraint manufacturers (Concepts Analysis Corp. (Concepts), CEW, and Takata) supported an increase in seat back height, with CEW agreeing with the proposed seat back height and barrier area and both Concepts and Takata recommending that the minimum seat back be increased as set forth in FMVSS No. 202a. Three school bus manufacturers and associations (Thomas Built Buses, Inc. (Thomas), National Truck Equipment Association/Manufacturers Council of Small School Buses (NTEA/MCSSB), and Girardin Minibus, Inc. (Girardin)) agreed with the proposed increase in seat back height. However, Thomas, NTEA/MCSSB, and Girardin requested that this requirement not apply to the last row of seats because it was believed that there is no rearward occupant to compartmentalize, driver visibility through the rear window would be better, and a lower seat back would allow for more knee room in the last row. Those opposing the proposal expressed concern about reduced driver visibility of students.

Agency Response

This final rule increases the minimum seat back height for school bus seats to 610 mm (24 in), as proposed in the NPRM.

1. In response to Takata
et al.
, when FMVSS No. 202a begins to phase-in for rear seats in the 2011 model year, it will require that any head restraints provided in the rear outboard seats (they are optional) must have a minimum height of 750 mm (29.5 inches) above the H-point.
37

This requirement will be applicable to passenger vehicles, trucks

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

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

It should be noted that this final rule only requires that seat backs be a minimum of 610 mm (24 inches). If individual states, counties, or school districts wish to specify a seat back higher than 610 mm (24 inches), they are free to do so. As noted above, FMVSS No. 202a would apply to small school buses with seat backs above 700 mm.

2. We are denying the request that the minimum seat back height requirement not be applied to the last row of seats. There is no current exemption for the seat back height of the last row of seats. Given that there are rigid structures in a school bus rearward of the last row, this additional seat back height will provide added potential protection to the occupants of the last row in the event of a rear impact. Further, the occupants of the last row should be afforded the better whiplash protection offered by the 610 mm (24 inch) seat back.

The argument that the height should be reduced to improve driver visibility is not persuasive. Since the row directly forward of the last row would not be exempted from the seat back height requirement, any decrease in driver visibility due to the seat back of the rearmost row would be minimal. (Further discussion of the driver visibility issue is provided below.)

Finally, it was stated that additional knee space would be available if the last row did not have to be 610 mm (24 inches) high. If we assume a seat back with a 12 degree angle from the vertical, the higher seat back height would necessitate the rear seat row to move forward approximately 21 mm (0.84 inches) [100 mm × tan(12deg.)]. This change could be spread evenly over the entire length of the vehicle, resulting in a negligible difference in leg room for each row of seats.

3. With regard to reduced driver visibility of the students, as discussed in the NPRM preamble and in comments from school transportation providers, a number of states, including Illinois, New Jersey, New York, Ohio, North Carolina and Washington, already require seat back heights of 610 mm (24 inches) in their school buses. We are not aware of reports of visibility problems or insufficient discipline of students on the buses. In fact, the Monroe-Woodbury Central School District indicated that the 24-in seat back improved student behavior as students were unable to easily hang over the tops of the seat backs to interact with friends in distant rows, but instead had to converse with passengers around him or her while staying seated. Additionally, as pointed out by some commenters, increasing the minimum seat back height to 610 mm (24 inches) would make the minimum seat back height the same as the industry designations from the 2005 edition of the National School Transportation Specification and Procedures (NSTSP) for minimum seat back height.

4. Mr. James Hofferberth stated that NHTSA “has failed to consider alternative [compartmentalization] strategies, such as a reduction of seat height to reduce cost, coupled with the provision of a vertical transverse containment panel from the top of the seat to the ceiling of the bus.” To our knowledge, there is no compartmentalization strategy such as that discussed by the commenter that has been tested and proven in both effectiveness and feasibility as compartmentalization. Therefore, at this time, such alternatives are not viable alternatives to the heightened seat back approach.

b. Seat Cushion Latches

NHTSA proposed to amend S5.1.5 of FMVSS No. 222 to require latching devices for school bus seats that have latches that allow them to flip up or be removed for easy cleaning. We also proposed a test procedure that would require the latch to activate when a 22 kg (48 pounds) mass is placed on top of the seat at the seat cushion's center. The 22 kg (48 pounds) mass is that of an average 6-year-old child. The test was to ensure that any unlatched seat cushion would latch when a child occupant sits on the seat.

