[Federal Register Volume 76, Number 12 (Wednesday, January 19, 2011)]
[Rules and Regulations]
[Pages 3212-3305]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-547]



[[Page 3211]]

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Part II





Department of Transportation





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National Highway Traffic Safety Administration



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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

[[Page 3212]]


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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.

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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 202-493-2739. For legal issues, you may contact Ms. 
Deirdre Fujita, NHTSA Office of Chief Counsel, telephone 202-366-2992, 
fax 202-366-3820.
    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

[[Page 3213]]

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

[[Page 3214]]

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.
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    \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.
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    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.
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    \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.
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    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
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Fatalities..............................................             373
Serious Injuries........................................             476
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                        Table 2--Estimated Costs*
                            [2009 economics]
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Per Vehicle...............................  $31.
Total Fleet (16.5 million vehicles).......  $507 Million
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* 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
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                                                             7% Discount
                     3% Discount rate                           rate
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$1.4M.....................................................        $1.7M
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[[Page 3215]]


                                     Table 4--Annualized Costs and Benefits
                                         [In millions of $2009 dollars]
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                                                                                    Annualized
                                                                   Annual costs      benefits      Net benefits
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3% Discount Rate................................................           $507M         $2,279M          $1,773
7% Discount Rate................................................            507M          1,814M           1,307
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    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\
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    \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).
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    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\
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    \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).
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    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.
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    \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.
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    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.
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    \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
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Windshield................................................             1,517             1,400             1,078
First-Row Windows.........................................            14,293             4,980             5,589
Second-Row Windows........................................             1,700               641               796

[[Page 3216]]

 
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
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    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.

[[Page 3217]]

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%
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 3218]]

 
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

[[Page 3219]]

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

[[Page 3220]]

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

[[Page 3221]]

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.
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    \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.''
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    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

[[Page 3222]]

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\
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    \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.
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    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.

[[Page 3223]]

    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\
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    \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.
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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.
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    \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.
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    \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.
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    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 HIC<INF>36</INF>\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

[[Page 3224]]

system) and 1020 N (5th percentile female tested with laminate only).
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    \36\ HIC<INF>36</INF> is the Head Injury Criterion computed over 
a 36 msec duration. HIC<INF>36</INF> = 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\
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    \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.
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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:
    <bullet> Inflatable devices prevented ejection of test dummies in 
simulated rollover tests, but design differences accounted for 
differences in performance;
    <bullet> 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;
    <bullet> Adding pre-broken advanced glazing to an air bag system 
enhanced the ability of the system to contain the dummy; and,
    <bullet> 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

[[Page 3225]]

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&mid=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

[[Page 3226]]

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

[[Page 3227]]

 
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
                                                                       -----------------------------------------
07 Ford 500...............................            O           192               113               (24 km/h)
                                                                       -----------------------------------------
07 Ford Edge..............................            O           129     (24 km/h)       No data     (24 km/h)
07 Ford Edge..............................            N           148       No data            67       No data
07 Ford Expedition........................            O           151      To Stops           137     (24 km/h)
07 Jeep Commander.........................            O      To Stops           175           155     (24 km/h)
07 Jeep Commander w/lam...................            O       No data       No data            73       No data
07 Mazda CX9..............................            N            76       No data            67       No data
07 Saturn Vue.............................            O      To Stops           130           191            28
08 Dodge Caravan..........................            O           112       No data           162     (24 km/h)

[[Page 3228]]

 
08 Ford Taurus X..........................            O           110       No data       No data     (24 km/h)
                                                                       -----------------------------------------
08 Subaru Tribeca.........................            O           180               106               (24 km/h)
                                                                       -----------------------------------------
09 Chevy Equinox..........................            O           149       No data           200     (24 km/h)
Average...................................  ............          140           112           132            15
Standard Deviation........................  ............         36.5          55.7          56.7          39.0
----------------------------------------------------------------------------------------------------------------


                           Table 12--Front Row Window, 16 km/h Impact, 6 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. A1       Pos. A2       Pos. A3       Pos. A4
----------------------------------------------------------------------------------------------------------------
03 Navigator..............................            O      To Stops            74      To Stops           -30
03 Navigator w/lam........................            O           157           -36           137       No Data
04 Volvo XC90.............................            O           161            73            78           -22
04 Volvo w/lam............................            O            96            26            59       No Data
05 Chevy Trailblazer......................            O           121           192           124       No Data
05 Chevy Trailblazer w/lam................            O       No Data           102       No Data       No Data
05 Chevy Trail. w/lam. (4 hole)...........            O       No Data            92       No Data       No Data
05 Honda Odyssey..........................            O       No Data            69            77           -54
05 Infinity FX35..........................            O            88            22            40             9
05 Nissan Pathfinder......................            O           117           104           195            43
05 Toyota Highlander......................            O           205           210           152            69
06 Dodge Durango..........................            O           138           135           167            13
06 Dodge Durango w/lam....................            O       No Data       No Data           142       No Data
06 Dodge Dur. w/lam. (4 hole).............            O            97            58           145       No Data
06 Mercury Monterey.......................            O           222           183       No Data            35
06 Toyota Land Cruiser....................            O           146           207           229            16
06 Volvo C70..............................            O           135     No Target     No Target     No Target
07 Chevy Silverado........................            O           145           244           115            -7
07 Chevy Tahoe............................            O            42             6            10          -136
                                                                       -----------------------------------------
07 Ford 500...............................            O           151               58                      -16
                                                                       -----------------------------------------
07 Ford 500 w/lam.........................            O            96       No Data       No Data       No Data
07 Ford Edge..............................            O           103           -42             7           -56
07 Ford Edge..............................            N           123       No Data            33       No Data
07 Ford Expedition........................            O           141           205           109             3
07 Jeep Commander.........................            O           255           144           136           -89
07 Jeep Commander w/lam...................            O       No Data            56            62       No Data
07 Jeep Commander w/lam. (4 hole).........            O       No Data            50            60       No Data
07 Mazda CX9..............................            O            54           -38            44           -53
07 Mazda CX9..............................            N            67       No Data            31       No Data
07 Saturn Vue.............................            O           184           180           186            72
08 Dodge Caravan..........................            O            85           -39           121          -141
08 Ford Taurus X..........................            O           104           -13            39           -88
                                                                       -----------------------------------------
08 Subaru Tribeca.........................            O           122               77                       -1
                                                                       -----------------------------------------
08 Toyota Highlander......................            O            36             0            54           -62
08 Toyota Highlander......................            N           119       No Data            52       No Data
09 Chevy Equinox..........................            O           125            25           178           -46
Average...................................  ............          125            82            99           -25
Standard Deviation........................  ............         50.1          87.2          61.1          58.1
----------------------------------------------------------------------------------------------------------------


                          Table 13--Second Row Window, 24 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. B1       Pos. B2       Pos. B3       Pos. B4
----------------------------------------------------------------------------------------------------------------
03 Ford Navigator.........................            O      To Stops       No data       No data            40
04 Volvo XC90.............................            O     (20 km/h)       No data       No data            69
04 Volvo XC90 w/lam.......................            O            92       No data       No data            62
05 Chevy Trailblazer......................            O           122       No data       No data            35
05 Honda Odyssey..........................            O           152           193            71            80
05 Infinity FX35..........................            O           148       No data       No data            47
05 Nissan Pathfinder......................            O           167       No data       No data           133
05 Toyota Highlander......................            O           152       No data       No data           154
06 Dodge Durango..........................            O            86            82            76            91
06 Mercury Monterey.......................            O           171           193            72            78
06 Toyota Land Cruiser....................            O           159           157            75     No Target
07 Chevy Silverado........................            O           153     (20 km/h)            78           117

[[Page 3229]]

 
07 Chevy Tahoe............................            O     (20 km/h)           161            24            74
07 Chevy Tahoe w/lam......................            O       No data            48       No data       No data
07 Ford 500...............................            O           184            50           102           157
07 Ford 500 w/lam.........................            O            91       No data       No data           111
07 Ford 500 w/lam. (4 hole)...............            O       No data       No data       No data            99
07 Ford Edge..............................            O            39            21           -22            27
07 Ford Edge..............................            N            51            33       No data            26
07 Ford Expedition........................            O           164            55            66            75
07 Jeep Commander.........................            O           140     (20 km/h)            64       No data
07 Mazda CX9..............................            O            36             2            51             9
07 Mazda CX9..............................            N            22       No data            44       No data
07 Saturn Vue.............................            O     No Target           144            66     No Target
08 Dodge Caravan..........................            O            59            27           -16            -7
08 Ford Taurus X..........................            O            45            34            22            31
08 Subaru Tribeca.........................            O           133            85            80           111
08 Toyota Highlander......................            O           106           110            55           109
08 Toyota Highlander......................            N           125           144       No data           133
08 Toyota High. w/liner...................            N           133           138       No data            77
09 Chevy Equinox..........................            O            72            22            39            45
Average...................................  ............          112            89            53            76
Standard Deviation........................  ............         49.2          63.0          32.7          44.0
----------------------------------------------------------------------------------------------------------------


                          Table 14--Second Row Window, 20 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. B1       Pos. B2       Pos. B3       Pos. B4
----------------------------------------------------------------------------------------------------------------
03 Ford Navigator.........................            O      To Stops       No data       No data           -14
04 Volvo XC90.............................            O           183       No data       No data     (24 km/h)
04 Volvo XC90 w/lam.......................            O            94       No data       No data     (24 km/h)
05 Chevy Trailblazer......................            O            68       No data       No data             8
05 Honda Odyssey..........................            O           134            84            42            34
05 Infinity FX35..........................            O            90       No data       No data            21
05 Nissan Pathfinder......................            O           143       No data       No data           111
05 Toyota Highlander......................            O           110       No data       No data           106
06 Mercury Monterey.......................            O           155            52            42            51
06 Toyota Land Cruiser....................            O           127           128            53     No Target
07 Chevy Silverado........................            O           114           232     (24 km/h)           101
07 Chevy Tahoe............................            O           249       No data     (24 km/h)     (24 km/h)
07 Ford 500...............................            O           152       No data            89           128
07 Ford Expedition........................            O           146            23     (24 km/h)     (24 km/h)
07 Jeep Commander.........................            O           122           107     (24 km/h)       No data
07 Saturn Vue.............................            O     No Target           111            40     No Target
08 Subaru Tribeca.........................            O           105       No data     (24 km/h)       No data
08 Toyota Highlander......................            O       No data            67     (24 km/h)            88
08 Toyota Highlander......................            N            92            89       No data           110
Average...................................  ............          130            99            53            64
Standard Deviation........................  ............         43.4          59.3          20.7          49.9
----------------------------------------------------------------------------------------------------------------


                           Table 15--Second Row Window, 16 km/h Impact, 6 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. B1       Pos. B2       Pos. B3       Pos. B4
----------------------------------------------------------------------------------------------------------------
03 Ford Navigator.........................            O           126       No data       No data           -27
04 Volvo XC90.............................            O           189       No data       No data            29
04 Volvo XC90 w/lam.......................            O            63       No data       No data             9
05 Chevy Trailblazer......................            O           127       No data       No data            47
05 Honda Odyssey..........................            O           121            28            12            55
05 Infinity FX35..........................            O            64       No data       No data            20
05 Nissan Pathfinder......................            O           111       No data       No data            78
05 Toyota Highlander......................            O           143       No data       No data           110
06 Dodge Durango..........................            O            36            18             3            71
06 Mercury Monterey.......................            O           223           142            54            54
06 Toyota Land Cruiser....................            O           107           113            49     No Target
07 Chevy Silverado........................            O           124           194            53            63
07 Chevy Tahoe............................            O           120           -83           -21            15
07 Chevy Tahoe w/lam......................            O            66       No data       No data       No data
07 Chevy Tahoe w/lam. (4 hole)............            O            58       No data       No data       No data
07 Ford 500...............................            O           133            -3            56            94
07 Ford 500 w/lam.........................            O            64       No data       No data       No data
07 Ford Edge..............................            O           -16           -40           -76           -25

[[Page 3230]]

 
07 Ford Expedition........................            O            89           159            22            34
07 Jeep Commander.........................            O           107            99            27            57
07 Mazda CX9..............................            O           -15           -58             5           -35
07 Saturn Vue.............................            O       No data           138            26       No data
08 Dodge Caravan..........................            O           -58           -29           -55           -56
08 Ford Taurus X..........................            O           -17           -19           -13           -40
08 Subaru Tribeca.........................            O            76            19            28            20
08 Toyota Highlander......................            O            49            59            32            57
08 Toyota Highlander......................            N            87           105       No data            93
09 Chevy Equinox..........................            O            15           -51             1           -14
Average...................................  ............           81            44            12            31
Standard Deviation........................  ............         63.9          84.5          37.2          46.8
----------------------------------------------------------------------------------------------------------------


                          Table 16--Third Row Window, 24 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. C1       Pos. C2       Pos. C3       Pos. C4
----------------------------------------------------------------------------------------------------------------
05 Honda Odyssey..........................            O       No data     (20 km/h)       No data           175
06 Mercury Monterey.......................            O           188     (20 km/h)           119       No data
06 Toyota Land Cruiser....................            O             NC            NC          180             NC
07 Chevrolet Tahoe........................            O            91     No Target           194     No Target
07 Chevrolet Tahoe w/lam..................            O       No Data           106           141       No Data
07 Ford Expedition........................            O     (20 km/h)       No data            81           186
07 Jeep Commander.........................            O           229           155           120           102
08 Dodge Caravan..........................            O           -42           112            35           -41
08 Ford Taurus X..........................            O     No Target      To Stops            48     No Target
08 Toyota Highlander......................            O           -42            42            92       No data
08 Toyota Highlander......................            N       No data       No data           110       No data
08 Toyota Highlander w/liner..............            N       No data       No data            42       No data
Average...................................  ............           85           104           106           106
Standard Deviation........................  ............        126.1          46.6          53.1         104.5
----------------------------------------------------------------------------------------------------------------


                          Table 17--Third Row Window, 20 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O*         Pos. C1       Pos. C2       Pos. C3       Pos. C4
----------------------------------------------------------------------------------------------------------------
05 Honda Odyssey..........................            O       No data      To Stops            58           122
06 Dodge Durango..........................            O       No data      To Stops            66       No data
06 Mercury Monterey.......................            O           147           212            75       No data
06 Toyota Land Cruiser....................            O             NC            NC          128             NC
07 Chevrolet Tahoe........................            O            58     No Target       No data     No Target
07 Ford Expedition........................            O           241       No data       No data            51
07 Jeep Commander.........................            O       No data           115           102       No data
08 Ford Taurus X..........................            O     No Target            86     (24 km/h)     No Target
08 Toyota Highlander......................            N       No data       No data            88       No data
Average...................................  ............          149           138            86            86
Standard Deviation........................  ............         91.5          66.0          25.8          50.6
----------------------------------------------------------------------------------------------------------------


                           Table 18--Third Row Window, 16 km/h Impact, 6 Second Delay
----------------------------------------------------------------------------------------------------------------
                  Vehicle                       N/O *        Pos. C1       Pos. C2       Pos. C3       Pos. C4
----------------------------------------------------------------------------------------------------------------
05 Honda Odyssey..........................            O      To Stops      To Stops            44           80.
06 Dodge Durango..........................            O       No Data       No Data            52      No Data.
06 Mercury Monterey.......................            O           186           204           142          225.
06 Toyota Land Cruiser....................            O             NC            NC           98             NC.
07 Chevrolet Tahoe........................            O            30     No Target            64    No Target.
07 Chevrolet Tahoe w/lam..................            O       No Data            57            66      No Data.
07 Ford Expedition........................            O           233       No Data            49           34.
07 Jeep Commander.........................            O           170           104            92           56.
08 Dodge Caravan..........................            O           -91            34           -42         -113.
08 Ford Taurus X..........................            O     No Target            60             7    No Target.
08 Toyota Highlander......................            O       No Data           -23            37      No Data.
Average...................................  ............          106            73            55           56.
Standard Deviation........................  ............        133.4          76.5          48.2        120.6.
----------------------------------------------------------------------------------------------------------------


[[Page 3231]]

Trends in Performance of Ejection Mitigation Systems by MY Using Old 
Impactor
    Based on the vehicles the agency tested, there appears to be a 
trend toward improved performance as each model year passes. This is 
demonstrated by increased coverage of the window opening in the more 
recent MY vehicles tested and the ability of the countermeasure to 
restrain displacement of the impactor. While it is difficult to 
quantify this trend, the trend is shown graphically below by plots of 
displacement values by model year for the 1st row (Figure 2) and 2nd 
Row (Figure 3). These graphs are restricted to the 24 km/h-1.5 second 
test using the old impactor and exclude any testing with advanced 
glazing.

    Note: Not shown in the figure are data from older vehicles which 
often had no curtain coverage at a particular target. If there was 
no curtain coverage, we did not test the target since the 100 mm 
displacement limit would have been exceeded. Although these vehicles 
are not shown on the graph, their improved curtain coverage in 
recent MY vehicles is indicative of improved performance over time.

    Since the graphs span multiple vehicles, there is scatter in the 
data. Nonetheless, when a trend line is plotted through the data for 
each impact location it shows decreasing displacement for newer models.
[GRAPHIC] [TIFF OMITTED] TR19JA11.001


[[Page 3232]]


[GRAPHIC] [TIFF OMITTED] TR19JA11.002

    One comparison to note for illustration purposes is the improved 
performance of the MY 2008 Highlander in comparison to the MY 2005 
Highlander. Table 19 shows the change in displacement values for the 
two model years of the Highlander at each target location and across 
impact speeds. The largest change in displacement value was for the 16 
km/h tests at targets A1 and A2 (169 mm and 210 mm, respectively). On 
an average basis, the MY 2008 Highlander had 103 mm less displacement 
across all tested target locations, for a 76 percent overall reduction. 
This is illustrative of the improved performance of later MY vehicles. 
We believe that the MY 2008 Highlander had increased coverage of the 
ejection mitigation curtain and increased size of the inflated chambers 
which helped to restrain the impactor.

  Table 19--Old Impactor, Absolute and Percentage Change in Displacement (mm) Between MY2005 and MY2008 Toyota
                                                   Highlander
----------------------------------------------------------------------------------------------------------------
                Test vel.                     A1          A2          A3          A4          B1          B4
----------------------------------------------------------------------------------------------------------------
24......................................  ..........         -96         -88        -104         -46         -45
16......................................        -169        -210         -98        -131         -94         -53
                                         -----------------------------------------------------------------------
Average (mm)............................                                   -103
----------------------------------------------------------------------------------------------------------------
24......................................  ..........        -70%        -62%        -90%        -30%        -29%
16......................................        -82%       -100%        -64%       -190%        -66%        -48%
                                         -----------------------------------------------------------------------
Average (%).............................                                   -76%
----------------------------------------------------------------------------------------------------------------

Comparing Results of Tests With Old and New Impactors
    Several vehicles (the MY2008 CX9, Edge and Highlander) were tested 
using both the old and new impactor.
    Table 20 shows the difference in displacements measured at target 
locations where both impactors were used.\55\ Not surprisingly, these 
data generally indicate that the new impactor tends to result in 
greater displacement (positive difference); we believe this is due to 
lower dynamic friction. Yet, the old impactor displacement exceeded the 
new impactor (negative difference) at several targets as well.
---------------------------------------------------------------------------

    \55\ In some cases average values were used to calculate the 
differences.
---------------------------------------------------------------------------

    The CX9 was the only vehicle that was impacted multiple times at 
the same targets by both the old and new

[[Page 3233]]

impactor. A student's t-test was performed to determine if the 
difference in the results were significant.\56\ Table 21 shows the 
displacement values and statistics for targets A1 and A3. The 
difference in displacement was statistically significant (p<=0.05) for 
the A1 target, but not the A3 target.
---------------------------------------------------------------------------

    \56\ The one sided t-test was performed assuming equal variance 
to determine if the new test device had produced larger displacement 
values compared to the old device.

