Document ID: NHTSA-2014-0085-0002
Agency: nhtsa
Document Type: Proposed Rule
Title: Federal Motor Vehicle Safety Standards: Bus Rollover Structural Integrity, Motorcoach Safety Plan
Posted Date: 2014-08-06T04:00Z

[Federal Register Volume 79, Number 151 (Wednesday, August 6, 2014)]
[Proposed Rules]
[Pages 46089-46123]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-18326]

[[Page 46089]]

Vol. 79

Wednesday,

No. 151

August 6, 2014

Part VI

 Department of Transportation

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National Highway Traffic Safety Administration

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49 CFR Part 571

Federal Motor Vehicle Safety Standards; Bus Rollover Structural 
Integrity, Motorcoach Safety Plan; Proposed Rule

  Federal Register / Vol. 79 , No. 151 / Wednesday, August 6, 2014 / 
Proposed Rules  

[[Page 46090]]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2014-0085]
RIN 2127-AK96

Federal Motor Vehicle Safety Standards; Bus Rollover Structural 
Integrity, Motorcoach Safety Plan

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: NHTSA is issuing this NPRM to propose a new Federal motor 
vehicle safety standard to enhance the rollover structural integrity of 
certain types of large buses (generally, over-the-road buses (of any 
weight) and non-over-the-road buses with a gross vehicle weight rating 
(GVWR) greater than 11,793 kilograms (kg) (26,000 pounds (lb)). The 
agency is proposing performance requirements that new large buses of 
these types must meet in a test in which the vehicle is tipped over 
from an 800 millimeter (mm) raised platform onto a level ground 
surface. The performance requirements would ensure that these vehicles 
provide a sufficient level of survival space to restrained occupants in 
rollover crashes. The performance requirements would also ensure that 
seats and overhead luggage racks remain secured and window glazing 
attached to its mounting during and after a rollover crash, and would 
ensure that emergency exits remain closed during the rollover crash and 
operable after the crash.
    This NPRM is among the rulemakings issued pursuant to NHTSA's 2007 
Approach to Motorcoach Safety and DOT's Departmental Motorcoach Safety 
Action Plan. In addition, establishing roof strength and crush 
resistance requirements, to the extent warranted under the National 
Traffic and Motor Vehicle Safety Act, would fulfill a statutory 
provision of the Motorcoach Enhanced Safety Act of 2012 (incorporated 
and passed as part of the Moving Ahead for Progress in the 21st Century 
Act).

DATES: Comments must be received on or before October 6, 2014.

ADDRESSES: You may submit comments to the docket number identified in 
the heading of this document by any of the following methods:
     Federal eRulemaking Portal: go to http://www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility, M-30, U.S. Department of 
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery or Courier: West Building Ground Floor, Room 
W12-140, 1200 New Jersey Avenue SE., between 9 a.m. and 5 p.m. Eastern 
Time, Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    Regardless of how you submit your comments, please mention the 
docket number of this document.
    You may also call the Docket at 202-366-9324.
    Instructions: For detailed instructions on submitting comments and 
additional information on the rulemaking process, see the Public 
Participation heading of the Supplementary Information section of this 
document. Note that all comments received will be posted without change 
to http://www.regulations.gov, including any personal information 
provided.
    Privacy Act: Please see the Privacy Act heading under Rulemaking 
Analyses and Notices.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, Ms. Shashi 
Kuppa, Office of Crashworthiness Standards (telephone: 202-366-3827) 
(fax: 202-493-2990). Ms. Kuppa's mailing address is National Highway 
Traffic Safety Administration, NVS-113, 1200 New Jersey Avenue SE., 
Washington, DC 20590.
    For legal issues, Mr. Jesse Chang, Office of the Chief Counsel 
(telephone: 202-366-2992) (fax: 202-366-3820). Mr. Chang's mailing 
address is National Highway Traffic Safety Administration, NCC-112, 
1200 New Jersey Avenue SE., Washington, DC 20590.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Executive Summary
II. Background
    a. NHTSA's Statutory Authority
    b. NHTSA's 2007 Approach to Motorcoach Safety
    c. DOT's 2009 Task Force Action Plan
    d. NTSB Recommendations
    e. NHTSA's Seat Belt Final Rule
III. Safety Need
    a. FARS Data and Recent Crashes
    b. Rollover and Ejection Statistics
IV. NHTSA's Large Bus Rollover Structural Integrity Research
    a. Findings of the FMVSS No. 220-Based Tests
    b. Findings of the ECE R.66-Based Tests
V. Proposed Requirements
    a. Overview
    b. Applicability
    c. Test Procedure
    d. Survival Space
    e. Overhead Luggage Rack and Seat Retention
    f. Emergency Exits
    g. Side Window Glazing
VI. Regulatory Alternatives
    a. FMVSS No. 216
    b. FMVSS No. 220
    c. ECE R.66 Alternative Compliance Methods
    d. Comments Requested on Alternative Levels of Stringency
VII. Other Issues
    a. Retrofitting
    b. Lead Time
    c. Additional MAP-21 Considerations
VIII. Overview of Costs and Benefits
IX. Regulatory Analyses
X. Public Participation

I. Executive Summary

    This rulemaking is part of both NHTSA and DOT's continual effort to 
improve safety in motorcoaches and other types of large buses. In 2007, 
NHTSA published its Approach to Motorcoach Safety describing NHTSA's 
comprehensive strategy to improve motorcoach safety.\1\ The plan was 
developed to respond to several National Transportation Safety Board 
(NTSB) recommendations, and also to address several crashes that 
occurred after those recommendations were issued. In 2009, DOT issued a 
Departmental Motorcoach Safety Action Plan, \2\ which outlined a 
Department-wide strategy to enhance motorcoach safety, addressing 
additional factors such as driver fatigue and operator maintenance 
issues.
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    \1\ See Docket No. NHTSA-2007-28793, NHTSA's Approach to 
Motorcoach Safety. In NHTSA's plan, ``motorcoach'' referred to 
inter-city transport buses.
    \2\ An update to the 2009 plan was published in December 2012, 
http://www.fmcsa.dot.gov/safety-security/pcs/Motorcoach-Safety-Action-Plan.aspx.
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    NHTSA's Approach to Motorcoach Safety identified four specific 
areas where NHTSA could most effectively address open NTSB 
recommendations and potentially improve motorcoach safety. The four 
priority areas were: Reducing the risk of passenger ejection from the 
motorcoach, improving rollover structural integrity, enhancing 
emergency evacuation, and upgrading fire safety.
    NHTSA has published a final rule (RIN 2127-AK56) on the first area 
detailed in NHTSA's Approach to Motorcoach Safety, requiring seat belts 
for each passenger seating position in: (a) All new over-the-road buses 
\3\; and (b) in new buses other than over-the-road buses, with a GVWR 
greater than 11,793 kg (26,000 lb).\4\ Today's NPRM

[[Page 46091]]

builds on the seat belt final rule by proposing to require those buses 
to meet increased structural integrity and other requirements to 
protect both restrained and unrestrained occupants in rollover crashes.
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    \3\ An over-the-road bus is a bus characterized by an elevated 
passenger deck located over a baggage compartment.
    \4\ Some buses are excluded from this latter category, such as 
transit and school buses.
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    On July 6, 2012, the President signed the ``Moving Ahead for 
Progress in the 21st Century Act'' (MAP-21).\5\ MAP-21 incorporates the 
``Motorcoach Enhanced Safety Act of 2012'' (Motorcoach Enhanced Safety 
Act) in Subtitle G (Sec. Sec.  32701 et seq.) Among other matters, the 
Motorcoach Enhanced Safety Act requires DOT to ``establish improved 
roof and roof support standards for motorcoaches that substantially 
improve the resistance of motorcoach roofs to deformation and intrusion 
to prevent serious occupant injury in rollover crashes involving 
motorcoaches'' if such standards ``meet the requirements and 
considerations set forth in subsections (a) and (b) of section 30111 of 
title 49, United States Code.'' \6\ In addition, MAP-21\7\ directs DOT 
to consider ``portal improvements to prevent partial and complete 
ejection of motorcoach passengers, including children.'' Under MAP-21, 
``motorcoach'' means an over-the-road bus, but does not include a bus 
used in public transportation provided by, or on behalf of, a public 
transportation agency, or a school bus.
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    \5\ Moving Ahead for Progress in the 21st Century Act, Pub. L. 
112-141.
    \6\ See MAP-21, Sec. Sec.  32703(b)z6-(b)(1).
    \7\ Id., Sec. Sec.  32703(b)(2).
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    We have issued this NPRM in furtherance of NHTSA's goal to enhance 
the safety of all heavy buses used in intercity bus transportation, 
including over-the-road buses, which were the focus of the Motorcoach 
Enhanced Safety Act of MAP-21. Similar to the seat belt rule, we are 
not proposing that this standard apply to school buses and urban 
transit buses.
    Transportation by over-the-road buses (and other similar large 
buses) is an overall safe form of transportation. Over the ten year 
period between 2000 and 2009, there were 87 fatal crashes involving the 
large bus types covered by today's proposed rule. These crashes 
resulted in 209 occupant fatalities (168 passenger and 41 driver 
fatalities). During this period, on average, 21 fatalities have 
occurred annually to occupants of these buses in crashes. Annually 17 
of these fatalities were passengers and 4 were drivers. Nonetheless, 
given the high occupancy of these vehicles, a significant number of 
fatal or serious injuries can occur in a single crash. NHTSA 
tentatively believes that standards improving structural integrity and 
thereby side window glazing retention, issued pursuant to Sec. Sec.  
32703(b)-(b)(2) of MAP-21 and the National Traffic and Motor Vehicle 
Safety Act (``Motor Vehicle Safety Act''), would meet the need for 
safety. Among the 87 fatal crashes (involving the bus types covered by 
today's proposal) that occurred from 2000-2009, data from NHTSA's 
Fatality Analysis Reporting System (FARS) indicate that 32 were 
rollover crashes resulting in 114 fatalities. While fatal rollover 
crashes were only one-third of all fatal crashes involving these bus 
types, they represent more than half of all the occupant fatalities. 
Further, approximately two-thirds of the rollover crash fatalities were 
attributable to occupant ejections.
    In developing today's NPRM, the agency turned to United Nations 
Economic Commission for Europe Regulation 66 (ECE R.66).\8\ Today's 
NPRM proposes a test for rollover structural integrity based on the 
complete vehicle rollover test of ECE R.66. We also examined the school 
bus roof crush standard set forth in Federal Motor Vehicle Safety 
Standard (FMVSS) No. 220, ``School bus rollover protection,'' but chose 
to base our new standard on ECE R.66's complete vehicle test because 
the latter appears to more closely simulate a real-world rollover crash 
involving the large bus types that are associated with the highest 
crash risk. Further, an ECE R.66-based test enables us to better 
evaluate particular aspects of performance that are pertinent for 
safety of these types of buses (e.g., the affixing of side glazing 
panels--an area of concern of MAP-21--and attachment of overhead 
luggage racks). Using a procedure based on ECE R.66 also furthers 
NHTSA's efforts to harmonize with international standards when 
feasible.
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    \8\ Uniform Technical Prescriptions Concerning the Approval of 
Large Passenger Vehicles with Regard to the Strength of their 
Superstructure, ECE R.66, February 2006, http://live.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/r066r1e.pdf.
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    This NPRM proposes performance requirements that the buses must 
meet when tested by NHTSA using an ECE R.66-based test. The vehicle is 
placed on a tilting platform that is 800 mm above a smooth and level 
concrete surface. One side of the tilting platform along the length of 
the vehicle is raised at a steady rate of not more than 5 degrees/
second until the vehicle becomes unstable, rolls off the platform, and 
impacts the concrete surface below.
    The rollover structural integrity test is illustrated below in 
Figure 1.

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[GRAPHIC] [TIFF OMITTED] TP06AU14.005

    The following are the main proposed performance requirements that 
buses covered by this proposed rule must meet when subjected to the 
rollover structural integrity test:
    (1) Intrusion into the ``survival space,'' demarcated in the 
vehicle interior, by any part of the vehicle outside the survival space 
is prohibited;
    (2) each anchorage of the seats and overhead luggage racks must not 
completely separate from its mounting structure;
    (3) emergency exits must remain shut during the test and must be 
operable in the manner required under FMVSS No. 217 after the test; and
    (4) each side window glazing opposite the impacted side of the 
vehicle must remain attached to its mounting such that there is no 
opening that will allow the passage of a 102 mm diameter sphere.
    We believe these proposed requirements would provide reasonable and 
needed improvements to the types of buses with the greatest safety risk 
in rollovers. They supplement the agency's final rule on passenger seat 
belts. With passengers more likely to be retained in the bus interior 
as a result of the agency's seat belt final rule, today's NPRM improves 
the protective attributes of the occupant compartment in which they are 
retained.
    The proposed requirements for maintaining the survival space and 
ensuring that seats, overhead luggage racks, and window glazing remain 
attached to their mounting structures would set a minimum level of 
structural integrity for these buses, to help prevent dangerous 
structural intrusions into the occupant survival space. The proposed 
requirement that emergency exits remain closed during the rollover 
structural integrity test and operable after the test is to increase 
the likelihood that emergency exits do not become ejection portals 
during rollover crashes. The requirement also helps ensure that the 
emergency exits remain an effective means of egress after the crash.
    NHTSA believes that this rulemaking would be cost beneficial.\9\
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    \9\ NHTSA has developed a Preliminary Regulatory Evaluation 
(PRE) that discusses issues relating to the potential costs, 
benefits and other impacts of this regulatory action. The PRE is 
available in the docket for this NPRM and may be obtained by 
downloading it or by contacting Docket Management at the address or 
telephone number provided at the beginning of this document.
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    The agency estimates the annual cost of this proposed rule to be 
between $5.28 million and $13.26 million (see Table 1 below). The 
countermeasures may include stronger roof structure, support pillars, 
and side walls, shock resistant latches for emergency exits, stronger 
seat and overhead luggage rack anchorages, and improved window 
mounting, resulting in material costs for each bus covered under 
today's proposed rule ranging from $282 to $507. We estimate the total 
weight increase will range from 564 to 1,114 pounds (lb) for each of 
these buses and cost an additional $2,118 to $5,523 in fuel per vehicle 
over the lifetime of the vehicle.
    Beyond the benefits attributable to the agency's final rule on seat 
belts and a potential final rule on electronic stability control (ESC) 
that also may

[[Page 46093]]

apply to this universe of vehicles, \10\ we estimate that requiring new 
buses of the aforementioned types to meet the proposed performance 
criteria would save approximately 2 lives annually. In addition, we 
expect that the proposed rule would reduce the number of seriously 
injured occupants by approximately 4 annually. Thus, we estimate that 
approximately 3.1 equivalent lives are saved annually if 15 percent of 
occupants use seat belts, and approximately 2.3 equivalent lives are 
saved annually (undiscounted) if 84 percent of occupants use seat belts 
(see Table 2 below).
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    \10\ An ESC rulemaking for the buses is also included in MAP-21. 
The statute directs us to consider requiring motorcoaches to be 
equipped with stability enhancing technology, such as ESC, to reduce 
the number and frequency of rollover crashes. See Sec.  32703(b)(3).
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    The cost per equivalent life saved is estimated to be $2.09 million 
to $4.72 million when belt use is estimated to be 15 percent, and $2.91 
million to $6.42 million when belt use is estimated to be 84 percent 
(see Table 3 below). The net cost/benefit impact ranges from a net 
benefit of $9.47 million to $19.35 million if seat belt usage is 15 
percent. If the seat belt usage rate is 84 percent, the estimated net 
cost/benefit impact ranges from a net benefit of $4.69 million to a net 
benefit of $13.06 million (see Table 4 below). While the cost and 
benefits of this rule will vary depending on the material/fuel costs 
per vehicle and on the belt use rate, all the available information 
indicate that this proposed rule--if made final--would be cost 
beneficial.

                     Table 1--Estimated Annual Costs
                             [2010 Dollars]
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------------------------------------------------------------------------
Potential Costs:
    Material Costs Per Vehicle.  $282 to $507.
    Material Costs, Total New    $0.6 million to $1.1 million.
     Fleet.
Fuel Costs per Vehicle @3%.....  $2,814 to $5,523.
Fuel Costs per Vehicle @7%.....  $2,118 to $4,156.
Fuel Costs, Total New Fleet....  $4.7 million to $12.2 million.
                                ----------------------------------------
    Total Annual Cost..........  $5.3 million to $13.3 million.
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                   Table 2--Estimated Annual Benefits
                  [Undiscounted equivalent lives saved]
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------------------------------------------------------------------------
15 percent belt usage................................                3.1
84 percent belt usage................................                2.3
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                 Table 3--Cost per Equivalent Life Saved
                [Across 3% and 7% discount, 2010 dollars]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
15 percent belt usage..........  $2.09 million to $4.72 million.
84 percent belt usage..........  $2.91 million to $6.42 million
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                                     Table 4--Annualized Costs and Benefits
                                        [In millions (M) of 2010 dollars]
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                                             Annual costs           Annual benefits            Net benefits
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15% belt usage:
    3% Discount Rate.................  $6.81 M--$13.26 M......  $26.16 M...............  $12.9 M--$19.35 M.
    7% Discount Rate.................  $5.28 M--$10.26 M......  $19.73 M...............  $9.47 M--$14.45 M.
84% belt usage:
    3% Discount Rate.................  $6.81 M--$13.26 M......  $19.87 M...............  $6.61 M--$13.06 M.
    7% Discount Rate.................  $5.28 M--$10.26 M......  $14.95 M...............  $4.69 M--$9.67 M.
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    NHTSA has considered retrofit requirements. Based on our tests of 
older buses, the agency believes that major structural changes to the 
vehicle's entire sidewall and roof structure would be needed for some 
existing buses (that are of the type covered by this rule) to meet the 
rollover structural integrity requirements proposed in today's NPRM. 
Such structural changes are likely to be cost-prohibitive, making 
retrofitting for rollover structural integrity quite impractical. Thus, 
the agency has tentatively not included roof structure retrofitting 
requirements for existing vehicles in today's proposal.
    However, today's NPRM proposes requirements for emergency exit 
integrity and operability and side window glazing retention through 
enhanced structural integrity, aspects of performance included in Sec.  
32703(b)(2) of MAP-21. Section 32703(e)(2)(A) of MAP-21 states that 
``the Secretary may assess the feasibility, benefits, and costs with 
respect to the application of any requirement established under [Sec.  
32703(b)(2)] to motorcoaches manufactured before the date on which the 
requirement applies to new motorcoaches.'' Subsection (e) states that 
the Secretary shall submit a report on the assessment to Congress not 
later than July 2014. Thus, the agency is requesting comments on the 
feasibility, benefits, and costs of any potential requirement to 
retrofit existing buses with stronger emergency exit mechanisms and 
enhanced structural integrity to increase side window glazing retention 
to afford a similar level

[[Page 46094]]

of anti-ejection protection for passengers riding in existing buses.

