[Federal Register Volume 76, Number 12 (Wednesday, January 19, 2011)]
[Rules and Regulations]
[Pages 3212-3305]
[FR Doc No: 2011-547]

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

Part II

Department of Transportation

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

National Highway Traffic Safety Administration

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

49 CFR Parts 571 and 585

Federal Motor Vehicle Safety Standards, Ejection Mitigation; Phase-In
Reporting Requirements; Incorporation by Reference; Final Rule

Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 /
Rules and Regulations

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

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 571 and 585

[Docket No. NHTSA-2011-0004]
RIN 2127-AK23

Federal Motor Vehicle Safety Standards, Ejection Mitigation;
Phase-In Reporting Requirements; Incorporation by Reference

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

ACTION: Final rule.

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

SUMMARY: This final rule establishes a new Federal Motor Vehicle Safety
Standard No. 226, ``Ejection Mitigation,'' to reduce the partial and
complete ejection of vehicle occupants through side windows in crashes,
particularly rollover crashes. The standard applies to the side windows
next to the first three rows of seats, and to a portion of the cargo
area behind the first or second rows, in motor vehicles with a gross
vehicle weight rating (GVWR) of 4,536 kilogram (kg) or less (10,000
pounds (lb) or less). To assess compliance, the agency is adopting a
test in which an impactor is propelled from inside a test vehicle
toward the windows. The ejection mitigation safety system is required
to prevent the impactor from moving more than a specified distance
beyond the plane of a window. To ensure that the systems cover the
entire opening of each window for the duration of a rollover, each side
window will be impacted at up to four locations around its perimeter at
two time intervals following deployment.
    The agency anticipates that manufacturers will meet the standard by
modifying existing side impact air bag curtains, and possibly
supplementing them with advanced glazing. The curtains will be made
larger so that they cover more of the window opening, made more robust
to remain inflated longer, and made to deploy in both side impacts and
in rollovers. In addition, after deployment the curtains will be
tethered near the base of the vehicle's pillars or otherwise designed
to keep the impactor within the boundaries established by the
performance test. This final rule adopts a phase-in of the new
requirements, starting September 1, 2013.
    This final rule advances NHTSA's initiatives in rollover safety and
also responds to Section 10301 of the Safe, Accountable, Flexible,
Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU).
That section directs NHTSA to initiate and complete rulemaking to
reduce complete and partial ejections of vehicle occupants from
outboard seating positions, considering various ejection mitigation
systems.

DATES: Effective date: The date on which this final rule amends the
Code of Federal Regulations (CFR) is March 1, 2011. The incorporation
by reference of certain publications listed in the standard is approved
by the Director of the Federal Register as of March 1, 2011.
    Petitions for reconsideration: If you wish to petition for
reconsideration of this rule, your petition must be received by March
7, 2011.
    Compliance dates: This final rule adopts a phase-in of the new
requirements. The phase-in begins on September 1, 2013. By September 1,
2017, all vehicles must meet the standard, with the exception of
altered vehicles and vehicles produced in more than one stage, which
are provided more time to meet the requirements. Manufacturers can earn
credits toward meeting the applicable phase-in percentages by producing
compliant vehicles ahead of schedule, beginning March 1, 2011 and
ending at the conclusion of the phase-in.

ADDRESSES: If you wish to petition for reconsideration of this rule,
you should refer in your petition to the docket number of this document
and submit your petition to: Administrator, National Highway Traffic
Safety Administration, 1200 New Jersey Avenue, SE., West Building,
Washington, DC 20590.
    The petition will be placed in the docket. Anyone is able to search
the electronic form of all documents 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).
    For access to the docket to read background documents or comments
received, go to http://www.regulations.gov and follow the online
instructions for accessing the docket. You may also visit DOT's Docket
Management Facility, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001 for on-line access to
the docket.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may contact
Mr. Louis Molino, NHTSA Office of Crashworthiness Standards, telephone
202-366-1740, fax<PHONE_NUMBER>. For legal issues, you may contact Ms.
Deirdre Fujita, NHTSA Office of Chief Counsel, telephone<PHONE_NUMBER>,
fax<PHONE_NUMBER>.
    You may send mail to these officials at the National Highway
Traffic Safety Administration, U.S. Department of Transportation, 1200
New Jersey Avenue, SE., West Building, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Safety Need
III. Congressional Mandate
IV. Summary of the NPRM
V. Summary of the Comments
VI. How the Final Rule Differs From the NPRM
VII. Foundations for This Rulemaking
    a. Advanced Glazing
    b. Full Window Opening Coverage Is Key
    c. Comparable Performance in Simulated Rollovers and Component-
Level Impact Tests
    d. Advantages of a Component Test Over a Full Vehicle Dynamic
Test
VIII. Availability of Existing Curtains
IX. Existing Curtains
    a. Existing Curtains Tested to Proposed Requirements
    b. Field Performance
X. Response to Comments and Agency Decisions
    a. Impactor Dimensions and Mass
    1. NPRM
    2. Comments
    3. Agency Response
    b. Measurement Plane and Displacement Limit (100 mm)
    1. NPRM
    2. Comments
    3. Agency Response
    c. Times and Speed at Which the Headform Impacts the
Countermeasure
    1. NPRM on Time Delay (Ejections Can Occur Both Early and Late
in the Rollover Event)
    i. Comments on Time Delay
    ii. Agency Response
    2. Speed at Which the Headform Impacts the Countermeasure
    i. Comments on Impact Speed
    ii. Agency Response
    d. Target Locations
    1. Why We Are Focusing on Side Windows and Not Other Openings
    2. Why We Are Focusing on the Side Windows Adjacent to First
Three Rows
    i. First Three Rows
    ii. Method of Determining 600 mm Behind Seating Reference Point
(SgRP)
    iii. Increasing 600 mm Limit for Vehicles With One or Two Rows
of Seats
    3. Answers to Questions About Method for Determining Three-Row
Area
    e. How We Are Testing the Ability of These Side Windows To
Mitigate Ejections
    1. What is a ``window opening''?
    i. 50 mm Inboard of the Glazing

    ii. Conducting the Test With Various Items Around the Window
Opening
    iii. Removing Flexible Gasket Material
    iv. Testing With Weather Stripping in Place
    v. Metal Dividers in Glazing
    2. How We Determine Impactor Target Locations in an Objective
and Repeatable Manner
    i. Testing in ''Any'' Location
    ii. Methodology
    iii. Reorienting the Targets
    iv. Suppose Even With Rotating the Headform the Vehicle Has No
Target Locations
    v. Decision Not To Test Target of Greatest Displacement
    vi. Reconstitution of Targets
    f. Glazing Issues
    1. Positioning the Glazing
    2. Window Pre-Breaking Specification and Method
    g. Test Procedure Tolerances
    h. Impactor Test Device Characteristics
    i. Readiness Indicator
    j. Other Issues
    1. Rollover Sensors
    2. Quasi-Static Loading
    3. Full Vehicle Test
    4. Minor Clarifications to the Proposed Regulatory Text
    k. Practicability
    l. Applicability
    1. Convertibles
    2. Original Roof Modified
    3. Multi-Stage Manufacture of Work Trucks
    4. Other
    m. Lead Time and Phase-In Schedules; Reporting Requirements
XI. Costs and Benefits
XII. Rulemaking Analyses and Notices

I. Executive Summary

    This final rule establishes a new Federal Motor Vehicle Safety
Standard (FMVSS) No. 226, ``Ejection Mitigation,'' to reduce the
partial and complete ejection of vehicle occupants through side windows
in crashes, particularly rollover crashes. Countermeasures installed to
meet this rule will also reduce the number of complete and partial
ejections of occupants in side impacts. This final rule responds to
section 10301 of the Safe, Accountable, Flexible, Efficient
Transportation Equity Act: A Legacy for Users,'' (SAFETEA-LU), Public
Law 109-59 (Aug. 10, 2005; 119 Stat. 1144), which requires the
Secretary of Transportation to issue an ejection mitigation final rule
reducing complete and partial ejections of occupants from outboard
seating positions.
    Addressing vehicle rollovers is one of NHTSA's highest safety
priorities. In 2002, NHTSA conducted an in-depth review of rollovers
and associated deaths and injuries and assessed how this agency and the
Federal Highway Administration (FHWA) could most effectively improve
safety in this area.\1\ The agency formulated strategies involving
improving vehicle performance and occupant behavior, and with the FHWA
taking the lead, improving roadway designs. Vehicle performance
strategies included crash avoidance and crashworthiness programs, and
included four wide-ranging initiatives to address the rollover safety
problem: prevent crashes, prevent rollovers, prevent ejections, and
protect occupants who remain within the vehicle after a crash. Projects
aimed at protecting occupants remaining in the vehicle during a
rollover included improved roof crush resistance and research on
whether seat belts could be made more effective in rollovers.
---------------------------------------------------------------------------

    \1\ The assessment was carried out by one of four Integrated
Project Teams (IPTs) formed within NHTSA, whose recommendations
culminated in the agency's priority plan, ``NHTSA Vehicle Safety
Rulemaking and Supporting Research: 2003-2006'' (68 FR 43972; July
18, 2003) http://www.nhtsa.dot.gov/cars/rules/rulings/PriorityPlan/FinalVeh/Index.html. The IPT Report on Rollover was published in
June 2003 (68 FR 36534, Docket 14622).
---------------------------------------------------------------------------

    A major undertaking implementing the first two initiatives was
completed in 2007 when NHTSA adopted a new FMVSS No. 126 (49 CFR
571.126), ``Electronic Stability Control Systems,'' to require
electronic stability control (ESC) systems on passenger cars,
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating (GVWR) of 4,536 kg (10,000 lb) or less (72 FR 17236,
April 6, 2007, Docket NHTSA-2007-27662). ESC systems use automatic
computer-controlled braking of the individual wheels of a vehicle to
assist the driver in maintaining control in critical driving situations
in which the vehicle is beginning to lose directional stability at the
rear wheels (spin out) or directional control at the front wheels (plow
out). Because most loss-of-control crashes culminate in the vehicle's
leaving the roadway--an event that significantly increases the
probability of a rollover--preventing single-vehicle loss-of-control
crashes is the most effective way to reduce deaths resulting from
rollover crashes.\2\ The agency estimates that when all vehicles (other
than motorcycles) under 4,536 kg GVWR have ESC systems, the number of
deaths each year resulting from rollover crashes would be reduced by
4,200 to 5,500. From 2001 to 2007, there were more than 10,000 deaths
in light vehicle rollover crashes. Rollover deaths have decreased
slightly in 2008 (9,043) and 2009 (8,267), as have fatalities in all
crash types.
---------------------------------------------------------------------------

    \2\ NHTSA estimates that the installation of ESC will reduce
single-vehicle crashes of passenger cars by 34 percent and single
vehicle crashes of sport utility vehicles (SUVs) by 59 percent.
NHTSA further estimates that ESC has the potential to prevent 71
percent of the passenger car rollovers and 84 percent of the SUV
rollovers that would otherwise occur in single-vehicle crashes.
NHTSA estimates that ESC would save 5,300 to 9,600 lives and prevent
156,000 to 238,000 injuries in all types of crashes annually once
all light vehicles on the road are equipped with ESC systems.
---------------------------------------------------------------------------

    While ESC systems will avoid many of the roadway departures that
lead to rollover, vehicle rollovers will continue to occur.\3\ Once a
rollover occurs, vehicle crashworthiness characteristics play a crucial
role in protecting the occupants. According to agency data, occupants
have a much better chance of surviving a crash if they are not ejected
from their vehicles.
---------------------------------------------------------------------------

    \3\ NHTSA has developed a Final Regulatory Impact Analysis
(FRIA) for this final rule that discusses issues relating to the
target population and the potential costs, benefits and other
impacts of this regulatory action. The FRIA is available in the
docket for this final rule and may be obtained by downloading it or
by contacting the Docket Management facility at the address provided
at the beginning of this document.
---------------------------------------------------------------------------