In general, comments addressing this issue supported the proposal. The NSTA noted that New York and Connecticut already require self-latching mechanisms for seat cushions in their buses, and NCDPI stated that they now require positive locking devices on their school bus seats. They did not provide any details on the specifications they require. CEW noted that currently, manually operated seat cushion latches can inadvertently be left unlatched after cleaning, and that the proposed self-latching mechanisms could “benefit safety in a crash situation.” Concepts believed that this requirement “should add only pennies to the cost of [a] school bus seat.”

While NTSB supported a requirement for self-latching mechanisms for school bus seat cushions, it had concerns about the proposed test requirements regarding the mass required to activate the latch. It stated that its concern that “some designs of flip-up or removable seats that comply with this standard may allow the seat to come loose during a crash or rollover if a sufficient weight is not applied to the seat cushion for the self-latch to activate.” NTSB stated that the load requirement should be removed from the proposed seat cushion retention standard unless NHTSA can verify that all seats with this design are hinged and cannot fully separate from the seat frame when the latch is not activated.

Agency Response

This final rule adopts the requirement that self-latching mechanisms be installed on school bus seat cushions that flip up or are removable. We acknowledge that, under the requirement, some cushions could still come loose during a crash because the latch would only be required to activate under a 22 kg (48 pounds) mass. While latching devices which activate under the weight of the seat cushion alone (as NTSB suggested) would be preferred, at this time we have not received any data indicating the minimum loads that are required to activate latches of this type. We specify 22 kg (48 pounds) because that is the mass of the 50th percentile 6-year-old child,
i.e.
, a child in kindergarten or first grade. The cushion will thus latch when a child sits on it. We received no data in response to the NPRM that indicate alternative loads. Therefore, we do not have the information necessary to support removing or reducing this load requirement.

One commenter described the currently-used seat cushion latches as “primitive” and “hard to open,” and state that “they are not always secured fully when [they] get the seat back down.” We believe that such problems

may be the main reason why school bus seat cushions are not always secured to the seats in current school buses. With self-latching devices that meet the proposed requirements, a bus driver would only have to firmly push down on the top of the seat cushion to re-attach it after cleaning. This greatly simplifies the process of latching the seat cushions, making it much more likely that they will be properly attached to the seats.

Finally, regarding a comment from the National Child Care Association, we do not require that seat cushions flip up, but rather have adopted a requirement for self-latching mechanisms that would be installed on seat cushions that do flip up or are removable.

VII. Upgrades for Small School Buses

a. Requiring Lap/Shoulder Belts

The agency proposed that small school buses be required to have lap/shoulder belts at all passenger seating positions. Since the FMVSSs were first promulgated, small school bus passenger seats have been required to have passenger lap belts (defined as Type 1 belts in FMVSS No. 209) as specified in FMVSS No. 208, belts that meet the lap belt strength requirements specified in FMVSS No. 210. Lap/shoulder belts provide an increased level of protection from lap belts in small school buses by reducing the potential of head and neck injuries in frontal impacts.

All commenters supported the proposal. Accordingly, this final rule adopts the requirement for the reasons stated in the NPRM. The seat belt systems are required to meet the performance requirements of FMVSS Nos. 208, 210, and 222 as discussed in the NPRM and this final rule. (Under current requirements, the seat belts already must meet FMVSS No. 209, “Seat belt assemblies.”)

b. Raising the Weight Limit for Small School Buses

Historically the dividing line between what is considered a “large” and a “small” school bus is the GVWR delineation. School buses with a GVWR above 4,536 kg (10,000 pounds) are large school buses, while school buses with a GVWR of 4,536 kg (10,000 pounds) or less are small school buses.