II. Background

    Each year, the motorcoach industry transports millions of people 
for long and short distance travel, tours, school field trips, 
commuter, and entertainment-related trips. According to the 2008 
Motorcoach Census,\11\ there were 3,432 over-the-road bus carriers in 
the United States and Canada in 2007. These carriers operated over 
33,536 over-the-road buses,\12\ logged 751 million trips made by 
passengers, and traveled over 1.8 billion miles yearly. The services 
provided by over-the-road buses in 2007 included charter services (46.4 
percent of the miles driven), moving people between cities or between 
cities and rural areas (26.5 percent of the miles driven), transporting 
people between home and work (10.3 percent of the miles driven), and 
shuttle services to and from the airport (3.4 percent of the miles 
driven). In 2007, each over-the-road bus was driven an average of 
54,000 miles.
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    \11\ The ``2008 Motorcoach Census,'' funded by the American Bus 
Association (ABA), defines a motorcoach as an over-the-road bus, 
designed for long-distance transportation of passengers, 
characterized by integral construction, and with an elevated 
passenger deck located over a baggage compartment. See ``Motorcoach 
Census 2008, A Benchmarking Study of the Size and Activity of the 
Motorcoach Industry in the United States and Canada in 2007.'' Paul 
Bourquin, Economist and Industry Analyst, December 18, 2008. The 
buses included in the 2008 Motorcoach Census are over-the-road buses 
that are at least 35 feet in length and have a capacity of more than 
30 passengers. Traditionally, these over-the-road buses are 
considered to be motorcoaches. We note that this rule would apply to 
a larger set of vehicles than those within the ABA's definition of 
motorcoach, and therefore the statistics from the 2008 Motorcoach 
Census presented in this section are only applicable to over-the-
road buses.
    \12\ The 2008 Motorcoach Census defines motorcoaches to include 
a smaller set of vehicles than those covered by this NPRM. Thus, we 
have used the term ``over-the-road buses'' to describe the set of 
vehicles referenced by the 2008 Motorcoach Census.
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    Over the ten year period between 2000 and 2009, there were 45 fatal 
crashes of cross-country/intercity buses resulting in 134 occupant 
fatalities \13\ according to the FARS data \14\ collected by the 
agency. During this period, on average, 13 fatalities (11 passengers 
and 2 drivers) have occurred annually to occupants of cross-country/
intercity buses. This field and market data suggest that over-the-road 
(cross-country/intercity) bus transportation overall is a relatively 
safe form of transportation.
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    \13\ There was one cross-country/intercity bus fire in 2005 in 
Wilmer, Texas where 23 bus occupants died. The 134 occupant 
fatalities in cross-country/intercity buses does not include the 23 
fatalities from the bus fire since it did not occur as a result of a 
bus crash or rollover.
    \14\ The FARS database categorizes the vehicle body type of 
over-the-road buses as cross-country/intercity buses.
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    However, given the high occupancy of over-the-road buses (and the 
other large buses considered in today's proposed rule) and the speed at 
which they travel, a single crash can result in a significant number of 
fatal or serious injuries. Therefore, in this NPRM, the agency is 
proposing to enhance the safety of these vehicles by improving their 
crashworthiness relative to crush resistance, structural integrity, and 
reducing portal openings during rollover crashes.

a. NHTSA's Statutory Authority

    NHTSA is proposing today's NPRM pursuant to its authority under the 
Motor Vehicle Safety Act and the relevant provisions of MAP-21.
National Traffic and Motor Vehicle Safety Act
    Under 49 U.S.C. Chapter 301, Motor Vehicle Safety (49 U.S.C. 30101 
et seq.), the Secretary of Transportation is responsible for 
prescribing motor vehicle safety standards that are practicable, meet 
the need for motor vehicle safety, and are stated in objective terms. 
``Motor vehicle safety'' is defined in the Motor Vehicle Safety Act as 
``the performance of a motor vehicle or motor vehicle equipment in a 
way that protects the public against unreasonable risk of accidents 
occurring because of the design, construction, or performance of a 
motor vehicle, and against unreasonable risk of death or injury in an 
accident, and includes nonoperational safety of a motor vehicle.'' 
``Motor vehicle safety standard'' means a minimum performance standard 
for motor vehicles or motor vehicle equipment. When prescribing such 
standards, the Secretary must consider all relevant, available motor 
vehicle safety information. The Secretary must also consider whether a 
proposed standard is reasonable, practicable, and appropriate for the 
types of motor vehicles or motor vehicle equipment for which it is 
prescribed and the extent to which the standard will further the 
statutory purpose of reducing traffic accidents and associated deaths. 
The responsibility for promulgation of Federal motor vehicle safety 
standards is delegated to NHTSA.15 16 In making the 
proposals in today's NPRM, the agency carefully considered all the 
aforementioned statutory requirements.
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    \15\ See 49 CFR 1.95.
    \16\ The Secretary also delegated to NHTSA the authority set out 
for Section 101(f) of Public Law 106-159 to carry out, in 
coordination with the Federal Motor Carrier Safety Administrator, 
the authority vested in the Secretary by subchapter 311 and section 
31502 of title 49, U.S.C., to promulgate safety standards for 
commercial motor vehicles and equipment subsequent to initial 
manufacture when the standards are based upon and similar to a 
Federal Motor Vehicle Safety Standard promulgated, either 
simultaneously or previously, under chapter 301 of title 49, U.S.C.
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Motorcoach Enhanced Safety Act of 2012 (Incorporated in MAP-21)
    On July 6, 2012, President Obama signed MAP-21, which incorporated 
the ``Motorcoach Enhanced Safety Act of 2012'' into Subtitle G.\17\ 
Section 32703(b) of MAP-21 requires the Secretary to prescribe 
standards that would address certain aspects of motorcoach crash 
performance within two years if the Secretary determines that the 
standards would meet the requirements and considerations of Sec. Sec.  
30111(a) and (b) of the Motor Vehicle Safety Act.\18\ There are two 
subsections of Sec.  32703(b) that are particularly relevant to this 
NPRM. Subsection (b)(1) specifies that the Secretary is to establish 
improved roof and roof support standards that ``substantially improve 
the resistance of motorcoach roofs to deformation and intrusion to 
prevent serious occupant injury in rollover crashes involving 
motorcoaches.'' Subsection (b)(2) directs the Secretary to ``consider 
advanced glazing standards for each motorcoach portal and [to] consider 
other portal improvements to prevent partial and complete ejection of 
motorcoach passengers, including children.'' \19\
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    \17\ See Moving Ahead for Progress in the 21st Century Act, Pub. 
L. 112-141 (Jul. 6, 2012).
    \18\ See id. at Sec.  32703(b).
    \19\ While today's NPRM is mainly aimed at addressing the 
rollover structural integrity of specific large bus types, the 
proposed rule also addresses some of the safety risks associated 
with occupant ejection through side window glazing retention and 
emergency exit requirements. Thus, both subsection (b)(1) and 
subsection (b)(2) are relevant to this notice.
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    MAP-21 contains various other provisions that are relevant to this 
rulemaking. Section 32702 states that ``motorcoach'' has the meaning 
given to the term ``over-the-road bus'' in section 3038(a)(3) of the 
Transportation Equity Act for the 21st Century (TEA-21).\20\ Section 
3038(a)(3) of TEA-21 (see 49 U.S.C. 5310 note) defines ``over-the-road 
bus'' as ``a bus characterized by an elevated passenger deck located 
over a baggage compartment.'' However, Sec.  32702 of MAP-21 excludes 
transit buses and school buses from the ``motorcoach'' definition.\21\
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    \20\ See Moving Ahead for Progress in the 21st Century Act, Pub. 
L. 112-141, Sec.  32702(6).
    \21\ See id. at Sec.  32702(6)(A)-(B).

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[[Page 46095]]

    MAP-21 further directs the Secretary to apply any regulation 
prescribed in accordance with Sec.  32703(b) (and several other 
subsections) to all motorcoaches manufactured more than 3 years after 
the date on which the regulation is published.\22\ In addition, the 
Secretary may assess the feasibility, benefits, and costs of applying 
any requirement established under Sec.  32703 (b)(2) to ``motorcoaches 
manufactured before the date on which the requirement applies to new 
motorcoaches'' (retrofit).\23\ Finally, MAP-21 also authorizes the 
Secretary to combine the required rulemaking actions as the Secretary 
deems appropriate.\24\
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    \22\ See id. at Sec.  32703(e)(1).
    \23\ See id. at Sec.  32703(e)(2). ``Retrofit Assessment for 
Existing Motorcoaches.''
    \24\ See id. at Sec.  32706.
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b. NHTSA's 2007 Approach to Motorcoach Safety

    In 2007, NHTSA undertook a comprehensive review of motorcoach 
safety issues and the course of action that the agency could pursue to 
address them. The agency considered various prevention, mitigation, and 
evacuation approaches in developing the course of action. Many 
considerations were factored into determining the priorities, 
including: cost and duration of testing, development, and analysis 
required; likelihood that the effort would lead to the desired and 
successful conclusion; target population and possible benefits that 
might be realized; and anticipated cost of implementing the ensuing 
requirements into the motorcoach fleet.
    The result was NHTSA's 2007 plan, NHTSA's Approach to Motorcoach 
Safety (Docket No. NHTSA-2007-28793-001), in which we identified the 
following areas as the highest priorities for possible near term 
regulatory action to enhance motorcoach safety: (1) Passenger ejection; 
(2) rollover structural integrity; (3) emergency egress; and (4) fire 
safety.
    For passenger ejection (action (1) above), we pursued the 
incorporation of passenger seat belts as the most effective and 
expeditious way to mitigate ejection. The agency's seat belt 
rulemaking, discussed further below, began NHTSA's implementation of 
our Motorcoach Safety Plan. Today's document advances the 
implementation of the plan.

c. DOT's 2009 Task Force Action Plan

    In 2009, DOT issued a Departmental Motorcoach Safety Action Plan, 
which outlined a Department-wide strategy to enhance motorcoach 
safety.\25\ An update of the plan was issued on December 2012.\26\ In 
addition to the four priority action items specified in NHTSA's 2007 
plan, the 2009 DOT plan, and the 2012 updated plan identified 
additional factors for enhancing motorcoach safety, such as electronic 
stability control systems (ESC), event data recorders (EDRs), and 
driver fatigue and operator maintenance issues. Various DOT agencies 
are working on the motorcoach safety initiatives related to their 
administrations.
---------------------------------------------------------------------------

    \25\ http://www.fmcsa.dot.gov/documents/safety-security/MotorcoachSafetyActionPlan_finalreport-508.pdf.
    \26\ http://www.fmcsa.dot.gov/safety-security/pcs/Motorcoach-Safety-Action-Plan.aspx.
---------------------------------------------------------------------------

d. NTSB Recommendations

    As a part of its motorcoach crash investigations, NTSB has issued 
recommendations to NHTSA relating to actions that NTSB believes could 
improve motorcoach safety. The following NTSB recommendations related 
to motorcoach structural integrity pertain to this NPRM.
    In an NTSB Highway Special Investigation Report (1999), Bus 
Crashworthiness Issues,\27\ NTSB cited an October 1971 rollover of a 
1970 Motor Coach Industries (MCI) bus as justification for the 
following recommendations:
---------------------------------------------------------------------------

    \27\ National Transportation Safety Board. 1999, Bus 
Crashworthiness Issues. Highway Special Investigation Report NTSB/
SIR-99/04. Washington, DC.
---------------------------------------------------------------------------

    ``H-99-50 (MW): In 2 years, issue performance standards for 
motorcoach roof strength that provide maximum survival space for all 
seating positions and that take into account current typical motorcoach 
window dimensions.''
    ``H-99-51: Once performance standards have been developed for 
motorcoach roof strength, require newly manufactured motorcoaches to 
meet those standards.''
    In November 2009, after investigating an August 2008 Sherman, Texas 
bus crash,\28\ the NTSB issued two new safety recommendations. In this 
rollover crash, the failure of the overhead luggage rack on the vehicle 
impeded passenger egress and rescue efforts. Thus, NTSB stated that the 
Sherman accident and NHTSA's motorcoach testing indicate that the lack 
of standards for overhead luggage racks on motorcoaches leaves 
passengers at risk of serious injury from interaction with overhead 
luggage racks in a crash and made the following recommendations:
---------------------------------------------------------------------------

    \28\ NTSB/HAR-09/02 PB2009-916202; Motorcoach Run-Off-the-Bridge 
and Rollover Sherman, Texas August 8, 2008; October 2009; http://www.ntsb.gov/doclib/reports/2009/HAR0902.pdf.
---------------------------------------------------------------------------

    ``H-09-23: Develop performance standards for newly manufactured 
motorcoaches to require that overhead luggage racks remain anchored 
during an accident sequence.''
    ``H-09-24: Develop performance standards for newly manufactured 
motorcoaches that prevent head and neck injuries from overhead luggage 
racks.''
    In June 2010, after investigating a 2009 motorcoach rollover crash 
in Dolan Springs, the NTSB issued two additional recommendations:
    ``H-10-03: In your rulemaking to improve motorcoach roof strength, 
occupant protection, and window glazing standards, include all buses 
with a gross vehicle weight rating above 10,000 pounds, other than 
school buses.''
    ``H-10-04: Develop performance standards for all newly manufactured 
buses with a gross vehicle weight rating above 10,000 pounds to require 
that overhead luggage racks are constructed and installed to prevent 
head and neck injuries and remain anchored during an accident 
sequence.''

e. NHTSA's Seat Belt Final Rule

    Completing the first initiative of NHTSA's 2007 ``NHTSA's Approach 
to Motorcoach Safety'' plan and one of the principal undertakings of 
DOT's 2009 Motorcoach Safety Action Plan, and fulfilling a statutory 
mandate of the Motorcoach Enhanced Safety Act, NHTSA issued a final 
rule amending FMVSS No. 208, ``Occupant crash protection.'' The final 
rule required lap/shoulder seat belts for each passenger seating 
position in: (a) All new over-the-road buses; and (b) in new buses 
other than over-the-road buses, with a GVWR greater than 11,793 kg 
(26,000 lb).\29\ (The notice of proposed rulemaking preceding the final 
rule called buses with GVWR greater than 11,793 kg (26,000 lb) 
``motorcoaches.'')
---------------------------------------------------------------------------

    \29\ Some buses are excluded from this latter category, such as 
transit buses, school buses, and buses with perimeter-seating.
---------------------------------------------------------------------------

    NHTSA's safety research on seat belts in large buses (greater than 
11,793 kg (26,000 lb) GVWR) completed in 2009, showed that the 
installation of lap/shoulder belts on the vehicles is practicable and 
effective and could reduce the risk of fatal injuries in rollover 
crashes by 77 percent, primarily by preventing occupant ejection. Lap/
shoulder belts are also highly effective in preventing fatalities and 
serious injuries in frontal crashes, and will

[[Page 46096]]

enhance protection in side crashes in the affected buses. By requiring 
passenger lap/shoulder seat belts on (a) new over-the-road buses, and 
(b) new buses, other than over the road buses, with a GVWR greater than 
11,793 kg (26,000 lb), the final rule significantly reduces the risk of 
fatality and serious injury in frontal crashes and the risk of occupant 
ejection in rollovers, thus considerably enhancing the safety of these 
vehicles.

III. Safety Need

    The rulemakings that are being conducted pursuant to the 
requirements of the Motor Vehicle Safety Act and MAP-21, and as part of 
NHTSA's Approach to Motorcoach Safety and the DOT Motorcoach Safety 
Action Plan, explore whether there are unreasonable safety risks 
associated with motorcoach transportation. If there are such risks, we 
explore whether those safety risks can be reasonably reduced by having 
minimum levels of performance specified for crashworthiness and crash 
avoidance standards, such as a standard for rollover structural 
integrity.
    NHTSA found in the seat belt final rule that, generally, a 
significant majority of fatalities are attributable to rollovers. 
Because more than three-quarters of rollover fatalities are 
attributable to ejections, NHTSA issued a seat belt requirement to 
mitigate those ejections. For purposes of today's proposal, we believe 
that, hand-in-hand with that seat belt proposal, there is a need to 
ensure enhanced structural integrity of the interior of these buses, to 
better protect the restrained occupants who, due to the belts, will be 
retained in the bus interior. Moreover, independent of a seat belt 
requirement, we believe that more can be done to improve the vehicle 
structure to reduce the likelihood of ejection of occupants who may not 
be restrained at the time of the crash. For instance, emergency exits 
should not open during a rollover crash (an open emergency exit forms a 
portal through which occupants could be ejected). Today's NPRM proposes 
requirements to meet these objectives.

a. FARS Data and Recent Crashes

    To determine the types of vehicles that should be covered by the 
rulemakings conducted pursuant to the Motor Vehicle Safety Act and MAP-
21 and as part of the NHTSA's Approach to Motorcoach Safety plan and 
the DOT Motorcoach Safety Action Plan, the agency examined FARS data 
files to gain a better understanding of fatal crashes involving over-
the-road buses and other bus types.\30\ FARS contains data on a census 
of fatal traffic crashes within the 50 States, the District of 
Columbia, and Puerto Rico. To be included in FARS, a crash must involve 
a motor vehicle traveling on a traffic way customarily open to the 
public, and must result in the death of an occupant of a vehicle or a 
non-occupant within 30 days of the crash.
---------------------------------------------------------------------------

    \30\ Previous discussions of the FARS data is set forth in the 
seat belt final rule, and in the DOT 2009 Motorcoach Action Plan, 
http://www.nhtsa.gov/staticfiles/DOT/NHTSA/reports/HS811177.pdf.
---------------------------------------------------------------------------

    For the seat belt rulemaking and other ``motorcoach'' rulemakings, 
we analyzed 10 years of FARS data to assess what type of vehicle should 
be covered by NHTSA's motorcoach safety plan initiatives. We analyzed 
FARS data of high-occupancy vehicles (buses) that are in fatal crashes. 
FARS data for fatalities of occupants in high occupancy vehicles (buses 
with a GVWR greater than 4,536 kg (10,000 lb), other than school buses 
and transit buses) over 10 years show that 83 percent of the occupant 
fatalities were in buses with a GVWR greater than 11,793 kg (26,000 
lb). Based on these data, NHTSA determined that the vehicles of 
significance are those with a GVWR of greater than 11,793 kg (26,000 
lb). These buses appear to have a higher risk of involvement in fatal 
crashes involving passenger fatalities than buses with a GVWR of 11,793 
kg (26,000 lb) or less.
    For the seat belt final rule and for purposes of today's NPRM, the 
agency analyzed FARS data for vehicles coded in FARS as ``cross-
country/intercity buses,'' ``other buses,'' and ``unknown buses.'' \31\ 
Among these buses (cross-country/intercity buses, other buses, unknown 
buses) with a GVWR greater than 11,793 kg (26,000 lb), there were a 
total of 209 occupant fatalities \32\ in crashes during the 10-year 
period between 2000-2009. This number includes 134 occupant fatalities 
in cross-country/intercity buses, 47 in other buses, and 28 in unknown 
buses (see Figure 1 and Table 5 below). In contrast, with regard to 
buses with a GVWR less than 11,793 kg (26,000 lb), there were a total 
of 44 fatalities in cross-country/intercity buses, other buses, and 
unknown buses with a GVWR of 11,793 kg (26,000 lb) or less in the 2000-
2009 FARS data files. This is approximately one-fifth of the fatalities 
in such buses with a GVWR greater than 11,793 kg (26,000 lb).
---------------------------------------------------------------------------

    \31\ The FARS database has five bus body type categories: (1) 
Cross-country/intercity bus, (2) transit bus, (3) school bus, (4) 
other bus, and (5) unknown bus. Transit bus and school bus body 
types were excluded from the analysis because they are easily 
recognized and categorized as such by crash investigators and those 
coding the FARS data. Thus, those vehicles are unlikely to be 
miscoded as other buses.
    \32\ There were 232 occupant fatalities in the large bus types 
considered in today's NPRM during this 10-year period. However, 23 
fatalities occurred due to a fire (Wilmer, Texas bus fire) and were 
not related to a crash event and therefore are not included in the 
fatality count resulting from crashes.

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

[[Page 46097]]

[GRAPHIC] [TIFF OMITTED] TP06AU14.006

               Table 5--Number of Bus Occupant Fatalities in Crashes by Bus Body Type, GVWR, and Occupant Type. FARS 2000-2009 Data Files
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Bus body type
                                                 -------------------------------------------------------------------------------------------------------
                    GVWR (lb)                           Cross-Country                 Other                    Unknown                    Total
                                                 -------------------------------------------------------------------------------------------------------
                                                     Driver        Pass        Driver        Pass        Driver        Pass        Driver        Pass
--------------------------------------------------------------------------------------------------------------------------------------------------------
10,000-26,000...................................            0            2            5           26            2            7            7           35
>26,000.........................................           22          112           11           36            8           20           41          168
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Among the 209 occupant fatalities in the 10-year period, the FARS 
data show that 168 (80 percent) were passengers, and 41 (20 percent) 
were drivers. In addition, the data show that 64 percent of the 
fatalities were in cross-country/intercity buses and 36 percent were in 
the other bus and unknown bus categories (see Table 5 above).
    As shown in Figure 1, fatalities in certain years are significantly 
higher than average. There were more than 20 occupant fatalities in 
2002, 2004, 2007, and 2008 in crashes involving these vehicles. We note 
that such increases in fatality statistics were often attributable to a 
small number of serious crashes during that year which caused a large 
number of fatalities.
    For example, the majority of fatalities in 2004 resulted from a 
crash in Arkansas, which involved a bus hitting a highway signpost and 
subsequently rolling over. The rollover and partial detachment of the 
roof resulted in the ejection of all 30 occupants. This crash resulted 
in 15 fatalities, including the driver. All 14 passengers who died in 
this crash were ejected.
    The 42 passenger fatalities in 2008 were mainly a result of 3 
separate crashes. The first event was a rollover crash that occurred in 
Mexican Hat, Utah, where the bus overturned as it departed the roadway 
and rolled one full turn, striking several rocks in a drainage ditch 
bed at the bottom of the embankment, and came to rest on its wheels. 
The roof of the vehicle separated from the body, and 51 of the 53 
occupants were ejected. Nine passengers were fatally injured and 43 
passengers and the driver received various injuries.
    The second 2008 event was a crash in Sherman, Texas, where the bus 
went through the bridge railing and off the bridge. As a result of the 
accident, 17 passengers died. Among the NTSB findings, the report 
concluded that the overhead luggage rack had detached from its mounting 
and fell diagonally across the aisle onto the passengers and impeded 
passenger egress and rescue efforts.
    The third 2008 event was a rollover crash near Williams, 
California, where the bus flipped and rolled into a ditch, killing 9 
people and injuring more than 30 others. According to a media 
report,\33\ 30 to 38 people suffered critical injuries, while the rest 
of the passengers received moderate to minor injuries. Approximately a 
dozen passengers were ejected from the vehicle.
---------------------------------------------------------------------------

    \33\ http://www.kcra.com/news/17630435/detail.html.
---------------------------------------------------------------------------

    Separately, in 2009, a large number of fatalities were a result of 
a January 30, 2009 crash in which a 29-passenger tour bus overturned on 
a highway near the Hoover Dam, killing 7 occupants and injuring 10 
others. According to the

[[Page 46098]]

NTSB report,\34\ the 29-passenger mid-size bus veered left out of its 
lane. After the driver overcorrected, the bus rolled 1.25 times before 
stopping. During the rollover, 15 of the 17 occupants were fully or 
partially ejected.
---------------------------------------------------------------------------

    \34\ NTSB/HAR-10/01 PB2010-916201; Bus Loss of Control and 
Rollover Dolan Springs, Arizona; January 30, 2009.
---------------------------------------------------------------------------

b. Rollover and Ejection Statistics

    Using the aforementioned FARS bus type categories, the agency 
examined the FARS data to understand the proportion of occupant 
fatalities that resulted from rollover crashes and occupant ejections. 
The FARS data show that rollovers account for more than half of the 
occupant fatalities in these bus types. Figure 2, below, shows the 209 
fatalities categorized by rollover/first impact point for the 10-year 
period 2000-2009. If a vehicle was involved in a rollover, it is 
categorized as a rollover crash since it is generally the most harmful 
event in a crash and results in most of these fatalities. Vehicles not 
involved in a rollover are categorized by first impact point (front, 
side, and rear).
[GRAPHIC] [TIFF OMITTED] TP06AU14.007

    Among the 209 occupant fatalities, rollovers accounted for 114 
fatalities (55 percent). Also, 71 percent of crash fatalities in cross-
country buses were in rollover crashes, while 25 percent of the 
fatalities in other and unknown buses were in rollover crashes. There 
were no fatalities in rear and side impacts in cross-country and 
unknown bus body type categories.
    The agency further examined these data and found that the vast 
majority of fatalities in rollover crashes involve occupant ejections. 
Figure 3 shows the distribution of fatalities in) rollover crashes 
involving these bus types (cross-country, other, and unknown buses with 
a GVWR greater than 11,793 kg (26,000 lb)) by occupant type and 
ejection status. For the ten year period from 2000 to 2009, there were 
32 fatal rollover crashes, resulting in 114 fatalities. In these 
rollover crashes, two thirds (78 out of 114) of the fatalities were 
occupants who were ejected. Three drivers (3 percent) involved in 
rollover crashes were ejected.