    Concurrent with the agency's work on ESC, NHTSA began work on the
third initiative on rollover safety, pursuing the feasibility of
installing crashworthiness safety systems to mitigate occupant
ejections through side windows in rollovers (``ejection mitigation'').
Major strides on this third initiative were realized in 2007 when the
agency published a final rule that incorporated a dynamic pole test
into FMVSS No. 214, ``Side impact protection'' (49 CFR 571.214)
(``Phase 1 FMVSS No. 214 rulemaking'').\4\ The pole test, applying to
motor vehicles with a GVWR of 4,536 kg or less, requires vehicle
manufacturers to provide side impact protection for a wide range of
occupant sizes and over a broad range of seating positions. To meet the
pole test, manufacturers are installing new technologies capable of
improving head and thorax protection in side crashes, i.e., side
curtain air bags and torso air bags.
---------------------------------------------------------------------------

    \4\ 72 FR 51908; September 11, 2007, Docket No. NHTSA-29134;
response to petitions for reconsideration, 73 FR 32473, June 9,
2008, Docket No. NHTSA-2008-0104, 75 FR 12123, March 15, 2010,
Docket No. NHTSA-2010-0032. On August 10, 2005, the ``Safe,
Accountable, Flexible, Efficient Transportation Equity Act: A Legacy
for Users,'' (SAFETEA-LU), Public Law 109-59 (Aug. 10, 2005; 119
Stat. 1144) was enacted, to authorize funds for Federal-aid
highways, highway safety programs, and transit programs, and for
other purposes. Section 10302(a) of SAFETEA-LU directed the
Secretary to complete the FMVSS No. 214 rulemaking by July 1, 2008.
The September 11, 2007 final rule completed the rulemaking specified
in section 10302(a). NHTSA estimates that the September 11, 2007
final rule will save 311 lives annually.
---------------------------------------------------------------------------

    Today's final rule launches a new phase in occupant protection and
ejection mitigation. It builds on and

improves existing technology while achieving cost efficiency and does
so expeditiously. This final rule enhances the side curtain air bag
systems installed pursuant to the FMVSS No. 214 side impact rulemaking.
Side curtain air bags \5\ will be made larger to cover more of the
window opening, more robust to remain inflated longer, enhanced to
deploy in side impacts and in rollovers, and made not only to cushion
but also made sufficiently strong to keep an occupant from being fully
or partially ejected through a side window. The side curtain air bags
required by this rule will be designed to retain the occupant
regardless of whether the occupant had his or her window glazing up,
down, or partially open, and even when the glazing is destroyed during
the rollover crash.
---------------------------------------------------------------------------

    \5\ In this document, this countermeasure is referred to as an
``ejection mitigation side curtain air bag,'' ``side curtain air
bag,'' ``air bag curtain,'' ``rollover curtain,'' or simply
``curtain.'' This countermeasure is designed to deploy in a rollover
crash. The same side curtain air bag meeting FMVSS No. 226 can be
used to meet the ejection mitigation requirements of FMVSS No. 214
with the addition of a rollover sensing system to deploy the side
curtain air bag in a rollover.
---------------------------------------------------------------------------

    The NPRM upon which this final rule is based was published on
December 2, 2009 (74 FR 63180, Docket No. NHTSA-2009-0183). Materials
underlying the development of this rule have been placed in that docket
and in a research and development docket created in 2006 (Docket No.
NHTSA-2006-26467).
    Rollover crashes can be complex and unpredictable. At this time
there is no conventional rollover scenario or test representative of
real-world rollover crashes that can be used in a dynamic test to the
agency's satisfaction to evaluate the performance of ejection
mitigation countermeasures. Yet, this final rule achieves ejection
mitigation benefits notwithstanding the absence of a dynamic procedure.
Agency research has found that full coverage of the side windows is a
key element to mitigating ejection. This standard adopts a component
test that assures there is full coverage of the side window to diminish
the potential risk of the windows as ejection portals and that assesses
ejection mitigation safety systems for as long in the crash event as
the risk of ejection reasonably exists.
    The test uses a guided impactor to assess the ability of the
countermeasure (e.g., a curtain system) to mitigate ejections in
different types of rollover and side impact crashes involving different
occupant kinematics. The test has been carefully designed to represent
occupant to vehicle interactions in a dynamic rollover event. The
impact mass is based on the mass imposed by a 50th percentile male's
head and upper torso on the window opening during an occupant ejection.
The mass of the impactor, 18 kilograms (kg) (40 lb), is propelled at
points around the window's perimeter with sufficient kinetic energy to
assure that the ejection mitigation countermeasure is able to protect a
far-reaching range of occupants in real world crashes.
    In the test, the countermeasure must retain the linear travel of
the impactor such that the impactor must not travel 100 millimeters
(mm) beyond the location of the inside surface of the vehicle glazing.
This displacement limit serves to control the size of any gaps forming
between the countermeasure (e.g., the ejection mitigation side curtain
air bag) and the window opening, thus reducing the potential for both
partial and complete ejection of an occupant.
    To evaluate the performance of the curtain to fully cover potential
ejection routes, the impactor will typically target four specific
locations per side window adjacent to the first three rows of the
vehicle. Impacting four targets around the perimeter of the opening
assures that the window will be covered by the countermeasure
(curtain), while imposing a reasonable test burden. Small windows will
be tested with fewer targets.
    Computer modeling has shown that ejections can occur early and late
in the rollover event. In the standard's test procedure, the ejection
mitigation side countermeasure will be tested at two impact speeds and
at two different points in time, to ensure that the protective system
will retain the occupant from the relatively early through the late
stages of a rollover.
    The times at which the impacts will occur are data-driven and
related to our goal of containment of occupants both early and late in
rollovers. Crash data show that slightly less than half of all fatal
complete ejections occurred in crashes with 5 or fewer quarter-turns.
Film analysis of vehicles that rolled 5 or fewer quarter-turns in
staged rollover tests indicates that it took about 1.5 seconds for the
vehicles to roll once completely. A vehicle rolling 11 quarter-turns
had a maximum roll time of 5.5 seconds. Data from the National
Automotive Sampling System (NASS) Crashworthiness Data System (CDS)
show that rollovers with eleven or fewer quarter-turns account for
about 98 percent of rollovers with fatal complete ejection.\6\ The
standard replicates these crash dynamics with the two impacts of the
headform. The first impact will be at 20 kilometers per hour (km/h)
(12.4 miles per hour (mph)), 1.5 seconds after deployment of the
curtain. The second impact will be at 16 km/h (9.9 mph), 6 seconds
after deployment of the curtain. The 20 km/h and 16 km/h tests
replicate the forces that an occupant can impart to the curtain during
the rollover event as well as during side impacts.
---------------------------------------------------------------------------

    \6\ This is based on 2000-2009 NASS data. The 1988--2005 NASS
data reported in the NPRM showed that 93 percent of rollovers with
fatal complete ejections had 11 or fewer quarter-turns.
---------------------------------------------------------------------------

    Under today's final rule, vehicle manufacturers must provide
information to NHTSA upon request that describes the conditions under
which ejection mitigation air bags will deploy. There is no presently
demonstrated need for us to specify in the standard the conditions
dictating when the sensors should deploy; field data indicate that
rollover sensors are overwhelmingly deploying effectively in the real
world. We will keep monitoring field data to determine whether future
regulatory action is needed in this area.
    This chapter in occupant protection will achieve tremendous
benefits at reasonable costs. We estimate that this rule will save 373
lives and prevent 476 serious injuries per year (see Table 1 below).
The cost of this final rule is approximately $31 per vehicle (see Table
2). The cost per equivalent life saved is estimated to be $1.4 million
(3 percent discount rate)-$1.7 million (7 percent discount rate) (see
Table 3 below). Annualized costs and benefits are provided in Table 4.

                       Table 1--Estimated Benefits
------------------------------------------------------------------------

------------------------------------------------------------------------
Fatalities..............................................             373
Serious Injuries........................................             476
------------------------------------------------------------------------

                        Table 2--Estimated Costs*
                            [2009 economics]
------------------------------------------------------------------------

------------------------------------------------------------------------
Per Vehicle...............................  $31.
Total Fleet (16.5 million vehicles).......  $507 Million
------------------------------------------------------------------------
* The system costs are based on vehicles that are equipped with an FMVSS
  No. 214 curtain system. According to vehicle manufacturers'
  projections made in 2006, 98.7 percent of Model Year (MY) 2011
  vehicles will be equipped with curtain bags and 55 percent of vehicles
  with curtain bags will be equipped with a rollover sensor.

                 Table 3--Cost per Equivalent Life Saved
------------------------------------------------------------------------
                                                             7% Discount
                     3% Discount rate                           rate
------------------------------------------------------------------------
$1.4M.....................................................        $1.7M
------------------------------------------------------------------------

                                     Table 4--Annualized Costs and Benefits
                                         [In millions of $2009 dollars]
----------------------------------------------------------------------------------------------------------------
                                                                                Annualized
                                                                   Annual costs      benefits      Net benefits
----------------------------------------------------------------------------------------------------------------
3% Discount Rate................................................           $507M         $2,279M          $1,773
7% Discount Rate................................................            507M          1,814M           1,307
----------------------------------------------------------------------------------------------------------------

    Accompanying today's final rule is a Final Regulatory Impact
Analysis (FRIA) analyzing the costs, benefits, and other impacts of
this final rule, and a technical report the agency has prepared that
presents a detailed analysis of engineering studies, and other
information supporting the final rule. Both documents have been placed
in the docket for this final rule. The documents can be obtained by
contacting the docket by the means specified at the beginning of this
document or by downloading them at www.regulations.gov.

II. Safety Need

    Rollover crashes are a significant and a particularly deadly safety
problem. As a crash type, rollovers are second only to frontal crashes
as a source of fatalities in light vehicles. Data from the last 10
years of Fatal Analysis Reporting System (FARS) files (2000-2009\7\)
indicate that frontal crash fatalities have averaged about 11,600 per
year, while rollover fatalities have averaged 10,037 per year. In 2009,
35 percent of all fatalities were in light vehicle rollover crashes.
The last 10 years of data from the National Automotive Sampling System
(NASS) General Estimates System (GES) indicate that an occupant in a
rollover is 14 times more likely to be killed than an occupant in a
frontal crash.\8\
---------------------------------------------------------------------------

    \7\ These data are updated from the 1998 to 2007 FARS data
reported in the NPRM.
    \8\ The relative risk of fatality for each crash type can be
assessed by dividing the number of fatalities in each crash type by
the frequency of the crash type. The frequency of particular crash
types is determined by police traffic crash reports (PARs).
---------------------------------------------------------------------------

    Ejection is a major cause of death and injury in rollover crashes.
According to 2000-2009 FARS data, on average 47 percent of the
occupants killed in rollovers were completely ejected from their
vehicle. During this time period, there were 358 fully ejected
occupants killed for every 1,000 fully ejected occupants in rollover
crashes, as compared to 14 of every 1,000 occupants not fully ejected
occupants killed.\9\ A double-pair comparison from the last ten years
of FARS data show that avoiding complete ejection is associated with a
64 percent decrease in the risk of death.\10\
---------------------------------------------------------------------------

    \9\ The data combines partially-ejected and un-ejected occupants
together, because partial ejection is sometimes difficult to
determine and the PAR-generated FARS data may not be an accurate
representation of partially-ejected occupant fatalities.
    \10\ ``Incremental Risk of Injury and Fatality Associated with
Complete Ejection,'' NHTSA, 2010 (see the docket for this final
rule).
---------------------------------------------------------------------------

    The majority of rollover crashes involve the vehicle rolling over
two quarter-turns or less. However, the distribution of ejected
occupants who are seriously injured (maximum abbreviated injury scale
(MAIS) 3+) or killed is skewed towards rollovers with a higher number
of quarter-turns. According to NASS Crashworthiness Data System (CDS)
data of occupants exposed to a rollover crash from 2000 to 2009, half
of all fatal complete ejections occurred in crashes with six or more
quarter-turns.
    Most occupants are ejected through side windows. In developing the
target population estimates for this final rule we found that
annualized injury data from 1997 to 2008 NASS CDS and fatality counts
adjusted to the annual average from FARS for these same years\11\
indicate that ejection through side windows is the greatest contributor
to the ejection problem.\12\ There were 16,272 MAIS 1-2 injuries, 5,209
MAIS 3-5 injuries, and 6,412 fatalities resulting from ejections
through the side windows adjacent to the first three rows.
---------------------------------------------------------------------------