                                         Table 20--Change in Displacement Between Old and New Impact Test Device
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 Vehicle                        Test vel. (km/h)          A1          A3          B1          B2          B3          B4          C3
--------------------------------------------------------------------------------------------------------------------------------------------------------
08 Ford Edge.............................  24.......................        29.0        69.0        12.0        12.0  ..........        -1.0  ..........
08 Mazda CX9.............................  24.......................        15.5         3.0       -14.0         0.0        -7.0         0.0  ..........
08 Toyota Highlander.....................  24.......................        38.5        23.0        19.0        34.0  ..........        24.0        18.0
08 Ford Edge.............................  20.......................        18.5  ..........  ..........  ..........  ..........  ..........  ..........
08 Toyota Highlander.....................  20.......................  ..........  ..........  ..........        22.0  ..........        22.0  ..........
08 Ford Edge.............................  16.......................        19.5        26.0  ..........  ..........  ..........  ..........  ..........
08 Mazda CX9.............................  16.......................        13.0       -13.0  ..........  ..........  ..........  ..........  ..........
08 Toyota Highlander.....................  16.......................        83.0        -2.0        38.0        46.0  ..........        36.0  ..........
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           Average..................        31.0        17.7        13.8        28.5        -7.0        20.3        18.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                             Average All                                                  21.6
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                   Table 21--Impactor Comparison for Mazda CX9
----------------------------------------------------------------------------------------------------------------
                                                          A1                                  A3
            Test Vel. (km/h)             -----------------------------------------------------------------------
                                                 Old               New               Old               New
----------------------------------------------------------------------------------------------------------------
24......................................                94               110                84                90
                                                        98               113                89                89
Average.................................              96.0             111.5              86.5              89.5
Std.....................................               2.8               2.1               3.5               0.7
                                         -----------------------------------------------------------------------
P-Value.................................                 0.013
                                                         0.180
----------------------------------------------------------------------------------------------------------------

    Despite the differences in test results, the test results from the 
old impactor provided useful data to assess the relative performance of 
ejection mitigation countermeasures. The results from the impactor are 
useful when analyzing data obtained from the old impactor alone, to 
compare vehicles to each other or to previous model year vehicles, or 
compare data from impact points on a vehicle.
Research Testing With New Impactor
    As part of our analysis of the data, we evaluated data from only 
the new impactor to avoid confounding the comparison of data by 
impactor differences. Table 22 shows the change in displacement between 
the 24 km/h-1.5 second, 20 km/h-1.5 second and 16 km/h-6 second tests 
at various target locations for the MY 2007 Edge, MY 2007 CX9 and MY 
2008 Highlander. The 24 km/h-1.5 second test always had greater 
displacement than the 20 km/h-1.5 second test. On average this 
difference was 38.3 mm when averaged over all vehicles and target 
locations. This is an expected result because the only difference is 
the impact speed.

              Table 22--New Impactor, Change in Displacement (mm) Between 24 km/h 1.5 Second, 20 km/h 1.5 Second and 16 km/h 6 Second Tests
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Test
                              Vehicle                                 comparison      A1          A3          B1          B2          B4          C3
--------------------------------------------------------------------------------------------------------------------------------------------------------
07 Ford Edge.......................................................        24-20          28          88  ..........  ..........  ..........  ..........
07 Mazda CX9.......................................................        24-20          36          23  ..........  ..........  ..........  ..........
08 Toyota Highlander...............................................        24-20  ..........  ..........          33          55          23          22
07 Ford Edge.......................................................        24-16          53         122  ..........  ..........  ..........  ..........
07 Mazda CX9.......................................................        24-16          45          59  ..........  ..........  ..........  ..........
08 Toyota Highlander...............................................        24-16         -17          25          38          39          40  ..........
07 Ford Edge.......................................................        20-16          25          34  ..........  ..........  ..........  ..........
07 Mazda CX9.......................................................        20-16           9          36  ..........  ..........  ..........  ..........
08 Toyota Highlander...............................................        20-16  ..........  ..........           5         -16          17  ..........
                                                                    ------------------------------------------------------------------------------------
Average All--24-20..............................................................                       38.3
Average All--24-16..............................................................                       44.7
Average All--20-16..............................................................                       15.7
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 3234]]

    There were only two vehicles/target locations that had more than 
one impact at multiple test speeds. Although this is extremely limited 
data, they allow a t-test to be performed.\57\ The results are given in 
Table 23. The results indicate that the 16 km/h-1.5 second impact had 
statistically significant less displacement than both the higher speed 
tests at target A1.
---------------------------------------------------------------------------

    \57\ The one sided t-test was performed assuming equal variance 
to determine if the 24 km/h impact produced larger displacement 
values compared to the 20 km/h impact.

          Table 23--New Impactor, Comparison of Target A1 Displacement as a Function of Impact Velocity
----------------------------------------------------------------------------------------------------------------
             Vehicle                                CX9                                    Edge
----------------------------------------------------------------------------------------------------------------
            Test Type               16 km/h-6 sec.     24 km/h-1.5 sec.     16 km/h-6 sec.     20 km/h-1.5 sec.
----------------------------------------------------------------------------------------------------------------
                                                  75                 110                 126                 152
                                                  59                 113                 119                 143
----------------------------------------------------------------------------------------------------------------
Average.........................                67.0               111.5               122.5               147.5
Std.............................                11.3                 2.1                 4.9                 6.4
----------------------------------------------------------------------------------------------------------------
P-Value.........................                   0.016
                                                   0.024
----------------------------------------------------------------------------------------------------------------

b. Field Performance

    The agency evaluated available crash data to better understand the 
field performance of the current fleet equipped with side curtain air 
bags. A focus of this evaluation was the performance of the rollover 
sensors and their ability to detect the rollover event and activate 
deployment of the side curtain air bags. We also sought to understand 
the occupant containment provided by the vehicle system. Several 
sources of available data were reviewed. These included detailed 
analysis on a limited number of rollover crashes by NHTSA's Special 
Crash Investigation (SCI) division, case reviews of NASS CDS cases from 
the target population of the final rule, and data from a new Rollover 
Data Special Study project. Detailed reviews of some of these cases can 
be found in the technical report accompanying this final rule.
SCI Cases Presented in the NPRM
    The following seven SCI cases were discussed in the NPRM. The 
agency's SCI division analyzed seven real-world rollover crashes of 
Ford vehicles where the subject vehicles contained a rollover sensor 
and side curtain air bags. (Ford had agreed to notify SCI of the 
crashes.) The subject vehicles were Ford Expeditions, a Ford Explorer, 
a Mercury Mountaineer, and a Volvo XC90. Table 24 gives details about 
each case.
    In each case, the rollover sensor deployed the side curtain air 
bag. Of the seven cases, there were a total of 19 occupants, 15 of whom 
were properly restrained. All were in lap/shoulder belts, except one 
child in a rear facing child restraint system (CRS). A single crash 
(DS04-016) had all of the unrestrained occupants, serious injuries, 
fatalities and ejections in this set of cases. Two of the four 
unrestrained occupants were fully ejected from the vehicle, resulting 
in one fatal and one serious injury. The fatality was a 4-month-old 
infant, seated in the middle of the 2nd row. The ejection route was not 
determined. The seriously injured occupant was an adult in the left 3rd 
row, ejected through the uncovered right side 3rd row window. One non-
ejected, restrained occupant received a fatal cervical fracture 
resulting from roof contact and another was seriously injured. The 
injuries to the remaining occupants were ``none'' to ``minor.''

[[Page 3235]]



                                                                                        Table 24--Ford SCI Rollover Cases (Presented in the NPRM)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                     Occupants                                                                            Deploy
              Case                     Make            Model            MY       ------------------------------------------------   \1/4\ Rot.   ---------------------------------------------------------------------------------------
                                                                                       Row 1           Row 2           Row 3                           Angle                   Time (ms)                         Rate (deg/s)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CA02-059........................  Mercury.......  Mount.........  2002..........  1R............  1R............  ..............  1.............  17............  ..................................                            17 to 25
CA04-010........................  Ford..........  Expl..........  2003..........  1R............  ..............  ..............  1.............  43............                                  20                                  75
IN-02-010.......................  Ford..........  Exped.........  2003..........  1R............  ..............  ..............  2.............  45............                                 146                                 111
2004-003-04009..................  Ford..........  Exped.........  2003..........  1R............  2R............  ..............  5.............  Yes...........                             Unknown                             Unknown
DS04-016........................  Ford..........  Exped.........  2003..........  2R............  2R,             1R,             5.............  Yes...........                             Unknown                             Unknown
                                                                                                   2NR[dagger].    2NR[dagger].
DS04017.........................  Ford..........  Exped.........  2004..........  1R............  ..............  ..............  12............  Yes...........                             Unknown                             Unknown
2003-079-057....................  Volvo.........  XC90..........  2003..........  1R............  1R............  ..............  6.............  Yes...........                             Unknown                             Unknown
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R = Restrained, NR = Not Restrained.
[dagger] One NR 2nd and 3rd row occupant ejected (total of 2 ejected).


[[Page 3236]]

Rollover Data Special Study (RODSS)
    RODSS is a new source of rollover crash data that began in April 
2007. NHTSA initiated RODSS as a pilot project to obtain additional 
field data for rollover crashes not covered by other agency databases. 
Cases were identified through the FARS database. NASS CDS and SCI cases 
were excluded from consideration because detailed information from 
those crashes would be available from those databases. However, remote 
SCIs were performed on selected cases.\58\ The technical report for 
this final rule includes a discussion of the RODSS study conducted for 
this final rule.
---------------------------------------------------------------------------

    \58\ A remote SCI is one where, for a variety of reasons, the 
investigator is not able to physically examine the crash location 
and vehicles. The investigation is done through the use of police 
accident reports, scene diagrams and photographs.
---------------------------------------------------------------------------

    RODSS is not a random sample and is not intended to be 
statistically representative of all rollover crashes nationally. Also, 
the sample size is small and becomes even smaller when separating the 
data into subcategories. Accordingly, observations based on the RODSS 
data about the relationship of side curtains and ejection are 
inherently limited.
    To become part of the RODSS sample, the vehicle had to be exposed 
to a rollover crash and have a side curtain air bag and/or electronic 
stability control (ESC)/rollover stability control (RSC). The curtain 
air bag did not have to be deployable in a rollover, i.e., the curtain 
air bag could be an FMVSS No. 214 side impact air curtain without a 
rollover sensor, but some vehicles did have a rollover sensor.
    The study first reviewed a total of 328 crashes occurring in 2005 
through 2008. Of these 328 case vehicles, 315 were coded as exposed to 
a lateral rollover. Of these 315 case vehicles, 115 were believed to be 
equipped with side curtain air bags. Of these 115 case vehicles, 21 
were believed to have a rollover sensor (rollover curtain). Of these 21 
case vehicles, 18 had their curtains deploy during the rollover and 3 
did not. These three cases of non-deployment are of interest relative 
to sensor performance and will be discussed in more detail later, along 
with a non-deployment SCI case.
    Curtain deployment coding was tied to the driver or passenger, 
i.e., if there was someone seated on the side of the vehicle where the 
curtain deployed, it was coded as deployed for that occupant. There 
were 120 side curtain air bags deployed adjacent to occupants of the 
vehicles (58 drivers and 62 passengers). Limiting RODSS occupant 
selection to those in vehicles exposed to a lateral rollover, and those 
who had a known ejection status, then separating by known curtain 
deployment, results in Table 25, below. This table shows 119 occupants 
(57 drivers and 62 passengers) who were exposed to a curtain deployment 
and 496 (244 drivers and 252 passengers), who were not.

  Table 25--RODSS Driver and Passenger in Lateral Rollovers With Known
               Ejection Status by Known Curtain Deployment
------------------------------------------------------------------------
                                                                  All
          Curtain deployment             Drivers   Passengers  occupants
------------------------------------------------------------------------
Yes...................................         57          62        119
No....................................        244         252        496
                                       ---------------------------------
    Total.............................        301         314        615
------------------------------------------------------------------------

General Observations From RODSS About Ejection Rates Relative to 
Curtain Air Bags
    Again, any observations made based on the RODSS data about the 
relationship of side curtains and ejection must be prefaced by the fact 
that RODSS is not a random sample and is not intended to be 
statistically representative of all rollover crashes nationally.
    The data from the 615 occupants in Table 25 form the basis of a 
comparison on ejection status versus curtain air bag deployment found 
in Tables 26 and 27. The ``curtain deployed'' group is made up of 
vehicles that had a rollover sensor and vehicles that did not (the 
latter vehicles may have had a side impact sensor only). The ``curtain 
not deployed'' group is made up of vehicles equipped or not equipped 
with a curtain, i.e., one possible reason for the curtain not deploying 
is that it did not exist.
    We studied the data to see if side curtains had an effect in 
mitigating rollover ejections. We were aware that care should be taken 
in drawing conclusions from these results. Most of the curtain-equipped 
vehicles exposed to lateral rollovers had only FMVSS No. 214 side 
impact curtains (94 vehicles), rather than rollover curtains (21 
vehicles). It is possible that if a side impact curtain deployed during 
the crash, the crash might be different than a crash where a side 
impact curtain did not deploy. An important difference when examining 
ejection data is rollover severity as quantified by number of quarter-
turns. To help determine if there was an obvious bias in the data, we 
examined the difference between the quarter-turns in the rollover 
crashes where the side impact curtains deployed and the number of 
quarter turns in the rollover crashes where they did not deploy.
    RODSS data indicate that deployment of any curtain (even a side 
impact curtain) has a positive effect on reducing the rate of side 
window ejection. Table 26 shows that 10.9 percent [13/119] of all 
occupants adjacent to a curtain air bag deployment were ejected through 
the side windows, in comparison to 27.6 percent [137/496] of those 
occupants who were not adjacent to a curtain deployment.
    Restricting the data to occupants protected by a curtain deployed 
by a rollover sensor, 5.3 percent [2/38] were ejected. The cases 
involving the two occupants who were ejected, even though the rollover 
curtain deployed, are discussed in a later section.

[[Page 3237]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.003

    Table 27 examines the subset of occupants from Table 26 who were 
unbelted. Table 27 shows that 22.7 percent [10/44] of unbelted 
occupants in vehicles with curtain air bag deployment were ejected 
through the side windows, in comparison to 51.9 percent [108/208] of 
those unbelted occupants in vehicles where the curtain did not deploy. 
Rollover severity (as represented by number of quarter-turns) does not 
seem to account for the difference in the ejection rates for these two 
unbelted groups.
    When the data are restricted to only unbelted occupants protected 
by rollover curtains, 10.0 percent [1/10] were ejected through the side 
window, as compared to 26.5 percent [9/34] of unbelted occupants 
protected by side impact curtains. We note that two unbelted occupants 
were not ejected in vehicles with deployed rollover curtains.
[GRAPHIC] [TIFF OMITTED] TR19JA11.004

Cases Where Occupants Were Ejected Through Rollover Curtain-Equipped 
Windows
    We examined SCI rollover crashes, NASS CDS cases from the target 
population of the final rule and data from the RODSS project and found 
six case vehicles where occupants were ejected through the side window 
opening that a rollover deployed curtain presumably covered. These 
cases are listed in Table 28, along with the number of quarter turns, 
occupant seating position, belt use, occupant age, degree of ejection, 
ejection route, and level of injury.
    The average number of quarter-turns was 5.5. These six crashes 
involved nine occupants, six of whom were partially or completely 
ejected through a protected side window. Four occupants were partially 
ejected and two were completely ejected. All six were front seat 
occupants, although one was ejected through a second row window. Four 
of the ejected occupants were killed in the crash. One fatal partial 
ejection was ejected through a window protected by both a curtain and a 
laminated window. Four of these cases involved curtain damage. In two, 
the A-pillar tether detached. It is not possible to know if these 
instances of curtain damage occurred during the rollover or post-crash 
due to extrication.

[[Page 3238]]



               Table 28--RODSS, NASS CDS and SCI Cases With Occupants Who Were Ejected Through Side Windows Protected by Rollover Curtains
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 1/4                      Seat
         Case ID            Year/Make/Model     Turns     Curt. depl.     pos.      Belt use      Age        Eject.          Route         Injury/ MAIS
--------------------------------------------------------------------------------------------------------------------------------------------------------
          RODSS
 
7238 *..................  06 Ford Explorer...        6  Yes...........       11  No...........      84y  Comp.........  Row 1 L........  Fatal.
8289 *..................  03 Lincoln Aviator        8+  Yes...........       11  Yes..........      62y  Part.........  Row 1 L........  Fatal.
                           [Dagger].
8289 *..................  03 Lincoln Aviator        8+  Yes...........       12  Yes..........      28y  No...........  NA.............  Serious.
                           [Dagger].
8289 *..................  03 Lincoln Aviator.       8+  Yes...........       23  Yes..........      65y  No...........  NA.............  Moderate.
 
        NASS CDS
 
2003-04-048 *...........  02 Ford Explorer...        4  Yes...........       11  Yes..........      54y  No...........  NA.............  1.
2003-04-048.............  02 Ford Explorer...        4  Yes...........       13  Yes..........      49y  Part.........  Row 1 R........  1.
2006-79-089.............  04 Lexus RX330.....        1  Yes...........       11  No...........      27y  Part.........  Row 2 L........  Fatal.
2008-03-108.............  08 Honda Pilot.....        6  Yes...........       11  No...........      48y  Part.........  Row 1 L........  3.
2008-12-159.............  05 Mercury Mont....        8  Yes...........       11  No...........      23y  Comp.........  Row 1 L........  Fatal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* These are also SCI cases.\59\
[Dagger] These seating positions had laminated glazing adjacent to them.

Non-Deployed Rollover Curtains in Rollover Crashes
---------------------------------------------------------------------------

    \59\ Both RODSS cases were made into SCI remote investigations 
to facilitate documentation of photographs and other crash details. 
The SCI case numbers are CA09069 (RODSS 7238) and CA10006 (RODSS 
8289).
---------------------------------------------------------------------------

    We examined SCI rollover crashes, NASS CDS cases from the target 
population of the final rule and data from the RODSS project to find if 
the rollover sensors deployed the rollover side air curtains in a 
rollover. In general, field data indicate that rollover sensors have 
been recognizing a rollover and deploying rollover curtains in rollover 
crashes.
    We found five case vehicles where the vehicle was apparently 
equipped with a side curtain air bag that was supposed to be deployed 
by a rollover sensor and the curtains did not deploy in the rollover 
event (see Table 29). There were two completely ejected occupants and 
one partial ejected occupant in these crashes. The results of these 
ejections were 3 fatalities. All of these ejections were through side 
windows except one where the front passenger door was dislodged from 
the vehicle and provided the ejection route for the unbelted driver.
    Consistent among these non-deployment cases is that the rollover 
was preceded by a significant frontal impact. Four of the five non-
deployment cases had a significant frontal impact that preceded the 
rollover. The MY 2006 Ford Explorer in RODSS case 6121 had a right 
front corner impact with a large tree prior to the rollover. The MY 
2003 Lincoln Aviator in RODSS case 7242 had an offset frontal impact 
with an oncoming vehicle prior to the rollover. The MY 2006 Cadillac 
SRX in SCI case DS07009 impacted a large tree prior to the rollover. 
The EDR data from this case indicated that the tree impact had a 
longitudinal and lateral [Delta]V of - 38.9 mph and - 10.2 mph, 
respectively. The EDR also indicated that the rollover sensor status 
was ``invalid'' and the curtain deployment was not commanded. The MY 
2009 Dodge Journey had a narrow offset frontal impact with another 
vehicle, which the crash investigator stated disrupted the power supply 
from the battery. The frontal air bags deployed in the above four 
crashes. (There is some doubt as to whether RODSS case 6121 (SCI 
CA9062) was definitely equipped with a rollover sensor, since the 
system was an option on this vehicle. Ultimately, no definitive 
determination was made.) For the cases involving initial frontal 
impacts, these impacts may have destroyed the vehicle battery and thus 
eliminated the primary power source for deploying the rollover curtain.
    In RODSS case 5032 (SCI CA9061), it appears the sensor may not have 
been able to make a determination that a rollover occurred. However, in 
studying the details of this case, the vehicle's kinematics were very 
complex and may have included some motion not typical of a lateral 
rollover.

                                    Table 29--RODSS and SCI Rollover Cases Where the Rollover Curtain Did Not Deploy
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               Quarter                    Seat
         Case ID            Year/Make/Model     turns     Curt. depl.     pos.      Belt use      Age        Eject.          Route         Injury/ MAIS
--------------------------------------------------------------------------------------------------------------------------------------------------------
          RODSS
 
5032 *..................  04 Lincoln Aviator         3  No............       11  No...........      68y  Comp.........  Row 2 R........  Fatal.
                           [Dagger].
6121 *..................  06 Ford Explorer...        4  No............       11  No...........      23y  Comp.........  Door (13)......  Fatal.
7242 *..................  03 Lincoln Aviator         3  No............       11  Yes..........      28y  No...........  NA.............  Serious.
                           [Dagger].
7242 *..................  03 Lincoln Aviator         3  No............       13  Yes..........      26y  No...........  NA.............  Serious.
                           [Dagger].
7242 *..................  03 Lincoln Aviator.        3  No............       21  CRS..........       3y  No...........  NA.............  Serious.
7242 *..................  03 Lincoln Aviator.        3  No............       23  Yes..........       7y  No...........  NA.............  Serious.
 