[[Page 46099]]

[GRAPHIC] [TIFF OMITTED] TP06AU14.008

    While a large percentage of fatalities in rollover crashes are due 
to the occupants being ejected, some fatalities can be attributed to 
the collapse of structure during the rollover event. On May 31, 2011, a 
2000 Setra bus carrying 58 passengers from Greensboro, North Carolina 
to New York City on Interstate 95 departed the roadway near Doswell, 
Virginia, rolled 180 degrees, and landed on its roof. NTSB, which is 
investigating this accident, noted that there was considerable 
deformation of the roof into the occupant survival space as evidenced 
by the seat back deformation resulting from contact with the roof 
structure. The passenger seats were not equipped with seat belts. Four 
passengers were killed as a result of encroachment of the occupant 
survival space by the roof and fourteen passengers sustained serious 
injuries. The driver, restrained by a lap belt, was not injured.
    The agency is proposing the requirements in today's NPRM to improve 
rollover safety in large buses. The aforementioned data show that 
crashes involving rollovers and ejections present the greatest risk of 
death to the occupants of these buses. The majority of fatalities occur 
in rollovers, and two-thirds of rollover fatalities are associated with 
occupant ejection, particularly passenger ejection. There is also real 
world evidence that bus occupants retained in the bus during rollover 
events may sustain serious to fatal injuries due to structural 
collapse. The proposed requirements work in conjunction with the seat 
belt requirements by enhancing the protection of restrained and 
retained occupants in rollovers and reducing the risk of ejection of 
occupants who are not restrained.

IV. NHTSA's Large Bus Rollover Structural Integrity Research

    In support of this rulemaking initiative, the agency evaluated two 
existing roof crush/rollover standards: FMVSS No. 220, ``School bus 
rollover protection,'' and ECE R.66, ``Uniform Technical Prescriptions 
Concerning the Approval of Large Passenger Vehicles with Regard to the 
Strength of their Superstructure.'' \35\ We sought to evaluate the 
extent to which the standards would address the aforementioned safety 
concerns, particularly as to providing a minimum level of protection 
for vehicle occupants who are retained in the vehicle after a rollover.
---------------------------------------------------------------------------

    \35\ ECE R.66 defines ``superstructure'' as ``the load-bearing 
components of the bodywork as defined by the manufacturer, 
containing those coherent parts and elements which contribute to the 
strength and energy absorbing capability of the bodywork, and 
preserve the residual space in the rollover test.'' ``Bodywork'' 
means ``the complete structure of the vehicle in running order, 
including all the structural elements which form the passenger 
compartment, driver's compartment, baggage compartment and spaces 
for the mechanical units and components.'' (Footnote added.)
---------------------------------------------------------------------------

    The agency purchased three different bus models for this test 
program. Two older models were selected because they were 
representative of the range of roof characteristics (such as design, 
material, pillars, shape, etc.) of large bus roofs in the U.S. fleet. 
The vehicles selected were two 12.2 meters (m) (40 feet) long MY 1992 
MCI model MC-12, and two 12.2 m (40 feet) long MY 1991 Prevost model 
(Prevost) LeMirage buses. The MCI and Prevost models were selected 
because they were similar in size and weight but exhibited visible 
differences in construction. The most discernible difference between 
these two models was that of the two, the Prevost LeMirage had smaller 
side windows and more roof support pillars.
    Many buses, newer than those MCI and Prevost models, are 13.7 m (45 
feet) instead of 12.2 m (40 feet) in length. Thus, the agency believed 
that manufacturers could have significantly redesigned their bus models 
when introducing the longer designs. Thus, the agency also procured a 
MY 2000 MCI bus, Model 102-EL3, that was 13.7 m (45 foot) in length.
    All five of the buses purchased were tested to requirements in 
either FMVSS No. 220 or ECE R.66. For further information on the four 
older buses tested, a detailed discussion of the tests and results are 
available in the docket entry NHTSA-2007-28793-0019. For further 
information on the newer vehicle tested, see the test report, ``ECE 
Regulation 66 Based Research Test of Motorcoach Roof Strength, 2000 MCI 
102-EL3 Series Motorcoach, NHTSA

[[Page 46100]]

No.: MY0800,'' October 1, 2009, Report No.: ECE 66-MGA-2009-001, which 
can be found on NHTSA's Web site.\36\
---------------------------------------------------------------------------

    \36\ http://www-nrd.nhtsa.dot.gov/database/aspx/searchmedia2.aspx?database=v&tstno=6797&mediatype=r&r_tstno=6797, 
Report 8. Step-by-step instructions on accessing the research report 
can be found in a memorandum in Docket No. NHTSA-2007-28793-0025.
---------------------------------------------------------------------------

a. Findings of the FMVSS No. 220-Based Tests

    In evaluating FMVSS No. 220, the agency used one of the MY 1992 MCI 
buses and one of the MY 1991 Prevost buses.
    The FMVSS No. 220 test applies a uniformly distributed compressive 
load (equivalent to 1.5 times the unloaded vehicle weight (UVW) of the 
bus), on the roof of the bus along the vehicle's longitudinal 
centerline using a 915 mm (3 feet) wide platen that is 305 mm (1 foot) 
shorter than the bus length. The requirements are that the bus roof 
must not compress more than 130 mm (5.118 inches) and that the 
emergency exits remain operable.
    Since there were some uncertainties regarding the strength of the 
bus roofs and whether they could withstand a force of 1.5 times the 
unloaded vehicle weight (UVW), we slightly changed how the FMVSS No. 
220 test was conducted. In particular, when the applied force reached 
the magnitude of 0.5 times UVW and 1.0 times UVW, the force was held 
constant at that level for a period of time in order to examine the 
operability of the emergency exits. In addition, survival space 
templates \37\ (similar to those used in the ECE R.66 test) were 
installed for comparison with the results with the ECE R.66 tests.
---------------------------------------------------------------------------

    \37\ The templates are used to delineate the occupant survival 
space. The templates are 1,250 mm (50.2 inches) tall and are tapered 
from the sidewall a distance of 150 mm (5.9 inches) at the bottom 
and 400 mm (15.8 inches) at the top. Several templates are placed in 
the bus passenger compartment. Encroachment of any bus structure 
into the survival space, as delineated by the templates, would be 
prohibited by ECE R.66.
---------------------------------------------------------------------------

    Neither the MY 1992 MCI nor the MY 1991 Prevost bus was able to 
meet the 1.5 times the UVW required for school buses. For the MCI bus, 
a peak load of 0.91 times UVW was achieved when the force application 
device reached its maximum displacement range. Approximately 13 seconds 
after the peak force was recorded, contact was made between the front 
survival space template and the left and right overhead luggage racks. 
The emergency exit windows were operable after the load reached 0.5 
times UVW and after the test with the load removed.
    For the MY 1991 Prevost bus, a peak load of 1.17 times UVW was 
achieved during the test. This peak load was reached when the force 
application device reached its maximum displacement range. 
Approximately 12 seconds after the peak load was reached, contact was 
made between the front survival space template and the left and right 
overhead luggage racks. The emergency exit windows were operable after 
the load reached 0.5 times UVW and after the test with the load 
removed. However, no measurements were made at 1.0 times UVW for safety 
reasons.
    We made the following observations from the tests. Even though the 
buses we tested were heavier, larger, and structurally different than 
school buses,\38\ the testing demonstrated that FMVSS No. 220's test 
protocol could be adapted to test these vehicles with only minor 
changes to the test device and procedure for mounting and stabilizing 
the bus on the test device. The testing further showed that the front 
sections of these two bus models are weaker than the back. We believe 
this is because the windshield and service door are located in the 
front of the bus and offered little resistance to the compressive load. 
The front of the MY 1992 MCI bus yielded to the compressive load at 
0.91 times UVW, while the front of the MY 1991 Prevost bus yielded at 
1.17 times UVW.
---------------------------------------------------------------------------

    \38\ Generally, large bus designs are integral constructions 
whereas school buses are the traditional body-on-chassis designs. 
The loads specified in FMVSS No. 220 are applied to the frame 
structure of the school bus chassis which is easy to identify. In 
contrast, identifying load bearing points on a large bus can be 
challenging and requires some understanding of its construction. The 
location of load bearing points can vary for different designs. In 
the two large buses tested, the loads were applied at load bearing 
points near the wheel supports.
---------------------------------------------------------------------------

b. Findings of the ECE R.66-Based Tests

Testing of Older Bus Models
    The agency also used one of the MY 1992 MCI buses and one of the MY 
1991 Prevost buses to evaluate the ECE R.66 test procedure.
    In the ECE R.66 full vehicle test, the vehicle is placed on a 
tilting platform that is 800 mm above a smooth and level concrete 
surface. One side of the tilting platform along the length of the 
vehicle is raised at a steady rate of not more than 5 degrees/second 
until the vehicle becomes unstable, rolls off the platform, and impacts 
the concrete surface below. The vehicle typically strikes the hard 
surface near the intersection between the sidewall and the roof. The 
encroachment of the survival space during and after the rollover 
structural integrity test may be assessed using high speed photography, 
video, deformable templates, electric contact sensors, or any other 
suitable means.
    In our research, high speed video cameras and transfer media were 
applied to each survival space template in order to determine if any 
portion of the vehicle interior had entered the occupant survival space 
during the rollover crash. In addition, two Hybrid III (HIII) 50th 
percentile adult male Anthropomorphic Test Devices (ATDs) (test 
dummies) were installed in the vehicle to measure injury potential and 
seat anchorage performance.
    We observed the following in our tests of the older buses:
--The testing demonstrated that it is practicable to apply the ECE R.66 
complete vehicle test to the large buses being considered in today's 
NPRM. However, neither of the two buses tested was able to meet the 
requirement to maintain the integrity of the survival space during and 
after the test. Contact between the front survival space template and 
left side window was made on both bus models. As in the FMVSS No. 220-
based tests, the testing indicated that the front sections of these two 
models were weaker than the rear. We believe this is because the 
windshield and service door are in the front of the bus and offered 
little resistance upon impact with the ground.
--On both buses, the windows on the impact side remained intact. The 
high speed video footage from both tests indicated that the side 
windows located on the far-side of the impact underwent a substantial 
amount of flexion during the impact with the ground but remained 
intact. The windshield broke from its mounting and fell to the ground.
-- For both buses, the roof emergency exits opened when the bus 
impacted the ground. The video footage also indicated that the side 
emergency exit windows on the Prevost bus unlatched and opened but 
closed when the bus came to its final resting position.
--On the MY 1992 MCI bus, all of the left side overhead luggage rack 
inboard hangers (hangers connect the overhead luggage rack to the 
ceiling of the vehicle, and are spaced along the length of the rack to 
hold it up) rearward of the front two hangers, broke during the impact, 
leaving exposed sharp metal edges.
--For the MY 1991 Prevost bus, all the seats on the right side 
(opposite the impact side) of the bus detached from their wall mounts 
and the seat with the restrained dummy broke completely from its 
anchorages.
--The Injury Assessment Reference Values (IARVs) were relatively low 
for the ATDs restrained by the seat belts

[[Page 46101]]

(even for the seat in the Prevost bus that broke away from its side and 
floor anchorages). However, for the ATDs that were unrestrained, the 
type and severity of the injury indicated by the dummy IARVs depended 
on how they fell from their initial seated position during the rollover 
sequence. In the case of the MCI bus, the unrestrained ATD received 
only one IARV (neck injury criterion Nij = 1.10) that was over the 
performance limit used in FMVSS No. 208, ``Occupant crash protection.'' 
However, in the case of the MY 1991 Prevost bus, the unrestrained ATD 
fell across the bus head-first onto the side window which was in 
contact with the ground, resulting in multiple IARVs exceeding the 
performance limits specified in FMVSS No. 208. The dummy resulted in 
multiple IARVs that were well above the acceptable limits.
Testing of a Newer Bus Model
    NHTSA also conducted the ECE R.66 test on a MY 2000 MCI bus Model 
102-EL3 that was 13.7 m (45 foot) in length. This test was conducted to 
determine whether the ECE R.66 test protocol could be applied to the 
larger and heavier buses sold in the United States and to examine 
different ballasting methods. Survival space templates were installed 
and the vehicle was placed on a tilting platform that was 800 mm above 
a smooth and level concrete surface. One side of the tilting platform 
was raised at a steady rate of not more than 5 degrees/second until the 
vehicle became unstable, rolled off the platform, and impacted the 
concrete surface below. See, ``ECE Regulation 66 Based Research Test of 
Motorcoach Roof Strength, 2000 MCI 102-EL3 Series Motorcoach, NHTSA 
No.: MY0800,'' October 1, 2009, supra.
    Occupant ballasts were used in the test, as specified in ECE R.66. 
ECE R.66 specifies the option of two different methods of securing 
occupant ballast to the passenger seats. NHTSA tested both types of 
ballasts to determine the feasibility of each and the differences (if 
any) that exist between the two. The agency believed that ballasting 
was important because it increases the weight and raises the center of 
gravity of the vehicle, making the rollover structural integrity test 
more stringent and representative of a rollover crash of a fully loaded 
bus. In addition, the seat anchorages experience the forces in a 
rollover when the seat is occupied by an average sized restrained 
occupant.
    NHTSA evaluated the two ballasting methods to assess the 
feasibility and merits of the ballast methods. Four anthropomorphic 
ballasts, commercially available ``water dummies,'' \39\ were installed 
in one full row of seats (four seating positions) and were secured with 
ratchet straps that were configured to simulate Type 2 seat belts. The 
dimensions of the anthropomorphic ballasts used in this test are shown 
in Figures 5(a) and 5(b), below. The water dummies were each filled 
with 68 kg (150 lb) of sand. Steel ballasts, 68 kg (150 lb) per seating 
position, were installed in a second full row of seats (four seats). In 
this row, steel plates were placed on top of each seat cushion and were 
secured with bolts that passed through the cushion and attached to a 
bar which clamped onto the seat frame. (In the ECE R.66 test, each 
designated seating position with occupant restraints would be 
ballasted.)
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    \39\ These water dummies are plastic containers constructed to 
simulate the torso shape of a passenger and can be secured in place 
using belts. Such water dummies have the capacity to be loaded to a 
weight of 176 pounds (80 kg). However, since the GVWR of a vehicle 
is typically estimated using an occupant weight of 150 pounds per 
seating position and since ECE R.66 specifies ballasts of 150 
pounds, the agency only loaded the water dummies to 150 pounds. The 
water dummies were filled with sand instead of water because filling 
the ballast partially with water would cause the water's mass to 
slosh during the rollover test, possibly introducing some 
variability.
[GRAPHIC] [TIFF OMITTED] TP06AU14.009

[[Page 46102]]

[GRAPHIC] [TIFF OMITTED] TP06AU14.010

    We also seated two 50th percentile adult male ATDs on the opposite 
side of the impact. This arrangement was similar to the earlier tests 
with the older buses.
    We observed the following in our test of this MY 2000 bus:

--Based on an analysis of image data from the high-speed camera located 
outside the vehicle, it appears that a side pillar in the front of the 
vehicle along the impact side may have intruded into the survival 
space. However, this was not assessed using the survival space 
templates since they were not located at the position of the side 
pillar during the test, and there was no contact between the survival 
space templates and the bus structure.
--During impact, the glazing on five of the seven windows on the right 
side of the bus (opposite the impacted side) dislodged from their 
window mounting and fell into the occupant compartment during the test. 
The glazing in one of the windows was retained by an overhead TV 
monitor and prevented the window pane from separating from its mounting 
gasket and falling into the bus. The glazing in the last window near 
the rear shattered, but was retained and did not fall into the 
passenger compartment, apparently because the window was shorter in 
length than the other windows. After the bus impacted the ground, both 
sides of the windshield lost retention and fell from its supporting 
structure.
--All side emergency exit windows remained latched during the test. 
However, both roof emergency exits opened when the roof of the bus 
impacted the ground.
--The ATD restrained by the seat belt measured forces that were below 
the FMVSS No. 208 IARVs. However, the unrestrained ATD had multiple 
IARVs that were well above the acceptable limits.
--In terms of the feasibility of the test procedure, the testing showed 
that it was possible to ballast the seats with either the 
anthropomorphic ballast or steel weights. All of the seats with both 
types of ballast remained attached to their original anchorages.

V. Proposed Requirements

a. Overview

    This NPRM proposes performance requirements that the large buses 
covered by this rulemaking must meet when tested by NHTSA using a test 
substantially modeled after the complete vehicle test of ECE R.66.\40\ 
In the rollover structural integrity test, the vehicle would be loaded 
with up to 68 kg (150 lb) of weight in ballasts at each designated 
seating position in order to simulate the load of occupants on both 
vehicle structure and the seat anchorages. The following are the 
proposed performance requirements when the vehicle is subjected to the 
rollover structural integrity test:
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    \40\ ECE R.66 includes several ``equivalent approval tests,'' 
including body section testing and computer simulations. In a later 
section, we discuss why we believe these alternative compliance 
methods would not be suitable for incorporation into today's 
proposed Federal motor vehicle safety standard.
---------------------------------------------------------------------------

    (1) Intrusion into the survival space, demarcated in the vehicle 
interior, by any part of the bus outside the survival space is 
prohibited;
    (2) each anchorage of the seats and interior overhead luggage racks 
and compartments shall not completely separate from its mounting 
structure;
    (3) emergency exits must remain shut during the test and roof and 
rear emergency exits must be operable in the manner required under 
FMVSS No. 217 after the test; and
    (4) each side window glazing opposite the impacted side of the 
vehicle must remain attached to its mounting such that there is no 
opening that will allow the passage of a 102 mm diameter sphere.

b. Applicability

    In this rulemaking, the agency's goal is to apply the proposed 
requirements in today's NPRM to generally the same group of vehicles 
that are covered by the seat belt final rule. The agency tentatively 
believes that it would make sense to apply today's proposed 
requirements generally to the same group of vehicles that are covered 
by the seat belt final rule. Both rulemakings are intended to address 
different facets of occupant harm occurring from the rollover event. 
Both standards would apply to the vehicles associated with unreasonable 
risk of harm in rollovers. The agency tentatively concludes that this 
rollover-specific NPRM should apply to high-occupancy vehicles 
associated with unreasonable risk of fatal rollover involvement and 
that these vehicles are generally buses with a GVWR greater than 11,793 
kg (26,000 lb).
    In order to achieve this, the agency proposes to apply the 
requirements to two types of buses: (a) All new over-the-road buses 
(regardless of GVWR) and (b) all new buses other than over-the-road 
buses, with a GVWR greater than 11,793

[[Page 46103]]

kg (26,000 lb).\41\ While the vast majority of over-the-road buses have 
a GVWR greater than 11,793 kg (26,000 lb), the agency proposes to take 
this two-prong approach towards determining applicability of the 
proposed standard in order to cover all of the buses covered by MAP-21 
and all of the buses with similar safety risks as the buses covered 
under MAP-21.
---------------------------------------------------------------------------

    \41\ Transit buses, school buses, and perimeter-seating buses 
would be excluded from the standard under this latter category.
---------------------------------------------------------------------------

MAP-21 and Over-the-Road Buses
    As described above, the large bus rulemaking provisions in MAP-21 
apply to ``motorcoaches'' which are defined as ``over-the-road buses.'' 
An over-the-road bus is, in turn, defined as ``a bus characterized by 
an elevated passenger deck located over a baggage compartment.'' In 
order to cover this group of vehicles, we propose in this NPRM to use 
the language from MAP-21 and apply the proposed requirements to ``over-
the-road buses.'' Further, we propose to adopt the definition 
incorporated in MAP-21 and define over-the-road buses as buses that are 
characterized by an elevated passenger deck located over a baggage 
compartment.\42\
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    \42\ As described further, below, over-the-road buses include 
buses operated by public transit agencies so long as they meet the 
over-the-road bus definition (buses characterized by an elevated 
passenger deck located over a baggage compartment).
---------------------------------------------------------------------------