    \11\ The target population estimate for the NPRM used 1997 to
2005 FARS data. The estimate for this final rule is based on an
additional three years of data.
    \12\ In our data analysis for the NPRM to determine ejection
routes, we assumed that an ejection route coding of ``rear'' in NASS
CDS meant a second row window and that ``other'' glazing meant third
and higher row side window ejections. The assumption was based on
the coding of seat position in NASS. Since then, we have determined
that an occupant coded as ejected through a ``rear'' window did not
necessarily go through the second row window. Similarly, the coding
of ``other'' glazing was determined not necessarily to mean third
and higher row. Thus, for this final rule, for cases coded as
ejected through ``rear'' or ``other'' glazing, we assume that the
ejection was through a second row window in the following
circumstances: the occupant was seated in the first two rows of a
vehicle, or the vehicle was a convertible, two-door sedan, or four-
door sedan (i.e., these are vehicles without a third row or cargo
area). If an occupant was coded as seated in the third or higher row
and was coded as ejected through a rear window or ``other'' glazing,
we used the NASS Case Query System to undertake a hard copy review.
We determined ejection routes in this manner for 41 unweighted rear
window cases and 17 unweighted ``other'' glazing cases. A hard copy
review of the ``other'' glazing cases showed that 9 were known 3rd
row side window ejections, but five cases were miscoded. Four were
actually backlight ejections and one was a sunroof ejection. The
known 3rd row ejections were recoded as ``Row 3 Window'' ejections.
---------------------------------------------------------------------------

    Table 5 below shows the MAIS 1-2, MAIS 3-5, and fatality
distribution of ejected occupants by 11 potential ejection routes.\13\
The ``Not Glazing'' category captures ejected occupants that did not
eject through a glazing area or the roof (perhaps a door or an area of
vehicle structure that was torn away during the crash). Roof ejections
have been separated into ``Roof Panel or Glazing'' and ``Roof Other.''
The former groups sunroofs, t-tops and targa-tops into a single
category, whether made of glazing or having a sheet metal skin. The
latter combines convertibles, modified roofs, camper tops and removable
roofs. No distinction could be made as to whether these roof structures
were open or closed prior to ejection.
---------------------------------------------------------------------------

    \13\ All crash types are included, but the counts are restricted
to ejected occupants who were injured.

                Table 5--Occupant Injury and Fatality Counts by Ejection Route in All Crash Types
                                      [Annualized 1997-2008 NASS and FARS]
----------------------------------------------------------------------------------------------------------------
                      Ejection route                            MAIS 1-2          MAIS 3-5            Fatal
----------------------------------------------------------------------------------------------------------------
Windshield................................................             1,517             1,400             1,078
First-Row Windows.........................................            14,293             4,980             5,589
Second-Row Windows........................................             1,700               641               796

Third-Row Windows.........................................               279                88                27
Fourth-Row Windows........................................                 0                 0                39
Fifth-Row Window..........................................                 0                 0                 7
Cargo Area Rear of Row 2..................................               342                17                52
Backlight.................................................             1,621             1,364               495
Roof Panel or Glazing.....................................             1,000               367               324
Roof Other................................................               420               105                81
Multiple Windows..........................................                 0                19                 0
Not Glazing...............................................             2,848             2,207             1,814
                                                           -----------------------------------------------------
    Subtotals:                                              ................  ................  ................
        Rows 1-3..........................................            16,272             5,709             6,412
        4th, 5th Row and Cargo............................               342                17                98
                                                           -----------------------------------------------------
    Total.................................................            24,020            11,188            10,302
----------------------------------------------------------------------------------------------------------------

    Table 6, below, provides the percentage of the total at each injury
level. The injuries and fatalities resulting from ejections through the
first three rows of windows constitute 68 percent of MAIS 1-2 injuries,
51 percent of MAIS 3-5 injuries, and 62 percent of all ejected
fatalities.

             Table 6--Occupant Injury and Fatality Percentages by Ejection Route in All Crash Types
                                      [Annualized 1997-2008 NASS and FARS]
----------------------------------------------------------------------------------------------------------------
                      Ejection route                            MAIS 1-2          MAIS 3-5            Fatal
----------------------------------------------------------------------------------------------------------------
Windshield................................................              6.3%             12.5%             10.5%
First-Row Windows.........................................             59.5%             44.5%             54.2%
Second-Row Windows........................................              7.1%              5.7%              7.7%
Third-Row Windows.........................................              1.2%              0.8%              0.3%
Fourth-Row Windows........................................              0.0%              0.0%              0.4%
Fifth-Row Window..........................................              0.0%              0.0%              0.1%
Cargo Area Rear of Row 2..................................              1.4%              0.2%              0.5%
Backlight.................................................              6.8%             12.2%              4.8%
Roof Panel or Glazing.....................................              4.2%              3.3%              3.1%
Roof Other................................................              1.7%              0.9%              0.8%
Multiple Windows..........................................              0.0%              0.2%              0.0%
Not Glazing...............................................             11.9%             19.7%             17.6%
                                                           -----------------------------------------------------
    Subtotals:                                              ................  ................  ................
        Rows 1-3..........................................             67.7%             51.0%             62.2%
        4th, 5th Row and Cargo............................              1.4%              0.2%              1.0%
                                                           -----------------------------------------------------
    Total.................................................            100.0%            100.0%            100.0%
----------------------------------------------------------------------------------------------------------------

    Since the countermeasure covering side window openings will be made
more effective in preventing ejections, this rulemaking will also
reduce the number of complete and partial ejections of occupants in
side impacts. These benefits go beyond those achieved in the rulemaking
adopting an oblique pole test into FMVSS No. 214 (Phase 1 FMVSS No. 214
rulemaking) because a side air bag installed to meet FMVSS No. 214 is
not necessarily wide or robust enough to effectively contain occupants
in certain side impacts. In fact, NHTSA found that FMVSS No. 214's
requirements could be met by a seat-mounted head/torso side air bag or
a side head protection curtain air bag together with a seat-mounted or
door-mounted torso bag. Further, FMVSS No. 214's pole test does not
apply to rear seats. In short, FMVSS No. 214 does not require the large
curtain needed for full coverage of side window openings.
    Accordingly, this ejection mitigation safety standard will reduce
the number of partial and complete ejections of occupants in side
impacts. The Phase 1 FMVSS No. 214 rulemaking included reduction of
partial ejections of adults (age 13+ years) through side windows in
side impacts, but did not include complete ejections. The Phase 1 side
impact rulemaking also did not include any impact where a rollover was
the first event. In addition, benefits were only assumed in the Phase 1
FMVSS No. 214 rulemaking for side impact crashes with a change in
velocity ([Delta]V) between 19.2 and 40.2 km/h (12 to 25 mph) and
impact directions from 2 to 3 o'clock and 9 to 10 o'clock. The side
curtain air bags used to meet FMVSS No. 226's ejection mitigation
requirements will directly prevent many ejection-induced injuries and
fatalities in side impacts that could not be saved by a side air bag
that minimally complies with FMVSS No. 214.

Target Population

    In general, the target population for this ejection mitigation
final rule is composed of occupants injured or killed by ejection from
the first three rows of side windows in vehicles to which the standard
applies. Later in the preamble, we discuss some slight adjustments made
concerning occupants ejected through cargo area window openings.

The target population does not include occupants ejected in all crash
types, but rather is restricted to ejections that occur in crashes
involving rollovers and some types of planar only side impacts. The
limitation on side impacts, change in velocity ([Delta]V), and certain
occupants in those side impacts is necessary to not count benefits
anticipated by FMVSS No. 214.
    Tables 7-9 provide the counts and/or percentages of the injured and
killed side window (rows 1-3) ejected occupants by the window row they
were ejected through. These data are restricted to rollover crashes and
side impacts in the relevant [Delta]V range (target population type
crashes).
    Tables 7 and 8 show the ejection degree and restraint condition for
occupants in the first three rows of target population type crashes.
Among the side windows, the first row windows provide the ejection
route for most of the injured and killed occupants. The greatest number
of fatally ejected occupants (3,837) went through the first row window.
This represents 88 percent of all side window ejected fatalities.
Similarly, 3,979 (89 percent) MAIS 3-5 and 10,017 (87 percent) MAIS 1-2
injured occupants went through the row 1 windows. Within each row, the
greatest number of fatal and MAIS 3-5 occupants were completely ejected
and unbelted. There were 2,623 fatally injured (59 percent) and 2,269
MAIS 3-5 injured (50 percent) occupants who were unbelted and
completely ejected through the row 1 windows.

   Table 7--Distribution of First 3 Rows of Side Window Ejected Occupants by Ejection Row and Injury Level by Ejection Degree and Belt Use, In Target
                                                                 Population Type Crashes
                                                          [Annualized 1997-2008 NASS and FARS]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Row 1                            Row 2                            Row 3
          Ejection degree                 Belted      --------------------------------------------------------------------------------------------------
                                                        MAIS 1-2   MAIS 3-5    Fatal     MAIS 1-2   MAIS 3-5    Fatal     MAIS 1-2   MAIS 3-5    Fatal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Complete..........................  Yes..............         95         29         54        139         78          5          0          8          0
Complete..........................  No...............      3,501      2,269      2,623        782        309        421         95         54         23
Partial...........................  Yes..............      4,345      1,097        484         43         32         38        109          0          0
Partial...........................  No...............      2,076        584        675        103         80        123          4          0          0
                                                      --------------------------------------------------------------------------------------------------
    Total.........................  .................     10,017      3,979      3,837      1,067        499        587        207         62         23
--------------------------------------------------------------------------------------------------------------------------------------------------------

Table 8--Distribution of First 3 Rows of Side Window Ejected Occupants by Ejection Row and Injury Level by Ejection Degree and Belt Use, as a Percentage
                                            of Totals at each Injury Level, in Target Population Type Crashes
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Row 1                            Row 2                            Row 3
          Ejection degree                 Belted      --------------------------------------------------------------------------------------------------
                                                        MAIS 1-2   MAIS 3-5    Fatal     MAIS 1-2   MAIS 3-5    Fatal     MAIS 1-2   MAIS 3-5    Fatal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Complete..........................  Yes..............         1%         1%         1%         1%         2%         0%         0%         0%         0%
Complete..........................  No...............        31%        50%        59%         7%         7%         9%         1%         1%         1%
Partial...........................  Yes..............        38%        24%        11%         0%         1%         1%         1%         0%         0%
Partial...........................  No...............        18%        13%        15%         1%         2%         3%         0%         0%         0%
                                                      --------------------------------------------------------------------------------------------------
    Total.........................  .................        87%        89%        88%        86%         9%        11%        13%         2%         1%
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 9 shows the ejection degree and vehicle type for occupants in
the first three rows of target population type crashes. The greatest
numbers of fatalities result from occupants completely ejected from
passenger cars. These account for 28 percent of the total fatalities.
    Combining partial and complete ejections, cars account for 43
percent of fatalities and 42 percent of MAIS 3 to 5 injuries. Pickup
trucks and sport utility vehicles (SUVs) combined account for 50
percent of fatalities and 54 percent of MAIS 3 to 5 injuries. Since the
early 1990s, the SUV segment has provided an increasing proportion of
rollover fatalities. SUVs represented approximately 16 percent of
fatalities in 1997, and nearly 27 percent in 2008. Vans comprise 7
percent of the fatalities and 4 percent of the MAIS 3-5 ejections.