           SCI
 
DS07009.................  06 Cadillac SRX....        4  No............       11  No...........      81y  Part.........  Row 1 L........  Fatal.
DS09071.................  09 Dodge Journey...        4  No............       11  Yes..........      63y  No...........  NA.............  2.
DS09071.................  09 Dodge Journey...        4  No............       13  Yes..........      60y  No...........  NA.............  1.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* These are also SCI cases.\60\
[Dagger] These seating positions had laminated glazing adjacent to them.


[[Page 3239]]

X. Response to Comments and Agency Decisions
---------------------------------------------------------------------------

    \60\ These three RODSS cases were made into SCI remote 
investigations to facilitate documentation of photographs and other 
crash details. The SCI case numbers are RODSS 5032 (CA09061), RODSS 
6121 (CA9062) and RODSS 7242 (CA9063).
---------------------------------------------------------------------------

    Laboratory and field data indicate that window curtains covering 
side windows can substantially reduce ejections in rollovers. NHTSA 
issued the NPRM to require that the side windows next to the first 
three rows of seats be subject to performance requirements that ensure 
the vehicle has an ejection mitigation countermeasure that would 
prevent an 18 kg headform from moving more than 100 mm beyond the zero 
displacement plane of each window when the window is impacted.
    The NPRM proposed requirements for: (a) The impactor dimensions and 
mass; (b) the displacement limit; (c) impactor time and speed of 
impact; (d) target locations, and (e) testing the targets. We also 
discussed: (f) glazing issues; (g) test procedure tolerances; (h) test 
device characteristics; and (i) a proposal for a telltale requirement. 
The NPRM did not specifically require a rollover sensor. A 3-year lead 
time and 4-year phase-in was proposed, along with allowance of advanced 
credits to meet phase-in requirements. Costs, benefits, and other 
impacts were discussed in a PRIA accompanying the NPRM.

a. Impactor Dimensions and Mass

1. NPRM
    The component test involves use of a guided linear impactor that is 
designed to replicate the loading of a 50th percentile male occupant's 
head and upper torso during ejection situations. The portion of the 
impactor that strikes the countermeasure is a featureless headform that 
was originally designed for the upper interior head protection research 
program (FMVSS No. 201).\61\ It averages the dimensional and inertial 
characteristics of the frontal and lateral regions of the head into a 
single headform. The NPRM specified that the headform is covered with 
an approximately 10 mm thick dummy skin material whose outer surface 
dimensions are given in Figure 4, below. The Technical Analysis report 
accompanying the NPRM discusses other dimensional attributes of the 
headform, such as the curvature of the outer surface.
---------------------------------------------------------------------------

    \61\ ``Ejection Mitigation Using Advanced Glazings: A Status 
Report,'' November 1995, Docket NHTSA-1996-1782-3; ``Ejection 
Mitigation Using Advanced Glazings: Status Report II,'' August 1999, 
Docket NHTSA-1996-1782-21; ``Ejection Mitigation Using Advanced 
Glazings: Final Report,'' August 2001, Docket NHTSA-1996-1782-22.
---------------------------------------------------------------------------

    There are many possible ways of delivering the impactor to the 
target location on the ejection mitigation countermeasure. Both the old 
and new impactors used in agency research propel the shaft component of 
the impactor with a pneumatic piston. The shaft of the old impactor 
slides along a plastic (polyethylene) bearing. The new impactor uses 
curved roller bearings for part of the shaft support, which reduces the 
energy loss due to friction. The impactor has an 18 kg mass.\62\
---------------------------------------------------------------------------

    \62\ Since the performance criterion for this ejection 
mitigation standard is a linear displacement measure (a linear 
displacement measure would correlate to the actual gap through which 
an occupant can be ejected), a linear impactor is a suitable tool to 
dynamically measure displacement. The impactor can be placed inside 
the vehicle for testing the ejection mitigation curtains and glazing 
covering window openings.
[GRAPHIC] [TIFF OMITTED] TR19JA11.005


[[Page 3240]]


    The mass of the guided impactor was developed through pendulum 
tests, side impact sled tests, and modeling conducted to determine the 
mass imposed on the window opening by a 50th percentile adult male's 
upper torso and head during an occupant ejection (``effective 
mass'').\63\ Briefly, the pendulum impact tests were conducted on a 
BioSID anthropomorphic test device (50th percentile adult male) to 
measure effective mass of the head, shoulder, and upper torso. The 
BioSID was chosen because it was originally configured for side impact, 
unlike the Hybrid III dummy, and has a shoulder which the Side Impact 
Dummy (49 CFR 572, subpart F) used for FMVSS No. 214, ``Side impact 
protection,'' does not have. A linear impact pendulum weighing 23.4 kg 
was used to strike the head and shoulder of the dummy laterally 
(perpendicular to the midsagittal plane) using two impact speeds (9.7 
and 12.9 km/h) and four impact surfaces. In addition to the rigid 
impactor face, three types of padding were added to the impactor face 
to increase the contact time and replicate advanced glazing impacts.
---------------------------------------------------------------------------

    \63\ ``Technical Analysis in Support of a Notice of Proposed 
Rulemaking for Ejection Mitigation,'' supra.
---------------------------------------------------------------------------

    Effective mass was calculated by dividing the force time history 
calculated from the pendulum accelerometers by the acceleration time 
history from the dummy sensors. In general, higher speed impacts and 
impacts with softer surfaces generated higher effective mass. Based on 
these pendulum tests, a range for the effective mass of the head and 
upper torso was estimated to be 16 to 27 kg.
    In the sled tests, we used a side impact sled buck with a load 
plate representing a door and two load plates representing the glazing 
to measure shoulder and head impacts with three different stiffness 
foams. The purpose of these tests was to determine the effect lower 
body loading would have on the combined head and upper torso effective 
mass. Two impact conditions were simulated, one condition was described 
as being representative of a rollover event and the second was 
described as being representative of a side impact event.
    In the rollover condition, the impact speed was intended to be 16.1 
km/h (10 mph) and the dummy was positioned leaning towards the door 
such that the head and torso would contact the simulated glazing at the 
same time. This leaning position was intended to be more representative 
of an occupant's attitude in a rollover. For the test designed to be 
more representative of a side impact condition, the dummy was seated 
upright and the impact speed was intended to be 24.1 km/h (15 mph).
    In the preamble of the NPRM, we described the agency's analysis of 
these tests as follows. As was done for the pendulum data, the 
effective mass was calculated by dividing the force time history 
calculated from the pendulum accelerometers by the acceleration time 
history from the dummy sensors. Using this method, the effective mass 
of the head and upper torso calculated for the 16.1 km/h impact 
condition showed a quick rise to about 18 kg by about 5 ms, followed by 
an increase to about 40 kg at about 30 ms. The effective mass for the 
24.1 km/h impact condition showed an initial artificially high value or 
spike prior to 5 ms because of a lag between the force measured in the 
load plates and the acceleration measured at the upper spine. This 
spike was also seen in some pendulum shoulder impacts. The effective 
mass settled to about 9 kg at about 10 ms, with a slow rise to about 18 
to 20 kg at about 25 to 30 ms. Looking at the results, we deferred to 
the 18 kg effective mass since the test condition more closely 
represented a rollover. In addition, the 18 kg value was within the 
range of the pendulum impactor results discussed above, which showed an 
effective mass range between 16 and 27 kg.
    For this final rule, we have reanalyzed these sled tests primarily 
for the purpose of determining impact energy, which we address in 
detail later in this preamble.\64\ However, this analysis also 
generated estimates of the effective mass of the dummies in these 
tests. For the 24.1 km/h test, three methods (represented by equations 
2-4, infra) gave a range of the combined head and shoulder effective 
mass of 12.2 to 13.1 kg. We believe that a reasonable estimate is 13 
kg. The analysis for the 16.1 km/h test is more complex due to the time 
dependent dummy orientation. After making estimates of the impact 
energy using a simple sprung mass model, we back calculated the 
effective mass assuming the impact energy is equal to the kinetic 
energy prior to impact (represented by equation 3, infra). We also used 
the sled velocity as a surrogate for relative dummy speed and 
calculated effective mass directly by using an equation 4, infra. From 
these calculations we estimated a combined head and shoulder effective 
mass of 22 kg.
---------------------------------------------------------------------------

    \64\ The video from these tests and the data from the dummies, 
load wall and sled can be accessed from the NHTSA Biomechanics 
Database at http://www-nrd.nhtsa.dot.gov/database/aspx/biodb/querytesttable.aspx. The test numbers are 10282 through 10287. Tests 
reanalyzed in detail were 10282 (24 km/h test) and 10285 (16.1 km/h 
test).
---------------------------------------------------------------------------

    In the NPRM preamble, we reported that the agency also performed a 
computer modeling analysis of an 18 kg impactor and 50th percentile 
Hybrid III dummy impacting simulated glazing (foam). The comparison 
found that the total energy transferred by the 18 kg impactor was 
within the range of the total energy transferred by the entire dummy. 
For a 16.1 km/h dummy model impact with the foam, the effective mass 
that came in contact with the foam was between 12.5 kg and 27 kg.
    We noted in the NPRM that the 18 kg proposed mass is consistent 
with that used by General Motors (GM) in 16.2 km/h (10 mph) tests of 
ejection mitigation curtains.\65\ GM based this value on test results 
from 52 full-vehicle rollover tests that estimated the effective mass 
of occupant contact with the first row side window area. A more 
detailed analysis of this study can be found later in this preamble.
---------------------------------------------------------------------------

    \65\ O'Brian-Mitchell, Bridget M., Lange, Robert C., ``Ejection 
Mitigation in Rollover Events--Component Test Development,'' SAE 
2007-01-0374.
---------------------------------------------------------------------------

    The estimated effective mass for most belted tests was about 5 kg 
and all were less than 10 kg. The majority of belted tests had 
effective masses which were a combination of both the near and far side 
occupants. The effective mass for the unbelted occupants ranged from 5 
to 85 kg.
    In summary, the proposed impactor mass was based on the 
determination of an effective mass calculated through both pendulum and 
sled test impacts and modeling. These methods resulted in a large range 
of effective mass values. In the end, we deferred to the 18 kg 
equivalent mass seen during the sled test that was intended to be more 
representative of a rollover event, which was also the equivalent mass 
calculated from pendulum impact into the dummy shoulder. For this final 
rule we have reanalyzed the sled tests and estimated a range of 
effective mass from approximately 13 to 22 kg. Thus, the 18 kg 
effective mass is still considered to be a reasonable representation of 
an occupant's head and a portion of the torso. An effective mass more 
representative of just the head would be substantially smaller, and an 
equivalent mass accounting for more torso and lower body mass would be 
substantially more. The 18 kg mass is well within the GM estimates from 
vehicle rollover tests, and is consistent with the impactor that GM 
uses to evaluate side curtains.

[[Page 3241]]

2. Comments
    There was general support from the vehicle manufacturers and 
suppliers for using a linear impactor and performance metric based on 
the displacement of that impactor in a compliance test. There were only 
a few comments on the impactor dimensions and mass. These few comments 
were in favor of the proposed mass. While VW and others had comments on 
the impact energy imparted by the mass, which is an issue which will be 
addressed in a later section below, VW stated that ``the 18 kg mass for 
the impactor is well established * * *'' The Alliance referenced the 
fact that the GM test procedure for ejection mitigation uses an 18 kg 
linear impactor in stating that ``[t]he Alliance supports the use of 
the 18 kg headform proposed in the NPRM.''
    Some parties commented on the design of the headform. Takata stated 
that simulated animations have shown relative movement of head skull 
and headform, and that ``the incomplete fixation of the head skull is 
influencing the displacement behavior of the head form [sic].'' Takata 
suggested enlarging the head skull fixation in the lower portion, by 
adding a skull cap or enlarging the chin area in the rear for example. 
Similarly, TRW said that it found that the headform skin can become 
dislodged from the skull during testing and suggested using a backplate 
of smaller size on the headform to better clamp the headform skin 
flange to the skull. TRW also said that the headform skin can become 
displaced from the lower (chin) area of the skull.
    AORC recommended that NHTSA adopt specifications for the skin 
stiffness, skin friction coefficient, and skull surface finish, to 
address the headform skin partially dislocating on the headform as a 
result of friction between the countermeasure and the headform.
    TRW suggested changes to the preparation of the headform for 
testing. It stated that frictional attributes of the headform skin 
affect the manner in which the headform interacts with the rollover 
curtain, so talc, chalk, or other coatings could affect test results. 
TRW suggested that the standard specify that ``no coatings shall be 
applied to the headform skin during testing'' and asked, as did AORC, 
that the standard specify that prior to the test, the headform skin 
must be cleaned (TRW suggested cleaning the headform with isopropyl 
alcohol). TRW suggested changes to the headform drawing package to 
address: The outer surface finish requirements of the skull; the 
thickness tolerance and durometer hardness of the skin; inner/outer 
surface finish and tolerance requirements of the skin material type and 
material properties corridor for the skin; the definition of frictional 
characteristics of the skin, including the performance corridor; and 
test procedure and measurement technique for frictional characteristics 
of skin.
3. Agency Response
    We are adopting an 18 kg headform substantially similar to the 
device described in the NPRM.
    We are declining Takata's and TRW's requests to add a skull cap or 
modify the backplate of the headform. The modification is unnecessary 
as the new headform has not exhibited the problem these commenters 
describe. Further, the effect of the modification on actual test 
results has not been quantified by the commenters. Using modeling, 
Takata estimated about a 3 mm increase in displacement between the 
proposed headform and one with the suggested modification, but it is 
not clear this modeling is representative of an actual impact test.
    NHTSA is not inherently opposed to improvements in the headform 
design to possibly allow for a longer period of head skin use before it 
needs to be replaced. However, it has not been shown that there is a 
need to improve the headform at this time. If improvements are feasible 
and the effect of changing the headform on ejection mitigation 
countermeasure performance can be better assessed, we are open to 
considering fine-tuning adjustments to the headform at a future date.
    With respect to TRW's comments about the additions and revisions to 
the drawing package, the NPRM's drawing package already included 
specifications for the skin material type, thickness and durometer. It 
also included a specification for preparing the outer surface finish of 
the skull. TRW did not provide any reason to change these 
specifications, so they will remain as proposed in the final rule.
    We deny TRW's other requests that we specify the inner/outer skin 
surface finish, skin frictional characteristics, friction performance 
corridor and friction measurement technique. We do not believe there is 
a need for these specifications. NHTSA has not before found a need to 
specify skin surface finish and frictional characteristics for test 
dummy skin. The commenter provided no justification as to why the 
material properties provided were insufficient or how the requested 
parameters would improve the objectivity of the standard.
    We are denying the request to place a requirement in the regulatory 
text to clean the headform skin with isopropyl alcohol as per FMVSS No. 
201, ``Occupant Protection in Interior Impact.'' The commenters provide 
no data showing the necessity of such provision. FMVSS No. 201 has no 
requirement that the free motion headform be cleaned with alcohol prior 
to the testing. There is no FMVSS that specifies in the regulatory text 
that the dummy skin should be cleaned prior to vehicle testing.

b. Measurement Plane and Displacement Limit (100 mm)

1. NPRM
    We proposed that the linear travel of the impactor headform must be 
limited to 100 mm from the inside of the tested vehicle's glazing as 
measured with the glazing in an unbroken state. The 100 mm boundary 
would be first determined with the original glazing ``in position'' 
(up) and unbroken. Then, for the test, the original glazing would be in 
position but pre-broken if it were advanced glazing; or down or removed 
altogether if it were tempered glazing. It was proposed that advanced 
glazing would be in position but pre-broken for both the 1.5 second 
test and the 6-second test.
    The NPRM included a window-breaking procedure that damages but does 
not destroy advanced glazing, while it will obliterate tempered 
glazing. It was proposed that vehicle manufacturers may remove or 
completely retract tempered glazing since it would be destroyed in the 
pre-breaking procedure and would have no effect on the ejection 
mitigation results. When tested with the original glazing in position 
but pre-broken or with the glazing removed, the linear travel of the 
impactor headform must not exceed the 100 mm limit. If a side curtain 
air bag is present, and we anticipate that most, if not all, vehicles 
will have an ejection mitigation curtain, the curtain would be 
deployed.
    In the test, the ejection mitigation countermeasure must prevent 
the headform from exceeding the 100 mm limit. The principle underlying 
the 100 mm displacement limit is to ensure that the countermeasure does 
not allow gaps or openings to form through which occupants can be 
partially or fully ejected. In the research tests, targets that had 
displacements of less than 100 mm did not allow ejections in dynamic 
testing.
    In research tests, the TRW and Zodiac prototype ejection mitigation 
countermeasures were tested on a CK

[[Page 3242]]

pickup to the proposed impactor test procedure.\66\ The TRW prototype 
had no coverage at position A1 (front window forward lower position). 
These systems were later tested on the DRF with the 50th percentile 
male, 5th percentile female and 6-year-old dummies in upright seating 
positions, and a prone 6-year-old dummy aimed at approximately the 
target positions A1 and A2 (front window rear lower position). When 
tested on the DRF, the arms of the upright dummies flailed out of the 
window opening up to the shoulder at the sill (A1 and A2) and the prone 
6-year-old dummy was completely ejected at A1.
---------------------------------------------------------------------------

    \66\ There were only some slight variations in target locations.
---------------------------------------------------------------------------

    We recognize that dummy ejection did not occur all the time at 
targets that had displacements of over 100 mm. When tested with pre-
broken laminated glazing, at position A1, the TRW system had 181 mm of 
displacement at the 24 km/h (1.5 second delay) test and 104 mm of 
displacement in the 20 km/h (1.5 second delay) test, but did not eject 
either the prone or seated dummies in DRF tests. Nonetheless, the 
component and DRF testing indicated that there was an increased 
likelihood that an opening could be formed between the curtain and the 
window opening through which an occupant could be ejected if the 
displacement were over 100 mm in the headform test. In addition, a 100-
mm limit would also help guard against the countermeasure being overly 
pliable or elastic so as to allow excessive excursion of an occupant's 
head and shoulders outside of the confines of the vehicle even in the 
absence of a gap.\67\
---------------------------------------------------------------------------

    \67\ The agency further notes that an advantage to the 
displacement limit is that the linear displacement of the headform 
can be measured in a practicable and relatively straightforward 
manner, unlike a real-time dynamic measurement of a gap during an 
impact.
---------------------------------------------------------------------------

    NHTSA also noted in the NPRM that a 100-mm performance limit is 
used in several regulations relating to occupant retention. In FMVSS 
No. 217, ``Bus emergency exits and window retention and release,'' (49 
CFR 571.217), bus manufacturers are required to ensure that each piece 
of glazing and each piece of window frame be retained by its 
surrounding structure in a manner that prevents the formation of any 
opening large enough to admit the passage of a 100-mm diameter sphere 
under a specified force. The purpose of the requirement is to minimize 
the likelihood of occupants being thrown from the vehicle. This value 
is also used in FMVSS No. 206, ``Door locks and door retention 
components,'' (49 CFR 571.206, as amended 69 FR 75020), to mitigate 
occupant ejection through unintentional door openings in a crash. In 
FMVSS No. 206, the door is loaded with 18,000 N of force and the space 
between the interior of the door and the exterior of the door frame 
must be less than 100 mm.
    In addition, NHTSA also considered that a value of approximately 
100 mm is used by the International Code Council (ICC) in developing 
building codes used to construct residential and commercial 
buildings.\68\ The ICC 2006 International Building Code and 2006 
International Residential Code require guards to be placed around areas 
such as open-sided walking areas, stairs, ramps, balconies and 
landings. The guards must not allow passage of a sphere, 4 inches (102 
mm) in diameter, up to a height of 34 inches (864 mm). The ICC explains 
in the Commentary accompanying the Codes that the 4-inch spacing was 
chosen after considering information showing that the 4-inch opening 
will prevent nearly all children 1 year in age or older from falling 
through the guard.
---------------------------------------------------------------------------

    \68\ The ICC is a nonprofit membership association that works on 
developing a single set of comprehensive and coordinated national 
model construction codes. http://www.iccsafe.org/news/about/.
---------------------------------------------------------------------------

    The NPRM noted that GM has developed a test procedure that uses a 
100 mm displacement limit but in GM's procedure, the zero displacement 
plane is a plane tangent to the exterior of the side of the vehicle at 
the target location.<SUP>69 70</SUP> Displacement is measured 
perpendicular to this excursion plane. Thus, the allowable GM 
displacement is approximately 100/cos([thgr]) mm, with [thgr] being the 
angle with the vertical of the exterior plane, if other aspects of the 
test were identical to those of the NPRM. If [thgr] were 20 degrees, 
the GM limit would be approximately 106 mm. The GM method also results 
in a slightly different allowable final displacement position than the 
proposed method because of the separation between the flat excursion 
plane and the inside surface of the window at the target location.
---------------------------------------------------------------------------