    The agency believes that the vast majority of ``over-the-road 
buses'' are buses with a GVWR greater than 11,793 kg (26,000 lb). 
However, rather than simply applying the proposed requirements to buses 
(of any type) with a GVWR greater than 11,793 kg (26,000 lb) the agency 
tentatively believes that it is necessary to propose a separate 
definition for ``over-the-road buses'' and apply the proposed 
requirements to all of those buses. While most over-the-road buses have 
a GVWR greater than 11,793 kg (26,000 lb), the agency is not aware of 
any reason why buses characterized by an elevated passenger deck 
located over a baggage compartment (over-the-road buses) must 
necessarily have a GVWR greater than 11,793 kg (26,000 lb). As it is 
possible to design a bus with an elevated passenger deck located over a 
baggage compartment with a GVWR less than 11,793 kg (26,000 lb), the 
agency tentatively believes that it is necessary to apply the proposed 
requirements to all over-the-road buses (regardless of GVWR) in order 
to cover all the buses contemplated by Congress in MAP-21. In addition, 
the agency believes that over-the-road buses (as characterized in MAP-
21) are likely to be used for high-speed intercity travel (where 
rollover crashes are more likely to occur) regardless of the vehicle's 
GVWR.
Buses Other Than Over-the-Road Buses With a GVWR Greater Than 11,793 kg 
(26,000 lb)
    However, in addition to the buses contemplated by Congress in MAP-
21, the agency proposed to also cover other types of buses \43\ so long 
as those buses have a GVWR greater than 11,793 kg (26,000 lb). As 
discussed in the ``Safety Need'' section of this preamble, FARS data 
for 2000-2009 show that rollovers constitute a large safety problem for 
buses with a GVWR greater than 11,793 kg (26,000 lb). FARS data show 
that rollovers (32 crashes, 114 fatalities) accounted for 34 percent of 
the fatal crashes yet more than 50 percent of the occupant fatalities. 
In these rollover crashes, two-thirds of the fatalities were passengers 
who were ejected. The data indicate that, for these vehicles, rollover 
crashes and occupant ejections are more likely to cause fatalities than 
other types of crashes.
---------------------------------------------------------------------------

    \43\ Except transit buses, school buses, and perimeter seating 
buses
---------------------------------------------------------------------------

    As mentioned earlier, NHTSA is proposing to adopt the requirements 
in today's NPRM under its authority in both the Motor Vehicle Safety 
Act and the relevant provision of MAP-21. While the relevant provisions 
of MAP-21 instruct this agency to examine ``over-the-road buses'' 
(buses characterized by an elevated passenger deck located over a 
baggage compartment) in any roof strength and anti-ejection 
rulemakings,\44\ no provision in MAP-21 limits the agency's ability to 
examine other types of buses pursuant to its existing authority under 
the Motor Vehicle Safety Act.
---------------------------------------------------------------------------

    \44\ See Moving Ahead for Progress in the 21st Century Act, Pub. 
L. 112-141, Sec.  32703(b).
---------------------------------------------------------------------------

    Given the available data, the agency believes that limiting the 
scope of this rulemaking to ``traditional motorcoaches'' (over-the-road 
buses) would be only a partial and incomplete response to the safety 
problem. As discussed above, the FARS data for 2000-2009 show that 
buses other than over-the-road buses were often involved in high speed 
crashes involving multiple passenger fatalities. The FARS data show 
that 64 percent of the fatalities were in cross-country/intercity buses 
(considered traditional over-the-road type buses) and 36 percent were 
in the ``other bus'' and ``unknown bus'' categories. While these 
``other'' and ``unknown'' buses have a non-traditional (e.g., body-on-
chassis) design and appearance, these buses are of a similar size, 
seating configuration, and function as an over-the-road bus type. As a 
result, these buses are associated with similar safety risks as over-
the-road buses. Thus, the agency is currently unaware of a rationale 
that would support excluding these ``other'' and ``unknown'' buses from 
today's proposed requirements.
    As the data indicate, the safety risks associated with rollover 
accidents in large buses are not limited to only traditional 
motorcoaches (over-the-road buses). Thus, the agency proposes to apply 
the proposed requirements in today's NPRM to buses other than those 
called ``motorcoaches'' in MAP-21. Beyond the ``over-the-road'' buses 
identified by MAP-21, NHTSA proposes to apply the proposed requirements 
to generally the same universe of vehicles to which the seat belt final 
rule applies. The agency believes that the proposed rule should apply 
to all buses with similar rollover crash risks.
Buses Other Than Over-the-Road Buses With a GVWR Between 4,536 and 
11,793 kg (10,000 and 26,000 lb)
    On the other hand, buses with a GVWR between 4,536 and 11,793 kg 
(10,000 and 26,000 lb) do not have the same rollover crash risks as the 
aforementioned bus categories. Thus, while comment is requested on this 
subject, this NPRM tentatively has not included these buses in today's 
proposal. According to the FARS 2000-2009 data files, there were 42 
occupant fatalities in crashes involving cross-country buses, other 
buses, and unknown buses with a GVWR between 4,536 and 11,793 kg 
(10,000 and 26,000 lb) in this 10-year period (see Table 5, supra). 
Among these 42 occupant fatalities in buses with a GVWR between 4,536 
and 11,793 kg (10,000 and 26,000 lb), 24 fatalities were a result of 13 
rollover crashes. Thus, over the ten year period between 2000 and 2009, 
buses with a GVWR between 4,536 and 11,793 kg (10,000 and 26,000 lb) 
were associated with an average of 1.3 rollover crashes per year and 
2.4 fatalities per year. In contrast, there was an average of 3.2 
rollover crashes among buses in these same categories with a GVWR 
greater than 11,793 kg (26,000 lb) per year. These crashes resulted in 
an average of 11.4 fatalities per year. Among all fatalities occurring 
in rollover crashes in cross-country, other, and unknown buses with a 
GVWR greater than 4,536 kg (10,000 lb), 83

[[Page 46104]]

percent are in buses with a GVWR greater than 11,793 kg (26,000 lb).
    Further, the agency notes that buses with a GVWR between 4,536 and 
11,793 kg (10,000 and 26,000 lb) are frequently used for demand-
response transit \45\ services.\46\ These demand-response transit 
service vehicles are used in urban areas and rarely operate at highway 
speeds, which are the speeds at which the majority of bus rollover 
fatalities occur. Compared to the estimated number of large buses sold 
annually (approximately 2,200 buses), there are approximately 14,600 
buses with a GVWR between 4,536 and 11,793 kg (10,000 and 26,000 lb) 
produced annually.\47\ Given that more of the lower weight buses are 
manufactured than large buses annually, applying the proposed rule to 
buses with a GVWR between 4,536 and 11,793 kg (10,000 and 26,000 lb) 
may increase the potential costs of the rule more than the potential 
benefits.
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    \45\ Public transportation characterized by flexible routing and 
scheduling of small/medium vehicles operating in shared ride mode 
between pickup and drop-off locations according to passenger needs. 
It includes transporting persons with special mobility needs.
    \46\ Evaluation of the Market for Small-to-Medium Sized Cutaway 
Buses, Federal Transit Administration Project : MI-26-
7208.07.1, December 2007, available at http://www.fta.dot.gov/documents/AnEvaluationofMarketforSmalltoMediumSizedCutawayBuses.pdf.
    \47\ See Id.
---------------------------------------------------------------------------

    However, NHTSA requests comment on the issue and invites useful 
data, particularly related to the cost of applying the proposed rule to 
buses with a GVWR between 4,536 and 11,793 kg (10,000 and 26,000 lb). 
Are there data as to whether the cost of applying the proposed 
requirements to buses with a GVWR between 4,536 and 11,793 kg (10,000 
and 26,000 lb) will be significantly different when compared to buses 
with a GVWR greater than 11,793 kg (26,000 lb)? We request data that 
show whether the effectiveness of the countermeasures would be 
different between these two bus sizes. Are there data which show how 
the impact on small businesses would change if the requirements of 
today's proposal were extended to buses with GVWR between 4,536 and 
11,793 kg (10,000 and 26,000 lb)?
    Although the aforementioned data show that buses with a GVWR 
between 4,536 and 11,793 kg (10,000 and 26,000 lb) have historically 
been associated with less fatalities than buses with a GVWR above 
11,793 kg (26,000 lb), the agency notes these buses represent a 
significant number of bus sales, have a lower price ($50,000--$65,000), 
and higher fuel economy.\48\ As smaller buses can also be utilized to 
service similar routes as larger buses, it may be possible, in the 
future, that more crashes could occur in these types of buses if these 
buses experience higher sales volume and begin to service routes that 
result in a higher number of vehicles miles traveled. NHTSA recognizes 
that this proposal does not cover all the vehicles recommended by the 
NTSB in recommendations H-10-3 and H-10-4. As mentioned above, the NTSB 
recommended that NHTSA should include all vehicles with a GVWR of 4,536 
kg (10,000 lb) or greater in our rulemaking. Thus, the agency is 
requesting comment on the above concerns.
---------------------------------------------------------------------------

    \48\ See Id.
---------------------------------------------------------------------------

Transit, School, Perimeter Seating, Prison, and Double-Decker Buses
    While (in general) the agency proposes to apply the requirements in 
this NPRM to over-the-road buses (regardless of GVWR) and other buses 
with a GVWR greater than 11,793 kg (26,000 lb), the agency has 
considered various (more specialized) types of buses and whether or not 
these specific types of buses should be covered by the proposed 
requirements. Comments are requested on each of the following bus types 
and whether or not the agency should apply the proposed requirements in 
this NPRM to these bus types.
Transit Buses
    In today's proposal we have not included transit buses as a bus 
category that would be subjected to today's proposed requirements. The 
data show that the crash risk for transit buses (i.e., buses with a 
stop-request system that is sold for public transportation) is much 
lower than for the other bus types covered by today's proposal. In 
order to exclude transit buses, we propose to utilize the same 
definition for transit buses as in the seat belt final rule.\49\ Our 
reasoning, like in the seat belt final rule, is that there is a 
significantly lower crash risk for passengers of transit buses. We 
believe this difference in crash risk is due in part to the stop-and-go 
manner of transit bus operation. The FARS data from 2000-2009 show 
that, for all bus body types with a GVWR greater than 11,793 kg (26,000 
lb), transit buses have the fewest fatalities at 8.2 percent or 23 out 
of a total of 281. These same data show that there were 20 fatal 
crashes involving occupants of urban transit buses, resulting in 
fatalities of 11 drivers and 12 were passengers. Thus, fatal transit 
bus crashes involve about one fatality, on average. In summary, there 
are many fewer total fatalities and fatalities per crash for transit 
buses, and thus a significantly lower risk than in the other buses 
covered by today's proposed rule.
---------------------------------------------------------------------------

    \49\ Transit bus means a bus that is equipped with a stop-
request system sold for public transportation provided by, or on 
behalf of, a State or local government and that is not an over-the-
road bus.
---------------------------------------------------------------------------

    Like in the seat belt final rule, today's proposal explicitly 
states that over-the-road buses cannot qualify as transit buses (and be 
exempt from proposed requirements). While the agency acknowledges that 
state and local public transit agencies may purchase an over-the-road 
bus and equip such buses with a stop-request system, the agency 
believes that over-the-road buses used by transit agencies will likely 
be used in a similar manner as over-the-road buses purchased by private 
companies (i.e., for intercity transport carrying large numbers of 
passengers, over long distances, and at highway speeds). It is not 
uncommon to see commuter express buses traveling on the highway 
alongside privately-operated tour and charter buses of nearly identical 
construction. Thus, given the overall similarity of the buses in 
construction and use, we cannot distinguish, from a public safety 
standpoint, good reasons for distinguishing privately-operated versions 
of the over-the-road buses from those operated by state and local 
public transit agencies. Comments are requested on this topic.

School Buses

    As described in greater detail below, FMVSS No. 220 establishes 
roof strength requirements for school buses. While there are several 
reasons why the agency is proposing to use an ECE R.66-based test in 
today's NPRM, the agency is not proposing to alter the requirements for 
school buses. As further described below, there are various differences 
in the operating conditions the large buses covered under today's 
proposal and school buses covered under FMVSS No. 220 that make an ECE 
R.66-based test more suitable for the buses covered in today's 
proposal. As the safety record for school buses demonstrate that FMVSS 
No. 220 continues to be appropriate for those buses, the agency is not 
proposing to include school buses in today's proposal or to alter the 
requirements for school buses under FMVSS No. 220.
Buses With Perimeter Seating
    In the seat belt final rule, the agency did not apply the seat belt 
requirements to buses with perimeter seating (unless the bus with 
perimeter seating qualifies as an over-the-road bus). We propose to do 
the same for the requirements in

[[Page 46105]]

today's NPRM. While buses that qualify as over-the-road buses (under 
MAP-21) are covered under today's proposal regardless of seating 
configuration,\50\ we tentatively believe that it is appropriate to 
exclude perimeter buses that are not over-the-road buses because these 
buses with perimeter seating are used to carry people for a relatively 
short period, typically are meant to transport standees, and are 
spacious to accommodate baggage and other carry-on items and to 
maximize the speed of passenger boarding and alighting. Under these 
conditions, buses with perimeter seating are not expected to transport 
passengers for a long distance at relatively high speeds where rollover 
crashes are more common. However, the agency requests comment on 
whether it is likely that buses with a GVWR greater than 11,793 kg 
(26,000 lb) would be configured with perimeter seating and whether such 
buses would be used in conditions where rollover crashes are more 
likely to occur. We further request comment on whether such buses 
should be included as a bus type subject to this proposal.
---------------------------------------------------------------------------

    \50\ In order to cover all the buses that were covered under 
MAP-21, this proposal specifically defines ``perimeter seating 
buses'' as buses that are not over-the-road buses. Therefore, over-
the-road buses are covered under today's proposal without regard to 
their seating configuration.
---------------------------------------------------------------------------

Prison Buses
    While prison buses were excluded from meeting the requirements of 
the seat belt final rule, we have tentatively decided not to exclude 
prison buses from the proposed requirements of today's NPRM. In the 
seat belt final rule, the agency noted in response to comments that 
certain structural aspects of prison buses (e.g., fiberglass or 
stainless steel low-back seats or benches) are not conducive to install 
seat belts. Further, we noted the security concern that lap/shoulder 
belt equipment could pose hazards as the buckle hardware and belt 
webbing could be used as weapons or tools. However, these similar 
concerns are not present when considering the proposed requirements in 
today's NPRM.
    Designing the roof of a prison bus to better withstand an impact 
during a rollover crash is unlikely to involve any equipment that needs 
to be installed on the passenger seats or any equipment that could be 
potentially used as weapons/tools. However, the agency requests comment 
on whether or not it is reasonable to exclude prison buses from the 
proposed requirements in this rulemaking. If the recommendation is to 
exclude prison buses, what is the rationale for doing so? Is it 
reasonable to exclude prison buses from all of the requirements 
proposed in this NPRM or would it be appropriate to apply some--but not 
all--of the requirements proposed (e.g., emergency roof exit 
requirements but not the survival space requirements)?
Double-Decker Buses
    The agency notes that the requirements of ECE R.66 do not apply to 
double-decker buses while NHTSA's proposal does not exclude them from 
rollover structural integrity requirements.
    We have tentatively decided that the proposed test procedure is not 
appropriate for and should not be applied to the upper/open section of 
open-top double-decker buses because there would be no structure to 
intrude into any defined survival space in the upper/open level. 
However, we believe that lower/enclosed sections of such vehicles (or 
the upper/enclosed section of a double-decker bus) can still be tested 
under the proposed test procedure for compliance with the requirements 
of the proposed rule. In the lower/enclosed or upper/enclosed level, 
there would be vehicle structure that could intrude into the survival 
space in the same fashion as a traditional bus that does not have an 
open-top. Comments are requested on any technical reasons that would 
preclude the proposed test from being applied to the enclosed section 
of double-decker buses, and on whether additional provisions in the 
regulatory text are needed in order to further account for testing of 
double-decker buses.

c. Test Procedure

    The agency proposes in today's NPRM that compliance with the 
proposed performance requirements will be measured by NHTSA \51\ using 
a test substantially patterned after the complete vehicle test of ECE 
R.66. Similar to the ECE R.66 complete vehicle test, the proposed test 
would specify that the vehicle is placed on a raised platform that is 
800 mm (31.50 inches (in)) above a horizontal, dry and smooth concrete 
ground surface. The test would allow NHTSA to position the vehicle such 
that either side (right and left) of the vehicle may be tested for 
compliance. The tilting platform would be raised, on one side, at a 
rate not to exceed 5 degrees/sec along an axis no greater than a 100 mm 
horizontal distance from the edge of the impact surface closest to the 
tilting platform and 100 mm below the top of the platform surface, 
until the vehicle becomes unstable and commences the rollover. The 
tilting platform would be equipped with wheel supports to maintain the 
vehicle's position on the tilting platform before the vehicle becomes 
unstable and commences the rollover.
---------------------------------------------------------------------------

    \51\ As with all the FMVSSs, this standard would not require 
vehicle manufacturers to use the test to certify their vehicles. 
They may certify their vehicles using other means. Manufacturers 
must ensure, however, that their vehicles will meet the FMVSS 
requirements when tested by NHTSA when we use the test procedure 
specified in the FMVSS. If the vehicle does not meet the 
requirements when tested by NHTSA, we will ask the manufacturer for 
the basis for its certification. If the agency is satisfied that the 
manufacturer exercised due care in making the certification, the 
agency may decide not to pursue civil penalties against the 
manufacturer for the failure of the vehicle to comply. The 
manufacturer is still subject to the requirements of the National 
Traffic and Motor Vehicle Safety Act to recall the noncomplying 
vehicles and remedy the noncompliance free of charge.
---------------------------------------------------------------------------

Ballasts Representing Restrained Occupants
    To simulate a real-world rollover, the agency believes it would be 
appropriate to subject the vehicle to the forces resulting from the 
mass of restrained occupants. To achieve this, this NPRM proposes that 
a mass of 68 kg (150 lb) be secured in each designated seating position 
equipped with a seat belt system. The ballast would have to be 
restrained in such a manner that the ballast does not break away during 
the test. The 150-lb ballast would represent the mass of an ``average'' 
occupant at each designated seating position. (The 150 lb value is used 
in determining the vehicle's gross vehicle weight rating in accordance 
with 49 CFR Part 567, ``Certification.'')
    The agency believes that ballasting is important because it 
increases the weight and raises the center of gravity of the vehicle to 
simulate the forces upon the vehicle structure in a rollover crash when 
the seats are occupied by restrained passengers. Also, when occupants 
are belted into the vehicle, their mass imparts crash forces to the 
seat anchorages during a crash.
    While the agency believes that ballasting is important, we have 
tentatively concluded that the method of ballasting and type of ballast 
used is not important because these factors will not significantly 
alter the forces upon the vehicle structure or the seat anchorages 
during compliance testing, so long as the ballast is 150 lb. We note 
that ECE R.66 does specify the option of using two different occupant 
ballasts: anthropomorphic ballasts (commercially available ``water 
dummies''), and fixed steel plates. The ECE regulation stipulates that 
if the ballast is an anthropomorphic ballast, it is secured

[[Page 46106]]

using a seat belt restraint, and if the ballast is a rigid weight it is 
securely attached to the seat frame.
    In its research, NHTSA tested both ballasting methods from ECE R.66 
and the results did not show a significant difference between these 
methods in terms of the effect on test results. We tentatively believe 
that the test results of the complete vehicle rollover test will not be 
significantly altered so long as a 150-lb ballast is secured to each 
designated seating position equipped with the seat belt system. We 
recognize that the center of gravity of the ballast can vary depending 
on the manner in which it is secured to the seat and the type of 
ballast it is. However, as explained below, the agency tentatively 
believes that the difference in the ballasts will not significantly 
alter the loads applied to the vehicle structure (as a whole) or to the 
seat anchorages.
    We analyzed the effect of the different center of gravity heights 
for the anthropomorphic ballasts and the fixed weight ballasts and 
found that the overall center of gravity of the vehicle--and, 
consequently, the energy absorbed in the rollover structural integrity 
test of the fully loaded vehicle--is only slightly higher (less than 3 
percent higher) \52\ when using anthropomorphic ballasts as opposed to 
when using fixed weights as ballasts positioned on the seat cushion. We 
believe that this difference in the stringency of the rollover 
structural integrity test using different ballasts is small and within 
the overall accepted variability in the test procedure.
---------------------------------------------------------------------------

    \52\ The effect of ballasts (and the type of ballast) is 
greatest for the lowest weighing vehicle to which the rollover test 
applies, which is, by definition, a vehicle with a GVWR of 26,001 
pounds. For determining the effect of the ballasts and type of 
ballasts, the following estimations were made: The unloaded weight 
of the 55 occupant motorcoach is 26,001 pounds, the center of 
gravity of the unloaded motorcoach is 1.22 m (48 in) above ground, 
the height of the seat cushion of seats in the bus is 1.5 m (60 in) 
above ground, and the height of the center of gravity of a 68 kg 
rigid weight and that of an anthropomorphic ballast in the vehicle 
seat is 1.57 m (62 in) and 1.7 m (67 in) above ground, respectively. 
The addition of a 68 kg ballast at each of the 55 seats increases 
the weight of the vehicle by 32 percent. The center of gravity 
height above ground of the fully loaded vehicle is higher than that 
of the unloaded vehicle by 7 percent when rigid weights are used and 
by 9.5 percent when anthropomorphic ballasts are used. Through film 
analysis of the motorcoach rollover tests, we estimated that the 
center of gravity of the unloaded motorcoach drops approximately 
0.85 m during the test. We then estimated that the total energy 
absorbed by the fully loaded motorcoach (=9.81 X total mass (kg) X 
drop in center of gravity during the rollover test) is 3 percent 
greater when anthropomorphic ballasts are used than when rigid 
weights are used. Since the effect of ballasts is greatest for the 
26,001 lb GVWR motorcoach, the difference in the center of gravity 
height and the energy absorbed for different ballast types will be 
significantly less than 3 percent for motorcoaches with a GVWR more 
than 26,001 lb.
---------------------------------------------------------------------------