                     Table 9--Distribution of Fatalities and Injuries of First 3 Rows Side Window Ejected Occupants By Vehicle Type
                                                          [Annualized 1997--2008 NASS and FARS]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Vehicle               MAIS 1-2     MAIS 3-5      Fatal       MAIS 1-2     MAIS 3-5      Fatal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Complete Ejections.........................  Car..........................        1,158          928        1,239          10%          20%          28%
                                             PU...........................        1,236          812          793          11%          18%          18%
                                             SUV..........................        1,881          858          907          17%          19%          20%
                                             Van..........................          324          147          188           3%           3%           4%
                                             Other........................           12            2            0           0%           0%           0%
                                                                           -----------------------------------------------------------------------------
                                             Subtotal.....................        4,612        2,747        3,127          41%          61%          70%
--------------------------------------------------------------------------------------------------------------------------------------------------------

Partial Ejections..........................  Car..........................        1,429          971          660          13%          21%          15%
                                             PU...........................        2,515          375          190          22%           8%           4%
                                             SUV..........................        1,590          402          350          14%           9%           8%
                                             Van..........................        1,133           44          103          10%           1%           2%
                                             Other........................           13            0           17           0%           0%           0%
                                                                           -----------------------------------------------------------------------------
                                             Subtotal.....................        6,680        1,793        1,320          59%          39%          30%
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Ejections............................  Car..........................        2,588        1,899        1,899          23%          42%          43%
                                             PU...........................        3,750        1,187          983          33%          26%          22%
                                             SUV..........................        3,471        1,260        1,257          31%          28%          28%
                                             Van..........................        1,457          192          291          13%           4%           7%
                                             Other........................           25            2           17           0%           0%           0%
                                                                           -----------------------------------------------------------------------------
                                             Total........................       11,292        4,540        4,447         100%         100%         100%
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In summary, for the most part, the target population for this
ejection mitigation final rule is composed of occupants injured or
killed in an ejection from the first three rows of side windows in
vehicles to which the standard applies. The target population does not
include the population addressed by the Phase 1 FMVSS No. 214
rulemaking, and does not include persons benefited by the installation
of ESC systems in vehicles. (We assume that all model year 2011
vehicles and thereafter will be equipped with ESC, see FMVSS No. 126.)
As adjusted for ESC, the target population for this ejection mitigation
rulemaking is reduced to 1,392 fatalities, 1,410 MAIS 3-5 injuries and
4,217 MAIS 1-2 injuries. This target population constitutes 23 percent
of fatally-injured occupants ejected through a side window, 27 percent
of MAIS 3-5 injured, and 23 percent of MAIS 1-2 injured side window-
ejected occupants.\14\
---------------------------------------------------------------------------

    \14\ When discussing the target population in this preamble, we
will typically mean the pre-ESC adjusted values. We will
specifically state when we are referring to an ESC-adjusted target
population.
---------------------------------------------------------------------------

III. Congressional Mandate

    This final rule responds to section 10301 of SAFETEA-LU, which
requires the Secretary of Transportation to issue an ejection
mitigation final rule reducing complete and partial ejections of
occupants from outboard seating positions. Section 10301 amended
Subchapter II of chapter 301 (49 U.S.C. Chapter 301, National Traffic
and Motor Vehicle Safety Act) (``Vehicle Safety Act'') to add section
30128. Section 10301, paragraph (a), directs the Secretary to initiate
rulemaking proceedings, for the purpose of establishing rules or
standards that will reduce vehicle rollover crashes and mitigate deaths
and injuries associated with such crashes for motor vehicles with a
GVWR of not more than 10,000 pounds. Paragraph (c) directs the
Secretary to initiate a rulemaking proceeding to establish performance
standards to reduce complete and partial ejections of vehicle occupants
from outboard seating positions and that, in formulating the standards,
the Secretary shall consider various ejection mitigation systems.\15\
---------------------------------------------------------------------------

    \15\ Paragraph (c) states that the Secretary shall issue a final
rule under this paragraph by October 1, 2009. Paragraph (e) states
that if the Secretary determines that the subject final rule
deadline cannot be met, the Secretary shall notify and provide
explanation to the Senate Committee on Commerce, Science, and
Transportation and the House of Representatives Committee on Energy
and Commerce of the delay. On September 24, 2009, the Secretary
notified Congress that the final rule will be delayed until January
31, 2011.
---------------------------------------------------------------------------

    NHTSA's final rule fulfills the statutory mandate of section 10301
of SAFETEA-LU to issue an ejection mitigation final rule reducing
complete and partial ejections of occupants from outboard seating
positions. We have considered various ejection mitigation systems,
including advanced glazing,\16\ and have made appropriate decisions
based on that analysis. At the time of its implementation this final
rule will reduce fatality ejected occupants by about one third \17\ and
completes a decisive stage in the agency's rollover crashworthiness
program.
---------------------------------------------------------------------------

    \16\ One type of advanced glazing systems, usually referred to
as laminated glazing, has a multi-layer construction typically with
three primary layers. There is usually a plastic laminate bonded
between two pieces of glass. Advanced glazing was considered in the
1990s to have potential for use in ejection mitigation.
    \17\ This fatality reduction does not double-count benefits from
ESC and the recent FMVSS No. 214 upgrade.
---------------------------------------------------------------------------

    A few glazing manufacturers, a glazing manufacturers' association,
and two consumer groups expressed a view in their comments to the NPRM
that the rulemaking will fall short of the statutory mandate unless the
final rule ensured that windows will not allow any openings larger than
two inches to form during a rollover event (as a consequence, such a
requirement would encourage the use of advanced glazing). These
commenters also believed that SAFETEA-LU directed NHTSA to address
ejections through sun roofs, moon roofs,\18\ and rear windows in this
standard. We address these comments in detail in later sections of this
preamble.
---------------------------------------------------------------------------

    \18\ For this document, we refer to movable and fixed roof
panels made of glazing as ``moon roofs'' and movable panels having a
sheet metal exterior as ``sun roofs.'' We refer to both as roof
portals.
---------------------------------------------------------------------------

    With regard to the general assertion that this rulemaking does not
meet SAFETEA-LU, we cannot agree. As part and parcel of good
governance, all safety standards must be reasonable and appropriate. In
addition, in adding section 30128 to the Vehicle Safety Act, SAFETEA-LU
specifically requires us to issue an ejection mitigation final rule in
accordance with the criteria of that Act. The Vehicle Safety Act
requires each motor vehicle safety standard to be practicable, meet the
need for motor vehicle safety, and be stated in objective terms. (49
U.S.C. 30111(a).) We must also consider whether the standard is
reasonable, practicable, and appropriate for the particular type of
motor vehicle or motor vehicle equipment for which it is prescribed.
(49 U.S.C. 30111(b)(3).)
    This final rule requires protective barriers at side windows, the
ejection

portals through which 62 percent of occupants are fatally ejected in
all crash types. We did not adopt the suggestions in the comments of
the glazing manufacturers that could have bolstered increased use of
advanced glazing in side windows because we did not find a safety need
supporting the approaches. For back windows (backlight) and roof
portals, we found that not enough was known to appropriately evaluate
the costs, benefits and practicability of the requirements, at this
time, including the lack of a viable test procedure. (Fatal ejections
through the back light and roof portals account for 4.8 and 3.9 percent
of fatal ejections in all crash types.) An appropriate test procedure
that would assess ejection potential through portals on the vehicle's
roof is also unknown.
    In formulating this final rule, NHTSA considered various ejection
mitigation systems in accordance with section 10301 of SAFETEA-LU. We
sought to adopt performance measures that were design-neutral and
performance-oriented so as to provide substantial flexibility to
vehicle manufacturers in developing or enhancing ejection mitigation
countermeasures that meet the requirements of the standard. To
illustrate, the headform test procedure was originally developed in the
advanced glazing research program and can be used to assess the
performance of many different types of countermeasures at the side
windows. The final rule recognizes the beneficial effect advanced
glazing can have and permits the use of fixed glazing to achieve the
performance criteria specified in the standard. At the same time,
however, NHTSA determined after considering real-world field data on
advanced glazing that movable advanced glazing alone would not be a
satisfactory ejection mitigation countermeasure for side window
openings, given that 31 percent of front seat ejections are through
windows that were partially or fully rolled down, and given that it is
not unusual for advanced glazing to be heavily damaged and rendered
ineffective in a rollover crash. Accordingly, the standard does not
permit use of movable glazing alone to meet the requirements of the
standard. Movable glazing may be used in the high speed test, but it
must be used in conjunction with a deployable safety system that will
mitigate ejection throughout the stages of a rollover event, such as an
ejection mitigation side curtain air bag.
    In directing us to consider various ejection mitigation systems,
there is indication that Congress envisioned us focusing on ejections
through side windows. At the time of enactment of SAFETEA-LU, Congress
was aware of the agency's past work on advanced side glazing and of our
ejection mitigation research program. Congress was aware that side
curtain air bags were showing strong potential as an ejection
mitigation countermeasure and that we had redirected research and
rulemaking efforts from advanced side glazing to developing
performance-based test procedures for an ejection mitigation
standard.\19\
---------------------------------------------------------------------------

    \19\ ``Ejection Mitigation Using Advanced Glazing, Final
Report,'' NHTSA, August 2001, Docket 1782-22. See also, NHTSA's
termination of an advance notice of proposed rulemaking on advanced
glazing (67 FR 41365, June 18, 2002), infra.
---------------------------------------------------------------------------

    In addition, in the legislative history on section 10301, section
7251 of the Senate bill which the Conference committee adopted
(Conference Report of the Committee of Conference on H.R. 3, Report
109-203, 109th Congress, 1st Session) directed the Secretary to include
consideration of ``advanced side glazing, side air curtains, and side
impact air bags'' (emphases added) in establishing the standard. We
believe that Congress wanted us to take into account the knowledge
gained from our past work on side ejections in formulating this
standard, which we have, building on our knowledge gained from the
advanced side glazing and rollover crashworthiness programs.
    It would take a longer time than the timeframe allowed by SAFETEA-
LU to address fatal ejections through the back light and roof portals.
In contrast to the side window research program, which started in the
early 1990s, the agency had no research and development foundation upon
which requirements for the back light and roof portal could be based.
Much is unknown regarding a test procedure, effectiveness of current
designs, method of anchoring advanced glazing to the backlight frame
and roof portal, and possible other countermeasures and their costs.
The agency believed that Congress intended us to build on the knowledge
already attained and issue this final rule addressing side window
ejections, which account for 62 percent of all fatal occupant ejections
in all crashes, as quickly as possible, rather than delay this final
rule to venture into areas that account for 8.7 percent of those fatal
ejections.
    In sum, we developed this final rule to meet the criteria of
section 10301 of SAFETEA-LU and the Vehicle Safety Act, making sure
that it is a performance standard that reduces complete and partial
ejections from outboard seating positions and that it is reasonable,
practicable, and appropriate, that it meets the need for safety and is
stated in objective terms. Further, ensuring that the final rule is
consistent with Executive Order 12866, we have adopted requirements
that not only maximize the benefits of a cost-effective approach to
ejection mitigation, but do so with an approach that saves over 370
lives. This final rule wholly implements the instructions of our
statutory and administrative directives.

IV. Summary of the NPRM

    NHTSA issued a proposal for a new FMVSS No. 226 and proposed the
standard apply to passenger cars, multipurpose passenger vehicles,
trucks and buses with a GVWR of 4,536 kg or less. We proposed that the
side windows next to the first three rows of seats be subject to
performance requirements requiring the vehicle to have an ejection
mitigation countermeasure that would prevent an 18 kg (40 lb) headform
from moving more than 100 mm (4 inches) beyond the zero displacement
plane of each window when the window is impacted. Each side window
would be impacted at up to four locations around its perimeter at two
energy levels and time intervals following deployment. The first impact
was proposed to be at 24 km/h, 1.5 seconds after deployment of the
ejection mitigation side curtain air bag, assuming there was one
present (``24 km/h-1.5 second test''), and the second impact was
proposed to be at 16 km/h, at 6 seconds after deployment (``16 km/h-6
second test''). The NPRM proposed to allow windows of advanced glazing
to be in position during the test, but pre-broken, using a prescribed
method, to reproduce the state of glazing in an actual rollover crash.
    The NPRM discussed proposals for: (a) The impactor dimensions and
mass; (b) the displacement limit; (c) impactor speed and time of
impact; and (d) target locations. We also discussed: (e) glazing
issues; (f) test procedure tolerances; (g) test device characteristics;
and other issues, such as a requirement for a readiness indicator.
    The NPRM did not specifically require a rollover sensor to deploy
the curtains or attributes that the sensor must meet; manufacturers
currently provide sensors with their ejection mitigation curtains and
NHTSA believed they will continue to provide a sensor enabling
deployment regardless of an express requirement to do so. With regard
to applicability, the agency tentatively decided in the NPRM not to
exclude convertibles but requested comments on this issue and on the
applicability of the standard to other

types of vehicles, e.g., police vehicles with security partitions.
    Except for limited line and multistage manufacturers, the proposed
lead time was the first September 1 three years from the date of
publication of a final rule. The requirements were proposed to be
phased in over a four-year period, with 20 percent of each
manufacturer's vehicles manufactured during the first production year
required to meet the standard, 40 percent manufactured during the
second year required to meet the standard, 75 percent of vehicles
manufactured during the third year required to meet the standard, and
all vehicles (without use of advanced credits) manufactured on or after
the fourth year required to meet the standard. It was proposed that
limited line and multistage manufacturers would not have to achieve
full compliance until one year after the phase-in is completed.
    Accompanying the NPRM was a Preliminary Regulatory Impact Analysis
(PRIA) analyzing the potential impacts of the proposed ejection
mitigation requirements, and a technical analysis prepared by the
agency that presented a detailed analysis of engineering studies, and
other information supporting the NPRM (``Technical Analysis in Support
of a Notice of Proposed Rulemaking Ejection Mitigation''). Both
documents were placed in the docket for the NPRM (Docket No. NHTSA-
2009-0183).