    \69\ O'Brian-Mitchell, Bridget M., Lange, Robert C., ``Ejection 
Mitigation in Rollover Events--Component Test Development,'' SAE 
2007-01-0374.
    \70\ GM explained that its justification for the 100 mm 
displacement limit is that it represents half the height of the 50th 
percentile male Hybrid III head.
---------------------------------------------------------------------------

2. Comments
    There was general support for the use of a linear impactor as 
opposed to some other impacting device and performance metric based on 
the displacement of that impactor.\71\ However, many commenters had 
opinions about the 100 mm performance limit and how the displacement 
should be measured. In general, the net effect of the vehicle 
manufacturers' requests was to increase the allowable displacement, 
while that of the glazing manufacturers and consumer groups was to 
reduce it.
---------------------------------------------------------------------------

    \71\ This is aside from commenters who want the agency to use a 
completely different test method, i.e., full vehicle dynamic 
rollover.
---------------------------------------------------------------------------

    Both the Alliance and AIAM suggested that the final rule measure 
displacement from an initial reference point other than the point of 
contact of the headform with the glazing. Both requested that a method 
similar to that used by GM be used. This measurement method defines a 
line tangent to the side of the vehicle at the window opening. (We note 
that although the Alliance calls the longitudinal plane that passes 
through this line the excursion plane, see Figure 5, extracted from the 
Alliance comments, there would likely be a unique excursion plane at 
every target location due to the curvature of the vehicle sides.)
    Under the Alliance method, the headform contact with the excursion 
plane for that target location defines the point of zero displacement. 
The Alliance explained this zero plane by stating that ``the risk of 
injury is more closely tied to the amount of occupant excursion from 
the outside of the vehicle's structure as opposed to the side glass.'' 
The AIAM stated that its procedure ``takes into account the shape of 
the vehicle body near the side windows and the contribution the body 
makes in providing additional space before the occupant contacts the 
ground.''
    The Alliance and AIAM methods differ after the zero excursion plane 
is determined. For the Alliance, the maximum excursion plane is defined 
by translating the excursion plane 150 mm laterally. The point of 
contact of the headform with the maximum excursion plane provides the 
limit on displacement. The Alliance justifies its request for a 150 mm 
excursion limit by stating ``that the impactor mass and impact energy 
are based on the 50th male.'' Therefore, it believes that ``a 150 mm 
excursion limit based on the diameter of a 50th percentile male head 
(Hybrid III--153 mm, WorldSID = 159 mm, Featureless = 177 mm) is more 
appropriate.'' The Alliance and Volvo commented that excursion should 
not be based on the size of a child's head and impact energy of an 
adult male. For the AIAM, the maximum excursion plane is defined by 
translating the

[[Page 3243]]

excursion plane by 100 mm along a line normal to the excursion plane, 
rather than 150 mm laterally.
[GRAPHIC] [TIFF OMITTED] TR19JA11.006

    Honda agreed with the 100 mm displacement limit in the NPRM because 
it believes it to be appropriate to account for the size of a child's 
head. It also agreed that the horizontal measurement of the impactor 
displacement was appropriate because of its ``feasibility and 
measurement accuracy.'' However, Honda concluded ``that the proposed 
procedure * * * doesn't accurately simulate the degree of ejection 
toward the outside of the vehicle.''
    Honda suggested that the measured displacement should begin at the 
same location as proposed in the NPRM, i.e., the point of contact of 
the headform with the inside surface of the glazing. However, Honda 
suggested drawing a line normal to the glazing at the target 
center.\72\ The window cross-section in the lateral plane is then 
projected 100 mm along the normal line. The headform is then translated 
laterally and horizontally until it contacts the projected window 
cross-section, which provides the limit of displacement.
---------------------------------------------------------------------------

    \72\ Honda's diagram in its comment shows a line projected from 
the point of contact with the window, rather than the target center. 
(The target or target outline was defined in the NPRM as the x-z 
plane projection of the ejection headform face. The center of the 
target outline would be the target center.) We assume the graphic 
represents the intent of Honda's comment. The line emanates from the 
point of glazing contact with the headform. Honda also stated that 
the line projected from the point of contact is normal 
(perpendicular) to the window. However, most side windows curve out 
of the longitudinal vehicle plane and any normal to the window would 
not be contained in a lateral plane. Thus, we have assumed that only 
the component of the normal line in the lateral plane is of 
interest, i.e., only the line normal to the lateral cross-section of 
the glazing.
---------------------------------------------------------------------------

    TRW agreed with the measurement method and excursion limit of 100 
mm, with one caveat. The commenter noted that ``during an impact test, 
there can be considerable deflection of the door/window frame, door 
structure, door hinges, etc.'' TRW stated that ``[s]ince the objective 
of the Standard is to limit headform displacement to no more than 100mm 
beyond the zero displacement plane, movement of the plane due to the 
door system deflection should be considered during the test.''
    IIHS suggested that the 100 mm displacement limit might be 
unnecessarily small. It stated that ``[s]electing this value based on 
its use in other safety standards with very different test conditions 
or in building codes for guardrails on balconies and stairs may be 
unreasonable.'' IIHS indicated that the 12 vehicles tested by NHTSA, as 
reported in the NPRM, would have failed to comply with the 100 mm 
displacement limit, yet ``the crash performance of these vehicles has 
not been assessed to demonstrate a need for improved ejection 
mitigation systems.'' IIHS also stated that the potential negative 
effects of requiring air bags to be stiffer to meet a 100 mm 
displacement requirement are unknown.
    In general, glazing suppliers recommended that the final rule use 
the passage of a 40 mm sphere to assess any gaps in the 
countermeasures. They suggested we use industry standards published by 
the Society of Automotive Engineers (SAE), SAE J2568, ``Intrusion 
Resistance of Safety Glazing Systems for Road Vehicles,'' or by the 
British Standards Institution (BSI), BSI AU 209, ``Vehicle Security,'' 
which provide glazing intrusion resistance requirements from external 
impact (as opposed to ejection mitigation). These industry standards 
specify that after testing there must not be separation within the 
glazing or between the glazing and vehicle body that would allow for 
passage of a 40 mm diameter sphere. The EPGAA stated that it is 
necessary to ``specify a maximum opening after impact in addition to an 
excursion limit to adequately address the remaining gaps leading to 
partial ejections.'' It goes on to state that ``NHTSA currently 
requires gap quantification limitation for windshields to resist 
occupant ejection in FMVSS [No.] 205, which mandates compliance with 
ANSI/SAE Z26.1 where glazing tears are measured and limited after 
impact.'' In contrast, Batzer and Ziejewski indicated that the 100 mm 
displacement appeared appropriate.

[[Page 3244]]

    Advocates suggested that the proposed displacement limit be reduced 
by 50 percent, to 50 mm. It stated that a 100 mm displacement limit 
``allows enough excursion to permit serious injuries and deaths outside 
the vehicles. The 4-inch limit also devalues the major contribution 
that advanced glazing can make to reduce the chances of occupant 
ejections, including excessive occupant excursion outside side 
windows.''
3. Agency Response
    NHTSA does not agree with the requested changes to the displacement 
measurement method from the vehicle manufacturers and TRW, which would 
all effectively increase the allowable displacement. We also disagree 
with the additional post-impact gap measurement suggested by the 
glazing suppliers. We also do not concur with the requests of some 
commenters to increase the displacement limit, and of some to reduce 
it. We believe that the 100 mm limit strikes the appropriate balance 
between stringency and practicability. We address the issue of 
stringency and practicability further in a later section on the time 
delay of the impacts and impactor velocity.
Suggested Methods Would Increase the Displacement Limit
    We do not believe that the methods suggested by the commenters 
provide a better method of measuring the performance of the ejection 
countermeasure. No data was presented to support why the suggested 
methods are preferable to the method proposed in the NPRM.
    In the NPRM and the technical analysis supporting the NPRM, the 
agency estimated that the GM measurement method allowed about 6 percent 
more displacement than the proposed method of measurement. Below we 
analyze the displacement measurement methods requested by the 
commenters and compare the associated performance limits of the 
respective methods to the performance limit discussed in the NPRM. For 
this comparison, we used a graphical representation of a two 
dimensional lateral cross-section of the headform contact with the side 
window. For convenience, we used an approximation of the headform 
profile rather than the exact cubic equation prescribed in the NPRM. 
The vehicle cross-section included the window as well as the structure 
in its vicinity.
    Figure 6 shows how the 100 mm displacement put forward in the NPRM 
is measured from the contact point of the headform at the A2 target 
point with the side window glazing. In this example, the lateral cross-
section A-A of the glazing is represented by a 15 degree arc segment 
having a 201 cm radius, with the base of the arc oriented approximately 
7 degrees from the vertical.
[GRAPHIC] [TIFF OMITTED] TR19JA11.007

    Figure 7 shows the displacement measurement methods that Honda and 
the Alliance recommended in their comments. In the Honda method, the 
lateral cross-section of the glazing is projected 100 mm along the 
normal line at the point of contact of the headform. Using the Honda 
method, the headform's horizontal displacement at the A2 target is 101 
mm from the NPRM zero displacement point. The Alliance-recommended 
measurement method defines a line tangent to the side of the vehicle at 
the window opening as the zero excursion plane. The maximum excursion 
plane is defined by translating the excursion plane 150 mm laterally. 
Using the Alliance method, the headform's horizontal displacement at 
the A2 target is 161 mm from the NPRM zero displacement point. This 161 
mm value is the sum of the 11 mm distance between the contact point 
with the window and the excursion plane ([Delta] excursion plane) and 
the 150 mm

[[Page 3245]]

additional displacement to the maximum excursion plane.\73\
---------------------------------------------------------------------------

    \73\ In doing this analysis, we have assumed that the point of 
contact with the glazing is along the centerline of the headform. If 
we did not, the difference between the NPRM method and the Alliance 
and AIAM proposals would be even greater.
[GRAPHIC] [TIFF OMITTED] TR19JA11.008

    AIAM also recommended a displacement measurement method similar to 
the Alliance method in that an excursion plane is located tangent to 
the side of the vehicle window opening. However, the maximum excursion 
plane is defined by translating the excursion plane by 100 mm along a 
line normal to the excursion plane rather than 150 mm laterally.
    Because of the similarities between the Alliance and AIAM methods, 
once the angle of the excursion plane is known, a simple mathematical 
relationship can be used to calculate the AIAM displacement limit with 
respect to the NPRM measurement method from the limit determined by the 
Alliance method. From Figure 7 we see that the excursion angle is 17 
degrees from the vertical. Thus, the horizontal translation of the AIAM 
maximum excursion plane is 105 mm = 100/cos(17 deg.). The total AIAM 
displacement allowance from the headform when in contact with the 
window plane is the sum of the [Delta] Excursion Plane (11 mm) plus the 
horizontal translation of the excursion plane (105 mm), resulting in a 
value of 116 mm at target A2.
    The displacement measurement methods suggested by Honda, the 
Alliance, and AIAM are all more sensitive to the particular target 
location, the curvature and angle of the window, as well as the profile 
of the vehicle structure around the window opening, than the NPRM 
method. Figure 8 shows the NPRM displacement measurement at target A4 
for a side window having twice the base angle (13 degrees) as the 
previous example. The window curvature remains the same. Figure 9 shows 
a graphical determination of displacement measurements for Honda (109 
mm) and the Alliance (156 mm) at A4. Using the mathematical 
transformation described above, we calculate the AIAM value (114 mm).

[[Page 3246]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.009

[GRAPHIC] [TIFF OMITTED] TR19JA11.010

    The same exercise was performed for target position A2 with a 13 
degree window and for target position A4 with a 7 degree window. Figure 
10 shows the displacement limits calculated for the three commenters' 
methods at target positions A2 and A4 with a 7 and 13 degree window, 
subtracted from the 100 mm limit in the NPRM. The Honda

[[Page 3247]]

method provides the smallest differential with the NPRM method (1 to 9 
mm), the Alliance method provides the largest (55 to 61 mm). Again, the 
results will vary for other target locations and window/vehicle 
geometries. However, there does not appear to be a situation where any 
of the suggested methods will result in a lateral displacement limit of 
less than 100 mm. That is, each suggested method would reduce the 
stringency of the test by permitting the openings to be greater than 
100 mm. As explained in the section below, this we cannot accept.
[GRAPHIC] [TIFF OMITTED] TR19JA11.011

    TRW requested allowing the zero reference plane to move with the 
door frame. We are declining this request. It is unclear to us why 
allowing the reference plane to move in the manner suggested is 
preferable from a safety standpoint than simply maintaining the 
position of the zero plane with respect to ground. The latter (NPRM) 
method is preferable because the door frame provides a reaction surface 
for the curtain air bags or advanced glazing. The door frame is part of 
the system designed to retain the occupant in the vehicle. If the zero 
reference plane is tied to movement of the door frame, a weak door 
frame could render the displacement limit meaningless. For example, 
under the TRW method, a vehicle that allows an impactor displacement of 
150 mm with 50 mm of door deflection would be considered compliant, as 
would a vehicle that allows an impactor displacement of 100 mm with 0 
mm of door deflection.
    Further, the TRW suggestion would also add a significant amount of 
complexity to the testing. There would need to be a determination as to 
the sufficient number of measurement locations on the door and how the 
agency would assess movement of the door frame. The suggestion requires 
further study to properly integrate it into the test procedure and we 
are unable to conclude that use of our resources to pursue the matter 
would be warranted.
Unrealistic Assumptions
    The methods of measurement suggested by the Alliance, AIAM and 
Honda are dependent on assumptions about the performance of the vehicle 
that may not be realistic. The Alliance and AIAM methods are very 
similar. Both these methods use a tangent to the side of the vehicle 
(zero excursion plane), translated some distance, as the limit of 
displacement (maximum excursion plane). The assumption apparently is 
that occupant excursions within this zone will be protected.
    We do not agree with this assumption. For example, if vehicle A's 
exterior skin protrudes farther outboard than vehicle B's, but A's 
protruding exterior skin consists of only sheet metal or plastic or

[[Page 3248]]

some like material that provides little if any crush resistance, we do 
not agree that A's maximum excursion plane should be farther outboard 
at the bottom of the window opening than B's. More displacement of the 
headform would be permitted for vehicle A even though in a real-world 
crash, A's exterior skin could be easily leveled. Since the 
countermeasure of A would be permitted to allow more headform 
displacement outside of the window plane than that of B, the suggested 
approach would provide A's occupants less minimal protection in a 
rollover or side impact than the NPRM approach.
    Relatedly, when the excursion plane is derived from the undeformed 
vehicle structure, if the roof structure has significant lateral 
deformation after impact, the original excursion plane may have very 
little relevance to occupant protection.
    With Honda's method, it seems there is an underlying assumption 
that if ground contact occurs with the vehicle rotated 90 degrees, the 
door structure will be the initial point of contact, so that targets 
near the upper part of the glazing on a vehicle with a highly inclined/
curved glazing could be permitted to displace farther than targets at 
the center. Under this method, the greater the inclination and/or 
curvature of the glazing in the lateral plane, the more displacement is 
allowed compared to the NPRM's approach (9 percent more at A4 with the 
13 degree glazing). A vehicle with a more highly inclined glazing would 
be allowed more headform displacement at the top and bottom of the 
window compared to the NPRM. Given the unpredictable nature of rollover 
crashes, we cannot agree with this assumption. A vehicle might be 
rotated greater than 90 degrees during ground contact, resulting in 
initial contact near the upper glazing. Thus, to allow more 
displacement at the top of the glazing relative to the initial glazing 
position does not seem warranted.
Adding Complexity
    The measurement methods suggested by the Alliance, AIAM, Honda and 
TRW are more complicated to implement than the method proposed by the 
agency. The NPRM's method of measuring displacement is actually very 
simple and straightforward. The point of zero displacement is simply 
the contact point with the side window glazing. From there, it is only 
necessary to keep track of how far the linear impactor translates along 
its axis of motion. No digitization or CAD techniques are required. To 
find the zero displacement point for the Alliance or AIAM method, one 
must hold a relatively thin straight edge in a lateral vehicle plane, 
aligned with the target center, against the outside of the vehicle. 
Headform contact with this straight edge defines the point of zero 
displacement. This can be done by digitizing the exterior of the 
vehicle. However, it is somewhat more onerous than the NPRM method. The 
Honda method is just as simple as the NPRM method in finding the point 
of zero displacement, but after that, we believe the method would 
require a digitization of the glazing. This digitized glazing would 
then need to be manipulated in a CAD program to determine the allowable 
displacement. The complexity of the TRW method has been discussed 
above.
Increasing the Displacement Limit
    The agency is declining the requests to increase the allowable 
displacement limit.
    The Alliance and Volvo believe the limit should not be based on the 
size of a child's head and the impact energy of an adult male. (In 
contrast, Honda commented that basing the requirement on the size of a 
child's head was appropriate.) We disagree with the Alliance and Volvo 
on this point. It is reasonable for the agency to adopt a displacement 
limit based on the anthropometry of a child since the standard is 
intended to mitigate ejection of all sizes of occupants, not just the 
mid-size male. It is possible for a child occupant to interact with an 
ejection mitigation countermeasure with relatively high impact energy 
if a large portion of their mass is considered. For example, an average 
5-year-old child weighs about 18 kg (the same mass as the linear 
impactor). Due to the size of this child relative to a window opening, 
it would be much easier for their entire body mass to interact with the 
window opening than it would be for an adult. Also, the ejection 
mitigation countermeasure could be double-loaded by more than one 
occupant simultaneously during the rollover event, e.g., a child in the 
rear seat and the driver in the front seat or two unbelted occupants in 
the same row. The 100 mm limit reduces the likelihood that openings 
will form during the rollover that are large enough to pass the head or 
other body part of a child or an adult.
    The principle underlying the 100 mm displacement limit is to ensure 
that the entire window opening is covered, and covered by a 
countermeasure resilient enough to withstand the forces that could be 
imposed on it in a rollover without forming gaps or openings.\74\ We 
chose a 100 mm displacement limit as a reasonable and objective measure 
of acceptable performance, taking into account the practicability of 
meeting the displacement limit, safety need, and the SAFETEA-LU goal of 
a standard that reduces complete and partial ejections of vehicle 
occupants. We adopt a displacement limit that will ensure that the 
countermeasure covering the entire window is wide enough and strong 
enough to mitigate ejection of a child's head, limb or body, or those 
of an adult, in the chaotic and unpredictable phases of a rollover.
---------------------------------------------------------------------------

    \74\ 74 FR 63193.
---------------------------------------------------------------------------

    IIHS believed that the NPRM selection of 100 mm displacement, 
partially based on other standards (FMVSS Nos. 206 and 217) and 
building codes, may be unreasonable. It noted that the vehicle testing 
reported in the NPRM did not show any that passed all the target points 
at 100 mm of displacement even though the field performance of these 
vehicles may be acceptable. IIHS stated that if the displacement 
requirement is too stringent it will lead manufacturers to make their 
air bags too stiff, with unknown consequences from this increased 
stiffness.
    We understand the merits of having extensive field data that 
correlates the performance in the proposed test against ejection 
mitigation in the field. At the time of the NPRM development, there 
were very few rollover curtain-equipped vehicles in the available field 
data and the vehicles then-tested by the agency were not designed to 
have full window coverage as the NPRM requirements contemplated. Now 
more field data is available to us, and we have tested many more 
vehicles some of which have been designed to have extensive window 
opening coverage. However, the data set is still insufficient to 
correlate various displacement values and field performance.
    Nonetheless, we do not accept IIHS's argument that the 100 mm value 
may be unreasonable because the value is used in FMVSS No. 206 and 217 
and in the architectural code. These other standards and the 
architectural code referenced by the agency have basically the same 
purpose: retaining occupants, including children, in a vehicle in a 
crash event, or retaining children behind a barrier (railing). These 
precedents are supportive of the selected value. They were developed 
taking into consideration the size of children's heads and limbs and 
the ease or difficulty with which the parts can fit through openings. 
If the window opening countermeasure can limit the

[[Page 3249]]

opening to 100 mm when impacted by the headform at the prescribed 
velocities, the countermeasure is more likely to be able to restrict 
the opening as needed when impacted by a lower mass at the same or 
higher velocity, or the same or larger mass at a lower velocity.
Requests to Decrease Displacement Limit
    Advocates suggested that the proposed displacement limit be reduced 
by 50 percent to 50 mm. It believed that such a stringent requirement 
will ``ensure dramatic reductions in occupant ejection, including 
partial ejection * * *.'' It stated further that the proposed 100 mm 
value ``devalues the major contribution that advanced glazing can 
make'' and that more lives would be saved by ``a standard that 
effectively would encourage the use of advanced glazing in combination 
with air curtains * * *.'' \75\ The suggestion to reduce the 
displacement limit was made by other commenters as well, including 
glazing manufacturers.
---------------------------------------------------------------------------