    Further, we analyzed the forces and moments generated at the 
anchorages due to the ballasts during the rollover impact sequence and 
found that the difference in moment at the anchorages due to the 
loading from the fixed weight ballast and that from the anthropomorphic 
ballast during impact is approximately 350 Nm.\53\ This value is small 
in comparison to the moments at the seat anchorages due to the 3,000 lb 
loads on the belts in an FMVSS No. 210 test (approximately 20,000 Nm). 
Further, the agency tentatively believes that this difference in moment 
is small when we consider the racking forces that would be acting upon 
the seat anchorages as a result of the vehicle's impact on the impact 
surface during the rollover test. During our testing of the 1991 
Prevost LeMirage using the ECE R.66 complete vehicle test, all the 
seats on the opposite side of impact detached from their wall mounts 
due to the racking of the bus side walls, even though the seats were 
not ballasted. Therefore, we have tentatively concluded that the type 
of ballast does not have significant effect on the performance of the 
seat anchorages or the vehicle structure during the rollover structural 
integrity test.
---------------------------------------------------------------------------

    \53\ Assuming that the ballast is fully coupled to the seat, the 
moment at the seat anchorages generated by the ballast is equal to 
the product of the mass of the ballast, its acceleration, and the 
height of the ballast center of gravity. In the agency's three ECE 
R.66 tests, the peak motorcoach floor acceleration was approximately 
4 gs and since the seat is fully coupled to the floor, we estimated 
the ballast acceleration to be 4 gs. Thus the moment generated at 
the seat anchorages was calculated to be approximately 350 Nm (= 68 
kg x 4x9.81 x (1.7m-1.57m)).
---------------------------------------------------------------------------

    Nonetheless, comments are requested on our tentative conclusion. 
Should the agency specify a type of ballast? If so, which types of 
ballasts should the agency choose and what specifications are 
necessary? What repeatable method should the agency establish for 
mounting the ballast to each designated seating position? If 
anthropomorphic dummies from ECE R.66 are recommended, the agency 
requests comment on the availability of the anthropomorphic (water 
dummy) ballasts in the U.S. What substances can be used to fill 
anthropomorphic ballasts such that the ballast would achieve a weight 
of 150 lb with a consistent center of gravity? We note that the 
anthropomorphic (water dummy) ballasts specified in ECE R.66 were 
plastic containers (constructed to simulate the torso shape of a 
passenger) with the capacity to be loaded to a weight of 176 lb (80 
kg). Are anthropomorphic ballasts available which are designed to hold 
150 pounds?
    Separately, NHTSA has tentatively concluded that two aspects of the 
ballasting options allowed in the ECE R.66 complete vehicle test are 
not appropriate for application in our proposed test procedure.
    First, we note that ECE R.66 specifies different weights depending 
on the type of ballast that is used during the test. The ECE regulation 
requires that, when anthropomorphic ballasts are used, the entire 
estimated weight of an individual occupant's mass of 68 kg (150 lb) is 
required. However, when fixed ballasts are used, only 50 percent of the 
estimated individual occupant's mass (34 kg (75 lb)) should be 
attached. The agency tentatively concludes that securing only 50 
percent of the individual occupant's mass when using rigid weights 
would underestimate the load that will be placed on the vehicle and its 
seat anchorages during a rollover crash.
    We note that an Australian study \54\ estimated that 93 percent of 
a lap/shoulder belt restrained occupant mass, 75 percent of a lap 
belted occupant mass, and 18 percent of an unrestrained occupant mass 
are effectively coupled to the vehicle structure during rollover. In 
addition, a European Commission sponsored study \55\ found that the 
percentage of occupant mass coupled to the vehicle structure during 
rollover is 90 percent for lap/shoulder belted occupants and 70 percent 
for lap belted occupants. Based on the above research findings, the 
agency tentatively concludes that the vehicle should be ballasted to 
the full weight of 68 kg (150 lb) at all seating positions regardless 
of ballast method. Using a lower weight ballast for the fixed ballast 
setups does not appear to adequately simulate the loading conditions of 
the average restrained occupant.
---------------------------------------------------------------------------

    \54\ Anderson, J., et al., ``Influence of Passengers During 
Coach Rollover,'' Cranfield Impact Centre Ltd., ESV Proceedings, 
Nagoya, Japan, Paper No. 216, 2003.
    \55\ Enhanced Coach and Bus Occupant Safety (ECBOS), Project No. 
1999-RD.11130, European Commission, 5th Framework, August 2003.
---------------------------------------------------------------------------

    Second, ECE R.66 requires the rigid weight be fixed to the seat 
such that its center of gravity aligns with that of the anthropomorphic 
ballast (approximately 100 mm forward and 100 mm above the seating 
reference point). In our research, the agency found it difficult to 
position and fix the rigid weights according to this specification in a 
consistent and repeatable manner.
    Given that difficulty, we investigated whether affixing the rigid 
weights as specified by ECE R.66 is necessary. It

[[Page 46107]]

appears that the answer is no. As mentioned above, we analyzed the 
effect of the different center of gravity heights for the 
anthropomorphic ballasts and the fixed weight ballasts and found that 
the difference in center of gravity would not significantly affect the 
overall performance of the vehicle in the rollover test. Thus, assuming 
that steel ballasts similar to those allowed in ECE R.66 are specified 
in the final rule, the agency tentatively concludes that it would be 
sufficient to locate the steel ballasts on top of the seat cushion, 
since loading fixed ballasts to match the center of gravity of 
anthropomorphic ballasts present significant logistical challenges, 
without a noteworthy difference in the stringency of the test.
Vehicle Conditions
    To better ensure consistent and repeatable results, the proposed 
test procedure also includes specifications for various vehicle 
conditions. The proposed test specifies that the vehicle suspension is 
blocked to its normal riding position and that the vehicle tires are 
inflated to the manufacturer's recommended tire pressure. The proposed 
procedure also specifies that vehicle windows, doors, and emergency 
exits are fully closed and in the latched but unlocked positions. All 
fluids in the vehicle, including fuel, will be at maximum capacity. For 
environmental and test personnel safety, substitute fluids would be 
permitted provided the weight of the original fluid is maintained.
    The agency recognizes that vehicle fluids have the potential to add 
weight to the test specimen. As such, we request comment on whether 
there are certain vehicle fluids whose levels should not be included in 
the specifications for test conditions.

d. Survival Space

    To reduce unreasonable safety risks due to inadequate structural 
integrity during a rollover, the agency is proposing to set minimum 
standards for the structural integrity of the occupant compartment. We 
are proposing to define a volume of space in the occupant compartment 
(called the ``survival space'') and require that there shall be no 
intrusion of the survival space by any part of the vehicle or by the 
impact surface during movement of the tilting platform or resulting 
from impact of the vehicle on the impact surface.
    The agency is concerned that inadequate survival space may result 
in restrained occupants being injured by collapsing sidewalls, roof 
structure, or other objects. As the agency is currently conducting 
rulemaking to potentially require seat belts on the buses covered by 
this proposed rulemaking, the agency is also interested in ensuring 
that passengers (if belted) will be protected from further danger due 
to collapsing vehicle structure that intrudes into the survival space. 
Our research of the ECE R.66 test procedure showed that structural 
intrusions into the survival space occurred in the MY 1991, MY 1992, 
and MY 2000 buses. Our observations showed that the survival space 
templates came into contact with the side windows in the rollover 
structural integrity tests with the older buses. Further, our review of 
the outside high-speed video of the test on the MY 2000 bus indicates 
that the side pillars may have collapsed and intruded into the occupant 
survival space.
Defining the Survival Space
    The proposed rule defines ``survival space'' in a manner similar to 
ECE R.66's ``residual space.'' However, we propose to define the 
survival space by establishing the boundaries of the three-dimensional 
space, as opposed to the ECE R.66 method of defining the boundaries 
through the use of transverse planes which intersect a seat reference 
point. Thus, this NPRM proposes to define the survival space as a 
three-dimensional volume with a front boundary beginning at the 
transverse vertical plane 600 mm in front of the forward-most point on 
the centerline of the front surface of the seat back of the forward-
most designated seating position. The rear boundary of the survival 
space would be the inside surface of the rear wall of the occupant 
compartment of the vehicle. Comments are requested as to whether the 
term ``occupant compartment'' is clear.
    The vertical boundaries on both the left and right sides of vehicle 
centerline are defined by three line segments (see Figure 6 below). 
Segment 1 extends vertically from the floor to an end point that is 500 
mm above the floor and 150 mm inboard of the side wall. Segment 2 
starts at the end point of Segment 1 and extends to a point 750 mm 
above and 250 mm horizontally inboard of the end point of Segment 1. 
These values are used in ECE R.66. Segment 3 is a horizontal line 
beginning at the end point of Segment 2 and extending to the vertical 
longitudinal center plane of the vehicle.
    In proposing this requirement for a survival space, the agency 
intends to ensure that the vehicle has sufficient structural strength 
to ensure that the survival space during and after the rollover 
structural integrity test is maintained. We intend the dimensions of 
the survival space to define a volume of space that vehicles with a 
minimally acceptable degree of structural integrity should provide. The 
survival space requirement would serve as another indicator of the roof 
and sidewall strength of the vehicle. The requirement would be a 
reasonable proxy through which the agency could assess the adequacy of 
the structural integrity of the vehicle.
    The agency tentatively believes that the increased structural 
integrity countermeasures should be applied to substantially the entire 
length of the vehicle. Thus, this NPRM proposes a survival space volume 
which runs the length of the area that can be occupied by the driver 
and by the passengers. Therefore, this proposed rule defines the front 
boundary of the survival space as 600 mm in front of the forward-most 
point on the centerline of the forward-most designated seating 
position. Additionally, the proposed rule defines the rear boundary as 
the rear inside wall of the occupant compartment.
    The agency proposes to set the vertical boundary of the survival 
space using the three line segments outlined above and illustrated in 
Figure 6 below. These three line segments mirror the equivalent 
vertical boundaries used in the ECE R.66 test. The agency tentatively 
believes that the vertical boundaries of the survival space from the 
ECE regulation are appropriate for application in this proposed rule 
for several reasons. The vertical boundary appears reasonably related 
to the occupant space. Photographs from the MY 2000 MCI test report 
show the location of the vertical boundary of the survival space as 
just about level with the top of the head of the seated HIII 50th 
percentile adult male test dummies in the seat. ``ECE Regulation 66 
Based Research Test of Motorcoach Roof Strength, 2000 MCI 102-EL3 
Series Motorcoach, NHTSA No.: MY0800,'' October 1, 2009, supra. (We 
have also placed in the docket for this NPRM other photographs of the 
test dummies seated in front of survival space templates.) In addition, 
as increasing or decreasing the height of the vertical boundaries of 
the survival space could significantly alter the stringency of the 
rollover structural integrity test, the agency believes that there is a 
strong interest in maintaining similar requirements to ECE R.66 so as 
to reduce the regulatory burden on manufacturers having to comply with 
different European and U.S. standards.
    Further, as all the older model buses tested by the agency were 
unable to

[[Page 46108]]

meet the survival space requirements \56\ yet current vehicles in 
Europe are approved as meeting the requirements, the agency believes 
that setting the same vertical limits of the survival space increases 
the likelihood of the practicability of the U.S. standard. Therefore, 
the agency tentatively believes that this definition of the survival 
space is an appropriate, practical, and practicable proxy for ensuring 
that the roof and sidewalls will be able to withstand the racking 
forces of rollover crash.
---------------------------------------------------------------------------

    \56\ We note that while the survival space templates in the MY 
2000 motorcoach did not come into contact with objects outside of 
the survival space during the test, we observed intrusions into the 
survival space separate from the survival space templates.
---------------------------------------------------------------------------

    Comment is requested on the need and basis for different boundaries 
for the survival space.
[GRAPHIC] [TIFF OMITTED] TP06AU14.011

Determining Intrusions Into the Survival Space
    The NPRM proposes to prohibit any object that is outside the 
survival space from entering the survival space. Comments are requested 
on the use of survival space templates as tools in helping determine if 
there was intrusion into the survival space. Use of templates is 
consistent with ECE R.66. The templates are 1,250 mm (50.2 inches) tall 
and are tapered from the sidewall a distance of 150 mm (5.9 inches) at 
the bottom and 400 mm (15.8 inches) at the top.
    We anticipate using several survival space templates within the 
survival space to assist us in determining whether there was intrusion 
into the survival space. The templates would

[[Page 46109]]

contain a transfer medium (such as chalk or another substance capable 
of demonstrating contact between two objects) along the upper edge of 
each template. Transfer marks from contact with the survival space 
templates would demonstrate that an object intruded into the survival 
space during movement of the tilting platform or resulting from impact 
of the vehicle on the impact surface.
    We plan on securing the survival space templates to the vehicle 
floor such that they remain in their installed location during the 
test. We recognize, however, depending on seat placement and 
attachment, seats may have to be removed or shifted to accommodate the 
placement of the survival space templates or other testing equipment. 
Thus, we would move the seats forward or rearwards to make room for the 
equipment if the seat spacing is adjustable. If the seat spacing is not 
adjustable, we would remove seats from the vehicle and allow ballasts 
representing the weight of the seat and its occupants to be secured to 
the vehicle floor either forward or rearward of the original seat 
placement (within a specified tolerance \57\). Comments are requested 
on these procedures.
---------------------------------------------------------------------------

    \57\ The proposed text in this NPRM limit the placement of these 
ballasts to no farther forward than the forward-most point of the 
motorcoach seat directly in front of the removed seat and no farther 
rearward than the rearmost point of the motorcoach seat directly 
behind the removed seat.
---------------------------------------------------------------------------

    We emphasize that the templates are simply tools to assist in 
determining whether there was intrusion into the survival space. If an 
object intruded into the survival space without contacting the 
templates--such as if a television monitor fell into the survival 
space--that intrusion could be a noncompliance, even if contact with 
the templates did not occur. Other tools could also be used to help 
determine whether there was intrusion into the survival space, such as 
deformable templates, high speed video, photography, or a combination 
of means. NHTSA could use templates and/or other means of determining 
whether intrusion occurred.

e. Overhead Luggage Rack and Seat Retention

    The agency is proposing a retention requirement for overhead 
luggage racks and the passenger seats. The proposed retention 
requirement is that each anchorage of an overhead luggage rack or seat 
shall not completely separate from its mounting structure during 
movement of the tilting platform or resulting from impact of the 
vehicle on the impact surface.
    The NTSB identified overhead luggage racks as a safety concern in 
its investigation of the Sherman, Texas bus crash. The right side 
overhead luggage rack anchorages completely detached from the nine 
brackets at the connection points and fell diagonally across the aisle 
onto the passengers. NTSB stated that ``several passengers' heads 
contacted the overhead luggage rack and, although investigators were 
unable to determine exactly when in the accident sequence passenger 
injuries took place, it is possible that serious head or neck injury 
resulted from the interactions between the passengers and the overhead 
luggage rack.''
    Our research confirms the possibility of this danger. In the tests 
conducted by the agency, the overhead luggage rack on the older MCI bus 
broke, exposing sharp edges that pose a risk of injury to passengers. 
The overhead luggage racks did not break during testing of the newer MY 
2000 MCI bus. We thus acknowledge that, while this was one test, the 
finding indicated a possibility that manufacturers may have made some 
improvements to the strength of luggage rack mounts. It also indicates 
the practicability of meeting the proposed requirement.
    The overhead luggage rack retention requirement is an additional 
way of ensuring that vehicles provide a minimum level of structural 
integrity. The vehicle will have to limit its deformation and racking 
\58\ in the rollover structural integrity test, to ensure that the 
overhead luggage racks meet the retention requirement. The requirement 
would also reduce the risk that overhead luggage racks could be 
dislodged and injure occupants or block or impede emergency egress.
---------------------------------------------------------------------------

    \58\ The term, ``racking,'' means the tilting of the sides of 
the bus relative to the bus floor.
---------------------------------------------------------------------------

    The retention requirement would apply to luggage racks regardless 
of their position relative to the survival space. Suppose, in the 
rollover structural integrity test, an overhead luggage rack separates 
from its mounting structure and one of its anchorages completely 
separated from the anchorage's mounting structure but the overhead 
luggage rack does not enter the survival space. We would consider that 
to be a failure to meet the retention requirement.
    With regard to the seats in these buses, the agency is also 
concerned about the strength of the anchorages that secure the seats to 
the vehicle. The tests conducted by NHTSA revealed the possibility that 
seat anchorages have the potential to break and cause injury to 
passengers in these buses. In our test of the MY 1991 Prevost LeMirage 
bus, all seat anchorages detached from their sidewall mounting 
anchorages and the seat with the restrained occupant completely 
separated from its anchorages and fell with the test dummy still 
attached to the seat. We acknowledge that manufacturers may have made 
improvements since the manufacture of that MY 1991 Prevost bus. Also, 
seat anchorages would likely be strengthened if these buses had to meet 
the requirements under development for passenger seat belts. However, 
the agency believes it is highly important for passenger safety that 
the vehicle structure limit deformation and racking of the sidewall, 
such that the passenger seats will remain attached to the vehicle in a 
rollover (particularly if passengers are restrained to the seat). It is 
important to ensure the structural integrity of the bus in a rollover 
will enable the seat anchor to withstand the load of the seat and that 
of the restrained occupant.
    Compliance would be assessed by inspection of the component's 
mounting structure. We propose to permit the anchorage to be damaged or 
deformed during the course of the rollover, but we would prohibit any 
one anchorage from completely separating with the mounting structure. A 
complete separation is indicative of unacceptable structural integrity.
    Comments are requested as to what other items should be covered by 
these retention requirements (e.g., television monitors). Please 
provide data supporting the safety need for your suggestion. What 
methods are available to the agency to objectively and practicably 
evaluate the retention of the item?

f. Emergency Exits

    The agency is not only concerned with the protection of belted 
occupants, but also with protecting unbelted occupants. The agency 
recognizes there is a possibility that not all occupants traveling in 
the buses covered by today's proposal will be restrained at all times 
during travel. For instance, passengers may need to occasionally move 
about the occupant compartment during long, intercity journeys. 
Further, MAP-21 directs the agency to consider ``portal improvements to 
prevent partial and complete ejection of motorcoach passengers.'' \59\ 
Thus, the agency is considering--as a part of this rulemaking--
requirements that emergency exits remain latched so as to

[[Page 46110]]

avoid becoming an ejection portal for unrestrained occupants.
---------------------------------------------------------------------------

    \59\ See Moving Ahead for Progress in the 21st Century Act, Pub. 
L. 112-141, Sec.  32703(b)(2).
---------------------------------------------------------------------------

    In the ECE R.66 tests conducted by the agency in support of this 
NPRM, the emergency roof exits of all the tested buses (new and old) 
opened upon impact of the bus with the impact surface. The agency is 
concerned that emergency roof exits may become ejection portals through 
which unrestrained passengers could be ejected during a rollover crash. 
Therefore, the agency has proposed a requirement in today's NPRM that 
all emergency exits shall not open during the rollover structural 
integrity test. While the agency has tentatively determined that this 
requirement (remaining closed during and after the rollover test) would 
be appropriate for the emergency exits, the agency also requests 
comments on whether other similar openings exist in the bus that could 
also become ejection portals in a similar fashion to emergency exits 
and whether they should also be subject to the proposed requirements. 
For example, are there other windows or roof hatches that are designed 
to open in buses that are not emergency exits? Do these openings have 
similar safety concerns?
    In addition, for emergency exits, NHTSA also seeks to increase the 
likelihood that roof and rear door emergency exits are operable after a 
rollover crash.\60\ Inoperable emergency exits would impede emergency 
egress and emergency rescue efforts. Accordingly, we have proposed to 
require that the emergency exits on the roof and at the rear of the bus 
(installed to fulfill the emergency exit requirements of FMVSS No. 217) 
be able to operate as required under FMVSS No. 217 after the impact. 
The agency tentatively concludes that these requirements are necessary 
to ensure that these emergency exits are operable after being exposed 
to the racking forces of rollover crashes.
---------------------------------------------------------------------------

    \60\ The provisions of MAP-21 also direct the agency to consider 
the impact of portal improvement standards on the use of motorcoach 
portals as a means of emergency egress. See id.
---------------------------------------------------------------------------

    Note that we have tentatively concluded not to apply the above 
requirements (that the emergency exits be operable as required under 
FMVSS No. 217) to side emergency exit windows. A requirement that 
window exits facing the impact surface must open upon application of 
the FMVSS No. 217 forces would not make sense, since the exits are 
face-down on the ground. A requirement that window exits facing the sky 
on the opposite side of the impact surface must open as directed by 
FMVSS No. 217 might not be achievable with the vehicle on its side 
because of the mass of the window glazing and the effect of gravity.

g. Side Window Glazing

    NHTSA proposes that, after the rollover structural integrity test, 
each window glazing opposite the impacted side of the vehicle shall not 
detach from its mounting. The purpose of the requirement is to ensure 
that the vehicle's structural integrity will prevent heavy glazing 
panels from falling into the passenger compartment and becoming 
ejection portals. As with our discussion of emergency exits (above), 
this proposed requirement to enhance side window glazing retention 
through structural integrity is part of NHTSA's consideration of 
countermeasures that would help prevent partial and complete ejection 
of motorcoach passengers (pursuant to the provisions in MAP-21 \61\). 
NHTSA would assess compliance with this requirement by requiring that 
the side window opening not allow the passage of a 102 mm diameter 
sphere when a force of no more than 22 Newtons (N) is applied at any 
vector towards the exterior of the vehicle.
---------------------------------------------------------------------------