V. Summary of the Comments

    NHTSA received 35 comments on the NPRM. Comments were received from
motor vehicle manufacturers through their associations and
individually, from air bag and glazing equipment suppliers (also
through their associations and individually), and from consumer and
insurance groups, and individuals.
    The Alliance of Automobile Manufacturers (Alliance) \20\ stated
that it was generally supportive of many aspects of the NPRM, such as
the use of a linear headform impactor for evaluating rollover deployed
side curtains and the decision not to specify a protocol for testing
rollover sensors. However, the commenter disagreed with the proposed
performance requirements, believing that they are overly stringent and
may unnecessarily force the development of air bag systems that could
have adverse unintended consequences. The commenter stated that seat
belt use is the most effective countermeasure for ejection mitigation.
The Alliance stated its belief that there should be only one test at 16
km/h and at 3.4 seconds, with an excursion limit of 150 mm measured
from a plane tangent to the exterior of the vehicle. The Alliance also
stated its belief that the standard should not apply to convertibles
and to vehicles with partitions, for practicability reasons. Further,
the commenter asked for an additional year of lead time, and that
vehicles with a GVWR greater than 2,722 kg (6,000 lb) should have a
compliance date that is one year after the 100 percent phase-in date
for completed vehicles with a GVWR of 2,722 kg or less. The Alliance
also had technical comments on specific aspects of the test procedure.
---------------------------------------------------------------------------

    \20\ The Alliance member companies are BMW Group, Chrysler
Group, Ford Motor Company, General Motors, Jaguar Land Rover, Mazda,
Mercedes-Benz USA, Mitsubishi Motors, Porsche, Toyota, and
Volkswagen (VW).
---------------------------------------------------------------------------

    The Alliance's member companies commenting on the NPRM reiterated
the views of the Alliance, with some expounding on the following
matters of particular interest to them. General Motors (GM) stated that
the Alliance's suggested compliance date and phase-in schedule could be
met assuming that NHTSA adopts the modifications of the test procedure
identified by the Alliance and excludes convertibles and vehicles with
partitions. Ford commented that side glazing retention in real-world
rollover crashes is random and unpredictable and expressed the belief
that FMVSS No. 226 should be focused on rollover-activated side curtain
technology because these devices are designed to deploy regardless of
side glazing status in a rollover (e.g., retained, up, down or
partially open) or construction of the glazing. Mercedes raised
concerns about the difficulties larger vans such as the Sprinter would
have in meeting the requirements and asked for additional lead time for
vehicles over 8,500 lb GVWR. Porsche discussed the long lifecycles for
its sports cars and asked that manufacturers be allowed to use credits
earned for early compliance through the end of the 100 percent phase-in
year. Various manufacturers expressed technical views or had questions
about specific aspects of the test procedure.
    The Association of International Automobile Manufacturers Technical
Affairs Committee \21\ (AIAM) stated that it ``supports the agency's
basic approach in the proposed ejection mitigation standard'' but is
``concerned that there may be unintended consequences if test criteria
establish unnecessary high levels of energy for the test impactor.''
AIAM said that high test impact speeds could require the use of stiffer
side curtain air bags or advanced glazing of increased rigidity to meet
the specified displacement limit. ``Such consequences may increase the
risk of head/neck injuries.'' AIAM urged the agency to consider whether
the impactor energy specifications may be reduced to a level equivalent
to 180 Nm (corresponding to a 16 km/h test). The commenter believed
that convertibles should be excluded from the standard for
practicability reasons and also suggested that certain classes of
vehicle could be excluded from the high speed requirement due to
vehicle characteristics that can dissipate the energy of occupants in
rollovers, such as vehicles having high ``belt-lines'' (e.g., sports
cars that seat the occupants low relative to the window openings). AIAM
asked for an additional year of lead time prior to the start of the
phase-in period and asked that advanced credits be allowed to meet the
100 percent stage of the phase-in. AIAM also commented on specific
aspects of the test procedure and supported GM's suggested procedure
for measuring impactor displacement from a plane tangent to the
vehicle's exterior.
---------------------------------------------------------------------------

    \21\ AIAM Technical Affairs Committee members are American Honda
Motor Company (Honda), American Suzuki Motor Corp., Aston Martin
Lagonda of North America, Ferrari North America, Hyundai Motor
America (Hyundai), Isuzu Motor America, Kia Motors America, Maserati
North America, Nissan North America, Peugeot Motors of America,
Subaru of America, ADVICS North America, Delphi Corporation, Denso
International America, and Robert Bosch Corporation.
---------------------------------------------------------------------------

    AIAM members commenting on the NPRM generally reiterated AIAM's
views, with some separately raising issues of individual concern. Honda
stated its belief that with an energy level of 200 joules (J), occupant
ejection mitigation can be balanced with occupant protection without
unintended adverse consequences to occupant protection. The commenter
suggested the test procedure consist of one test at 17 km/h with a 3.0
second time delay. Honda agreed with the proposed 100 mm displacement
limit, but suggested that displacement along a line normal to the
actual window at the center of each target impact point should not
exceed 100 mm. Nissan suggested the agency adopt a 20 km/h test instead
of the proposed 24 km/h test. In their individual comments, various
vehicle manufacturers asked for clarification of or changes to
particular aspects of the proposed test procedure.
    Organizations representing specialized manufacturers commented on
the NPRM. Vehicle Services Consulting, Inc. (VSC) \22\ supported the

NPRM, but asked that convertibles be excluded from the standard. VSC
also asked for clarification of regulatory text applying to small
volume manufacturers. The National Truck Equipment Association (NTEA)
\23\ requested that NHTSA exclude from the ejection mitigation standard
work trucks built in two or more stages, particularly those with
partitions, and vehicles with alterations to the floor height.
---------------------------------------------------------------------------

    \22\ VSC states: ``Vehicle Services Consulting, Inc. assists
numerous small volume vehicle manufacturers with US certification-
related matters.''
    \23\ NTEA describes itself as a ``trade association representing
distributors and manufacturers of multi-stage produced, work related
trucks, truck bodies and equipment.''
---------------------------------------------------------------------------

    Air bag supplier groups commented in favor of the NPRM. Takata
Corporation, a manufacturer of air bags and other motor vehicle
equipment, stated that it supports NHTSA's goal to establish a new
FMVSS to reduce the partial and complete ejection of occupants in
rollover crashes.\24\ However, Takata expressed concern about the
effectiveness of applying the ejection mitigation standard to
convertibles at this time. TRW, a manufacturer of vehicle safety
systems, and the Automotive Occupant Restraints Council (AORC) \25\
supported the agency's proposal in general, but suggested that all
windows should be tested down or removed regardless of whether the
glazing is laminated since motorists occasionally drive with their
windows open. TRW and AORC also expressed concern about applying the
ejection mitigation requirements to convertibles. Each of these
commenters had detailed feedback on and suggestions for improving the
proposed test procedures.
---------------------------------------------------------------------------

    \24\ Takata also submitted information to NHTSA's ejection
mitigation research docket (NHTSA-2006-26467) indicating that
meeting the proposed performance requirements in non-convertibles
would be practicable.
    \25\ AORC describes itself as a non-profit organization whose
mission is to promote automotive safety through education and
technology. Its membership consists of safety system manufacturers
and their suppliers.
---------------------------------------------------------------------------

    Glazing manufacturers and suppliers commenting on the NPRM
generally supported the objectives and overall structure of the
proposed standard, but a number had the view that the agency fell short
of the congressional mandate of section 10301 of SAFETEA-LU, in that
roof glazing and backlight areas were not being regulated by the new
standard. Many of these groups also desired a reduction in the
performance limit, some by 50 percent (i.e., a displacement limit of 50
mm). Many of the groups commented that all windows should be tested in
the up (closed) position and several objected to the pre-test breaking
procedure for glazing as being excessive and suggested changes to it,
such as eliminating the specification to pre-break the interior surface
of the glazing. Many of these glazing supplier groups requested a
shorter lead time and phase-in period.
    Consumer groups Public Citizen (PC) and Advocates for Highway and
Auto Safety (Advocates) commented on the NPRM. PC stated that the NPRM
is flawed because it does not address occupant ejections through the
roof and because the cost-benefit analysis is ``devised with the same
misleading approach to determining a target population that NHTSA has
used in other rollover rulemakings.'' PC suggested NHTSA establish a
performance requirement that would encourage the dual use of laminated
glazing and side curtain air bags, but stated that NHTSA should not
permit laminated glazing in vehicles not equipped with side curtain air
bags. PC suggested that the phase-in schedule should begin and end one
model year earlier than proposed. The commenter also was critical that
``the agency has not taken a comprehensive, whole vehicle approach to
reducing fatalities in rollover crashes.''
    Advocates stated its belief that NHTSA interpreted SAFETEA-LU too
narrowly by addressing occupant ejection only through side windows and
not through side doors, tailgates, windshields, backlights, or sun
roofs. Advocates suggested that roofs can be strengthened and occupant
ejection reduced through the use of advanced glazing and that NHTSA
should promote pre-crash automated window closure to ensure that
vehicles with advanced glazing would be in the windows-up position.
Advocates supported ``mandatory anti-ejection countermeasures to be
applied at all designated seating positions, not just for outboard
occupants in the first, second, and third rows,'' including all
occupant positions in the rear seats of 15-passenger vans. Advocates
believed that the 100 mm proposed displacement limit should be 50 mm
and that areas outside of the target zones should be tested. The
commenter was concerned about the proposed time intervals for the
impactor tests \26\ and desired performance requirements for rollover
air curtain sensors. The commenter believed that manufacturers would
only need a two-year lead time and a three-year phase-in period to meet
the proposed requirements.
---------------------------------------------------------------------------

    \26\ Advocates was concerned that ``no sustained inflation is
tested between the 1.5 and 6 second tests, when excursion could
exceed the 4 inch maximum required by the proposed standard.''
---------------------------------------------------------------------------

    The Insurance Institute for Highway Safety (IIHS) said it supported
the NPRM because the commenter believed that the rulemaking is likely
to result in all passenger vehicles being equipped with side curtain
air bags that deploy in rollover crashes. However, IIHS stated that the
proposed 100 mm excursion limit may be overly restrictive. IIHS also
stated that the agency should provide an incentive to manufacturers to
equip vehicles with laminated side glazing.
    Several individuals responded in general support of the NPRM and
with several suggestions. National Forensic Engineers, Inc. supported
the use of laminated glazing in side windows to supplement side curtain
air bags. Stephen Batzer and Mariusz Ziejewski, and Byron Bloch, stated
that the standard should apply to vehicles above 4,536 kg, to daylight
openings adjacent to every designated seating position and to the
windshield, sunroof and backlight, and supported the use of laminated
glazing. Batzer and Ziejewski believed that a 10 mph impact would be
sufficient. Bloch urged the agency to evaluate ejection mitigation
through a dynamic full vehicle rollover test.