    \75\ NHTSA-2009-0183-0022, p. 3.
---------------------------------------------------------------------------

    NHTSA does not believe that the level of stringency requested by 
Advocates and others is warranted. We believe that the 100 mm limit 
will be highly effective in the reduction of both complete and partial 
ejections. Certainly, ejections will continue in situations where the 
severity of the crash and resulting occupant energy will overwhelm the 
capacity of the countermeasure. However, the 100 mm limit strikes the 
appropriate balance between stringency and practicability.
    There is no available data that can correlate various displacement 
values with field performance at this time. We cannot conclude that 
reducing the displacement limit by 50 percent will reduce ejection or 
side impact fatalities and injuries by a corresponding amount. The 
commenters did not provide data on this issue. On the other hand, we 
can estimate possible costs of indirectly requiring advanced glazing to 
be installed at side windows to meet a 50 mm displacement limit. In the 
FRIA, we estimated that the incremental difference in costs for going 
from tempered glass to laminated advanced glazing for a standard size 
side window in the first or row is $15. Thus, for a two row vehicle the 
total incremental cost would be $60. In addition, we believe that any 
costs associated with advanced glazing must be combined with the 
curtain bag incremental cost since a system with movable advanced 
glazing alone would not be able to perform to the level required for 
this standard. In comparison, the agency has determined that 
incremental cost of meeting the final rule with only curtain air bags 
will be $31 dollars per vehicle. The cost per equivalent fatality of a 
system comprised of a partial curtain in combination with laminated 
glazing was twice that of a system utilizing only a curtain.
Requests To Add Another Requirement
    Many glazing manufacturers were in favor of applying an additional 
post-impact requirement in which a 40 mm sphere is used to determine 
the size of any remaining gaps. According to the commenters, this 
requirement would be intended to eliminate gaps that can exacerbate 
partial ejections. It is our interpretation of the comments that this 
test is to be applied to all vehicles, i.e., those using a combination 
of advanced glazing and side curtain air bags to meet the standard, and 
those using only side curtain air bags.
    We do not agree with this suggestion. First, the requirement is not 
appropriate for vehicles with only side curtain air bags, given that 
there is a time dependence associated with a curtain's ejection 
mitigation performance. Once deployed, the pressure in the air bag 
continuously decreases. The 16 km/h test is done at 6 seconds to assure 
that the pressure does not decrease too quickly. It does not seem that 
the 40 mm gap test could be done after the 6-second impact, in any 
timeframe which is related to rollover and side impact ejections. 
Second, there is no shown safety need for the requirement. We cannot 
show that ejections that would not be prevented by the primary 100-mm 
displacement requirement would be prevented by a secondary 40-mm 
requirement. Third, it would seem that the 40-mm requirement would 
indirectly require installation of advanced glazing. As discussed 
above, the costs associated with advanced glazing installations at the 
side windows covered by this standard are substantial in comparison to 
a system only utilizing rollover curtains. For these reasons, the 
agency does not accept this suggestion.

c. Times and Speed at Which the Headform Impacts the Countermeasure

    We have determined that there is a need for a relatively high speed 
impact shortly after countermeasure deployment and a lower speed impact 
late in the deployment. The two time delays correspond to relatively 
early and late times in a rollover event.\76\ The first impact is at 20 
km/h, and at 1.5 seconds after countermeasure deployment (1.5 second 
time delay). (The 20 km/h speed is reduced from the NPRM's proposal of 
24 km/h; the rationale for which is discussed later in this preamble.) 
The second is a 16 km/h impact initiated 6 seconds after deployment.
---------------------------------------------------------------------------

    \76\ Each impact takes place on a test specimen (e.g., a 
curtain) that was not previously subject to an impact test.
---------------------------------------------------------------------------

1. Time Delay (Ejections Can Occur Both Early and Late in the Rollover 
Event)
i. NPRM
    Two impacts were proposed because ejections can occur both early 
and late in the rollover event. In the advanced glazing program, NHTSA 
performed a series of simulations to recreate three NASS-investigated 
rollover crashes with ejected occupants.\77\ The vehicles were a MY 
1991 Toyota pickup, a MY 1986 Toyota Corolla and a MY 1985 Volkswagen 
Jetta.\78\ Vehicle handling simulation software \79\ reconstructed the 
vehicle motion up to the point where the vehicle started to roll. The 
linear and angular velocity at the end of the vehicle handling 
simulation was then used as input to a MADYMO \80\ lumped parameter 
model of the vehicle to compute its complete rollover motion. The 
motion of the vehicle obtained from the MADYMO vehicle model was used 
as input to a MADYMO occupant simulation. Head and torso velocities of 
a Hybrid III 50th percentile male driver dummy were calculated for the 
three rollover simulations.
---------------------------------------------------------------------------

    \77\ ``Ejection Mitigation Using Advanced Glazings: A Status 
Report,'' November 1995, Docket NHTSA-1996-1782-3. Pg. 6-1.
    \78\ The circumstances of the Toyota pickup rollover was that 
the vehicle was traveling at 96 km/h and went into a sharp turn and 
yaw, which resulted in a rollover. In the case of the Corolla, it 
was also traveling 96 km/h on a gravel road. The vehicle went out of 
control and left the road, resulting in roll initiation. The 
Volkswagen was traveling at 88 km/h when the driver fell asleep and 
the vehicle left the road. It struck a rock embankment and rolled 
over.
    \79\ VDANL software user's manual V2.34, STI, 1992.
    \80\ MADYMO user's manual V5.1, TNO, 1994.
---------------------------------------------------------------------------

    Table 30 shows the simulation resultant head velocity through the 
open window at the time of ejection. As indicated in the table, for the 
unrestrained simulations, the occupant of the pickup was completely 
ejected early (1st quarter-turn for Toyota truck) while the occupants 
of the other vehicles were ejected late (last quarter-turn for Corolla 
and Jetta) in the rollover event.

[[Page 3250]]



    Table 30--Head and Torso Velocities of a Hybrid III 50th Percentile Male Dummy in 3 Rollover Simulations
----------------------------------------------------------------------------------------------------------------
                                            \1/4\ Turns                      Head to      Head to      Torso to
           Vehicle             Vehicle \1/  at complete    Restraint use   opening (km/ glazing (km/ glazing (km/
                                 4\ turns     ejection                          h)           h)           h)
----------------------------------------------------------------------------------------------------------------
Toyota PU....................           12  ...........  Yes.............           20           20            7
                               ...........            1  No..............            5           20           16
Toyota Corolla (86)..........            6  ...........  Yes.............           15           15           11
                               ...........            6  No..............           13           13           10
Volkswagen Jetta (85)........            4  ...........  Yes.............           14           14           10
                               ...........            4  No..............           22           18           16
----------------------------------------------------------------------------------------------------------------

    The agency also considered other data indicating that very early 
occupant contact with the window area is possible in rollover crashes. 
Table 31 gives information on 30 rollover tests the agency performed 
from the mid-1980s to the mid-1990s. This data set included Rollover 
Test Device (RTD) tests, 208 Dolly tests, guardrail tests and pole 
tests.\81\ A film analysis of dummy motion within the vehicles showed 
that, excluding a pole impact test, occupant contact with the window 
opening and surrounding area first occurred between 0.16 and 0.88 
seconds after the event began.\82\ We note, however, that the majority 
of these dummies were belted, which means they would be most 
representative of potential partial ejections. In addition, where the 
time of window breaking is known, most of these first contacts occurred 
prior to the window breaking due to roof contact.
---------------------------------------------------------------------------

    \81\ These tests were done as part of a research program 
evaluating full scale dynamic rollover test methods, occupant 
kinematics, and vehicle responses. The RTD tests were similar to the 
208 Dolly test except that the vehicle was initially 4 feet off of 
the ground instead of 9 inches, and hydraulic cylinders were used to 
push the vehicle from the cart and produce an initial roll rate. The 
guardrail tests used a guardrail as a ramp to initiate a vehicle 
roll. The pole tests rolled a vehicle into a pole. Twenty-four of 
these were RTD tests on passenger cars, pickups and vans (the RTD 
testing was not geared towards ejection testing since all of the 
test dummies were belted), and four were 208 Dolly tests on Ford 
Explorers. The test films are available at the National Crash 
Analysis Center (NCAC) at George Washington University 
(www.ncac.gwu.edu).
    \82\ ``Evaluation of Full Vehicle Rollover Films,'' 2008, Docket 
NHTSA-2006-26467.

                                               Table 31--NHTSA Full Vehicle Rollover Testing Film Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    Tilt                Vehicle
  Test <greek-i>            Make                  Model             MY           Test type         angle    Roll axis  speed (km/    \1/4\    Total time
                                                                                                   (deg.)     (deg.)       h)        Turns       (sec)
--------------------------------------------------------------------------------------------------------------------------------------------------------
878...............  Honda...............  Accord..............         84  RTD.................         41         45       33.8         2          1.29
888...............  Chevrolet...........  Celebrity...........         82  RTD.................         41         45       37.0         4          3.58
920...............  Dodge...............  Omni................         79  RTD.................         41         45       37.0         2          0.96
939...............  Mercury.............  Zephyr..............         82  RTD.................         41         60       37.0         2          2.08
1255..............  Ford................  Bronco..............         88  RTD.................         30         45       37.0         2          1.17
1266..............  Dodge...............  Caravan.............         88  RTD.................         30         45       48.3         1          0.50
1267..............  Chevrolet...........  Pickup..............         88  RTD.................         30         45       48.3         4          2.58
1274..............  Nissan..............  Pickup..............         88  RTD.................         30         45       48.3         6          3.76
1289..............  Nissan..............  Pickup..............         89  RTD.................         30         45       48.3         2          0.83
1391..............  Dodge...............  Caravan.............         89  RTD.................         30         45       48.3         8          5.08
1392..............  Ford................  Bronco..............         89  RTD.................         30          0       48.3         8          3.60
1393..............  Nissan..............  Pickup..............         89  RTD.................         30          0       48.3         4          2.35
1394..............  Nissan..............  Pickup..............         89  RTD.................         30          0       48.3         4          1.33
1395..............  Pontiac.............  Grand Am............         89  RTD.................         30          0       48.3         2          1.54
1471..............  Dodge...............  Colt................         89  RTD.................         30         90       48.3         2          0.99
1520..............  Ford................  Ranger..............         88  RTD.................         30          0       48.3         2          0.75
1521..............  Dodge...............  Ram.................         88  RTD.................         30          0       48.3         4          1.42
1530..............  Dodge...............  Caravan.............         88  Guardrail...........         NA         NA       96.6         1        N/A
1531..............  Nissan..............  Pickup..............         88  Guardrail...........         NA         NA       96.6         4        N/A
1546..............  Plymouth............  Reliant.............         81  RTD.................         41         45       33.8         6          3.00
1851..............  Volvo...............  240.................         91  RTD.................         30          0       48.3         6          2.50
1852..............  Volvo...............  740.................         91  RTD.................         30          0       48.3         8          3.00
1925..............  Nissan..............  Pickup..............         90  RTD.................         30          0       48.3         8          3.04
1929..............  Nissan..............  Pickup..............         90  RTD.................         30          0       48.3         6          2.25
2141..............  Nissan..............  Pickup..............         90  RTD.................         30          0       48.3         8          4.25
2270..............  Nissan..............  Pickup..............         89  RTD.................         30          0       48.3         8          3.50
2514..............  Ford................  Explorer............         94  208.................         23          0       48.3        11          5.50
2553..............  Ford................  Explorer............         93  208.................         23          0       48.3        10        N/A
3012..............  Ford................  Explorer............         94  208.................         23          0       48.3        11        N/A
3635..............  Ford................  Explorer............         94  208.................         23          0       48.3        12          5.17
--------------------------------------------------------------------------------------------------------------------------------------------------------
Analysis of 5+ \1/4\ turn Tests:
    Average..........................................................................................................       47.2         8.3        3.7
    Maximum..........................................................................................................       96.6        12          5.5
    Average +2 standard deviations...................................................................................       55.2        12.3        5.8
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 3251]]

    The agency proposed that the ejection mitigation countermeasure be 
first tested at 1.5 seconds after deployment of the ejection 
countermeasure. As indicated earlier in this preamble, slightly less 
than half of the complete ejection fatalities occur when the vehicle 
rolls up to 5 quarter-turns.\83\ As shown in Table 30, restricting the 
analysis to the tests with 5+ quarter-turns, the average amount of time 
to complete 1 full vehicle revolution (4 quarter-turns) was 1.62 
seconds with a standard deviation of 0.31 seconds. Thus, the 1.5 second 
represented a period of time in which one full vehicle revolution 
occurs in a high energy rollover event. (We also noted that at 1.5 
seconds into the rollover, roof contact would likely have occurred, 
leading to window breaking. Thus, as discussed later in this preamble, 
we proposed and adopt a requirement that if advanced glazing is 
present, it is pre-broken prior to this test.)
---------------------------------------------------------------------------

    \83\ The 50 percent point in the cumulative distribution occurs 
between 5 and 6 quarter turns.
---------------------------------------------------------------------------

    Additional rationale came from data obtained from the advanced 
glazing program (see Table 32, infra).\84\ In that program, NHTSA 
tested vehicles on the DRF with 5th percentile adult female and 50th 
percentile adult male test dummies (near and far side).\85\ Analysis of 
dummy head impacts with the glazing in the window opening showed that 
for the 5th percentile female far side occupant, the time to glazing 
impact after the DRF began rotating was between 1.3 and 1.8 seconds, 
which was in the range of two to three quarter-turns of rotation. 
Additional analysis of the DRF testing is presented later in this 
preamble.
---------------------------------------------------------------------------

    \84\ Duffy, S., ``Test Procedure for Evaluating Ejection 
Mitigation Systems,'' 2002 SAE Government/Industry Meeting.
    \85\ For this set of tests, the ``near'' and ``far'' side dummy 
configurations represent the trailing occupants in a rollover. The 
near side occupant simply means that they were initially placed near 
the door at what would have been behind the steering wheel, if the 
steering wheel were present. The far side occupant was moved to an 
initial position which was towards the centerline of the vehicle. 
This position could be thought of as a position that a trailing 
occupant could slide to as a yawed vehicle decelerates in the 
lateral direction, prior to rollover initiation.

                      Table 32--DRF Testing Results
------------------------------------------------------------------------
                                                      Far side  Far side
                                                       impact    impact
                        Dummy                           time    [frac14]
                                                       (sec.)     turns
------------------------------------------------------------------------
5th Female and 50th Male............................   1.3-1.8       2-3
------------------------------------------------------------------------

    The agency also proposed that ejection mitigation countermeasures 
be tested towards the end of a rollover. Data indicated that occupants 
could impact the window opening as late as 6 seconds after initiation 
of a rollover involving 5+ quarter-turns. The last three rows of Table 
31, supra, show the average and maximum number of quarter-turns and the 
total time of rollovers involving 5+ quarter-turns.\86\ This set of 
data contains 14 such tests. The average and maximum number of quarter-
turns are 8.3 and 12, respectively. The average plus two standard 
deviations is 12.3 quarter-turns. Thus, 12.3 quarter-turns is the 98th 
percentile value for this subset of data. The average and maximum times 
to complete the entire rollover event were 3.7 and 5.5 seconds, 
respectively. The 98th percentile value was 5.8 seconds, which is not 
much different than the maximum time for the entire data set, which was 
5.5 seconds.
---------------------------------------------------------------------------

    \86\ As mentioned earlier, just less than half of the complete 
ejection fatalities occur when the vehicle rolls up to 5 quarter-
turns.
---------------------------------------------------------------------------

    Other information we considered also supported a 6-second impact 
time. The 1988-2005 NASS-CDS showed that rollovers with eleven quarter-
turns account for about 90 percent of rollovers with fatal complete 
ejection, i.e., 10 percent of rollovers with fatal complete ejections 
have more than eleven quarter-turns. The data set provided in Table 31, 
supra, showed the vehicle that rolled eleven quarter-turns had the 
longest roll time (5.5 seconds) in the 208 Dolly test.\87\
---------------------------------------------------------------------------

    \87\ The agency explained in the NPRM that this does not mean 
that rollover crashes with eleven quarter-turns only take 5-6 
seconds. Five to six seconds may be a conservative assumption for 
this many quarter-turns for some types of rollover events. The 208 
Dolly test has a very quick rollover initiation (high initial roll 
rate); the beginning of the rollover is well defined. This test only 
represents about 1% of field crashes. Viano, supra. The vast 
majority of field cases are soil and curb trip crashes. Soil trips 
involve high lateral deceleration in combination with low initial 
roll rates. Ideally, the curtain air bag should deploy in this early 
phase when the roll rate is still low but the occupant is moving 
towards the window due to the lateral deceleration. The rollover has 
a slow initiation, leading to a need for longer inflation. 
Therefore, some rollover crashes with less than eleven quarter-turns 
may have 5-6 second roll times.
---------------------------------------------------------------------------

    A factor that the agency considered in determining the time delay 
for the lower speed impact was the practicability of curtains staying 
inflated for this length of time. Ford stated that its ``Safety 
Canopy'' system stays inflated for six seconds.\88\ GM reportedly 
stated that its side curtain air bags designed for rollover protection 
maintain 80 percent inflation pressure for 5 seconds.\89\ It appeared 
that a requirement that side curtain air bags must contain the headform 
when tested six seconds after deployment was realistic and attainable.
---------------------------------------------------------------------------

    \88\ http://media.ford.com/article_display.cfm?article_id=6447 
(Last accessed October 6, 2010.)
    \89\ ``Who Benefits From Side and Head Airbags?'' (http://www.edmunds.com/ownership/safety/articles/105563/article.html).
---------------------------------------------------------------------------

ii. Comments on Time Delay
    The Alliance and Honda suggested different time delays than that 
proposed by the NPRM. Both commenters referenced NASS CDS data of the 
distribution of rollovers by the number of quarter-turns. The 1997-2007 
data were presented in the PRIA. These data show that for all 
rollovers, not just those with ejections, the majority of the rollover 
population was at 1 to 2 quarter-turns. These commenters stated that 
since these data show that the cumulative percentage of rollovers is 90 
percent at 5 quarter-turns, and 96 percent at 7 quarter-turns, the time 
delay for the late impact should be greatly reduced. They correlated 
these 5 and 7 quarter-turn values with the agency's full vehicle 
rollover test data to arrive at their requested time delays of 3.4 
seconds (Alliance) and 3 seconds (Honda).
    Guardian requested that NHTSA conduct an analysis of what 
protection exists under conditions when an air bag does not deploy. The 
commenter seemed to be concerned that the 1.5 second impact test was 
not being performed early enough to address ejections in side impacts. 
It suggested that this may lead to air bag entrapment of partially 
ejected occupants and that advanced glazing can prevent this.
    Advocates was concerned about the test procedure impacting the 
ejection countermeasure at two discrete times. The commenter believed 
that the compliance test only takes a ``snapshot of air curtain and 
sensor performance at two brief intervals over the several seconds 
during which an air curtain is supposed to provide sustained inflation 
and prevent excursion beyond 4 inches. For example, 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.'' 
\90\ Advocates stated that a compliant system still may allow 
excursions beyond 100 mm at other points during the rollover, 
especially those longer than 6 seconds.
---------------------------------------------------------------------------

    \90\ NHTSA-2009-0183-0022, p. 12.
---------------------------------------------------------------------------

iii. Agency Response
    The agency declines to increase or decrease the time delay for the 
1.5 second and 6 second impacts. We also

[[Page 3252]]

have decided against adding a third impact test at a later time or 
performing any testing at time delays between 1.5 and 6 seconds or at a 
time representative of a side impact.
    In developing the time delays in the standard, NHTSA recognized 
that the majority of occupants exposed to rollover crashes are in 
vehicles that roll two quarter-turns or less. However, we recognized 
that the distribution of ejected occupants who are seriously injured 
(maximum abbreviated injury scale (MAIS) 3+) or killed is skewed 
towards rollovers with higher degrees of rotation. 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. We wanted to 
address the fatally and seriously injured populations.
    This information was illustrated in the NPRM by the Figure 11 
below. The updated target population for this final rule shows that the 
vast majority of the ejection fatalities (69 percent = 3,067/4,447) are 
complete ejections. This final rule is designed to mitigate ejections 
from rollover crashes that cause the most harm (those that result in 
complete ejection). By doing so, the countermeasures installed pursuant 
to this rule will reduce fatalities and injuries resulting from severe 
rollovers. Countermeasures installed to mitigate ejections in crashes 
with higher degrees of rotation will help occupants involved in those 
crashes as well as occupants exposed to rollovers of less severity. The 
inverse would not be true. 
[GRAPHIC] [TIFF OMITTED] TR19JA11.012