    \61\ As described above, MAP-21 directs the agency to establish 
improved roof and roof support standards (in section 32703(b)(1)) 
and consider glazing and other portal improvements to prevent 
partial and complete ejection of passengers (in section 
32703(b)(2)).
---------------------------------------------------------------------------

    Our test of the MY 2000 45-foot MCI bus demonstrated that side 
window glazing can detach during the rollover structural integrity test 
and collapse into the passenger compartment. Based on an assessment 
conducted in the agency's research to enhance emergency evacuation (the 
third action item in NHTSA's 2007 Approach to Motorcoach Safety), side 
windows in buses can weigh as much as 84 kg (185 lb).\62\ We are 
concerned that increasingly massive glazing panels are increasingly 
difficult to retain in the mounting structure in a crash. Because the 
rollover structural integrity test proposed today simulates significant 
racking forces which can deform the window glazing mounts, we believe 
that adopting a test that in effect determines if the glazing remained 
in its mounting structure will lead to increased structural integrity 
on these vehicles, and a reduced risk of injury from falling panels of 
glazing and occupant ejections.
---------------------------------------------------------------------------

    \62\ Human Factors Issues in Motorcoach Emergency Egress INTERIM 
REPORT 1--FINAL; John A. Volpe National Transportation Systems 
Center, Research and Innovative Technology Administration, August 
2009. Docket No. NHTSA-2007-28793.
---------------------------------------------------------------------------

    The 102 mm (4 in) performance limit is used in FMVSS No. 217, ``Bus 
emergency exits and window retention and release,'' (49 CFR 571.217). 
Under that standard, in order to minimize the likelihood of occupant 
ejection, bus manufacturers are required to ensure that when a force is 
applied to the window glazing as specified in that standard, each piece 
of glazing and each piece of window frame be retained by its 
surrounding structure in a manner that prevents the formation of any 
opening large enough to admit the passage of a 102 mm diameter sphere 
under a 22 N (5 lb) force.
    We tentatively conclude that the FMVSS No. 217 specification for 
assessing integrity of the window, based on passage of a 102 mm 
diameter sphere (and a force application of 22 N), is appropriate to 
test for window glazing remaining securely attached to its mounting at 
the conclusion of today's proposed test. The agency tentatively 
concludes that the proposed requirement specifies a minimum level of 
performance that better ensures that side window glazing and their 
mountings can withstand the racking forces associated with a rollover. 
As a result, occupants will be better protected from heavy window 
glazing that may collapse into the survival space, and from risk of 
ejections.
    We note that section 32703(b)(2) in MAP-21 also directs the agency 
(when considering portal improvements that can help prevent occupant 
ejection) to also consider the impact of such improvements on emergency 
egress. We are not currently aware of any data that show that the 
improvements to window mounting (proposed in this section) will have a 
detrimental impact on emergency egress. We are not aware of any large 
bus fatalities that were caused by non-functioning or unavailable 
emergency exits (i.e., trapping occupants inside the bus).\63\ On the 
other hand, the data clearly show a high correlation between occupant 
ejection and occupant fatality. The data also show that window glazing 
can become dismounted during a rollover crash and fall into the 
survival space where bus occupants will be. Thus, we tentatively 
conclude that the proposed improvements to window glazing mounting can 
address significant safety concerns and are

[[Page 46111]]

unlikely to produce any substantial negative impact on safety. We 
request comment on this tentative conclusion and whether there are any 
data/cases that show that improving side window mounting would lead to 
a negative safety impact outweighing the aforementioned safety 
benefits.
---------------------------------------------------------------------------

    \63\ However, as discussed in the section prior, we do propose 
to require that emergency exits will operate as specified under 
FMVSS No. 217 after being exposed to the crash conditions of the 
proposed test. We believe that this proposed requirement would also 
help alleviate any concerns that large bus occupants might be 
trapped in the vehicle after a crash without forgoing the important 
benefits of preventing occupant ejections and window glazing 
intrusions into the survival space.
---------------------------------------------------------------------------

VI. Regulatory Alternatives

    In deciding on the approach proposed in this NPRM, NHTSA has 
examined the following alternatives to this proposal.

a. FMVSS No. 216

    NHTSA considered the requirements of FMVSS No. 216, ``Roof crush 
resistance.'' FMVSS No. 216 applies to vehicles with a GVWR of 4,536 kg 
(10,000 lb) or less, and specifies a test that applies localized static 
loads to the front of the vehicle. Unlike passenger vehicles, the large 
buses that we propose to cover under today's NPRM are larger/heavier 
and are more likely to roll than yaw. As a result, in a rollover 
involving one of these vehicles, the entire length of the vehicle is 
loaded as in the ECE R.66 test. Therefore, the ECE R.66 test is more 
representative than the FMVSS No. 216 test since it imparts loads along 
the full length of the vehicle. In addition, the ECE R.66 is a dynamic 
test where additional safety issues specific to the vehicles covered by 
this rulemaking (opening of emergency exits, failure of seat and 
overhead luggage rack anchorages, and detachment of windows from their 
mountings) can be evaluated. This is not possible in the FMVSS No. 216 
test since it is a quasi-static test. Since two-thirds of rollover 
fatalities are due to ejections, addressing these additional safety 
issues is critical to addressing the safety problem in rollovers. 
Therefore, the agency believes that the ECE R.66 test is a better 
representation of a large bus rollover crash than the FMVSS No. 216 
test. Thus, the agency has tentatively chosen not to include a test 
based on FMVSS No. 216 in today's NPRM.

b. FMVSS No. 220

    FMVSS No. 220 is a school bus roof crush standard which places a 
uniformly distributed vertical force pushing directly downward on the 
top of the bus with a platen that is 914 mm (36 inches) wide and that 
is 305 mm (12 inches) shorter than the length of the bus roof. The 
standard specifies that when a uniformly distributed load equal to 1.5 
times the unloaded vehicle weight is applied to the roof of the 
vehicle's body structure through a force application plate, the 
downward vertical movement at any point on the application plate shall 
not exceed 130 mm (5.125 inches) and the emergency exits must be 
operable during and after the test.
    The agency included FMVSS No. 220 in its research into rollover 
structural integrity for large buses. However, we have tentatively 
decided to propose a test based on ECE R.66 rather than a test based on 
FMVSS No. 220 for several reasons. First, the agency believes that an 
ECE R.66 based test is more suitable for the vehicles covered by this 
proposed rule than an FMVSS No. 220 based test because a significant 
portion of fatalities in these rollovers result from occupant 
ejections. Unlike school buses, these large buses operating intercity 
routes typically travel at higher speeds than school buses transporting 
children to a local educational facility. Further, many of these buses 
are designed such that they have a higher center of gravity than school 
buses and utilize larger windows. These characteristics can lead to a 
higher incidence of occupant ejections during rollovers involving these 
types of buses. Thus, the dynamic rollover test in ECE R.66 affords the 
agency the opportunity to better evaluate ejection mitigating factors 
such as the emergency exits and side window glazing retention during a 
rollover crash.
    In addition, the vehicles covered by this proposed rule generally 
have more interior fixtures (such as luggage racks) than school buses 
and the data show that such interior fixtures have, at times, failed 
and created dangerous conditions. Again, the dynamic nature of the ECE 
R.66 protocol provides an opportunity to assess the strength of these 
internal fixtures, which have been identified as a safety concern in 
these types of vehicles.
    Second, ECE R.66 is an existing test, designed specifically to 
evaluate the performance of this vehicle type in rollover crashes. 
NHTSA has greater assurance (than with an FMVSS No. 220 based test) 
that this proposed standard can be applied to the large buses covered 
by today's proposal. Further, by basing our proposed test on ECE R.66, 
we believe that manufacturer familiarity with the proposed standard 
would help reduce many uncertainties in compliance. In addition, in the 
absence of data showing ECE R.66 should be preferred less than an 
alternative, the ECE R.66 based test proposed by today's NPRM is also 
merited because it allows the agency to further its harmonization 
efforts with the European Union.
    Due to these differentiating characteristics, the agency believes 
that ECE R.66 is more suited than FMVSS No. 220 for evaluating rollover 
structural integrity in the large bus types covered by today's 
proposal. Since FMVSS No. 220 is a quasi-static test, it also does not 
address the additional safety issues specific to these bus types. While 
FMVSS No. 220 has a proven record of ensuring rollover safety in school 
buses, it was not designed for the purpose of evaluating rollover crash 
performance of the buses that are the subject of today's proposal. 
Therefore, today's NPRM proposes a test based on ECE R.66.

c. ECE R.66 Alternative Compliance Methods

    The proposed test in today's NPRM is based on the complete vehicle 
test from ECE R.66. In addition to the complete vehicle test, ECE R.66 
provides manufacturers four alternative options for complying with ECE 
R.66 requirements.\64\ The following options are considered by ECE R.66 
to be equivalent approval tests: (1) Rollover structural integrity test 
of body sections representative of the vehicle, (2) quasi-static 
loading tests of body sections, (3) quasi-static calculations based on 
testing of components, and (4) computer simulation (finite element 
analysis) of complete vehicle.\65\
---------------------------------------------------------------------------

    \64\ There are significant differences in the manner in which a 
manufacturer demonstrates compliance with safety regulations in 
European Union and in the United States. In Europe, European 
governments use ``type approval,'' which means that they approve 
particular designs as complying with their safety standards. In the 
U.S., NHTSA issues performance standards, to which manufacturers 
self-certify that their vehicles or equipment comply. NHTSA does not 
pre-approve vehicles or equipment before sale. Under the National 
Traffic and Motor Vehicle Safety Act, the FMVSSs must be objective, 
repeatable, and meet certain other statutory criteria. NHTSA 
enforces the FMVSSs by obtaining vehicles and equipment for sale and 
testing them to the procedures specified in the FMVSSs.
    \65\ Further information regarding the alternative certification 
methods of ECE R.66 is available at: Motorcoach Roof Crush/Rollover 
Testing Discussion Paper, March 2009, Docket No. NHTSA-2007-28793-
0019.
---------------------------------------------------------------------------

    The agency has considered these alternative compliance methods but 
has determined they would not be practical for the agency's compliance 
testing.
    We have tentatively determined that Alternatives 1 and 2 would not 
be practical for use by the agency as they would not achieve the goals 
of this rulemaking. These alternative methods test body sections of the 
vehicle. The alternatives pose compliance difficulties. If NHTSA were 
to use Alternatives 1 and 2, the agency would likely have to acquire 
materials and information supplied from the manufacturers, or 
``section'' the vehicle ourselves, which is impractical.

[[Page 46112]]

Alternatives 1 and 2 require that the body-sections be representative 
of the entire vehicle. Determining the representativeness of a body-
section would require input and analysis from the manufacturer, and 
even with that, determining what is ``representative'' could be 
subjective and difficult for NHTSA to verify. (E.g., is the center of 
gravity of the body section representative of the whole vehicle?) Also, 
testing an entire vehicle rather than body sections is preferable to us 
because it would better ensure the assessment of all body sections, 
including representative as well as worse-case (weakest) sections of 
the bus. Also, if manufacturers were to provide the test specimens, a 
more conscientious effort might be taken by them to manufacture the 
specimen, and so the specimen might not be representative of the 
typical, mass produced bus. Thus, we prefer not to involve 
manufacturer-supplied body sections in NHTSA's compliance test.
    Alternatives 3 and 4, above, would not be suitable for 
incorporation into the FMVSS for NHTSA's compliance testing because 
they may not be sufficiently objective. NHTSA is directed to issue 
performance standards,\66\ the compliance with which must be measured 
objectively.\67\ Assessing compliance using calculations and 
extrapolations or computer simulations introduces an element of 
subjectivity into the compliance process. A manufacturer might believe 
that its vehicle met the structural integrity requirements based on its 
calculations and computer simulations, while someone else might not 
agree that the assumptions made in the calculations or on which the 
simulations were based were appropriate or correct for demonstrating 
compliance in the particular instance. While a manufacturer may have 
the knowledge of the materials and joint structure for their vehicles 
to be able to make a more accurate model, an external entity may not be 
able to easily reproduce these results. The variability of assumptions 
in such models makes this method unsuitable for use by NHTSA in 
evaluating compliance with an FMVSS. For example, for Alternative 3, we 
would need to identify the location of the plastic zones and plastic 
hinges as well as estimate their load-deformation curves. For 
Alternative 4, mathematical models that simulate accurately the actual 
rollover crash of the vehicle are required.
---------------------------------------------------------------------------

    \66\ In 49 U.S.C. 30102, the National Traffic and Motor Vehicle 
Safety Act defines ``motor vehicle safety'' as the ``performance'' 
of motor vehicles or motor vehicle equipment in a way such as to 
avoid creating an unreasonable risk of accident to the general 
public. The same Act defines ``motor vehicle safety standards'' as 
minimum standards for motor vehicle or motor vehicle equipment 
``performance.''
    \67\ In 49 U.S.C. 30111 (a), the National Traffic and Motor 
Vehicle Safety Act requires that Federal motor vehicle safety 
standards be stated in objective terms.
---------------------------------------------------------------------------

    Moreover, basing compliance on calculations and computer 
simulations does not take into account any differences that may occur 
between the analytical model and the vehicle as manufactured. Because 
they do not utilize an actual vehicle, these approaches do not account 
for variation or flaws in material properties, or defects or errors in 
the manufacturing build processes. In contrast, NHTSA prefers to test 
actually-manufactured vehicles, to assess not only the design of the 
vehicle but the real-world manufacturing processes as well.
    For these reasons, today's NPRM is based on the complete vehicle 
test of ECE R.66 and does not provide for NHTSA's use of Alternatives 1 
through 4 to determine compliance.

d. Comments Requested on Alternative Levels of Stringency

    As stated above, we believe that the ECE R.66 test is the most 
appropriate test for addressing the safety concerns related to the 
large buses covered under this NPRM. However, we request comment on 
potential alternative levels of stringency that could be used with this 
test. In this NPRM, we propose to use essentially the same survival 
space requirements as in ECE R.66. The agency is aware of research that 
supports the stringency levels adopted by ECE R.66 \68\ and (absent any 
data to the contrary) the agency believes that there is value in 
adopting a standard that is as harmonized with the EU as possible.
---------------------------------------------------------------------------

    \68\ A 2007 paper by Matolcsy reported on different types of 
rollover tests and a comparison of these tests to real world bus 
rollover events. The type of tests considered were a bus rolled down 
a 5.5 to 9 meter high embankment with two different grades (which 
would result multiple rolls of the bus) and the ECE R.66 type tip-
over test from an 800 mm platform on to a concrete surface (proposed 
in this document). Matolcsy found that the loads on the 
superstructure in the ECE R.66 were greater than those in the 
rollover tests down various grades of embankments. A reinforced bus 
superstructure that maintained its occupant survival space in the 
rollover test down a steep embankment performed poorly in the ECE 
R.66 test and needed further reinforcement. Matolcsy also presented 
real world rollover accidents involving buses designed to comply 
with ECE R.66 requirements and where the occupant survival space was 
not compromised. In one such accident, the ECE R.66 compliant bus 
rolled down a 9-10 meter high embankment with a 30-35 degree grade 
and completed 2 and 1/4 turns without compromising its survival 
space. See Matolcsy, M., ``The Severity of Bus Rollover Accidents,'' 
Scientific Society of Mechanical Engineers., ESV Proceedings, Lyon, 
France, Paper No. 07-0989, available at http://www-nrd.nhtsa.dot.gov/pdf/esv/esv20/07-0152-O.pdf.
---------------------------------------------------------------------------

    Thus, while we propose to adopt the survival space requirements 
specified in this document (which are essentially the ECE R.66 
requirements) we request comment on whether there is any data to 
indicate what the marginal benefits and costs would be for increasing 
or decreasing the survival space requirements. In other words, what 
other potential levels of stringency could the agency consider (i.e., 
larger or smaller survival spaces) and what data would support choosing 
that level of stringency? What would the safety impact be for that 
different level of stringency and how would the costs be different? 
What other types of adjustments in stringency should the agency 
consider? For example, should the agency consider adjusting the height 
of the platform used to tilt the bus during the test? This type of 
change could increase or decrease the severity of the bus' impact 
during the test.
    In addition, we note that our proposal includes additional 
performance requirements on the integrity of the luggage racks, seats, 
and window glazing attachments. As we stated, we believe these 
requirements are complementary to the survival space requirements. 
However, we acknowledge that these requirements make the proposal 
slightly more stringent than the ECE R.66 requirements. These 
additional performance requirements were included in the proposal 
because of observed failures of bus components that resulted in 
occupant injuries in real world bus rollover crashes or had the 
potential for injuring occupants. We seek comment on these additional 
performance requirements in the proposal over those specified in ECE 
R.66. Are there additional requirements that the agency should consider 
for this test? We also seek comment on whether the agency should remove 
these additional performance requirements from the proposal and thereby 
making the test slightly less stringent.

VII. Other Issues

a. Retrofitting

    The Secretary of Transportation has authority to promulgate safety 
standards for ``commercial motor vehicles and equipment subsequent to 
initial manufacture.'' \69\ The Office of the Secretary has delegated 
authority to NHTSA to ``promulgate safety standards

[[Page 46113]]

for commercial motor vehicles and equipment subsequent to initial 
manufacture when the standards are based upon and similar to a [FMVSS] 
promulgated, either simultaneously or previously, under chapter 301 of 
title 49, U.S.C.'' \70\ Further, Sec.  32703(e)(2) of MAP-21 states 
that the ``Secretary may assess the feasibility, benefits, and costs 
with respect to the application of any requirement established under 
subsection . . . (b)(2) to motorcoaches manufactured before the date on 
which the requirement applies to new motorcoaches.'' \71\ Subsection 
(b)(2) directs the agency to consider portal improvements to prevent 
partial and complete ejection of motorcoach passengers.
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    \69\ Under Sec. 101(f) of Motor Carrier Safety Improvement Act 
of 1999 (Pub. L. 106-159; Dec. 9, 1999).
    \70\ See 49 CFR 1.95(c). Additionally, the Federal Motor Carrier 
Safety Administration (FMCSA) is authorized to enforce the safety 
standards applicable to commercial vehicles operating in the U.S.
    \71\ See Moving Ahead for Progress in the 21st Century Act, Pub. 
L. 112-141, Sec.  32703(e)(2). Section 32703(e)(2)(B) states that 
the Secretary shall submit a report on the assessment to Congress 
not later than 2 years after date of enactment of the Act.
---------------------------------------------------------------------------

    Based on our testing of the MY 1991 Prevost and the MY 1992 MCI 
buses, the agency believes that major structural changes to the 
vehicle's entire sidewall and roof structure would be needed for some 
existing buses to meet the rollover structural integrity requirements 
proposed in today's NPRM. The agency is concerned that such extensive 
modifications may not be possible on all existing vehicles that would 
be covered by this proposed rule if the scope were expanded to include 
retrofitting requirements. In addition, we expect these major 
structural changes to carry significant additional costs beyond those 
estimated in our regulatory analysis, and possibly have a substantial 
impact on a significant number of small entities (e.g., owner-operators 
of large buses used for transport).
    In regards to the proposed requirements for side window glazing 
retention and emergency exits, the agency also believes that major 
structural changes would be necessary to ensure a comparable level of 
performance (when compared to a new large bus manufactured to meet 
today's proposed requirements). As emergency exits and side window 
glazing can create ejection portals during a rollover crash due to the 
structural deformation that can occur during a crash, the extensive 
modifications to the bus structure that would be necessary for enhanced 
side window glazing retention and emergency exit performance may also 
not be possible. Thus, the agency has tentatively concluded that 
requiring retrofitting of existing buses would be impracticable and 
NHTSA has tentatively decided not to include retrofitting requirements 
in today's NPRM.
    The agency seeks comment on these tentative conclusions. The agency 
notes that the service life of a bus can be 20 years or longer and that 
it is possible that the cost of retrofitting can vary substantially 
depending on the requirements being applied to used buses and the 
countermeasures available. Further, we note that the proposed 
``complete vehicle'' test of ECE R.66 is unlikely suitable for 
evaluating compliance with any requirements applied to used buses (as 
ECE R.66 is a destructive test).
    Thus, the agency seeks information on the technical and economic 
feasibility of a potential retrofit requirement. Which requirements in 
today's proposal could be appropriately applied to used buses? What 
potential test procedures could the agency utilize to objectively 
measure compliance? Would it be reasonable to assess compliance with a 
retrofit requirement by means of only visually inspecting the vehicle? 
What lead time and phase-in issues should the agency consider for a 
potential retrofit requirement? What would the potential costs be?

b. Lead Time

    If the proposed changes in this NPRM are made final, NHTSA is 
proposing a compliance date of three years after publication of a final 
rule. MAP-21 (in Sec.  32703(e)) directs the agency to apply 
regulations prescribed in accordance with Sec.  32703(b) ``to all 
motorcoaches manufactured more than 3 years after the date on which the 
regulation is published as a final rule.'' We believe that a three-year 
lead time after publication of final rule is appropriate as some 
design, testing, and development will be necessary to certify 
compliance to the new requirements.
    Based on our research, the agency believes that manufacturers may 
need to make structural design changes to their new models either by 
changing the strength of the material or the physical dimensions of the 
material. In addition, the manufacturers may need to strengthen the 
seat and luggage rack anchorage methods, improve the type of latches 
used on emergency exits, and improve the mounting of side windows. 
Thus, the agency tentatively concludes that three years of lead time 
would be needed to enable manufacturers to make the necessary changes.
    To enable manufacturers to certify to the new requirements as early 
as possible, optional early compliance with the standard would be 
permitted.