VI. How the Final Rule Differs From the NPRM

    The more important changes from the NPRM are listed in this section
and explained in detail later in this preamble. Changes more minor in
significance (e.g., changes that clarify test procedures) are not
listed below but are discussed in the appropriate sections of this
preamble.
    i. The high speed impact test, performed at 1.5 seconds after
ejection mitigation side curtain air bag deployment, will have an
impact velocity of 20 km/h instead of 24 km/h. After evaluating the
comments to the NPRM, the agency reanalyzed the test data upon which
the impact speed proposed in the NPRM was based, analyzed the new
testing conducted since the NPRM, and considered all submitted
information. Based on this analysis, we agree to decrease the impact
test speed to 20 km/h, as suggested by Nissan in its comment, which
results in 278 joules (J) of impact energy. This energy value is well
supported and more representative of the energy the ejection
countermeasure will typically be exposed to in the field, particularly
in rollovers. All target locations in each window opening will be
subject to the high speed test, performed at 1.5 seconds after ejection
mitigation side curtain air bag deployment (``20 km/h-1.5 second
test''), and to the low speed 16 km/h test

performed 6 seconds after deployment (``16 km/h-6 second test'').
    ii. If necessary, the headform and targets will be rotated by 90
degrees to a horizontal orientation if this results in more impact
locations than the vertical orientation (to a maximum of four target
locations). For long narrow windows, popular in many late model
vehicles, very limited target coverage of the opening is achieved if
the target is kept in the vertical orientation. It did not make sense
to exclude windows from being subject to full ejection mitigation
protection simply because the headform could not fit when oriented
vertically.
    iii. The standard does not permit the use of movable advanced
glazing as the sole means of meeting the displacement limit of the
standard. In addition, the 16 km/h-6 second test must be performed
without the use of advanced glazing for movable windows. Field data
indicates that even when initially up, movable advanced glazing may be
destroyed and made ineffective as a countermeasure beyond the initial
phase of a rollover. Therefore, the final rule will require that if a
vehicle has movable advanced glazing as part of the ejection
countermeasure, the 16 km/h-6 second test will be performed with the
glazing retracted or removed from the window opening. This approach
will assure a reasonable level of safety when side glazing is rolled
down or when the severity of the rollover damages or destroys the
effectiveness of the glazing, and still encourages the use of advanced
glazing as a countermeasure to supplement the vehicle's performance in
meeting the 20 km/h-1.5 second test.
    iv. The window opening for cargo areas behind the 1st and 2nd row
will be impacted. If there is a side window opening in a cargo area
behind the 1st row of a single row vehicle or behind the 2nd row of a
two-row vehicle, this final rule will extend coverage to those cargo
areas behind the 1st and 2nd rows of vehicles. The area of side window
openings in a cargo area will be bounded by a transverse plane 1,400 mm
behind the seating reference point (SgRP) of the rearmost seat in the
1st row of a single row vehicle or behind the SgRP of the rearmost seat
in the 2nd row of a two-row vehicle. Field data found that cargo area
ejections behind a 2nd row were similar in frequency to 3rd row
ejections. Such cargo area coverage is cost effective and is not any
more challenging than 3rd row coverage.
    v. Minor changes were made in the definition of and procedure for
determining the window opening. The final rule increases the lateral
distance defining the window opening from 50 to 100 mm. We have
examined interior trim components, such as panels covering the vehicle
pillars and found that relevant surfaces can be more than 50 mm from
the inside of the window glazing and that these trim components can be
difficult to remove.
    vi. The final rule slightly modifies the glazing pre-breaking
procedure by using a 75 mm offset pattern. (We disagree with the
comments that stated the pre-breaking procedure should be deleted or
should be restricted to four points on the glazing. We believe the pre-
breaking procedure is necessary to recreate the damage that will likely
occur in the field.)
    vii. Convertibles are excluded from this standard. Also excluded
are law enforcement vehicles, correctional institution vehicles, taxis
and limousines with a fixed security partition separating the 1st and
2nd or 2nd and 3rd rows, if the vehicle is a multistage or altered
vehicle.
    viii. The final rule has a 2-year lead time period, with 25 percent
of each manufacturer's vehicles manufactured during the first
production year required to meet the standard, 50 percent manufactured
during the second year required to meet the standard, 75 percent of
vehicles manufactured during the third year required to meet the
standard, and 100 percent of vehicles manufactured on or after the
fourth year required to meet the standard. The final rule allows
manufacturers to use advanced credits to meet the phase-in percentages,
including advanced credits in the last year (100 percent year) of the
phase-in schedule.
    ix. Characteristics of the guided linear impactor with the 18 kg
headform and the associated propulsion mechanism were refined to assure
sufficient repeatability and reproducibility of the test. The impactor
used in research tests was originally constructed in the advanced
glazing program of the 1990s. We have reduced the maximum allowable
dynamic coefficient of friction of the test device by a factor of 5,
from 1.29 (old impactor) to 0.25 (new impactor). The device has been
made less flexible along its shaft and thus better able to maintain its
orientation as it interacts with ejection countermeasures.

VII. Foundations for This Rulemaking

    This section discusses knowledge and insights we gained from past
research on ejection mitigation safety systems which underlie many of
the decisions we made in forming this final rule.

a. Advanced Glazing

    In formulating this final rule, NHTSA considered various ejection
mitigation systems in accordance with section 10301 of SAFETEA-LU. One
of the considered systems was advanced side glazing. In the 1990s,
NHTSA closely studied advanced glazing as a potential ejection
mitigation countermeasure \27\ but terminated an advance notice of
proposed rulemaking on advanced glazing in 2002 (67 FR 41365, June 18,
2002). The termination was based on our observation that advanced
glazing produced higher neck shear loads and neck moments than impacts
into tempered \28\ side glazing. In addition, the estimated incremental
cost for installing ejection mitigation glazing in front side windows
ranged from over $800 million to over $1.3 billion, based on light
vehicle annual sales of 17 million units in the 2005-2006 timeframe.
Also, because side curtain air bags were showing potential as an
ejection mitigation countermeasure, NHTSA decided to redirect its
research and rulemaking efforts toward developing performance-based
test procedures for an ejection mitigation standard.\29\
---------------------------------------------------------------------------

    \27\ Ejection mitigation glazing systems have a multi-layer
construction with three primary layers. There is usually a plastic
laminate bonded between two pieces of glass.
    \28\ Tempered glass is made from a single piece of specially
treated sheet, plate, or float glass possessing mechanical strength
substantially higher than annealed glass. When broken at any point,
the entire piece breaks into small pieces that have relatively dull
edges as compared to those of broken pieces of annealed glass. (See
FMVSS No. 205, ``Glazing Materials,'' incorporating by reference
standard ANSI/SAE Z26.1-1996.)
    \29\ ``Ejection Mitigation Using Advanced Glazing, Final
Report,'' NHTSA, August 2001, Docket No. NHTSA-1996-1782-22.
---------------------------------------------------------------------------

    Elements from the advanced glazing program underlie a substantial
part of today's final rule. The headform and the test procedure were
originally developed in the advanced glazing research program.
    Further, as with all of the FMVSSs, we drafted this final rule to
be performance-oriented, to provide manufacturers wide flexibility and
opportunity for design innovation in developing countermeasures that
could be used for ejection mitigation. We anticipate that manufacturers
will install ejection mitigation side curtain air bags in response to
this rulemaking, taking advantage of the side impact curtains already
in vehicles. Nonetheless, this final rule provides a role for advanced
glazing as a complement to ejection mitigation curtain systems.

    NHTSA tested several vehicles' ejection mitigation side curtain air
bags both with and without advanced glazing to the 18 kg impactor
performance test adopted by this final rule. In the tests, the glazing
was pre-broken to simulate the likely condition of the glazing in a
rollover. Tests of vehicles with advanced glazing resulted in a 51 mm
average reduction in impactor displacement across target locations.\30\
That is, optimum (least) displacement of the headform resulted from use
of both an ejection mitigation window curtain and advanced glazing. To
encourage manufacturers to enhance ejection mitigation curtains with
advanced glazing, the final rule allows windows of advanced glazing to
be in-position for the 20 km/h-1.5 second test, although pre-broken to
reproduce the state of glazing in an actual rollover crash. This
approach encourages advanced glazing as a countermeasure to supplement
the vehicle's performance in meeting the 20 km/h-1.5 second test.\31\
---------------------------------------------------------------------------

    \30\ See the technical analysis prepared by the agency in
support of the NPRM, placed in the docket for the NPRM (NHTSA-2009-
0183-007). ``Technical Analysis in Support of a Notice of Proposed
Rulemaking for Ejection Mitigation.'' Among other matters, the
report discusses the results of NHTSA's impactor testing of OEM and
prototype side window ejection mitigation systems.
    \31\ Yet, after reviewing comments to the NPRM and other
information, we have decided not to permit movable glazing to
supplement the primary ejection mitigation system in the 16 km/h-6
second test. This is because field data indicate that even when
initially up, movable advanced glazing may be destroyed and rendered
ineffective as an effective countermeasure beyond the initial phase
of a rollover. In addition, 30 percent of occupants are ejected
through windows that are partially or fully open prior to the crash.
---------------------------------------------------------------------------

b. Full Window Opening Coverage Is Key

    We considered the findings of several NHTSA research programs on
rollover crashworthiness protection in developing this final rule.
    A cornerstone program started with the development of a dynamic
rollover fixture (DRF) that could be used to produce full-dummy
ejection kinematics in an open window condition, where the peak roll
rate ranged between 330 to 360 degrees/second. The DRF was used to
assess the potential effectiveness of ejection mitigation
countermeasures in a rollover.\32\ These countermeasures included
several designs of inflatable curtain air bags, advanced glazing, and
combinations of curtains and advanced glazing. The results of the
assessment showed that not all ejection mitigation air bag curtains
work the same way. We found that full window opening coverage was key
to the effectiveness of the curtain in preventing ejection.
---------------------------------------------------------------------------

    \32\ NHTSA developed the DRF to produce full-dummy ejection
kinematics in a less costly manner than full-scale testing. The DRF
models a lateral rollover crash of approximately one vehicle
revolution. The DRF rotates approximately one revolution and comes
to rest through the application of a pneumatic braking system on one
end of the pivot axle. It does not simulate lateral vehicle
accelerations often encountered in a rollover crash prior to
initiation of the rollover event. The DRF has a test buck fabricated
from a Chevrolet CK pickup cab. The cab is longitudinally divided
down the center from the firewall to the B-pillar. The left (driver)
side is rigidly attached to the test platform. The Chevrolet CK was
chosen so that the advanced glazing systems developed in the
previous ejection mitigation research could be evaluated in this
program. A seat back and cushion were made from Teflon material, to
minimize the shear forces on the dummy buttocks for more desired
loading on the window area by the dummy's head and upper torso.
---------------------------------------------------------------------------

1. Tests with 50th Percentile Adult Male and 5th Percentile Adult
Female Test Dummies
    In the first research program, experimental roof rail-mounted
inflatable devices developed by Simula Automotive Safety Devices
(Simula) and by TRW were evaluated on the DRF, along with an advanced
side glazing system.\33\ In the tests, unrestrained 50th percentile
male and 5th percentile female Hybrid III dummies, instrumented with 6
axis upper neck load cells and tri-axial accelerometers in the head,
were separately placed in the buck.\34\ The DRF rotation resulted in a
centripetal acceleration of the dummy that caused the dummy to move
outwards towards the side door/window. In baseline tests of the
unrestrained dummies in the DRF with an open side window and no
countermeasure, the dummies were fully ejected. The ability of the
countermeasure to restrain the dummies could then be assessed and
compared to that baseline test.
---------------------------------------------------------------------------