    The Alliance indicated that a rollover time representing the 
cumulative percentage of at least 90 to 96 percent of rollovers is 
appropriate. Using this range of values and applying it to rollovers 
resulting in fatal complete ejections, the resulting number of quarter-
turns is in the range of 10 to 12 quarter-turns for the 1997-2005 NASS 
CDS data and approximately 8 to 10 quarter-turns for the more recent 
2000-2009 NASS CDS data. The Alliance showed a regression line through 
the quarter-turns versus rollover times for the agency's full vehicle 
rollover test data (Table 11 in the NPRM). The commenter did not show 
the equation for the line. We derived the equation as y = 0.48x, where 
y = rollover time in seconds and x = number of quarter-turns. Using 
this equation, the range of 8 to 12 quarter-turns gives the result of 
3.8 to 5.8 seconds. Thus the upper end of this range is consistent with 
the time of the low speed impact proposed in the NPRM \91\ and adopted 
by this final rule. (As noted in the NPRM, the 6-second value may be a 
conservative assumption for the corresponding number of quarter-turns 
seen in FMVSS No. 208 Dolly testing. Some rollover crashes with less 
than eleven quarter-turns may have 5 to 6 second roll times.)
---------------------------------------------------------------------------

    \91\ 74 FR 63196.
---------------------------------------------------------------------------

    Based on the analysis above, the agency declines to reduce the time 
delay for the second impact to less than 6 seconds, as reducing the 
time delay would not be consistent with our stated goal of protecting a 
``far-reaching population of people in real world crashes.'' \92\
---------------------------------------------------------------------------

    \92\ 74 FR 63182.
---------------------------------------------------------------------------

    Guardian's request that NHTSA conduct an analysis of what 
protection exists under conditions when an air bag does not deploy 
appears to relate to a concern with the 1.5 second impact test not 
being performed early enough to address ejections in side impacts. In a 
side crash, the occupant will interact with the side of the vehicle 
within a few tenths of a second. In response to Guardian, our 
experience with vehicles with side curtains that deploy in rollovers is 
that manufacturers design them to deploy in side impacts as well. These 
side curtain must provide head and thorax protection in an oblique pole 
test, pursuant to FMVSS No. 214, and

[[Page 3253]]

must be designed to deploy and be in position in a matter of 
milliseconds. In recent testing of side impact air curtains to FMVSS 
No. 214 and New Car Assessment Program protocols, we have not found 
non-deployment of or entrapment by side impact curtain air bag 
entrapment to be a problem.
    Advocates requested that we add a third impact test with a delay 
time greater than 6 seconds. We decline to do so. In the NASS CDS 
database, combining MAIS 3+ injuries and fatalities results in only 
about 0.4 percent of ejected occupants are in rollovers with more than 
16 quarter-turns (see Figure 11). Using the linear regression from the 
208 Dolly testing (y = 0.48x) would result in a duration of 7.7 seconds 
at 16\1/4\-turns. Hence, there is a diminishing return in terms of the 
population of ejection rollovers covered by increasing the delay time 
for the impact test beyond 6 seconds. In addition, there will be costs 
to redesigning ejection mitigation systems to accommodate a third 
impact after 6 seconds, assuming the design is practicable; NHTSA 
cannot conclude the redesign will be cost-effective. With regard to 
Advocates' concern 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,'' we will not add a test to assess 
the countermeasure between 1.5 seconds and 6 seconds. We know of no 
ejection mitigation side curtain system that deflates and inflates 
itself midway through the test.
    Finally, we note that the regulatory text (S5.5(a)) has been 
clarified to indicate that the time delay applies to deployable 
countermeasures. For a daylight opening with a non-deployable 
countermeasure, e.g., fixed advanced glazing, there is no time 
dependence for the impact. The impactor can be propelled at any time.
2. NPRM on Speed at Which the Headform Impacts the Countermeasure
i. NPRM on Impact Speed
    As discussed above, our examination of field crash data has led to 
the conclusion that the impact test should have both a relatively high 
speed impact shortly after countermeasure deployment and a lower speed 
impact late in the deployment.
    The first test in the NPRM was at a 24 km/h impact velocity, 1.5 
seconds after countermeasure deployment. Field data show that crashes 
with 6 or more quarter-turns result in the majority of complete 
ejection fatalities. The 1.5 second time delay for the high speed 
impact corresponds well to the film analysis of vehicles that roll 5 or 
more quarter-turns in FMVSS No. 208 Dolly tests, for the amount of time 
it takes for one complete vehicle revolution. The NPRM reported that 
laboratory testing using the DRF showed that at around 1.5 seconds, a 
far side occupant could strike the window opening at nearly 30 km/
h.\93\ MADYMO computer simulation of three actual rollover crashes 
predicted that the maximum head speed into the window openings was 22 
km/h.\94\ Additional justification for the 24 km/h impact speed was 
found in side impact field data. NASS CDS shows that 35% of occupants 
completely ejected through the side windows in side impact are exposed 
to impacts with a [Delta]V greater than 24 km/h. It was also noted that 
FMVSS No. 201 also uses a 24 km/h impact speed for the upper interior 
tests.
---------------------------------------------------------------------------

    \93\ The agency has reassessed the video data of the DRF testing 
and calculated lower speeds than originally reported. This is 
covered in more detail later in this preamble.
    \94\ 74 FR at 63195
---------------------------------------------------------------------------

    The second test in the NPRM has a 6 second delay and a 16 km/h 
impact speed. Agency film analysis found that the maximum roll time was 
5.5 seconds for a vehicle that rolled 12 quarter-turns. A separate film 
analysis of a much smaller data set found a maximum head speed into the 
window opening of 17 km/h.\95\ Modeling of three rollover crashes 
showed a maximum torso impact speed of 16 km/h.
---------------------------------------------------------------------------

    \95\ 74 FR at 63197
---------------------------------------------------------------------------

ii. Comments on Impact Speed
    The Alliance, AIAM, and a number of vehicle manufacturers commented 
on the impact speed. All of these commenters requested that NHTSA 
reduce the impact speed of the higher speed 24 km/h test.\96\ The 
requested levels of reduction varied. The commenters did not agree 
there was a need for a 24 km/h speed, and expressed concern about the 
potential adverse effects and unintended consequences of not reducing 
the impact speed, particularly as they relate to side impact 
protection, protection of out-of-position occupants, and performance in 
NCAP testing.
---------------------------------------------------------------------------

    \96\ The 24 km/h test imparts about 400 joules of energy, while 
the 16 km/h test imparts approximately 178 J.
---------------------------------------------------------------------------

    The Alliance requested that the 24 km/h test be reduced to 16 km/h. 
As discussed in the previous section, the Alliance suggested that a 16 
km/h test be the only test and be performed at 3.4 seconds after 
curtain deployment. The Alliance stated that GM \97\ and Ford \98\ 
conducted extensive research in this area and have both concluded that 
the maximum impact energies in the range of 180 to 200 joules (J) were 
appropriate to address the vast majority of real world rollover events. 
The commenter stated that this energy level was also validated by the 
agency's own sled test research (see 74 FR at 63192) simulating both 
rollover and side impact events, which both produced kinetic energies 
in the range of 180 to 200 J.
---------------------------------------------------------------------------

    \97\ O'Brian-Mitchell, Bridget M., Lange, Robert C., ``Ejection 
Mitigation in Rollover Events--Component Test Development,'' SAE 
2007-01-0374.
    \98\ Docket No. NHTSA-2006-26467-0002.
---------------------------------------------------------------------------

    Referring to the GM research, the Alliance stated the 16.2 km/h 
impact speed was derived from analysis of a series of rollover sensor 
development tests, in which data was collected in an attempt to 
quantify the kinetic energy associated with an occupant loading the 
roof rail airbag system. The 52 tests included both belted and unbelted 
test dummies. The Alliance stated that in all cases, the kinetic energy 
value associated with the dummy's interaction with the roof rail airbag 
surrogate (referred to in the study as a window membrane) was less than 
180 J.
    The Alliance stated that another very influential study that 
solidified GM's decision to test at 16.2 km/h was the NHTSA sled 
testing referenced in the NPRM. The sled tests were conducted to 
determine the effect lower body loading would have on the combined head 
and upper torso effective mass. The Alliance stated, ``The sled testing 
representing the rollover condition was conducted at 16 km/h, while the 
side impact simulation was run at 24 km/h. Once the effective mass was 
determined, both impact conditions produced a kinetic energy between 
180-200 J.'' The commenter suggested that this validates the approach 
GM had adopted in simulating the occupant kinetic energy in a rollover 
with an 18 kg impactor at a speed of 16.2 km/h, and shows that the 
kinetic energy associated with this subsystem test would be applicable 
to side impact as well.''
    The Alliance indicated that since they agree with the impactor mass 
of 18 kg, the appropriated impact ``is derived from the equation for 
linear kinetic energy (KE = 1/2mv\2\; m = mass and v = speed). The 
Alliance's recommended impact speed is calculated by substituting m = 
18 kg and KE = 178 Joules, resulting in a speed of 16 km/h (4.44 m/
s).''
    To emphasize their belief that the 24 km/h test is too severe, both 
the

[[Page 3254]]

Alliance and Volvo referred to the agency's analysis in the PRIA,\99\ 
which indicated that a 24 km/h speed (for occupant to ejection 
countermeasure) corresponds to a pre-crash velocity of 133 km/h (83 
mph). They indicated that such a pre-crash speed is too rare an 
occurrence to be reflected in the final rule.
---------------------------------------------------------------------------

    \99\ NHTSA-2009-0183-0002, p. VIII 18.
---------------------------------------------------------------------------

    AIAM and VW recommended that the agency first determine the 
appropriate impact energy and then establish the impactor mass and 
velocity based on this. AIAM was concerned that impact speeds projected 
by the agency are typically associated with masses smaller than the 
proposed 18 kg impactor. VW recommended an impact energy of 180 J, 
which would correspond to a 18 kg impactor traveling at 16 km/h. VW 
provided a table of its modeling results from a linear impactor into an 
air bag (Table 3 in VW comments) showing that impact excursion is 
primarily a function of the initial kinetic energy of the impactor, as 
opposed to mass and impact speed.
    Honda requested that the agency focus on a maximum energy level of 
200 J. The commenter referred to the analysis of GM showing that the 
effective mass of an occupant's initial contact with a side window in a 
full vehicle rollover test indicates a constant energy of less than 200 
J. Honda stated that its own testing showed that the estimated peak 
head velocity and effective mass, when tested in accordance with FMVSS 
No. 208, were also less than 200 J. Honda stated that an upper 
threshold of 200 J would account for the energy imparted on the side 
window by a belted occupant.
    Nissan commented that its preliminary study of impact energy 
associated with occupant ejection showed values below 207 J. Based on 
this and concerns of safety tradeoffs that could exist between FMVSS 
No. 214, it recommended that the final rule limit the higher speed 
impact to 20 km/h, corresponding to an energy of approximately 280 J.
    Batzer and Ziejewski stated that based on the ``testing and 
analysis that we have seen and performed, NHTSA's 15 mph [24.1 km/h] 
impact velocity choice is inappropriately high.'' They stated that a 
``two impacts against the upper half of the glazing'' at 16.1 km/h 
would be an adequate requirement. They continue that ``in side impacts, 
although a large relative occupant-to-glazing nominal velocity may 
result, the door actually takes the brunt of the energy and momentum.''
    Air bag supplier Takata expressed support for the proposed 24 km/h 
test, stating: ``We believe it is important to test all the locations 
at the high energy level to ensure structural integrity of the 
countermeasure device.'' \100\ The commenter also informed NHTSA that a 
24 km/h test speed requirement would be practicable. (NHTSA-2006-26467-
0019, infra.)
---------------------------------------------------------------------------

    \100\ NHTSA-2009-0183-0015, p. 2.
---------------------------------------------------------------------------

iii. Agency Response
    As explained in this section, NHTSA has evaluated the comments 
asking us to base a decision on the impact speed on the findings of a 
GM study and a Ford study. After reviewing the findings of the studies, 
we do not find those GM and Ford data sufficiently informative.
    However, we have carefully considered the comments recommending 
that the agency reassess the impactor speed proposed on the basis of 
what should be the impact energy imparted to the ejection mitigation 
countermeasure, given an impactor mass of 18 kg. We agree that, 
particularly in the case of a curtain air bag countermeasure, the 
energy imparted by the linear impactor is a critical factor in the 
determination of the stringency of the performance requirement as 
compared to only considering the impact speeds or impactor mass. We 
acknowledge that some data available to the agency, e.g., DRF testing, 
vehicle interior video of FMVSS No. 208 Dolly tests, and MADYMO 
simulations, only allow for an assessment of impact speed. Estimates of 
energy from these data require assumptions to be made about effective 
mass values or further computational modeling.
    Accordingly, we have reanalyzed sled test data from the advanced 
glazing program to measure the energy the mid-size adult male dummy 
imparted to the countermeasure. We analyzed the data from a 24.1 km/h 
(15 mph) test meant to be more indicative of a side impact condition 
and a 16.1 km/h (10 mph) test meant to be more indicative of a rollover 
condition. For the 24.1 km/h (side impact) test, we determined the 
energy imparted to the window opening was 290 J. For the 16 km/h 
(rollover) condition, the energy on the window opening was calculated 
to be 220 J. These were the only laboratory test data available to the 
agency for direct analysis of impact energy. For the limited conditions 
tested, the results were not at the estimated energy levels in the 400 
J range, equivalent to the impactor energy when traveling at the 24 km/
h speed considered by the NPRM.
    After reviewing the comments, we also reanalyzed DRF data used in 
the NPRM and found that the original transcription of the film speed 
used to determine impact speed was not done properly. We stated in the 
NPRM that video analysis of dummy head impact velocities with the 
glazing showed that for the 5th percentile female far side occupant, 
the peak impact speed was 31 km/h. After reanalyzing the data for this 
final rule, we determined that the peak head and shoulder impact speeds 
were approximately half that reported in the NPRM.
    We have determined that, based on a thorough analysis of all 
available information, including the reanalyzed sled testing used by 
the agency in the advanced glazing program and the DRF data discussed 
in the NPRM, the test speed for the 1.5 second test adopted by this 
final rule should be 20 km/h, rather than the proposed 24 km/h. A 20 
km/h test would better represent the energies to which the ejection 
countermeasure will be exposed to in the field, particularly in 
rollovers.
A. Analysis of GM Study on Impact Energy
    Several commenters referred to a GM study in which GM determined 
the effective mass and impact energy on a membrane covering the first 
row window. The agency had analyzed this study and provided a review of 
it in the NPRM and the Technical Analysis supporting the NPRM, 
regarding the basis for the impactor mass determination of 18 kg. A 
brief description of the study is provided below.
    GM conducted a study to develop rollover sensors, using 52 full 
vehicle rollover tests. It also attempted to assess the effective mass 
and impact energy on the front window area by belted and unbelted test 
dummies. Forty-six percent of the tests were less than a quarter-turn, 
27 percent were one quarter-turn and 27 percent were two quarter-turns. 
In the tests, the two front seats were occupied by 50th percentile 
adult male Hybrid III dummies. Half of the tests were with belted 
dummies and half were unbelted. The belt status versus number of 
quarter-turns was not reported by the authors.
    The method used to estimate the effective mass required the 
calculation of the resultant loading on the dummy head by the window 
membrane using head acceleration, neck loading and a dummy head mass 
assumed to be 4.204

[[Page 3255]]

kg.\101\ The effective mass was then determined by using this head 
contact force along with the resultant head and chest accelerations. 
Energy levels were calculated by using effective mass and peak head 
velocity. As noted by various commenters to the NPRM for today's final 
rule, the estimated effective mass for most belted tests was about 5 kg 
and all were less than 10 kg. The effective mass for the unbelted 
occupants ranged from 5 to 85 kg. The authors reported that the highest 
energy level was 182.3 Nm.
---------------------------------------------------------------------------

    \101\ Although the membrane had force measurement 
instrumentation at each corner, these measurements were not used in 
the analysis due to a ``data integrity issue.''
---------------------------------------------------------------------------

    We believe that the GM data set has little relevance to this 
rulemaking with respect to the loading of the side window openings in 
crashes that cause the most ejection harm. With regard to the energy 
values derived from this study, it is important to identify several key 
limitations. First, the study was done as a development tool for 
sensors, not as a means of determining the range of potential occupant 
loading/energy on ejection countermeasures in relatively severe 
rollover crashes. As such, vehicle dynamics that show a vehicle on the 
threshold of rolling or not rolling is of great interest in sensor 
development. From the distribution of quarter-turns in these tests, the 
focus of the study was on the minimum thresholds for sensor deployment, 
i.e., rollovers of two or fewer quarter-turns. In contrast, to cover 90 
percent of all rollovers inducing serious injury and fatal ejections, a 
study of rollovers involving 8 or more quarter-turns is more 
appropriate. Regarding rollovers causing complete fatal ejections, a 
cumulative population of 90 percent of these crashes would necessitate 
an analysis of crashes involving 9 or more quarter-turns. The force 
imparted on the side window openings in these types of crashes is 
substantially greater than that discerned by GM in this study.
    Second, although the authors state that the highest energy level 
estimated was below 182.3 J, they subsequently report a case where they 
estimate that the trailing side occupant alone imparts 243 J to the 
membrane. We thus believe it is more accurate to state that the highest 
energy calculated in this set of tests was at least 243 J. It would 
also be very important to know if the leading occupant was applying 
load at the same time as the trailing occupant, perhaps adding to the 
243 J value. Nonetheless, we note that a single unbelted leading 
occupant was estimated to have more than 100 J of energy. If both a 
trailing and leading occupant were to load the window area 
simultaneously, the total energy would be 343 J. Restricting ourselves 
to consideration of the 243 J value, we can correlate this energy to 
the ejection mitigation test procedure by assuming an impactor mass of 
18 kg. The corresponding impact velocity would be 18.7 km/h.
    Third, the methodology and data presented in the GM study seem to 
indicate that only membrane loading from the dummy heads was estimated. 
The agency's sled testing indicated that more load is transmitted 
through the shoulder than the head, and even more load is imparted when 
both the head and shoulder impart loads at the same time. We do not 
believe only head loading should be considered when evaluating the load 
impacted by an occupant on the ejection mitigation countermeasure, even 
for unbelted dummies, as this may have contributed to lower energy 
estimates.
B. Analysis of Ford Study on Impact Energy
    Several comments from vehicle manufacturers made reference to 
modeling Ford performed in which Ford estimated the effective mass and 
impact energy that occupants would impart to the first row window in a 
rollover. This information was originally presented to NHTSA at a 
February 7, 2007 meeting with the agency.\102\ Ford conducted computer 
modeling on three vehicle models, with belted and unbelted 50th 
percentile adult male and 5th percentile adult female Hybrid III 
dummies. This was originally done ``to determine the appropriate energy 
for a headform impact test procedure for Safety Canopy development.'' 
The reported effective mass range was about 5 to 35 kg (average of 14 
kg) for belted occupants and 5 to 50 kg (average of 24 kg) for unbelted 
occupants. The reported peak energy values were similar for belted and 
unbelted occupants, at about 180 J. These maximum values appeared to 
occur early in the simulations (< 200 ms).
---------------------------------------------------------------------------

    \102\ Docket No. NHTSA-2006-26467-0002.
---------------------------------------------------------------------------

    Ford indicated that they modeled curb trip and SAE J2114--Dolly 
Rollover Recommended Test Procedure (Dolly) tests. The speeds, vehicle 
roll rates, and quarter-turns were not reported.\103\ As such, it is 
very difficult for us to assess the severity of the rollovers that were 
simulated. As was the case in our analysis of the GM study, rollovers 
that only produce a few quarter-turns are not representative of the 
ejection-causing crashes that we are attempting to cover by this 
standard.
---------------------------------------------------------------------------

    \103\ The SAE J2114 test uses the same test configuration as the 
208 Dolly test. However, the 208 Dolly test is performed at a speed 
of 48 km/h. SAE J2114 does not have a recommended speed.
---------------------------------------------------------------------------

    The majority of the data was reported before 600 ms into the event. 
This is probably less than 2 quarter-turns into the event, depending on 
how Ford determined time zero. It is unclear if Ford only modeled part 
of the event. For vehicles that undergo many more quarter-turns, there 
may be impacts with the window area that were not captured by Ford's 
modeling only the first few quarter-turns.
    The agency analyzed the Ford study and did not find the results to 
be persuasive. The fact that a set of simulations result in energy 
estimates below 180 J is of limited use to the agency's determination 
of an impact speed/energy that will protect a far-reaching population 
of occupants.
C. Reanalysis of Agency Data From NHTSA Sled Testing
    Several commenters to the NPRM stated that the agency's own sled 
testing indicated that the appropriate energy of the impact should be 
below 200 J. They are referring to sled testing that was performed in 
1993 as a follow-up to dummy pendulum impacts.\104\ The sled tests were 
conducted to determine the appropriate mass of a linear impactor to be 
used in the testing of advanced glazing (the headform impactor).\105\
---------------------------------------------------------------------------

    \104\ ``Ejection Mitigation Using Advanced Glazing: A Status 
Report,'' November 1995, Docket No. NHTSA-1996-1782-3. Pg. 7-10.
    \105\ These have been entered as test Nos. 10282--10287 in the 
NHTSA Biomechanics Test Database. They are accessible at http://www-nrd.nhtsa.dot.gov/database/aspx/biodb/querytesttable.aspx.
---------------------------------------------------------------------------

    These tests were described as incorporating a ``side impact'' 
condition and a ``rollover'' condition, although they were both side 
impact sled tests. For the test designed to be more representative of a 
side impact condition, the target impact speed was 24.1 km/h and the 
dummy (a 50th percentile adult male BioSID) was positioned was seated 
upright. In the rollover condition, the target impact speed was 
described as 16.1 km/h \106\ and the dummy was positioned leaning 
towards the door such that its head and torso would contact the 
simulated glazing (foam) at about the same time. This leaning position 
was intended to be more representative of an occupant's attitude in a 
rollover. In both conditions the foam was positioned such that head and 
shoulder contact with the foam was achieved at similar times.
---------------------------------------------------------------------------

    \106\ Although we refer to this as the 16.1 km/h test, we found 
that the actual test speed for the test we analyzed in detail was 
15.2 km/h.