In response to the NPRM, several commenters suggested raising the weight limit for small school buses from 4,536 kg (10,000 pounds) to 6,576 kg (14,500 pounds). IMMI stated that the small school bus requirement that lap/shoulder belts be installed at all seating positions should apply to all school buses that are built on a van chassis, which are known in the industry as type “A” school buses. The commenter stated that these consist of type “A-1” school buses, which have a GVWR of 4,536 kg (10,000 pounds) or less, and type “A-2” school buses, which have a GVWR that can range up to 6,576 kg (14,500 pounds). IMMI explained that both the type A-1 and the type A-2 buses are built on similar van chassis, and so they are both exposed to similar operating and crash environments. Another commenter stated that the National School Transportation Specifications and Procedures (NSTSP) for school bus types defines Type A-1 school buses as having an upper weight limit of 6,576 kg.
38

Thus, this comment suggested, it would be easier to determine which school buses must comply with the lap/shoulder belt requirement if NHTSA's definition of small school buses followed the NSTSP recommendation.

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

Agency Response

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

c. FMVSS No. 207, Seating Systems

In the NPRM, we proposed to apply FMVSS No. 207 to small school buses with lap/shoulder belts because the load imposed by FMVSS No. 207 appears to be greater than the load that would be imposed by FMVSS No. 222's seat performance requirements at S5.1.3.

There was no consensus between commenters. CEW disagreed with the proposal to apply the FMVSS No. 207 loading to small school buses. It explained that “[m]any of our customers request that we pull the FMVSS No. 210 test to higher forces than those required by NHTSA to insure that they have a ‘safety margin' above NHTSA's requirement * * * Most of our customers ask us to pass FMVSS No. 210 by 110% or 120% * * * If FMVSS No. 207 and FMVSS No. 210 are added and customers still want 110% and 120%, we would be adding safety factors to safety factors, as well as undue additional costs.” In contrast, IMMI agreed that FMVSS No. 207 should apply to all small schools buses and “all van-based, A type school buses, regardless of their GVWR.”

Blue Bird Corp. (Blue Bird) disagreed with the proposal. Using the data the agency provided in the NPRM, it provided an extensive analysis showing that for a seat bench with three lap/shoulder belts, the FMVSS No. 210 load is 130 percent [18,000 pounds/(11,802 + 2,040) pounds] of the total dynamic load on the seat, plus the load that would be imposed by FMVSS No. 207.

If the final rule makes FMVSS No. 207 applicable to small school buses with lap/shoulder belts, Blue Bird requested an exemption for a “davenport” mounted seat which “consists of separate seat cushion and seat back assemblies of wood or plastic, foam, and upholstery fastened to the bus body structure forming the front and top of the engine compartment.” However, Blue Bird stated that it was unaware of such rear engine configurations for small school buses.

Agency Response

With respect to Blue Bird's analysis, the commenter used the peak total force on the seat in the large bus sled tests performed by the agency (35,000 N (7,869 pounds)).
39

Using an assumption expressed in the NPRM (regarding the quasi-static test) that belt loads for the small school bus situation would be 1.5 times that of the large school bus, the commenter estimated that the total seat force for a small school bus seat occupied by two persons would be 52,000 N (11,803 pounds).
40

39
These seats were occupied by two 50 percentile male Hybrid III dummies.

40
Rather than the value used by Blue Bird, however, the agency actually derived a range of potential ratios for the small to large school bus belt loads from 1.1 to 2.4 times. We choose 1.5 in the NPRM out of a concern for practicability in the quasi-static test.

The agency now has actual measurements of total seat load in a small school bus crash pulse, and has found that the ratio of large to small school bus forces is about 58 percent.
41 42

Using this actual small school bus total seat loading, we have estimated the extent to which the FMVSS No. 210 load combined with the FMVSS No. 207 load exceeds the actual measured total load on the seat.

41
“NHTSA Technical Analysis to Support the Final Rule Upgrading Passenger Crash Protection in School Buses,” September 2008.

42
“NHTSA Vehicle Research and Test Center's Technical Report on Dynamic and Quasi-Static Testing for Lap/Shoulder Belts in School Buses,” September 2008.

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

we calculate that the total FMVSS No. 210 loading is 80,064 N (18,000 pounds) [3 × 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 × 20 g × 9.81)/(2 × 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 × 20 g × 9.81)/(2 × 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

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

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

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3AE8-24755. Public record. Not legal advice.