    \33\ ``Status of NHTSA's Ejection Mitigation Research Program,''
Willke et al., 18th International Technical Conference on the
Enhanced Safety of Vehicles, paper number 342, June 2003.
    \34\ Two dummy positions were used. The first was behind the
steering wheel. The second position was more inward, toward the
pivot axle, which generated higher contact velocities. Film analysis
was used to measure the dummy's relative head and shoulder contact
velocity with the side window plane from these two seating
positions. (For the final rule, we digitized the films and
reanalyzed the impact speeds using data from state-of-the-art
software. The resulting impacts speeds were lower than those
reported in the NPRM. The analysis will be discussed later in this
document.) From the first position behind the steering wheel, the
shoulder impact speeds were 7.0 km/h (4.3 mph) for the 5th
percentile female dummy and 9.0 km/h (5.6 mph) for the 50th male.
From the second (inboard) position, the velocities were 15.5 km/h
(9.6 mph) for the 5th female dummy and 15.8 km/h (9.8 mph) for the
50th male.
---------------------------------------------------------------------------

    In the tests of the experimental inflatable devices, the air bags
were pre-deployed and their inflation pressure was maintained
throughout the test by the use of an air reservoir tank mounted on the
platform.\35\ In the tests, the dummy's upper body loaded the
inflatable device, which limited the dummy's vertical movement toward
the roof and caused the pelvis to load the side door throughout the
roll, rather than to ride up the door. The inflatable devices contained
the torso, head, and neck of the dummy, so complete ejection did not
occur. However, both devices did allow partial ejection of the dummy's
shoulder and arm below the bags, between the inflatable devices and the
vehicle door.
---------------------------------------------------------------------------

    \35\ Since these were experimental systems, they were not
deployed through pyrotechnic or in-vehicle compressed gas, as might
be the case with production designs. The air pressure supplied by
the laboratory reservoir kept the systems fully inflated over the
test period.
---------------------------------------------------------------------------

    In the test of the advanced side glazing (laminated with door/
window frame modifications around the entire periphery to provide edge
capture), the glazing contained the dummies entirely inside the test
buck. The glazing was not pre-broken before the testing. There was some
flexing of the window frame when the dummies loaded the glazing, and
the 50th percentile male dummy's shoulder shattered the glass when the
dummy was located behind the steering wheel.
    In the test of the combined systems, the dummies remained entirely
inside the buck. Although the dummy's shoulder and arm escaped under
the inflatable devices, the advanced glazing prevented the partial
ejection seen in tests of the inflatable devices alone.
    In these tests, the ejection mitigation systems did not show a high
potential for producing head and neck injury. However, head and neck
loading were higher than the open window condition. The highest load
with respect to the Injury Assessment Reference Values (IARVs) was 82
percent for the neck compression for the 5th percentile female tested
with the Simula/laminate combination. The highest injury response for
the 50th percentile male dummy was 59 percent for the neck compression
with the TRW system alone. All HIC36\36\ responses were
extremely low and ranged from 8 to 90, with the maximum occurring in an
open window test. Lateral shear and bending moment of the neck were
also measured, although there are no established IARVs. The maximum
lateral neck shear loads were 950 N (50th percentile male tested with
TRW

system) and 1020 N (5th percentile female tested with laminate only).
---------------------------------------------------------------------------

    \36\ HIC36 is the Head Injury Criterion computed over
a 36 msec duration. HIC36 = 1,000 represents an onset of
concussion and brain injury.
---------------------------------------------------------------------------

2. Tests With 6-Year-Old Child Test Dummy Showed a Risk of Ejection
Through Openings Not Fully Covered
    The second research program involved a series of tests on the DRF
using an unrestrained Hybrid III 6-year-old dummy. In previous tests
with the 50th percentile adult male and 5th percentile adult female
dummies, a gap formed between the inflatable devices and the window
sill (bottom of the window opening), which allowed partial ejection of
those adult dummies. The second program investigated whether the gap
allowed ejection of the 6-year-old child dummy.\37\
---------------------------------------------------------------------------

    \37\ ``NHTSA's Crashworthiness Rollover Research Program,''
Summers, S., et al., 19th International Technical Conference on the
Enhanced Safety of Vehicles, paper number 05-0279, 2005.
---------------------------------------------------------------------------

    In baseline testing with an open side window without activation of
an ejection mitigation countermeasure, the child dummy was fully
ejected. In tests of the two inflatable systems tested in the first
program (at the time of the second research program, the inflatable
device formerly developed by Simula was then developed by Zodiac
Automotive US (Zodiac)), the inflatable devices prevented full ejection
of the 6-year-old child dummy in upright-seated positions (no booster
seat was used). However, dummy loading on the systems produced gaps
that did allow an arm and/or hand to pass through in some tests.
Moreover, in a series of tests with the dummy lying in a prone position
(the dummy was placed on its back at the height of the bottom of the
window opening), representing a near worst-case ejection condition, the
dummy was completely ejected at positions near the bottom of the
inflatable devices (above the sill) with the TRW curtain, while the
Zodiac system contained the dummy inside the test buck in all testing.
Adding pre-broken advanced glazing with the TRW system managed to
contain the dummy inside the test buck in all tests.\38\
---------------------------------------------------------------------------

    \38\ Id.
---------------------------------------------------------------------------

3. Differences in Design Between the Two Inflatable Systems
    The two prototype inflatable devices tested had fundamentally
different designs. The Zodiac/Simula prototype system used an
inflatable tubular structure (ITS) \39\ tethered near the base of the A
and B-pillars that deployed a woven material over the window opening.
(The Zodiac system differed from the originally-tested Simula design in
that it had more window coverage. This was achieved by placing the ITS
tether locations lower on the pillars and adding additional woven
material.) The TRW prototype was more akin to a typical air bag curtain
and was fixed to the A- and B-pillar at its end points and along the
roof rail, but not tethered. The ITS differed from conventional air
bags in that it was not vented.
---------------------------------------------------------------------------

    \39\ ITS systems were originally introduced by BMW as a side
impact countermeasure.
---------------------------------------------------------------------------

    We believe that the better performance of the Zodiac prototype
system compared to that of TRW, in the DRF testing described above and
in impactor test results provided later in this preamble, was due to
the greater window coverage by the Zodiac prototype along the entire
sill and A-pillar.
4. Insights
    The DRF research provided the following insights into ejection
mitigation curtains:
     Inflatable devices prevented ejection of test dummies in
simulated rollover tests, but design differences accounted for
differences in performance;
     Gaps in the inflatable device's coverage of the window
opening at the sill and A-pillar allowed partial ejection of adult
dummies and full ejection of a 6-year-old child dummy;
     Adding pre-broken advanced glazing to an air bag system
enhanced the ability of the system to contain the dummy; and,
     To optimize ejection mitigation potential, a performance
test should ensure that the countermeasure has full coverage of the
window opening.

c. Comparable Performance in Simulated Rollovers and Component-Level
Impact Tests

    Because full-vehicle rollover crash tests can have an undesired
amount of variability in vehicle and occupant kinematics, in the
advanced glazing program NHTSA developed a component-level impact test
for assessing excursion and the risk of ejection. We use the component-
level test in this final rule for ejection mitigation.
    The test involves use of a guided linear impactor designed to
replicate the loading of a 50th percentile male occupant's head and
shoulder during ejection situations. The impactor \40\ is described
later in this preamble. There are many possible ways of delivering the
impactor to the target location on the ejection mitigation
countermeasure. The ejection mitigation test device \41\ used by the
agency in the advanced glazing program and for the research used to
develop the NPRM (``old impactor'') has a propulsion mechanism \42\
with a pneumatic piston that pushes the shaft component of the
impactor. The old impactor shaft slides along a plastic (polyethylene)
bearing. The impactor has an 18 kg mass.
---------------------------------------------------------------------------

    \40\ The ``ejection impactor'' is the moving mass that strikes
the ejection mitigation countermeasure. It consists of an ejection
headform attached to a shaft.
    \41\ The ejection mitigation test device consists of an ejection
impactor and ejection propulsion mechanism.
    \42\ The ``ejection propulsion mechanism'' is the component that
propels the ejection impactor and constrains it to move along its
axis or shaft.
---------------------------------------------------------------------------

    The component-level test identified four impact locations to
evaluate a countermeasure's window coverage and retention capability.
Two of the positions were located at the extreme corners of the window/
frame and were located such that a 25 mm gap existed between the
outermost perimeter of the headform and window frame. A third position
was near the transition between the upper window frame edge and A-
pillar edge. The fourth position was at the longitudinal midpoint
between the third position and the position at the upper extreme corner
of the window/door frame, such that the lowest edge of the headform was
25 mm above the surface of the door at the bottom of the window
opening.
    At each impact location, different impact speeds and different time
delays between air bag deployment and impact were used. To simulate
ejection early in a rollover event and in a side impact, the air bags
were impacted 1.5 seconds after air bag deployment, at 20 and 24 km/h.
To simulate ejection late in a rollover event, the air bags were
impacted after a delay of 6 seconds at an impact speed of 16 km/h.
Findings
    The two inflatable systems tested in the above-described research
programs (the inflatable devices developed by Zodiac and by TRW) were
installed on a Chevrolet CK pickup cab and subjected to the component-
level impact test. The air bag systems were evaluated for allowable
excursion (impactor displacement) beyond the side window plane. The
tests also assessed the degree to which the component-level test was
able to replicate the findings of the DRF tests.
    The component-level tests mimicked the DRF tests by revealing the
same deficiencies in the side curtain air bags that were highlighted in
the dynamic test. On the other hand, the Zodiac

system \43\ did not allow the impactor to go beyond the plane of the
window in the 16 km/h and 20 km/h tests. The air bag allowed only 12
and 19 mm of excursion beyond the window plane in the 24 km/h tests.
---------------------------------------------------------------------------

    \43\ Testing was restricted to the extreme corners of the window
due to limited availability of this system.
---------------------------------------------------------------------------

    In the 24 km/h tests of the TRW system, the curtain was not able to
stop the impactor before the limits of travel were reached (about 180
mm beyond the plane for the vehicle window for that test setup) at the
position at the extreme forward corner of the window sill. This is the
position at which the TRW prototype system allowed excessive excursion
of the test dummies in the DRF dynamic tests. In the DRF tests, the 6-
year-old dummy was completely ejected through that window area even
when the prone dummy was aimed at the position at the other extreme
corner of the window. In other tests, the TRW prototype system was able
to stop the impactor before the impactor reached its physical stops.

d. Advantages of a Component Test Over a Full Vehicle Dynamic Test

    NHTSA determined that the component test not only distinguishes
between acceptable and unacceptable performance in side curtain air
bags, but has advantages over a full vehicle dynamic test. The
acceptable (or poor) performance in the laboratory test correlated to
the acceptable (or poor) performance in the dynamic test. The component
test was able to reveal deficiencies in window coverage of ejection
mitigation curtains that resulted in partial or full ejections in
dynamic conditions. Incorporating the component test into an ejection
mitigation standard ensures that ejection mitigation countermeasures
provide sufficient coverage of the window opening for as long in the
crash event as the risk of ejection exists, which is a key component
contributing to the efficacy of the system.
    As noted earlier, rollover crash tests can have an undesirable
amount of variability in vehicle and occupant kinematics. In contrast,
the repeatability of the component test has been shown to be good.\44\
Moreover, there are many types of rollover crashes, and within each
crash type the vehicle speed and other parameters can vary widely. A
curb trip can be a very fast event with a relatively high lateral
acceleration. Soil and gravel trips have lower lateral accelerations
than a curb trip and lower initial roll rates. Fall-over rollovers are
the longest duration events, and it can be difficult to distinguish
between rollover and non-rollover events. Viano and Parenteau \45\
correlated eight different tests to six rollover definitions from NASS-
CDS.\46\ Their analysis indicated that the types of rollovers occurring
in the real-world varied significantly. Soil trip rollovers accounted
for more than 47 percent of the rollovers in the field, while less than
1 percent of real-world rollovers were represented by the FMVSS No. 208
Dolly test (``208 Dolly test'').
---------------------------------------------------------------------------

    \44\ ``NHTSA's Crashworthiness Rollover Research Program,''
supra.
    \45\ Viano D, Parenteau C. Rollover Crash Sensing and Safety
Overview. SAE 2004-01-0342.
    \46\ ``Technical Analysis in Support of a Notice of Proposed
Rulemaking for Ejection Mitigation,'' supra.
---------------------------------------------------------------------------

    Occupant kinematics will also vary with these crash types,
resulting in different probabilities of occupant contact on certain
areas of the side window opening with differing impact energies. A
single full vehicle rollover test could narrowly focus on only certain
types of rollover crashes occurring in the field.\47\ Assuming it is at
all possible to comprehensively assess ejection mitigation
countermeasures through full vehicle dynamic testing, multiple crash
scenarios would have to be involved.
---------------------------------------------------------------------------

    \47\ The agency has in the past performed dolly type dynamic
testing. The agency has not performed enough repeat tests of the
same vehicles to draw any conclusions about the repeatability of
these tests to determine occupant containment. However, regardless
of the level of repeatability of dummy kinematics, it still only
represents a part of the kinematics that would occur in the field.
---------------------------------------------------------------------------

    Such a suite of tests imposes test burdens and costs that could be
avoided by a component test, such as that adopted today. We also note
that a comprehensive suite of full-vehicle dynamic tests would involve
many more years of research, which would delay this rulemaking action
and the implementation of life-saving curtain air bag technologies.
Such a delay is unwarranted and undesirable since the component test
will be an effective means of determining the acceptability of ejection
countermeasures.