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

[[Page 3256]]

    It should be understood that the testing was not designed to 
directly measure the energy the countermeasure must absorb in order to 
prevent an occupant ejection. Rather, this set of tests was a follow-up 
to dummy pendulum impacts used to determine the appropriate mass of a 
linear impactor used to test advanced glazing. (If energy assessment 
had been the goal, a means of measuring displacement of the loaded 
reaction surface (foam or surface behind it) could have been 
undertaken. As it is, no direct measurement of the displacement of the 
loaded surface was made.)
    In response to the comments to the NPRM, we reanalyzed the sled 
test data in an effort to estimate the energy the incoming dummy 
imparted to the foam. This new analysis is discussed in detail in the 
technical report accompanying this final rule. Briefly stated, for the 
24.1 km/h (side impact) test, we determined that the energy imparted to 
the window opening was approximately 290 J (rounded up from 287 J). We 
believe this energy likely represents a minimum value for this test 
configuration.\107\ From this energy value we estimated the effective 
mass of the test to be 13 kg. As described below, the energy and 
effective mass estimates for the 16.1 km/h (rollover) test were more 
complex. However, based on this analysis we estimate the energy of that 
impact to be 200 J and the effective mass to be 22 kg. However, this 
test was actually performed at approximately 15.5 km/h. If it had been 
correctly performed at 16.1 km/h (10 mph), the energy would have been 
220 J. (Note that these values do not support the commenters to the 
NPRM that stated that the agency's sled testing indicated that the 
appropriate energy of the impact should be below 200 J. These sled 
tests alone provide a range of energies between 220 to 290 J that, 
assuming an impactor mass of 18 kg, correspond to a range of impact 
velocities of 18.5 to 20.6 km/h.)
---------------------------------------------------------------------------

    \107\ We say ``minimum'' because by the nature of impact into 
foam, there were energy losses that would not be reflected in the 
estimated impact energy.
---------------------------------------------------------------------------

24 Km/h Test
    The process of reanalysis started with the 24.1 km/h upright (side 
impact) tests. The energy into the foam padding was determined by 
assessing the ``work'' done on the dummy, i.e., the integral of the 
lateral force versus lateral displacement on the dummy. The lateral 
force on the dummy was assumed to be the force measured by the load 
cells behind the foam (the foam was a surrogate for the window 
countermeasure) for the head and shoulder load cells. Equation (1) 
represents the energy of the head into the foam. A similar equation can 
be written for the shoulder.
[GRAPHIC] [TIFF OMITTED] TR19JA11.013


Where:

F<INF>h</INF> = Force measured at head foam pad, assumed to be 
lateral force on dummy head.
y<INF>h/s</INF> = y (lateral) displacement of the dummy head 
relative to the sled.
T = Time

    The analysis is set forth in detail in the technical report. We 
determined that, because in the 24.1 km/h test the dummy was initially 
positioned upright (i.e., the midsagittal plane aligned with a vertical 
axis), the head and shoulders of the dummy contacted the foam pads at 
about the same time. This resulted in the dummy maintaining its upright 
position during force application through the foam. We assumed there 
was no significant rigid body rotation; examination of the test video 
confirmed this assumption. This assumption allowed the use of the 
measured head c.g. (center of gravity) acceleration to be integrated 
once for velocity and twice for displacement. In the case of the torso/
shoulder loading, the accelerometer at the first thoracic vertebra (T1) 
was used.
    Three different types of foam padding were used in the original 
tests.\108\ In order of increasing stiffness, the foams were: 
Polystyrene, Arsan and Ethafoam LC 200. Table 33 shows the estimated 
impact energy and the measured maximum force at the head and shoulder 
on the Ethafoam pads, as well as the maximum combined values. The 
combined maximum energy value was 287 J. We believe it is appropriate 
to consider the total energy value that combines the maximum head and 
shoulder components in that this would represent the total amount of 
energy that the countermeasure must absorb. The same type of energy 
estimate was made for the tests with Arsan and polystyrene using eq. 1. 
The energy estimates were 282 J and 252 J for Arsan and polystyrene, 
respectively. We expect the less stiff Arsan and polystyrene to result 
in lower energy estimates.
---------------------------------------------------------------------------

    \108\ We recognize that for all of the tests there was energy 
loss into the foam, i.e., the foam absorbed the energy of the impact 
without returning it to the dummy. The foam cells were heated, 
deformed beyond their elastic limit and/or were destroyed. Thus, the 
loads imparted to the dummy were lower than would be the case if 
foam were not present. Since energy was derived from the load cell 
force measured behind the foam pad and the displacement of the head 
(or shoulder) in the direction of force, the lower force imparted to 
the dummy resulted in a lower calculated energy. This is to say, the 
estimate of the work/energy needed for an ejection countermeasure 
was likely an underestimate. The extent of the underestimation is 
not known.

 Table 33--Energy (Eq. 1) and Force on the Ethafoam Padding in the 24.1
                             km/h Sled Test
------------------------------------------------------------------------
                                                  Maximum      Maximum
                                                energy  (J)   force  (N)
------------------------------------------------------------------------
Head..........................................         97.1        2,569
Shoulder......................................        190.1        3,220
                                               -------------------------
Combined--Total...............................        287    ...........
------------------------------------------------------------------------

    We also reassessed the effective mass calculations in the 24.1 km/h 
Ethafoam test. Effective mass was calculated in three different ways. 
As was reported in the 1995 Advanced Glazing Report, we estimated the 
effective mass as a function of time during the foam contact by using 
eq. (2). Again, this is done for both the head and torso separately, 
and is added for a total effective mass estimate. The estimate over 
time was averaged to provide a single value of effective mass. However, 
averaging over different time periods can result in very different 
estimates of effective mass. The estimate below uses the time period 
between when the peak force value is achieved to when the minimum 
relative velocity between the dummy and the sled is achieved.

[[Page 3257]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.014


Where:

EM = effective mass
a<INF>y</INF> = acceleration in the y (lateral) direction

    The second method used to calculate effective mass was to solve for 
mass in the equation of kinetic energy by assuming that the estimated 
impact energy is equal to the kinetic energy of the effective mass 
prior to impact, as is shown in eq. (3).
[GRAPHIC] [TIFF OMITTED] TR19JA11.015


Where:

Ei = Energy of impact
V<INF>y0</INF> = Lateral velocity relative to sled just prior to 
foam contact

    The third and final method was to use impulse moment equations by 
integrating the force applied to the dummy and dividing by the change 
in velocity relative to the sled. This is shown in eq. (4).
[GRAPHIC] [TIFF OMITTED] TR19JA11.031


Where:

V<INF>yf</INF> = Lateral velocity relative to sled at maximum foam 
compression
tf = time of maximum foam compression (minimum relative velocity)

    The estimates of effective mass of the combined head and shoulder 
from all three methods, which range from 12.2 to 13.1 for the 24.1 km/h 
impact, are shown in the fourth through the fifth columns in Table 34. 
The impulse method estimate is lower than the other two estimates, 
which match very closely. The second column in Table 34 shows the 
individual values of impact speed for the head and shoulder.

  Table 34--Impact Energy on the Ethafoam Padding in the 24 km/h Sled Test From Measured Force and Acceleration
                                                      Data
----------------------------------------------------------------------------------------------------------------
                                                               Method of Effective Mass Determination (kg)
                                                        --------------------------------------------------------
                                           V0 (m/s)      Avg. Accel.  (eq.
                                                                 2)          Energy  (eq. 3)    Impulse  (eq. 4)
----------------------------------------------------------------------------------------------------------------
Head................................               6.85               4.32               4.14               4.19
Shoulder............................               6.53               8.58               8.92               7.97
----------------------------------------------------------------------------------------------------------------
    Combined........................  .................              12.9               13.1               12.2
----------------------------------------------------------------------------------------------------------------

    The estimate of impact energy can also be made other than by using 
eq. (1). An alternate method rearranges the terms in eq. (3) and uses 
the effective mass in combination with the pre-impact dummy speed. If 
an effective mass of 13 kg were used in combination with a theoretical 
impact speed of 24.1 km/hr (6.71 m/s), the energy generated would be 
293 J. Based on the above analysis, we believe that a reasonable 
estimate for the combined head and shoulder effective mass and energy 
for a 24.1 km/h impact to be 13 kg and 290 J, respectively. We can 
correlate this energy value to the ejection mitigation test procedure 
by assuming an impactor mass of 18 kg. The corresponding impact 
velocity is 20.5 km/h.
16.1 km/h Test
    We also reanalyzed the 16.1 km/h testing with the dummy midsagittal 
plane oriented 25 degrees from the vertical (rollover configuration). 
The analysis of this test configuration was more complex, mainly 
because the coordinate system of the dummy was not aligned with that of 
the sled, and changed as the sled moved and particularly as the dummy 
interacted with the foam padding. We initially compensated for the 
dummy orientation by dividing the component of the local y (lateral) 
accelerometer values by the cosine of 25 degrees. Single and double 
integration is required to calculate the dummy velocity and 
displacement, respectively. Table 35 below shows the estimated impact 
energy on the Ethafoam padding in the 16.1 km/h sled test test using 
the same methods as used for the 24.1 km/h test. Application of eq. (1) 
for the head and a similar equation for the shoulder provided the 
estimate of impact energy shown in the fifth column of Table 35, below. 
We also generated the effective mass values by use of eq. (4), shown in 
the third column of Table 35. We used this effective mass estimate and 
the velocity relative to the sled of the head and shoulder at contact 
with the foam to estimate the incoming kinetic energy by rearranging 
the terms in eq. (3), shown in the fourth column of Table 35.\109\
---------------------------------------------------------------------------

    \109\ As discussed below, the actual sled speed at the time of 
dummy contact with the foam was 15.2 km/h (4.24 m/s) to 15.5 km/h 
(4.30 m/s) and lower than the intended sled speed of 16.1 km/h (4.47 
m/s).

[[Page 3258]]



 Table 35--Impact Energy on the Ethafoam Padding in the 16.1 km/h Sled Test From Measured Force and Acceleration
                                                      Data
----------------------------------------------------------------------------------------------------------------
                                           Vo (m/s)         EM  (eq. 4)      Energy  (eq. 3)    Energy  (eq. 1)
----------------------------------------------------------------------------------------------------------------
Head................................               4.84             6.7 kg             78.5 J             68.3 J
Shoulder............................               4.06            13.1 kg              108 J             92.5 J
    Combined........................  .................            19.8 kg              187 J              161 J
----------------------------------------------------------------------------------------------------------------

    We do not have a great deal of confidence in the energy values 
presented in Table 35, particularly in the estimate using eq. (1). As 
stated above, these estimates require integration of the dummy head and 
T1 acceleration values. To the extent the dummy head or torso becomes 
misaligned with the 25 degree tilt prior to and after foam contact, the 
integration of the sensor readings compounds the error in estimated 
velocity and displacement. Differences in the calculated initial head 
and shoulder velocity of 4.84 m/s and 4.06 m/s, respectively, are 
indicative of dummy rotation prior to foam contact. Examination of the 
video confirmed the rigid body rotation during dummy free-flight and 
after foam contact. Short of performing a much more rigorous video 
analysis of the test films, we opted for another strategy to estimate 
the energy of the 16.1 km/h impact configurations.
    One strategy we employed was based on the fact that the 
constitutive properties of the foam for both the 16.1 km/h impact into 
the Ethafoam padding and 24.1 km/h impact into Ethafoam did not change, 
i.e., the foam properties did not change. Based on this, we attempted 
to derive the dummy motion in the direction of force applied by the 
foam. We assumed that once in contact with the foam, the lateral force 
on the head or shoulder of the dummy can be represented by a mass on a 
spring, in parallel with a viscous dashpot. To simplify this analysis 
we assume the damping coefficient is zero and the force on the mass is 
simply a function of the spring stiffness (F = -ky). We can thus 
represent the energy stored in a spring, as shown in eq. (5).
[GRAPHIC] [TIFF OMITTED] TR19JA11.016


Where:

Es = Energy stored in a spring

    Using this concept we can derive eq. (6) to determine the impact 
energy of the 16.1 km/h test since we know the energy of the 24.1 km/h 
impact and the forces measured at the foam pads for each impact speed. 
The head and shoulder impact energies have ratios of 61 percent and 75 
percent, respectively. The resulting estimate of total impact energy 
for the 16.1 km/h impact is 202 J. Using this energy value and the 
estimate for initial head and shoulder velocity as inputs to eq. (3), 
the effective mass for the head and shoulder are 5.1 kg and 17.3 kg, 
respectively. The combined effective mass is 22.3 kg. The results are 
given in Table 36.
[GRAPHIC] [TIFF OMITTED] TR19JA11.017


  Table 36--Impact Energy and Force on the Ethafoam Padding in the 16.1 km/h Sled Test Estimated From a Spring
                                                      Model
----------------------------------------------------------------------------------------------------------------
                                       Max. energy (J)     Max. force (N)    Ratio of energy     Effective mass
----------------------------------------------------------------------------------------------------------------
Head................................               59.2              2,005              60.9%               5.05
Shoulder............................              143                2,789               75.0              17.3
                                     ---------------------------------------------------------------------------
    Combined........................              202    .................  .................              22.3
----------------------------------------------------------------------------------------------------------------

Another strategy employed to estimate the energy of the 16.1 km/h test 
was based on the assumption that the estimate of sled velocity was a 
better representation of the dummy impact speed than the speed derived 
from the dummy accelerometers. The second column in Table 37 shows the 
sled speed just prior to dummy head and shoulder contact. Equation 4 
can be used to estimate the effective mass if the time (t<INF>f</INF>) 
of minimum relative dummy to sled velocity (v<INF>yf</INF>) is known. 
However, the only estimate of this time is from the single integration 
of dummy accelerometers. Nonetheless, the EM and energy of impact, 
using eq. (3), are given in Table 37.

   Table 37--Head Impact Energy Into the Ethafoam for the 16.1 and 24.1 km/h Tests, Estimated by Assuming Sled
                                       Velocity Equals the Impact Velocity
----------------------------------------------------------------------------------------------------------------
                                                                             EM (eq. 6.6.4)       Energy (eq.
                                                             Vo (m/s)             (kg)               6.6.3)
----------------------------------------------------------------------------------------------------------------
Head..................................................               4.30                7.53             69.5 J
Shoulder..............................................               4.24               13.8               124 J
    Combined..........................................  .................               21.4               194 J
----------------------------------------------------------------------------------------------------------------

    By using the spring equation assumption (Table 36) and sled 
velocity rather than dummy sensor estimates for initial impact speed 
(Table 37), we estimate an effective mass range of 21.4 to 22.3 kg and 
an energy range of 194 to 202 J. We believe this range of estimates is 
superior to the energy and effective mass values using only dummy 
sensor derived estimates of dummy velocity and displacement (Table 35), 
particularly the estimate using eq. (1).

[[Page 3259]]

Thus, we believe that it is reasonable to estimate the effective mass 
and energy of the 16.1 km/h test as 22 kg (6.3 kg for the head and 15.6 
kg for the shoulder) and 200 J, respectively.
    Finally, we note that if the test had been actually performed at 
16.1 km/h (4.47 m/s) rather than the actual value of approximately 15.5 
km/h (4.3 m/s), the energy estimate for the test would be higher. There 
is no reason to believe that if the test were performed at a higher 
speed that it would change the effective mass estimate. Thus, if we use 
the 22 kg effective mass estimate, the impact energy at 16.1 km/h would 
be 220 J.
D. DRF Data
    We also reanalyzed DRF data used in the NPRM and found an error in 
the analysis of impact speed. In the NPRM (74 FR at 63196), we 
discussed video analysis of data from the advanced glazing program of 
vehicles tested on the DRF with a 5th percentile adult female dummy and 
a 50th percentile adult male test dummy (near and far side).\110\ We 
stated that video analysis of dummy head impact velocities with the 
glazing showed that for the 5th percentile female far side occupant, 
the time to glazing impact after the DRF began rotating was between 1.3 
and 1.8 seconds, which was in the range of two to three quarter-turns 
of rotation, and that the peak impact speed was 31 km/h. In Table 12 of 
the NPRM (id.), we showed the estimated velocities for the near and far 
side dummies.
---------------------------------------------------------------------------

    \110\ Duffy, S., ``Test Procedure for Evaluating Ejection 
Mitigation Systems,'' 2002 SAE Government/Industry Meeting.
---------------------------------------------------------------------------

    After reanalyzing the data for this final rule, we determined that 
the head impact speeds are approximately half of those reported in the 
NPRM. Apparently the reason for this was an error in film rate 
transcription during the original analysis. A reanalysis of the DRF 
videos found peak head and shoulder speeds between 15 and 16 km/h, see 
Table 38 below.\111\ There is no way to directly determine the energy 
of the interaction between the dummies and the glazing in these DRF 
tests. However, assuming an effective mass for the 50th percentile male 
of 6.3 kg and 15.6 kg for the head and torso impact, respectively, the 
resultant impact energy would be 209 J. We can correlate this energy 
value to the ejection mitigation test procedure by assuming an impactor 
mass of 18 kg. The corresponding impact velocity would be 17.3 km/h.
---------------------------------------------------------------------------

    \111\ Videos and electronic data from these tests have been 
placed in the NHTSA Component Database and can be accessed at www-nrd.nhtsa.dot.gov/database/aspx/comdb/querytesttable.aspx. Data from 
four tests are under test number 716. The file names for the 5th 
female near and far side tests are C00716C001 and C00716002, 
respectively. The file names for the 50th male near and far side 
tests are C00716C003 and C00716004, respectively.