c. Additional MAP-21 Considerations

    In addition to the aforementioned MAP-21 provisions, MAP-21 also 
directs the agency to consider the best available science, potential 
impacts on seating capacity, and potential impacts on the size/weight 
of motorcoaches.\72\ Further, MAP-21 directs the agency to consider 
combining the various motorcoach rulemakings contemplated by MAP-21 and 
to avoid duplicative benefits, costs, and countermeasures.\73\
---------------------------------------------------------------------------

    \72\ See Moving Ahead for Progress in the 21st Century Act, Pub. 
L. 112-141, Sec.  32703(e)(1).
    \73\ See id. at Sec.  32706(b)-(c).
---------------------------------------------------------------------------

    NHTSA has considered the best available science in developing 
today's NPRM. Regarding any potential impacts on seating capacity, the 
agency currently does not believe that the requirements proposed in 
today's NPRM will require structural reinforcements at the expense of 
seating capacity. However, the agency requests comment on this issue.
    Through today's NPRM and its accompanying Preliminary Regulatory 
Evaluation (PRE), the agency is considering potential impacts on the 
size and weight of motorcoaches (and other large buses that would be 
affected by the proposed rule).\74\ As described further in section 
VIII, infra, (and in the PRE) the agency has considered potential 
weight increase to motorcoaches as a potential cost of this proposed 
rule (due to increased fuel consumption). In the accompanying PRE, we 
have attempted to quantify and account for this potential cost (of 
increased fuel consumption) in our cost-benefit analysis of the rule. 
After considering all costs (including the potential weight increase), 
the agency tentatively believes that the proposed requirements in 
today's NPRM would be cost-beneficial.
---------------------------------------------------------------------------

    \74\ ``Motorcoach'' in this paragraph has the meaning given in 
MAP-21 (over-the-road buses).
---------------------------------------------------------------------------

    Further, the agency is considering combining the rulemakings 
contemplated by MAP-21 and avoiding the duplication of benefits/costs/
countermeasures in today's NPRM. As mentioned above, the agency 
believes that the proposed test (based on ECE R.66) can be used not 
only to evaluate the structural integrity of a large bus (such as an 
over-the-road bus) but also to evaluate the strength of its structural 
integrity in supporting side window glazing retention and emergency 
exit latches. As NHTSA's research on various motorcoach models showed 
that (during a rollover crash) side window

[[Page 46114]]

glazings have the potential to become dislodged and emergency exits 
have the potential to open, NHTSA tentatively believes that the 
proposed ECE R.66-based test can be used to address at least part of 
Congress's concerns under Sec.  32703(b)(2) (anti-ejection safety) in 
addition to the concerns under Sec.  32703(b)(1) (roof strength). Thus, 
the agency is combining these two aspects of MAP-21 into this 
rulemaking proceeding.
    Finally, NHTSA is avoiding the duplication of benefits, costs, and 
countermeasures in today's rulemaking proceeding with other potential 
NHTSA rules being considered pursuant to MAP-21. The agency does not 
believe that potential countermeasure used to meet the proposed 
requirements of today's NPRM would be duplicative of other rules. As 
described above, the agency believes that the potential requirements in 
today's NPRM would work hand-in-hand with the agency's final rule on 
seat belts. As described below in section VIII, infra, and the 
accompanying PRE, the agency is expressly considering the estimated 
costs and benefits of the final rule requiring seat belts on the large 
buses. The agency is not attributing the estimated costs and benefits 
of the final rule on seat belts to this rulemaking proceeding on 
structural integrity.
    In sum, we have issued today's NPRM after careful deliberation of 
the factors emphasized for consideration in MAP-21, which we note are 
also factors NHTSA routinely investigates carefully when the agency 
conducts rulemaking under the Motor Vehicle Safety Act.

VIII. Overview of Costs and Benefits

    Based on the FARS data over the ten year period between 2000 and 
2009, there were a total of 32 fatal rollover crashes involving the 
large bus types covered by this proposal, resulting in 114 occupant 
fatalities. Beyond the benefits attributable to the rule on seat belts 
for these vehicles and a possible rulemaking on electronic stability 
control systems,\75\ the agency estimates that today's proposed rule 
would save approximately 3.1 equivalent lives annually if 15 percent of 
occupants use seat belts, and approximately 2.3 equivalent lives 
annually if 84 percent of occupants use seat belts.\76\
---------------------------------------------------------------------------

    \75\ As we further discuss in the PRE supporting today's NPRM, 
we adjusted the target population based on the projected benefits 
that would be attributable to those rules. Separately, we also 
considered whether there have been any recent FMCSA actions which 
might affect the projected target population and we have tentatively 
concluded that they would not. FMCSA has issued several recent final 
rules directed at bus and truck safety, including Medical 
Certificate Requirements as Part of the Commercial Driver's License 
in 2008, Drivers of Commercial Vehicles: Restricting the Use of 
Cellular Phones in 2011, Hours of Service in 2011, and National 
Registry of Certified Medical Examiners in 2012. In addition, FMCSA 
has had several recent enforcement efforts to improve bus safety, 
including several nationwide ``Strike Force'' enforcement events. 
The agency has consulted with FMCSA and does not believe that the 
benefits estimated in this NPRM overlap with the benefits contained 
in recent FMCSA actions associated with bus safety.
    \76\ The PRE prepared in support of today's NPRM assumes that 
the seat belt use rate on motorcoaches would be between 15 percent, 
and the percent use in passenger vehicles, which was 84 percent in 
2009. In order to maintain consistency with the agency's rule to 
require seat belts on motorcoaches, we have utilized the same low 
belt usage rate estimate of 15% from that rule. See Final Regulatory 
Impact Analysis--FMVSS No. 208. We have also utilized the same 
source of information to establish the high belt usage rate estimate 
(the National Occupant Protection Use Survey). Today's NPRM uses the 
2009 data which estimates seat belt use of passenger vehicles to be 
84%. See 2009 National Occupant Protection Use Survey. More 
information at: http://www-nrd.nhtsa.dot.gov/pubs/811100.pdf.
---------------------------------------------------------------------------

    While occupants that are belted will benefit from increased 
structural integrity, the agency believes that unbelted occupants will 
receive additional protection as well. The proposed rulemaking will 
offer the unbelted occupant additional protection through reduced risk 
of ejection. The belted occupant will most likely benefit mainly from 
reduced intrusion, and seats remaining secured. Given these potential 
differences in effectiveness of structural improvements for belted and 
unbelted occupants, the agency has estimated benefits for each group 
separately.
    The benefits estimates also vary by seat belt use. Available 
research regarding seat belt use suggests that it can be highly 
variable and the agency has estimated the lower end of seat belt use at 
15 percent and the upper end of seat belt use to be consistent with 
that of passenger vehicles, at 84 percent. In spite of this, the agency 
expects belt use, initially, to be closer to the lower end (of 15%) in 
part because many passengers are not accustomed to using seat belts on 
these vehicles due to the current lack of availability of belts in 
these vehicles and the fact that passengers have not yet been educated 
regarding the benefits of buckling up in a large bus.
    Thus, we estimate that the proposed rule would reduce the number of 
seriously injured occupants by approximately 4 annually. We estimate 
that 3.1 equivalent lives are saved annually if 15 percent of occupants 
use seat belts, and approximately 2.3 equivalent lives are saved 
annually if 84 percent of occupants use seat belts (see Table 6 below).
    The agency estimates that, assuming steel is used to comply with 
the proposed requirements in this rule, material costs for each vehicle 
will range from $282 to $507 and cost between $0.6 million and $1.1 
million to equip the entire new large bus fleet annually (see Table 7 
below). We further estimate that, if steel is used to comply, the total 
weight increase will range from 564 to 1,114 lb and cost an additional 
$2,118 to $5,523 in fuel per vehicle over the lifetime of the vehicle. 
The total fuel cost for the new fleet is estimated to be $4.7 million 
to $12.2 million. The total costs would be approximately $5.3 million 
to $13.3 million annually. The cost per equivalent life saved is 
estimated to be between $2.09 million and $6.42 million (see Table 8 
below).
    All the available information indicates that this proposed rule--if 
made final--would be cost beneficial. Further, the agency anticipates 
that the projected net impact on the economy will be closer to the 
estimates for the 15% belt use rates than the 84% belt use rate. We 
note that the above estimates for the cost per equivalent life of this 
rule vary due to uncertainties regarding seat belt use rates and the 
incremental increase in weight that is necessary to meet today's 
proposed structural integrity standard. A large portion of the costs of 
this structural integrity rule is dependent on this incremental 
increase in weight. While the agency does not have more specific 
information regarding the likely weight increase to these vehicles, the 
agency does believe that seat belt usage rates will be closer to 15% 
rather than 84% because these vehicles are currently not equipped with 
seat belts and passengers have not yet been educated regarding the 
advantages of buckling up during travel on these vehicles. Thus, we 
anticipate that the proposed rule--if made final--would have a net 
beneficial impact on the economy that is closer to our estimates 
assuming a 15% belt use rate.
    In addition to our expectation that this proposed rule would be 
cost beneficial, the agency believes that the cost effectiveness of 
this proposed rule is not very sensitive to changes in belt usage rates 
because belted passengers will still realize safety benefits as a 
result of this rule. Many serious injuries that occur in large bus 
crashes can occur despite a passenger's use of a safety belt. For 
example, while a belted passenger may not be ejected, he or she can 
still be struck by the collapsing side wall of the bus. Therefore, even 
though increasing belt usage rates may mean that more passenger 
ejections (and fatalities) will be prevented by seat belts 
(consequently reducing the number of

[[Page 46115]]

prevented ejections attributable to structural changes), the proposed 
requirements in this NPRM will still be effective in preventing serious 
injuries to belted passengers. Thus, we expect that the monetized value 
of the benefits of this proposed rule is not very sensitive to 
fluctuations in belt use--even though the type of benefit will 
change.\77\
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    \77\ For further information, please reference the Preliminary 
Regulatory Evaluation prepared in support of this NPRM.

                   Table 6--Estimated Annual Benefits
                  [Undiscounted Equivalent Lives Saved]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
15 percent belt usage................................               3.09
84 percent belt usage................................               2.31
------------------------------------------------------------------------

                     Table 7--Estimated Annual Costs
                             [2010 Dollars]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Potential Costs:
    Material Costs Per Vehicle.........  $282 to $507.
    Material Costs, Total New Fleet....  $0.6 million to $1.1 million.
Fuel Costs per Vehicle @3%.............  $2,814 to $5,523.
Fuel Costs per Vehicle @7%.............  $2,118 to $4,156.
Fuel Costs, Total New Fleet............  $4.7 million to $12.2 million.
                                        --------------------------------
    Total Annual Cost..................  $5.3 million to $13.3 million.
------------------------------------------------------------------------

                 Table 8--Cost per Equivalent Life Saved
                [Across 3% and 7% Discount, 2010 Dollars]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
15 percent belt usage..................  $2.09 million to $4.72 million.
84 percent belt usage..................  $2.91 million to $6.42 million.
------------------------------------------------------------------------

    The cost of reinforcing the roof strength and structural integrity 
of these vehicles to meet the requirements proposed in this standard 
would be predominantly dependent upon the material and weight increases 
necessary to reinforce the superstructure. We estimate that the 
countermeasures may include stronger roof and side walls, shock 
resistant latches for emergency exits, stronger seat and luggage rack 
anchorages, and improved window mounting. As mentioned above, these 
material costs for each vehicle are estimated to be between $282 and 
$507. However, while the agency assumes in these estimates that steel 
is applied to reinforce the vehicle structure, the agency is aware that 
other methods of reinforcing the structure (such as the use of high 
strength steel sections, rigid polyurethane foam filling to reinforce 
and stabilize thin walled hollow sections, and optimized designs that 
redistribute the impact loads and enhance the energy absorption 
capability) may enable a vehicle to withstand greater crash forces 
without adding as much weight.\78\ Therefore, while our analysis has 
assumed the use of steel, the agency is aware that there may be other 
countermeasures that weigh less--which could result in lower fuel costs 
(than we have currently estimated) over the lifetime of the vehicle.
---------------------------------------------------------------------------

    \78\ See Lilley, K. and Mani, A., ``Roof-Crush Strength 
Improvement Using Rigid Polyurethane Foam,'' SAE Technical Paper 
960435, 1996. Available at: http://subscriptions.sae.org/content/960435/, see also Liang, C. and Le, G. Optimization of bus rollover 
strength by consideration of the energy absorption ability. 
International Journal of Automotive Technology. Vol. 11.(2) 173-185. 
Available at: http://www.springerlink.com/content/tk824863k66w0228/export-citation/.
---------------------------------------------------------------------------

    The agency also notes that, in addition to the quantifiable 
benefits mentioned above, there are certain unquantifiable benefits 
that can arise from today's proposed rule. Our economic analysis of 
this proposed rule is only able to calculate the benefits that can be 
realized in addition to the benefits attributable to proposed rules 
requiring seat belts and electronic stability control systems. In other 
words, we are only able to estimate the benefits to passengers whose 
serious and fatal injuries were not prevented by seat belts. When a 
passenger that would have been fatally injured due to an ejection is 
estimated as saved by the use of a seat belt that prevents the 
ejection, we can no longer estimate additional benefits for that 
particular passenger.
    However, we note that while a fatal ejection may be prevented by 
the use of seat belts, it is possible that poor structural integrity 
could still contribute towards an injury for this occupant. The type of 
injury that can occur to this occupant (fatal ejection prevented by 
seat belts but still seriously injured by collapsing structure 
intruding into the survival space) is similar to our earlier discussion 
regarding the benefits to belted passengers. However, it is important 
to note that while the agency was able to estimate benefits to belted 
passengers whose serious injuries and fatalities were not prevented by 
the seat belts, the agency is unable to estimate what additional 
(potential) benefits may be realized by those passengers who have 
already realized benefits because they were no longer fatally injured 
in an ejection due to seat belt use. As the agency is unaware of any 
available information that would permit the agency to quantify this 
benefit, the agency's economic analysis of this proposed rule only 
estimates the benefits to occupants that would not have been protected 
by the use of seat belts.
    For further information regarding the aforementioned cost and 
benefit estimates, please reference the PRE that NHTSA has prepared and 
placed in the Docket.\79\
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    \79\ The PRE discusses issues relating to the potential costs, 
benefits and other impacts of this regulatory action. The PRE is 
available in the docket for this NPRM and may be obtained by 
downloading it or by contacting Docket Management at the address or 
telephone number provided at the beginning of this document.

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[[Page 46116]]

    We have tentatively decided not to include retrofitting 
requirements at this time to require that used buses be retrofitted to 
meet the rollover structural integrity requirements. The service life 
of a large bus can be 20 years or longer. It may not be structurally 
viable to retrofit many of the used large buses that are currently in 
service. Also, it may not be economically feasible for many for-hire 
operators (many of which are small businesses) to fund the necessary 
structural changes. Thus, we have not included the costs of 
retrofitting in our analysis of the costs and benefits of the proposed 
rule.

IX. Regulatory Analyses

Executive Order 12866, Executive Order 13563, and DOT Regulatory 
Policies and Procedures

    NHTSA has considered the impact of this rulemaking action under 
Executive Order 12866, Executive Order 13563, and the Department of 
Transportation's regulatory policies and procedures (44 FR 11034; 
February 26, 1979). This NPRM is ``significant'' and was reviewed under 
the Executive Order. NHTSA has prepared a PRE for this NPRM.
    This NPRM proposes to increase roof strength and structural 
integrity for certain large bus types by establishing requirements for 
maintaining survival space, seat and overhead luggage rack retention, 
emergency exit operability, and window mounting strength during a 
rollover structural integrity test. This NPRM proposes a test procedure 
which tilts the vehicle on a platform until the vehicle becomes 
unstable and rolls over onto a level concrete impact surface.
    Beyond the benefits attributable to the rule on seat belts for this 
same group of vehicles and a possible rulemaking on electronic 
stability control systems, we estimate that requiring new large buses 
of these types to meet the aforementioned performance criteria would 
save approximately 3.1 equivalent lives annually if seat belt usage 
among occupants is 15 percent, and approximately 2.3 equivalent lives 
annually if seat belt usage is 84 percent. The total cost of making the 
necessary structural changes, and of lifetime fuel costs, would be 
approximately $5.3 million to $13.3 million annually (for the entire 
new fleet). The cost per equivalent life saved is estimated to be 
between $2.09 million and $6.42 million. The benefits, costs, and other 
impacts of this rulemaking are discussed at length in the PRE.

Executive Order 13609: Promoting International Regulatory Cooperation

    The policy statement in section 1 of Executive Order 13609 
provides, in part:

    The regulatory approaches taken by foreign governments may 
differ from those taken by U.S. regulatory agencies to address 
similar issues. In some cases, the differences between the 
regulatory approaches of U.S. agencies and those of their foreign 
counterparts might not be necessary and might impair the ability of 
American businesses to export and compete internationally. In 
meeting shared challenges involving health, safety, labor, security, 
environmental, and other issues, international regulatory 
cooperation can identify approaches that are at least as protective 
as those that are or would be adopted in the absence of such 
cooperation. International regulatory cooperation can also reduce, 
eliminate, or prevent unnecessary differences in regulatory 
requirements.

    As mentioned in the body of this preamble, the agency has 
considered regulatory approaches taken by foreign governments (namely, 
the European Union in ECE R.66) and decided to base its proposed rule 
on ECE R.66. In addition to the goal of reducing unnecessary 
differences in regulatory requirements between the U.S. and its trading 
partners, the agency has found the ECE R.66 test to be the most 
suitable test available for ensuring a minimum reasonable level of 
protection for passengers traveling in buses that are associated with 
the highest crash risk. While NHTSA has tentatively determined that it 
is not able to follow (in certain details) the entirety of the ECE R.66 
test and requirements, the agency has explained its rationale for its 
proposed decisions in the relevant sections above.

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of rulemaking for any proposed or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small governmental jurisdictions). 
The Small Business Administration's regulations at 13 CFR part 121 
define a small business, in part, as a business entity ``which operates 
primarily within the United States.'' (13 CFR 121.105(a)). No 
regulatory flexibility analysis is required if the head of an agency 
certifies that the rule will not have a significant economic impact on 
a substantial number of small entities. The SBREFA amended the 
Regulatory Flexibility Act to require Federal agencies to provide a 
statement of the factual basis for certifying that a rule will not have 
a significant economic impact on a substantial number of small 
entities.
    NHTSA has considered the effects of this rulemaking action under 
the Regulatory Flexibility Act. According to 13 CFR 121.201, the Small 
Business Administration's size standards regulations used to define 
small business concerns, manufacturers of the vehicles covered by this 
proposed rule would fall under North American Industry Classification 
System (NAICS) No. 336111, Automobile Manufacturing, which has a size 
standard of 1,000 employees or fewer. NHTSA estimates that there are 26 
manufacturers of these types of vehicles in the United States 
(including manufacturers of motorcoaches, cutaway buses, second-stage 
motorcoaches, and other types of large buses covered by this proposal). 
Using the size standard of 1,000 employees or fewer, we estimate that 
approximately 10 of these 26 manufacturers would be considered a small 
business.
    The agency does not believe that this proposed rule would have a 
significant economic impact on those small entities. First, the agency 
estimates that the incremental costs to each vehicle would be $282 to 
$507 per unit to meet the proposed rule. This incremental cost would 
not constitute a significant impact given that the average cost of the 
vehicles covered by this proposed rule ranges from $200,000 to 
$400,000. Further, these incremental costs, which are very small 
compared to the overall cost of the vehicle, can ultimately be passed 
on to the purchaser and user.
    In addition, the agency believes that certifying compliance with 
the proposed rule would not have a significant impact on the 
manufacturers. Small manufacturers have various options available that 
they may use in certifying compliance with the proposed standard. The 
economic impact of certifying compliance with the standard would not be 
significant. One option available to small entities is to certify 
compliance by using modeling and engineering analyses (such as a 
plastic hinge analysis of portal frames of the vehicle). ECE R.66 
itself accounts for and accommodates this compliance option, and this 
approach has been used for years by European manufacturers in meeting 
ECE R.66. Thus, there are established practices and protocols that 
small manufacturers may use to avail