VIII. Availability of Side Curtain Air Bags

    The availability of vehicles that offer inflatable side curtains
that deploy in a rollover has increased since they first became
available in 2002. In the middle of the 2002 model year (MY), Ford
introduced the first generation of side curtain air bags that were
designed to deploy in the event of a rollover crash. The rollover air
bag curtain system, marketed as a ``Safety Canopy,'' was introduced as
an option on the Ford Explorer and Mercury Mountaineer.\48\ For the
2007 MY, rollover sensors were available on approximately 95 models,
with 75 of these models being sport utility vehicles. The system was
standard equipment on 62 vehicles (65 percent) and optional on 33
vehicles (35 percent).
---------------------------------------------------------------------------

    \48\ http://media.ford.com/article_display.cfm?article_id=6447
(Last accessed October 8, 2010.)
---------------------------------------------------------------------------

    Annually, as part of NHTSA's New Car Assessment Program (NCAP), the
agency sends a questionnaire to manufacturers requesting information
about the availability of certain safety systems on their vehicles.\49\
Since 2008, NHTSA has asked manufacturers for voluntary responses
regarding whether their available side impact curtains will deploy in a
rollover crash. The voluntary responses were in the affirmative for 39
percent of MY 2008 make models and for 43 percent of MY 2010 make
models.
---------------------------------------------------------------------------

    \49\ The total number of make/models represented in the survey
is about 500. Slight model variations are represented as different
models and corporate twins are not combined.
---------------------------------------------------------------------------

IX. Existing Curtains

    Aside from the presence of a rollover sensor, there are two
important design differences between air bag curtains designed for
rollover ejection mitigation and air bag curtains designed only for
side impact protection. The first difference is longer inflation
duration. Rollover crashes with multiple full vehicle rotations can
last many seconds. Ford has stated that its Safety Canopy stays
inflated for 6 seconds,\50\ while GM stated that its side curtain air
bags designed for rollover protection maintain 80 percent inflation
pressure for 5 seconds.\51\ Honda stated that the side curtains on the
2005 and later Honda Odyssey stay fully inflated for 3 seconds.\52\ In
contrast, side impact air bag curtains designed for occupant protection
in side crashes, generally stay inflated for less than 0.1 seconds.
---------------------------------------------------------------------------

    \50\ Ibid.
    \51\ ``Who Benefits From Side and Head Airbags?'' (http://www.edmunds.com/ownership/safety/articles/105563/article.html).
(Last accessed October 5, 2010.)
    \52\ http://www.autodeadline.com/detail?source=Honda∣=HON2004083172678&mime=ASC. (Last accessed
October 5, 2010.)
---------------------------------------------------------------------------

    The second important air bag curtain design difference between
rollover and side impact protection is the size or coverage of the air
bag curtain. One of the most obvious trends in newer vehicles is the
increasing area of coverage for rollover curtains. Referring to earlier
generations of curtains, Ford has stated that its rollover protection
air bags covered between 66 and 80 percent

of the first two rows of windows, and that it was expanding the designs
so they cover all three rows in all models.\53\ GM stated that its
curtains designed for rollover protection are larger than non-rollover
curtains.\54\
---------------------------------------------------------------------------

    \53\ Ibid.
    \54\ Who Benefits From Side and Head Airbags?'' (http://www.edmunds.com/ownership/safety/articles/105563/article.html),
supra.
---------------------------------------------------------------------------

a. Existing Curtains Tested to Proposed Requirements

    The agency presented data in the NPRM from testing of eight MY 2003
through MY 2006 vehicles. Since the date of publication of the NPRM,
the agency tested 16 vehicle models to the proposed ejection mitigation
requirements. Data from these tests supplement the data from tests of
eight MY 2003 through MY 2006 vehicles discussed in the NPRM and are
discussed in this section. Most of the testing of the 16 vehicle models
was with the old impactor used in the NPRM tests. Tests from three
vehicles were performed with a new test device (``new impactor''). To
date we have performed nearly 700 impacts.
    Figure 1 shows the target location key for the test results. In the
data, the C1-C4 targets follow the same positioning as the B1-B4
targets. In a few instances, the A2 and A3 targets were eliminated
because they were too close and a target (A5) was placed back in the
window because the centers of remaining targets A1 and A4 were more
than 360 mm apart.
[GRAPHIC] [TIFF OMITTED] TR19JA11.000

General Results
    The results of the agency testing are given in Tables 10 through
18, below. The results are given in columns, by target location and are
in units of millimeters. (The technical report accompanying this
document has the data color-coded. Values exceeding the proposed 100 mm
limit of impactor displacement are in red or the darkest shading.
Results from 80 to 100 mm of displacement are purple or medium shading.
Results which are less than 80 mm are in green or the lightest
shading.) Some cells contain the average from several tests under the
same/similar conditions; these results are bolded. In some tests there
was so little resistance to the impactor that it continued past the
countermeasure to the point where the internal limit of the impact
prevented any additional displacement. In these cases, the numerical
value of displacement has no meaning so the cell is denoted as ``To
Stops.''
    On occasion, target locations were not tested at 24 km/h because
the 20 km/h results indicated displacements in excess of 100 mm at that
location. These cells are denoted by ``(20 km/h)'' and we assume the 24
km/h impact would also have exceeded 100 mm. Similarly, some target
locations were not tested at 20 km/h, but the cells contain ``(24 km/
h)'' indicating a value below 80 mm of displacement in the 24 km/h test
and we assume the 20 km/h impact would have resulted in a displacement
less than 80 mm.
    As detailed later, some vehicles were tested with pre-broken
advanced laminated (designated as ``w/lam.'' next to the vehicle name).
Various breaking methods were used. For simplicity in presenting the
data, we have averaged the results for various breaking methods, except
for the method of breaking the laminated in four places (designated as
``4 hole'' next to the vehicle name). Also, a few tests were performed
with the headliner in place (designated as ``w/liner'' next to the
vehicle name). ``N/O'' refers to whether the test was conducted with
the old ``O'' or new ``N'' impactor.
    Across all vehicles, as was the case with our previous analysis of
test data in the NPRM, target A1 remains the most challenging impact
location and A4 the least challenging for the 1st row. This is
consistent for all three impactor speeds and time delays. For the 2nd
row, B1 and B2 are the most challenging. The available data do not
present a clear trend for the 3rd row.
    The two best performing vehicles were the MY 2007 Mazda CX9 and the
MY 2008 Toyota Highlander. We will discuss the performance of these
vehicles in more detail in several of the sections below.

                          Table 10--Front Row Window, 24 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. A1       Pos. A2       Pos. A3       Pos. A4
----------------------------------------------------------------------------------------------------------------
03 Navigator..............................            O       No Data     (20 km/h)     (20 km/h)           -21
03 Navigator w/lam........................            O       No Data            35       No Data       No Data
04 Volvo XC90.............................            O     (20 km/h)           193           130            18
04 Volvo w/lam............................            O     (20 km/h)            44           118            15
05 Chevy Trailblazer......................            O           138           168           159       No Data
05 Chevy Trailblazer w/lam................            O       No Data       No Data     (20 km/h)       No Data
05 Chevy Trail. w/lam. (4 hole)...........            O       No Data            89       No data       No Data

05 Honda Odyssey..........................            O       No data           107           119       No data
05 Infinity FX35..........................            O           128           101            99            55
05 Nissan Pathfinder......................            O     (20 km/h)           167     (20 km/h)            79
05 Toyota Highlander......................            O     (20 km/h)           137           142           116
06 Dodge Durango..........................            O           174           156     (20 km/h)            54
06 Dodge Durango w/lam....................            O       No Data           101       No data       No Data
06 Dodge Dur. w/lam. (4 hole).............            O     (20 km/h)            95     (20 km/h)       No Data
06 Mercury Monterey.......................            O      To Stops           208       No data            32
06 Toyota Land Cruiser....................            O           229       No data     (20 km/h)            62
06 Volvo C70..............................            O     (20 km/h)     No Target     No Target     No Target
07 Chevy Silverado........................            O           177     (20 km/h)           183            -1
07 Chevy Tahoe............................            O      To Stops           168           125           -25
07 Chevy Tahoe w/lam......................            O           113           100           124       No data
07 Chevy Tahoe w/lam. (4 hole)............            O       No data            99           109       No data
                                                                       -----------------------------------------
07 Ford 500...............................            O     (20 km/h)               160                      38
                                                                       -----------------------------------------
07 Ford Edge..............................            O           146            17            86            -9
07 Ford Edge..............................            N           175       No data           155       No data
07 Ford Expedition........................            O     (20 km/h)     (20 km/h)     (20 km/h)            21
07 Jeep Commander.........................            O     (20 km/h)     (20 km/h)     (20 km/h)           -62
07 Jeep Commander w/lam...................            O       No data       No data           148       No data
07 Mazda CX9..............................            O            96             9            87             2
07 Mazda CX9..............................            N           112       No data            90       No data
07 Saturn Vue.............................            O     (20 km/h)     (20 km/h)     (20 km/h)            65
08 Dodge Caravan..........................            O           136            84     (20 km/h)           -61
08 Ford Taurus X..........................            O           146            73            99           -38
                                                                       -----------------------------------------
08 Subaru Tribeca.........................            O     (20 km/h)               146                      74
                                                                       -----------------------------------------
08 Toyota Highlander......................            O            64            41            54            12
08 Toyota Highlander......................            N           102       No data            77       No data
08 Toyota High. w/liner...................            N            90       No data            70       No data
09 Chevy Equinox..........................            O     (20 km/h)           101     (20 km/h)            30
Average...................................  ............          135           104           114            21
Standard Deviation........................  ............         42.1          55.8          33.7          45.9
----------------------------------------------------------------------------------------------------------------

                          Table 11--Front Row Window, 20 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. A1       Pos. A2       Pos. A3       Pos. A4
----------------------------------------------------------------------------------------------------------------
03 Navigator..............................            O       No Data           191      To Stops           -37
03 Navigator w/lam........................            O       No Data             6       No Data       No Data
04 Volvo XC90.............................            O           163            96           119            -3
04 Volvo w/lam............................            O           127            27            97     (24 km/h)
05 Chevy Trailblazer......................            O           112           121           127       No Data
05 Chevy Trailblazer w/lam................            O            86            80           109       No Data
05 Chevy Trail. w/lam. (4 hole)...........            O       No Data            62            98       No Data
05 Honda Odyssey..........................            O       No data            96            57           -45
05 Infinity FX35..........................            O           106            60            73            30
05 Nissan Pathfinder......................            O           192           138           248            60
05 Toyota Highlander......................            O           168           137           115            76
06 Dodge Durango..........................            O           160           140           180            18
06 Dodge Dur. w/lam. (4 hole).............            O           106            71           150       No Data
06 Mercury Monterey.......................            O           185           199       No data           -10
06 Toyota Land Cruiser....................            O           174       No data           256            31
06 Volvo C70..............................            O           200     No Target     No Target     No Target
07 Chevy Silverado........................            O           142           187           130     (24 km/h)
07 Chevy Tahoe............................            O           104           110            87     (24 km/h)
07 Chevy Tahoe w/lam......................            O           102       No data       No data       No data