[[Page 46117]]

themselves of this basis for certifying compliance with the standard.
    We explained in Section VI., Regulatory Alternatives, that the 
aforementioned engineering analysis model would not be appropriate as 
the agency's method of assessing the compliance of vehicles with a 
Federal motor vehicle safety standard. However, manufacturers are not 
required to use NHTSA's test as the basis for their certification. 
While the agency's test defined in the proposed regulatory test would 
be an objective test capable of determining which vehicles meet the 
minimum requirements, manufacturers can use other methods (such as the 
alternative compliance options in ECE R.66) in certifying the 
compliance of their own vehicles. Unlike NHTSA, manufacturers 
certifying compliance of their own vehicles have more detailed 
information regarding their own vehicles and can use reasonable 
engineering analyses to determine whether their vehicles will comply 
with the proposed requirements using alternative testing methods that 
may not be suitable for incorporation into an FMVSS.
    Under the Motor Vehicle Safety Act, a manufacturer can avoid civil 
penalties associated with a noncompliance if it showed that it 
exercised due care in certifying its vehicles. A showing of due care 
can be based on engineering analyses, computer simulations, and the 
like, and NHTSA will assess the due care upon which the certification 
is made by evaluating, among other factors, the size of the 
manufacturer and its resources. We believe that a small manufacturer 
would be closely familiar with its vehicle design and would be able to 
utilize modeling and relevant analyses on a vehicle-by-vehicle basis to 
reasonably predict whether its design will meet the requirements of 
today's proposed rule.
    Second, the small manufacturer could test body sections of the 
vehicle, as contemplated by ECE R.66, Alternatives 1 and 2. The 
manufacturer would be able to ``section'' the vehicle or otherwise 
obtain a body section representative of the vehicle and of the weakest 
section of the vehicle. It could base its certification on these tests, 
without testing a full vehicle.
    Third, we note that in the event small manufacturers elect to 
conduct a test of a full vehicle, there are various methods available 
to reduce the costs of the test. One such method is by testing a 
vehicle which is not completely new. As the proposed requirements in 
today's NPRM pertain to structural integrity, we believe that a 
manufacturer could test the relevant body design on an old bus chassis 
or other underlying structure, and could sufficiently assess and 
certify the compliance of the vehicle's structural integrity to the 
proposed standard. Similarly, the agency believes that more costly 
portions of the vehicle (such as the engine and other portions of the 
powertrain) could be replaced in a complete vehicle test of a bus with 
ballast equal to the weight of the absent components. The small 
manufacturer could base its certification on such testing, which do not 
involve a destructive test of an actual vehicle.
    Fourth, we also note that the product cycle of these vehicles is 
significantly longer than other vehicle types. With a longer product 
cycle, we believe that the costs of certification for manufacturers 
would be further reduced as the costs of conducting compliance testing 
and the relevant analyses could be spread over a significantly longer 
period of time.
    Finally, we note that the requirements in today's proposed rule may 
affect the operators of the buses that are the subject of today's 
NPRM--some of which may be small businesses--but only indirectly as 
purchasers of these vehicles. As mentioned above, we anticipate that 
the impact on these businesses will not be significant because 
(assuming that additional steel is used for compliance) the expected 
price increase of the vehicles used by these businesses is small ($282 
to $507 for each vehicle valued between $200,000 and $400,000). 
Further, we anticipate that fuel costs for these businesses will 
increase between $2,118 and $5,523 (in 2009 dollars) per vehicle over 
its lifetime. These expected increases in costs are small in comparison 
to the cost of each of these vehicles. In addition, we anticipate that 
these costs will equally affect all operators and therefore we expect 
that small operators will be able to pass these costs onto their 
consumers.
    For the aforementioned reasons, I hereby certify that if made 
final, this proposed rule would not have a significant economic impact 
on a substantial number of small entities.
    With regard to a retrofit requirement applying to a population of 
on-road vehicles, the agency has tentatively concluded that requiring 
retrofitting of existing vehicles would be impracticable and therefore 
has decided not to propose retrofitting requirements in today's NPRM. 
An estimated 78.8 percent of the 3,137 motorcoach carriers (according 
to the 2008 Motorcoach Census) in the United States in 2007 (i.e. about 
2,470 carriers) have less than 10 motorcoaches in their fleet. Further, 
these companies have an average of three vehicles and eleven employees. 
While the vehicles included in the motorcoach census are not exactly 
the same as the vehicles covered in today's proposal, we believe the 
industry's Motorcoach Census offers a reasonable estimate of the 
proportion of bus carrier companies that would be affected as owners/
operators of the buses covered in today's NPRM.
    NHTSA tentatively believes that to include retrofit requirements 
would be a substantial burden on these small carriers. The service life 
of each of the vehicles covered under today's proposal can be as much 
as 20 years or longer. Further, it may not be structurally viable for 
many of these used large buses to be retrofitted. Thus, NHTSA has 
tentatively decided not to include such requirements in today's 
proposal that on-road large buses be retrofitted to meet the roof 
strength requirements of this proposed rule, but requests comments on 
the issue. The agency is also seeking comment as to whether the 
proposed emergency exit and side window glazing retention requirements 
should be applied to used buses.

Executive Order 13132 (Federalism)

    NHTSA has examined today's proposed rule pursuant to Executive 
Order 13132 (64 FR 43255; Aug. 10, 1999) and concluded that no 
additional consultation with States, local governments, or their 
representatives is mandated beyond the rulemaking process. The agency 
has concluded that the rule does not have sufficient federalism 
implications to warrant consultation with State and local officials or 
the preparation of a federalism summary impact statement. The rule does 
not have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.''
    NHTSA rules can have preemptive effect in two ways. First, the 
National Traffic and Motor Vehicle Safety Act contains an express 
preemption provision:
    When a motor vehicle safety standard is in effect under this 
chapter, a State or a political subdivision of a State may prescribe or 
continue in effect a standard applicable to the same aspect of 
performance of a motor vehicle or motor vehicle equipment only if the 
standard is identical to the standard prescribed under this chapter. 49 
U.S.C. 30103(b)(1). It is this statutory command by Congress that 
preempts any non-identical State legislative and administrative law 
address the same aspect of performance.

[[Page 46118]]

    The express preemption provision described above is subject to a 
savings clause under which ``[c]ompliance with a motor vehicle safety 
standard prescribed under this chapter does not exempt a person from 
liability at common law.'' 49 U.S.C. 30103(e) Pursuant to this 
provision, State common law tort causes of action against motor vehicle 
manufacturers that might otherwise be preempted by the express 
preemption provision are generally preserved. However, the Supreme 
Court has recognized the possibility, in some instances, of implied 
preemption of State common law tort causes of action by virtue of 
NHTSA's rules--even if not expressly preempted.
    This second way that NHTSA rules can preempt is dependent upon the 
existence of an actual conflict between an FMVSS and the higher 
standard that would effectively be imposed on motor vehicle 
manufacturers if someone obtained a State common law tort judgment 
against the manufacturer--notwithstanding the manufacturer's compliance 
with the NHTSA standard. Because most NHTSA standards established by an 
FMVSS are minimum standards, a State common law tort cause of action 
that seeks to impose a higher standard on motor vehicle manufacturers 
will generally not be preempted. However, if and when such a conflict 
does exist--for example, when the standard at issue is both a minimum 
and a maximum standard--the State common law tort cause of action is 
impliedly preempted. See Geier v. American Honda Motor Co., 529 U.S. 
861 (2000).
    Pursuant to Executive Order 13132, NHTSA has considered whether 
this proposed rule could or should preempt State common law causes of 
action. The agency's ability to announce its conclusion regarding the 
preemptive effect of one of its rules reduces the likelihood that 
preemption will be an issue in any subsequent tort litigation.
    To this end, the agency has examined the nature (e.g., the language 
and structure of the regulatory text) and objectives of today's 
proposed rule and does not foresee any potential State requirements 
that might conflict with it. NHTSA does not intend that this proposed 
rule preempt state tort law that would effectively impose a higher 
standard on motor vehicle manufacturers than that established by 
today's rule. Establishment of a higher standard by means of State tort 
law would not conflict with the standards proposed in this NPRM. 
Without any conflict, there could not be any implied preemption of a 
State common law tort cause of action.

National Environmental Policy Act

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

Paperwork Reduction Act

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

National Technology Transfer and Advancement Act

    Under the National Technology Transfer and Advancement Act of 1995 
(NTTAA) (Pub. L. 104-113), ``all Federal agencies and departments shall 
use technical standards that are developed or adopted by voluntary 
consensus standards bodies, using such technical standards as a means 
to carry out policy objectives or activities determined by the agencies 
and departments.'' Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies, such as the Society of Automotive 
Engineers (SAE). The NTTAA directs this agency to provide Congress, 
through OMB, explanations when the agency decides not to use available 
and applicable voluntary consensus standards.
    While the agency is not aware of any voluntary standards that exist 
regarding rollover structural integrity for the large buses 
contemplated in today's proposed rule, the agency has examined the 
applicable European Union standard (ECE R.66). As discussed extensively 
above, we have proposed in this NPRM to adopt an ECE R.66-based test, 
in part, to avoid requiring manufacturers to meet fundamentally 
different rollover requirements than those required in the European 
Union. The areas of today's proposed rule which differ from ECE R.66, 
and the reasons in support, are extensively discussed in the earlier 
sections of this preamble.

Executive Order 12988

    With respect to the review of the promulgation of a new regulation, 
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR 
4729, February 7, 1996) requires that Executive agencies make every 
reasonable effort to ensure that the regulation: (1) Clearly specifies 
the preemptive effect; (2) clearly specifies the effect on existing 
Federal law or regulation; (3) provides a clear legal standard for 
affected conduct, while promoting simplification and burden reduction; 
(4) clearly specifies the retroactive effect, if any; (5) adequately 
defines key terms; and (6) addresses other important issues affecting 
clarity and general draftsmanship under any guidelines issued by the 
Attorney General. This document is consistent with that requirement.
    Pursuant to this Order, NHTSA notes as follows. The issue of 
preemption is discussed above in connection with E.O. 13132. NHTSA 
notes further that there is no requirement that individuals submit a 
petition for reconsideration or pursue other administrative proceeding 
before they may file suit in court.

Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 requires agencies to 
prepare a written assessment of the costs, benefits and other effects 
of proposed or final rules that include a Federal mandate likely to 
result in the expenditure by State, local or tribal governments, in the 
aggregate, or by the private sector, of more than $135 million annually 
(adjusted for inflation to 2009 dollars with base year of 1995). This 
NPRM would not result in expenditures by State, local or tribal 
governments, in the aggregate, or by the private sector in excess of 
$135 million annually.

Plain Language

    Executive Order 12866 and E.O. 13563 require each agency to write 
all rules in plain language. Application of the principles of plain 
language includes consideration of the following questions:
     Have we organized the material to suit the public's needs?
     Are the requirements in the rule clearly stated?
     Does the rule contain technical language or jargon that 
isn't clear?
     Would a different format (grouping and order of sections, 
use of headings, paragraphing) make the rule easier to understand?
     Would more (but shorter) sections be better?
     Could we improve clarity by adding tables, lists, or 
diagrams?
     What else could we do to make the rule easier to 
understand?

[[Page 46119]]

    If you have any responses to these questions, please include them 
in your comments on this proposal.

Regulation Identifier Number (RIN)

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

Privacy Act

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

X. Public Participation

How do I prepare and submit comments?

    Your comments must be written and in English. To ensure that your 
comments are correctly filed in the Docket, please include the docket 
number of this document in your comments.
    Your comments must not be more than 15 pages long. (49 CFR 553.21). 
We established this limit to encourage you to write your primary 
comments in a concise fashion. However, you may attach necessary 
additional documents to your comments. There is no limit on the length 
of the attachments.
    Comments may also be submitted to the docket electronically by 
logging onto the Docket Management System Web site at http://www.regulations.gov. Follow the online instructions for submitting 
comments.
    Please note that pursuant to the Data Quality Act, in order for 
substantive data to be relied upon and used by the agency, it must meet 
the information quality standards set forth in the OMB and DOT Data 
Quality Act guidelines. Accordingly, we encourage you to consult the 
guidelines in preparing your comments. OMB's guidelines may be accessed 
at http://www.whitehouse.gov/omb/fedreg/reproducible.html.

How can I be sure that my comments were received?

    If you wish Docket Management to notify you upon its receipt of 
your comments, enclose a self-addressed, stamped postcard in the 
envelope containing your comments. Upon receiving your comments, Docket 
Management will return the postcard by mail.

How do I submit confidential business information?

    If you wish to submit any information under a claim of 
confidentiality, you should submit three copies of your complete 
submission, including the information you claim to be confidential 
business information, to the Chief Counsel, NHTSA, at the address given 
above under FOR FURTHER INFORMATION CONTACT. In addition, you should 
submit a copy, from which you have deleted the claimed confidential 
business information, to the docket at the address given above under 
ADDRESSES. When you send a comment containing information claimed to be 
confidential business information, you should include a cover letter 
setting forth the information specified in our confidential business 
information regulation. (49 CFR part 512.)

Will the agency consider late comments?

    We will consider all comments received before the close of business 
on the comment closing date indicated above under DATES. To the extent 
possible, we will also consider comments that the docket receives after 
that date. If the docket receives a comment too late for us to consider 
in developing a final rule (assuming that one is issued), we will 
consider that comment as an informal suggestion for future rulemaking 
action.

How can I read the comments submitted by other people?

    You may read the comments received by the docket at the address 
given above under ADDRESSES. The hours of the docket are indicated 
above in the same location. You may also see the comments on the 
Internet. To read the comments on the Internet, go to http://www.regulations.gov. Follow the online instructions for accessing the 
dockets.
    Please note that even after the comment closing date, we will 
continue to file relevant information in the docket as it becomes 
available. Further, some people may submit late comments. Accordingly, 
we recommend that you periodically check the Docket for new material. 
You can arrange with the docket to be notified when others file 
comments in the docket. See www.regulations.gov for more information.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicles, motor vehicle safety.

Proposed Regulatory Text

    In consideration of the foregoing, NHTSA proposes to amend 49 CFR 
Part 571 as follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

Subpart B--Federal Motor Vehicle Safety Standards

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

    Authority:  49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.95.

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

Sec.  571.227  Standard No. 227; Bus Rollover Structural Integrity.

    S1. Scope. This standard establishes performance requirements for 
bus rollover structural integrity.
    S2. Purpose. The purpose of this standard is to reduce death and 
injuries resulting from the structural collapse of the bus body 
structure, the unintended opening of emergency exits, and the 
detachment of window glazing, seats, and overhead luggage racks.
    S3. Application.
    (a) Subject to S3(b), this standard applies to:
    (1) Over-the-road buses, and
    (2) buses that are not over-the-road buses, and that have a GVWR 
greater than 11,793 kilograms (26,000 pounds).
    (b) This standard does not apply to school buses, transit buses, 
and perimeter-seating buses.
    S4. Definitions.
    Anchorage means any component involved in transferring loads to the 
vehicle structure, including, but not limited to, attachment hardware, 
frames, and vehicle structure itself.
    Over-the-road bus means a bus characterized by an elevated 
passenger deck located over a baggage compartment.
    Perimeter-seating bus means a bus with 7 or fewer designated 
seating positions rearward of the driver's seating position that are 
forward-facing or can convert to forward-facing without the use of 
tools and is not an over-the-road bus.
    Stop-request system means a vehicle-integrated system for passenger 
use to signal to a vehicle operator that they are requesting a stop.
    Survival space means a three-dimensional space to be preserved in 
the occupant compartment during the

[[Page 46120]]

rollover structural integrity test. The survival space is all points 
within the following volume of the occupant compartment:
    (1) The front boundary of the survival space is a transverse 
vertical plane 600 mm in front of the forward most point on the 
centerline of the front surface of the seat back of the forward most 
seat when the seat is in its forward most position and the seat back is 
in the manufacturer's nominal design riding position.
    (2) The rear boundary of the survival space is the inside surface 
of the rear wall of the occupant compartment of the vehicle.
    (3) The outer boundary of the survival space at any transverse 
cross section between or at the front and rear boundaries is defined on 
each side of the vehicle by the following three line segments:
    (i) Segment 1 extends vertically from the floor to an end point 
that is 500 mm above the floor and 150 mm inboard of the side wall.
    (ii) Segment 2 starts at the end point of Segment 1. The end point 
of Segment 2 is 750 mm vertically above and 250 mm horizontally inboard 
of the end point of Segment 1.
    (iii) Segment 3 is a horizontal line that starts at the end point 
of Segment 2 and ends at the vertical longitudinal center plane of the 
vehicle.
    Survival space template means a structure that represents a 
vertical transverse cross section of the survival space as shown in 
Figure 1. The structure is a minimum of 15 mm thick and secured by a 
rigid support frame that allows attachment to the vehicle floor.
    Transit bus means a bus that is equipped with a stop-request system 
sold for public transportation provided by, or on behalf of, a State or 
local government and that is not an over-the-road bus.
    S5. Requirements. When tested under the conditions and procedures 
specified in S6, each bus shall meet the following:
    S5.1 No part of the vehicle which is outside the survival space 
shall intrude into the survival space during the movement of the 
tilting platform or resulting from impact of the vehicle on the impact 
surface.
    S5.2 Each anchorage of all vehicle seats and interior overhead 
luggage racks and compartments shall not completely separate from its 
mounting structure during the movement of the tilting platform or 
resulting from impact of the vehicle on the impact surface.
    S5.3 Emergency exits shall not open during the movement of the 
tilting platform or resulting from impact of the vehicle on the impact 
surface.
    S5.4 After the vehicle comes to rest on the impact surface, with 
the vehicle resting on its side, each roof and rear emergency exit of 
the vehicle provided in accordance with Standard No. 217 (Sec.  
571.217) shall be capable of releasing and opening according to the 
requirements specified in that standard.
    S5.5 After the vehicle comes to rest on the impact surface, with 
the vehicle resting on its side, window glazing and each surrounding 
window frame opposite the impacted side of the vehicle shall not allow 
the passage of a 102 mm diameter sphere when a force of no more than 22 
Newtons is applied to the sphere at any vector in a direction from the 
interior to the exterior of the vehicle.
    S6. Test conditions.
    S6.1 Tilting platform.
    S6.1.1 The tilting platform has a top surface that rests 
horizontally at its initial position and is of sufficient size to fully 
contact the bottom of the vehicle's tires.
    S6.1.2 The top surface of the tilting platform, at its initial 
position, is 800  20 millimeters (mm) above the impact 
surface specified in S6.1.6.
    S6.1.3 The axis of rotation of the tilting platform is a maximum of 
a 100 mm horizontal distance from the edge of the impact surface 
closest to the platform and a maximum of 100 mm below the horizontal 
plane at the top surface of the tilting platform as shown in Figure 3.
    S6.1.4 The tilting platform is equipped with wheel supports on the 
top surface as shown in Figure 3. At each vehicle axle, the wheel 
closest to the platform's axis of rotation is supported. The wheel 
supports are positioned to make contact with the outboard tire sidewall 
of the supported wheels with the vehicle positioned as specified in 
S6.3.1. Each wheel support has the following dimensions:
    (a) The height above the top surface of the tilting platform is no 
greater than two-thirds of the vertical height of the adjacent tire's 
sidewall.
    (b) The width is a minimum of 19 mm.
    (c) The length is a minimum of 500 mm.
    (d) The top inboard edge has a radius of 10 mm.
    S6.1.5 While raising the platform, the tilting platform roll angle, 
measured at the outside of each wheel farthest from the pivot point, 
does not differ by more than one degree.
    S6.1.6 The impact surface is horizontal, uniform, dry, and smooth 
concrete. The impact surface covers an area that is large enough to 
ensure that the vehicle does not strike beyond the impact surface 
edges.
    S6.2 Vehicle preparation.
    S6.2.1 The vehicle's tires are inflated to the manufacturer's 
recommended tire pressure.
    S6.2.2 Survival space templates may be secured to the bus floor 
anywhere within the survival space.
    S6.2.3 If a seat has adjustable anchorages, the seat may be moved 
forward or rearward to allow the installation of a survival space 
template. If a seat has fixed anchorages, the seats may be removed to 
allow the installation of any testing equipment. Ballast of any weight 
up to the weight of the removed seat and 68 kg per designated seating 
position may be secured to the bus floor. The ballasts are not placed 
farther forward than the forward most point of the vehicle seat 
immediately in front of the removed seat, and the ballasts are not 
placed farther rearward than the rear most point of the vehicle seat 
immediately behind the removed seat.
    S6.2.4 The fuel tank is filled to its maximum fuel capacity. All 
other vehicle fluids are at their maximum capacity. Fluids may be 
substituted if the weight of the original fluid is maintained.
    S6.2.5 Ballasting. The vehicle is loaded to any weight up to and 
including the gross vehicle weight rating (GVWR). Up to 68 kg of 
ballast is installed at all designated seating positions that are 
equipped with occupant restraints. The ballast is placed on the top of 
each seat cushion and attached securely to the seat frame such that it 
does not break away from the seat from the time the tilting platform 
begins movement to after the vehicle comes to rest on the impact 
surface.
    S6.3 Rollover structural integrity test procedure. Each vehicle 
shall meet the requirements of S5 when prepared as specified in S6.2 
and tested in accordance with the procedures set forth below.
    S6.3.1 Position the vehicle on the tilting platform as illustrated 
in the examples of Figures 2 and 3 with its longitudinal centerline 
parallel to the tilt platform's axis of rotation, the right or left 
side facing the impact surface at NHTSA's option, and with the outboard 
tire sidewall at the widest axle within 100 mm of the axis of rotation.
    S6.3.2 Attach a rigid wheel support to the tilting platform at each 
axle of the vehicle so that it contacts the outboard tire sidewall of 
the wheel closest to the impact surface.

[[Page 46121]]

    S6.3.3 Block the suspension system of the vehicle to be within 
25 mm of the normal riding attitude as loaded in S6.2.5.
    S6.3.4 Apply the vehicle parking brakes.
    S6.3.5 Place the vehicle windows, doors, and emergency exits in the 
fully closed and latched but not locked positions.
    S6.3.6 Tilt the vehicle at a rate not to exceed 5 degrees/sec until 
it starts to rollover on its own.
BILLING CODE 4910-59-P
[GRAPHIC] [TIFF OMITTED] TP06AU14.012

[[Page 46122]]

[GRAPHIC] [TIFF OMITTED] TP06AU14.013

[[Page 46123]]

[GRAPHIC] [TIFF OMITTED] TP06AU14.014

Issued in Washington, DC, under authority delegated in 49 CFR 1.95.
David M. Hines,
Acting Associate Administrator for Rulemaking.
[FR Doc. 2014-18326 Filed 8-5-14; 8:45 am]
BILLING CODE 4910-59-C