                                      Table 38--DRF Testing Peak Velocities
----------------------------------------------------------------------------------------------------------------
                                                        Impact speed (km/h)         Estimated impact energy (J)
                      Dummy                      ---------------------------------------------------------------
                                                     Near Side       Far Side        Near Side       Far Side
----------------------------------------------------------------------------------------------------------------
5th Female:
    Head........................................             7.2            14.5  ..............  ..............
    Shoulder....................................             7.0            15.5  ..............  ..............
50th Male:
    Head........................................             9.2            15.2  ..............             209
    Shoulder....................................             9.0            15.8
----------------------------------------------------------------------------------------------------------------

    It is important to emphasize that this set of DRF tests was 
performed at a peak roll rate of 330-360 deg./sec. An analysis of field 
data submitted by Batzer and Ziejewski suggests that higher peak roll 
rates can occur in the field.\112\ We would expect that if the DRF 
testing were performed at a higher roll rate, that higher impact speed 
would be possible. Modeling results provided by the agency in the NPRM 
showed a Toyota pickup rollover simulation with a head and torso to 
glazing speed of 20 and 16 km/h, respectively.\113\ This would result 
in a total energy of 251 J, assuming a 22 kg effective mass.
---------------------------------------------------------------------------

    \112\ An IMECE paper submitted with Batzer's comments indicates 
that this range of peak roll rate is consistent with a 7-9 \1/4\-
turn rollover.
    \113\ 74 FR at 63195.
---------------------------------------------------------------------------

E. Discussion and Conclusion
    We agree with the importance of impact energy as a critical 
parameter in the determination of the appropriate impact speed for the 
18 kg impactor in the ejection mitigation test procedure, particularly 
for a countermeasure consisting of side curtain air bags. Therefore, we 
have endeavored to take a fresh look at the available data provided by 
commenters and the data the agency used to justify the impact speed in 
the NPRM. Based on our analysis, best available data have led us to 
adopt an impact test speed of 20 km/h, consistent with Nissan's 
comment, and the associated 278 J energy level.
    We do not agree with requests by commenters to decrease the impact 
speed to any level below the 20 km/h value. Honda requested a 17 km/h 
impact speed (200 J), based on an analysis of peak head velocity and 
effective mass involving belted occupants. We decline to restrict our 
rulemaking to countermeasures that are subject to performance 
requirements that account for the energy imparted on the side window by 
belted occupants. The Alliance indicated that the appropriate impact 
speed should be based on an energy of 178 Joules, resulting in a speed 
of 16 km/h (4.44 m/s). We did not find the supporting GM and Ford 
studies persuasive. We believe the use of the GM energy estimates as a 
basis for the final rule is problematic because the rollover severity 
used in the study only represents a small minority of the most harmful 
ejection-inducing crashes. Also, the study seems to only measure, or 
only contain, occupant loading through the head. We would expect 
shoulder or combined shoulder and head loading to result in higher 
energy estimates. The Ford modeling study also has limited usefulness 
given that lack of specificity and detail provided about the modeling.
    We have also determined that commenters' contention that the 
agency's sled test data is supportive of only a 16 km/h impact to be 
unfounded. Our analysis showed these tests represent energies from 220 
to 290 J, which correlated to impact speeds in the range of 17.8 to 
20.4 km/h.
    We acknowledge that there are practical limitations to the level of 
performance mandated by this Federal safety standard; the standard does 
not reflect the worst case scenario. The speeds at which our sled tests 
were run

[[Page 3260]]

did not generate the highest possible speeds that occupants in the 
field could interact with the window opening. Some vehicles roll over 
with a higher roll rate than generated by the DRF tests, resulting in 
higher impact velocities than those measured in the laboratory, and 
some occupants will weigh more than the dummies used or have a greater 
proportion of their mass contact the window opening. Nonetheless, 
ejection mitigation countermeasures installed pursuant to this standard 
will provide a level of protection even under more dire conditions. 
Moreover, this standard sets a reasonable, appropriate, and practicable 
level of performance at a reasonable cost.\114\ It assures that 
vehicles will be equipped with ejection mitigation countermeasures 
suited to the energy generated in most rollover crashes. Consistent 
with the agency's principles for sound regulatory decision-making, the 
20 km/h impact test is data-driven and supported by all the technical 
data available to date. A 400 J energy value has not been supported by 
any of the technical assessments thus far conducted.
---------------------------------------------------------------------------

    \114\ Some commenters said that unintended safety disbenefits 
would result from a 24 km/h test, such as a greater risk to out of 
position occupants or less protection in FMVSS No. 214 side impact 
crashes. We respond to these commenters in a later section of this 
preamble.
---------------------------------------------------------------------------

    The FRIA discusses the impacts of adopting a 20 km/h test versus a 
24 km/h test. We performed a sensitivity analysis comparing the harm 
associated with crashes with an occupant impact speed of 20 km/h to 
that of crashes associated with an occupant impact speed of 24 km/h, 
and the resulting effect on the benefits analysis. This analysis 
settles on a supposition that the difference between a 20 km/h test 
speed and a 24 km/h test speed is about 7 percent of the overall 
benefits of the final rule. Nonetheless, we have several reasons for 
preferring the 20 km/h test requirement.
    We have analyzed costs and other impacts associated with the 20 km/
h and 24 km/h criteria, and have found the 20 km/h test requirement to 
be the most cost effective criterion. The FRIA compares the cost per 
equivalent life saved of a 20 km/h rollover curtain air bag with that 
of a 24 km/h rollover curtain air bag with a larger inflator (low end 
of cost range) to achieve higher air bag pressure and a 24 km/h 
rollover curtain air bag that has the same pressure as the 20 km/h 
curtain, but has greater volume (high end of the cost range). It is 
assumed that this system with greater volume requires additional air 
bag material and an additional inflator for a vehicle with 3 rows or 2 
rows and a cargo area. Using the 3 percent discount rate as a basis of 
comparison, the 20 km/h system is the most cost effective at $1.4 
million per equivalent life saved. This compares with a range in cost 
for the 24 km/h system from $1.6 to $2.8 million.
    Not only does the 20 km/h test requirement impose minimal costs for 
the maximum benefit, a 20 km/h test requirement, as discussed above, it 
is better supported by technical data than a 24 km/h requirement as it 
better represents the forces to which the ejection countermeasure will 
be exposed to in the field than a 24 km/h requirement, particularly in 
rollovers.
    Some vehicle manufacturers have commented that meeting a 24 km/h 
requirement will entail increasing air bag pressure in current bags, 
and have expressed concerns that more rigid bags will increase head 
injury criteria (HIC) values measured in a side impact test and IARVs 
measured in out-of-position (OOP) tests. Although whether those 
increased HIC values and IARVs in OOP tests from increased air bag 
pressure pose an unreasonable safety risk is not known, negative trade-
offs concern the agency in any rulemaking. Those possible trade-offs 
can be avoided with a 20 km/h requirement. To illustrate, in agency 
testing the MY 2007 Mazda CX9 was able to meet the 20 km/h performance 
test at all locations tested, without modification. This vehicle has a 
5-star side impact rating under the then-NCAP rating system.
    Finally, some manufacturers pointed to their successful experience 
with rollover curtains installed on their vehicles to argue that the 
performance requirements of the proposed standard are too high. VW 
stated that it was unaware of any ejections occurring in 100,000 
Tiguan, Q7 and Q5 vehicles with sealed curtain side air bags. GM stated 
that it started implementing ejection mitigation curtains with several 
2005 model year vehicles and it is unaware of injuries due to ejection 
past an ejection mitigation air bag. GM submitted case studies of 
twelve rollover crashes investigated by GM and the University of 
Michigan and found no ejections had occurred.
    In response to VW, the fact that VW is not aware of any ejections 
is not necessarily supportive of a conclusion that the ejection 
mitigation systems in the vehicles are sufficient. A much more detailed 
field data analysis of available rollover and side impact crashes would 
be necessary. For example, such information would have to include the 
number of rollover crashes, the number of quarter-turns, and the seat 
belt status of the occupants. Even then, it is difficult to draw 
conclusions from a limit number of crashes. Further, with regard to 
GM's twelve cases, almost all of these cases involved belted occupants. 
Our final rule focuses on ejection mitigation for both unbelted and 
belted occupants.
    In sum, based on our analysis of the comments and a reanalysis of 
the basis for the impact tests, we have adopted an impact test speed of 
20 km/h. We conclude that this level of energy is more representative 
of the energy the ejection countermeasure will typically be exposed to 
in the field, particularly in rollovers. Thus, the 20 km/h requirement 
is reasonable, appropriate, and practicable, and preferable to the 24 
km/h test requirement.

d. Target Locations

    This section discusses the NPRM's proposals concerning where the 
headform impactor will be aimed to assess the effectiveness of ejection 
mitigation countermeasures, the comments received on the NPRM, and our 
responses thereto. Because there are many issues relating to target 
locations, to make the discussion easier to follow we respond to the 
comments immediately after summarizing them issue by issue.
    This final rule adopts the test procedures proposed in the NPRM for 
locating target locations except as follows: (1) The window opening for 
cargo areas behind the 1st and 2nd row will be impacted; (2) the 
lateral distance defining the window opening is increased from 50 to 
100 mm; and (3) if necessary, the headform and targets will be rotated 
by 90 degrees to a horizontal orientation if this results in more 
impact locations (up to a maximum of four targets per window) than the 
vertical orientation. Additional changes include: instructing removal 
of gasket material or weather stripping used to create a waterproof 
seal between the glazing and the vehicle interior and the door and the 
door frame; allowing some portion of material bordering a window 
opening on the exterior of the vehicle to factor into our assessment of 
what is a window opening; and permitting the adjustment or removal of 
components that would interfere with the ejection impactor or headform 
in the test.
1. Why We Are Focusing On Side Windows and Not Other Openings
    In general, comments from glazing manufacturers and consumer groups 
asked that the agency expand coverage to sun/moon roofs and backlights. 
EPGAA stated that `[w]hile NHTSA addresses third row windows which

[[Page 3261]]

account for less than 1% of the injuries and deaths, it completely 
ignores sun roofs and rear windows which are also window openings 
through which outboard seated occupants could be ejected and together 
account for over 12% of the injuries and 7% of the deaths.'' Public 
Citizen (PC) commented that ``[t]he agency should consider whether 
laminated glazing would counter the potential for ejection through the 
roof, which can be expected to increase as a result of the side curtain 
airbags that the standard requires.'' PC also mentioned that the PRIA 
quoted a 2002 agency report that estimated that 15 percent of occupants 
are ejected through sun roofs. Batzer and Ziejewski stated that NHTSA's 
``statistics indicate that the most common windows acting as ejection 
portals include the first row windows, the windshield, the sunroof, and 
the backlite [sic].''
Agency Response
    We do not grant the request from Advocates for ejection mitigation 
coverage of doors and windshields. Door openings are already regulated 
by FMVSS No. 206, ``Door locks and door retention components,'' which 
was upgraded in 2009 expressly to improve door lock and hinge 
requirements to reduce door openings in crashes. (72 FR 5385, February 
6, 2007, Docket NHTSA-2006-23882.) Windshields are regulated by FMVSS 
No. 205, ``Glazing materials,'' and the associated performance 
requirements in FMVSS No. 212, ``Windshield mounting.'' No suggestion 
was made as to how these existing requirements could be enhanced.
    Ejection mitigation through the backlight and through movable or 
fixed roof panels is not addressed by FMVSS Nos. 206, 205, or 212. Our 
most recent analysis of ejection route data set forth in this final 
rule and in the FRIA indicates that backlight and roof ejections rank 
3rd, behind 2nd row window ejections.\115\ For all crash types the 
backlight and roof represent 4.8 percent and 3.1 percent of fatalities, 
respectively. When crashes are limited to target population crash 
types, i.e., crashes involving lateral rollovers and side impact 
crashes, the backlight and roof represent 5.9 percent and 3.9 percent, 
respectively. Backlights are on nearly every vehicle and sun/moon roofs 
are not, so given those data, if a roof opening is present, it 
represents a greater risk for ejection than the backlight.
---------------------------------------------------------------------------

    \115\ These rankings exclude ejections through non-glazing 
areas.
---------------------------------------------------------------------------

    In the updated data analysis for this final rule, we provide a much 
more refined analysis of the roof ejections than was provided in the 
NPRM. This was achieved by performing a manual review of each case. Our 
analysis was able to segment the data by those with roof glazing (moon 
roofs) and those with sheet metal panels (sun roofs) as well as the 
pre-crash position of the panel. Closed moon roofs represent about half 
the fatal and MAIS 3+ ejections through the roof.
    To fully understand this issue, the agency has assessed the cost 
effectiveness of using advanced glazing for the backlight and closed 
roof glazing. This analysis, set forth in the FRIA, includes all crash 
types (not limited to side impacts and rollovers) since the advanced 
glazing countermeasure does not need to deploy. The results are given 
in Table 39 at the 3 and 7 percent discount rates and at an assumed 
ejection effectiveness level of 20 percent. The 20 percent 
effectiveness value used in the FRIA is for illustration purposes. At 
the 20 percent level of effectiveness, the backlight glazing does not 
appear cost effective, while the roof glazing could be.

  Table 39--Cost per Equivalent Life Saved (ELS) of Ejections through Backlight and Roof Glazing with Advanced
                                                     Glazing
----------------------------------------------------------------------------------------------------------------
                                                                     Cost per ELS
                                   --------------------------------------------------------------------------------
 Assumed containment effectiveness                Backlight                             Roof glazing
                                   --------------------------------------------------------------------------------
                                            3%                 7%                 7%                 3%
-------------------------------------------------------------------------------------------------------------- ----
20%...............................             $11.3M             $14.2M              $4.1M              $5.1M
----------------------------------------------------------------------------------------------------------------

    Commenters to the NPRM argued that the PRIA stated that after 
implementation of FMVSS No. 226, roof ejections are likely to increase 
from their current level as a result of occupants, contained from side 
window ejections, being available for ejection from other portals. The 
agency agrees this is a reasonable possibility. In fact, our findings 
in analyzing the RODSS database cases with side curtains are consistent 
with this conclusion.\116\ Commenters also indicated their belief that 
roof ejections may increase due to more and larger sun/moon roofs in 
the future. This forecast seems speculative since there was no data 
provided to support it.
---------------------------------------------------------------------------

    \116\ It is important to emphasize that the RODSS data is not a 
statistically representative sample of field data.
---------------------------------------------------------------------------

    In any event, we have determined it is not reasonable to expand 
this final rule to roof glazing. A major impediment is the lack of a 
proven performance test procedure for roof glazing. The current 
configuration of an ejection propulsion mechanism and ejection impactor 
has been years in development and is specially designed for horizontal 
impacts on nominally vertical surfaces. A comparable performance test 
will have to be developed that delivers an appropriate amount of impact 
energy to a pre-broken roof glazing or the opening covered by some 
other countermeasure.
    Another factor that causes us not to expand this final rule to 
address ejections through the roof is an absence of notice to the 
public to add such a provision to the final rule. The public has not 
been provided meaningful notice that NHTSA was considering requirements 
for roof portals, and has not been provided an opportunity to comment 
on such requirements. Relatedly, the agency has not been given the 
benefit of the public's views of the matter. Accordingly, we are not 
extending this final rule to roof glazing.
    However, NHTSA is interested in learning more about roof ejections 
and would like to explore this area further. We plan to examine field 
data to better understand the current and future extent of roof 
ejections, and will seek to learn about the future implementation of 
sun/moon roofs in vehicles and ideas about effective ejection 
countermeasures through those portals. The results of this work may 
find that future rulemaking on roof ejections could be warranted.

[[Page 3262]]

2. Why We Are Focusing on the Side Windows Adjacent to First Three Rows
    We received comments on which side window openings should be 
subject to ejection mitigation requirements, and how the final rule 
should determine the rear boundary that defines which rear window 
openings are subject to the standard.
i. First Three Rows
    Advocates believed that the rule should extend to ``occupants in 
the rear seats of small buses and 15-passenger vans.'' Batzer and 
Ziejewski stated that ``[t]he reasoning behind why only the first three 
rows of seats are required to have coverage seems insufficient. Why 
would not every designated seating position in every vehicle have the 
same level of safety?''
Agency Response
    The final rule will not extend side window coverage beyond three 
rows. SAFTEA-LU directed us ``to reduce complete and partial ejections 
of vehicle occupants from outboard seating positions.'' Our position in 
the NPRM was that field data showed a compelling need for ejection 
countermeasures to cover daylight openings adjacent to the first two 
rows of seating coverage. The update of the field data presented in 
this final rule supports this decision. For all crash types, the first 
and second row windows rank 1st and 3rd (54.2 percent and 7.7 percent, 
respectively) as far as fatal occupant ejection routes.\117\ When 
crashes are limited to target population crash types, i.e., crashes 
involving lateral rollovers and side impact crashes, these rankings 
(50.3 percent and 7.7 percent, respectively) for fatal ejections do not 
change.
---------------------------------------------------------------------------

    \117\ These rankings exclude ejections through non-glazing 
areas. The second ranked fatal ejection route is the windshield, for 
both lateral rollovers and side impact crash populations.
---------------------------------------------------------------------------

    Third row ejections are a very limited part of the ejection 
population; in target population crashes they constitute only 0.3 
percent and 0.7 percent of fatalities and MAIS 3+ injuries. 
Nonetheless, we proposed coverage to three rows since many vehicles 
already on the market with three rows of seating are equipped with 
rollover deployable side curtain air bags that cover daylight openings 
adjacent to all three rows. This trend toward third row coverage has 
continued. Further, we wanted to cover as much of the side opening as 
reasonably possible because we were concerned that, if only the first 
two row windows were covered, in a rollover crash unbelted occupants 
contained from ejecting through the first two windows could be ejected 
from an uncovered opening adjacent to the third row. To reduce that 
risk of ejection, and importantly, given that the ejection mitigation 
side air curtains installed on current vehicles demonstrate the 
practicability and cost-efficiency of a curtain spanning the side of 
the windows from the first through third rows, we felt justified in our 
decision to provide coverage of third row windows. Vehicles the agency 
has tested for this rulemaking with air bag curtains covering rows 1, 2 
and 3 windows are the MY 2005 Honda Odyssey, MY 2006 Mercury Monterey, 
MY 2007 Chevrolet Tahoe, MY 2007 Ford Expedition, MY 2007 Jeep 
Commander, MY 2008 Dodge Caravan, MY 2008 Ford Taurus X, and MY2008 
Toyota Highlander. These designs are typically a single curtain 
covering tethered at the A and D-pillars.
    Insufficient reasons are available to support requiring side 
daylight opening coverage into 4th and higher rows.\118\ Fourth and 
higher row ejections are a very limited part of the ejection 
population; in target population crashes they constitute only 0.6 
percent and zero percent of fatalities and MAIS 3+ injuries, 
respectively. Extending coverage to 4+ rows goes beyond curtain air bag 
coverage that we have seen on any vehicle. It may be possible 
technically to extend a single curtain air bag to cover beyond 3 rows, 
or conceivably manufacturers could use two curtain air bags to cover 
the entire side of the vehicle. However, for a two curtain system 
without intervening pillars there is likely a need to tether the 
curtains together in order to provide tension near the curtain bottoms. 
We do not know if curtains tethered together will be able to meet the 
performance requirements of the standard adopted today. Moreover, 
depending on the design, the costs for covering windows adjacent to 4+ 
rows may be substantial.
---------------------------------------------------------------------------

    \118\ 74 FR 63201
---------------------------------------------------------------------------

    Glazing manufacturers have indicated that some vehicle 
manufacturers place advanced glazing in fixed window positions in the 
rearmost rows of large vans. However, we have not tested these glazing 
applications to the adopted requirements, nor has any data been 
submitted to the agency. Thus, the performance of a glazing-only 
application in these higher rows is not known to us.
    Given the above uncertainties about the availability and cost of 
countermeasures that could be used to cover windows adjacent to 4+ 
rows, and in view of the small numbers of ejections through those 
windows, we decline to extend this final rule to window openings beyond 
the 3rd row.
ii. Method of Determining 600 mm Behind Seating Reference Point (SgRP)
    The Alliance commented that limiting the daylight opening to 600 mm 
behind the SgRP of the last row seat or behind the rearmost portion of 
a seat not fixed in the forward seating direction, in combination with 
the targeting method, ``can result in targets being located in cargo 
areas and/or behind and below seat backs and head restraints.'' The 
Alliance believed that rearward occupant motion is resisted by the seat 
back and head restraint and that this is not considered by the ``600 mm 
method.'' It also stated its belief that the combination of seats and 
seat belts ``greatly reduces the risk of head and upper torso ejection 
in the area created by the proposed `600 mm' method.''
    The Alliance suggested an alternative of using the Head Restraint 
Measurement Device (HRMD) defined in FMVSS No. 202a to establish the 
rearward extent of the head. This approach would provide the limit of 
the daylight opening in the 3rd or last row.
    Honda suggested that the fact that the 600 mm limit in FMVSS No. 
226 is the same as in FMVSS No. 201 may not be appropriate when 
considering that FMVSS No. 201 has a different basis and objective than 
that of ejection mitigation. Honda suggested a different procedure to 
determine the daylight opening limit, which takes into consideration 
the movement of belted occupants in rollovers as well as the many fore-
aft and seat back angle adjustments. Honda's method is based on the 
height of a 95th percentile occupant, with 200 mm added (1,018 mm) to 
account for upward movement of a belted occupant during a rollover. A 
1,018 mm radius arc is centered at the SgRP and swept through the 
daylight opening. A reference line is drawn parallel to the torso line 
and translated 155 mm rearward and perpendicular to the torso line. The 
arc and the rear reference line provide the boundaries for the daylight 
opening.
    NTEA stated, ``NHTSA [should] consider adopting testing parameters 
similar to those found in [S6.3(b)] FMVSS 201 to effectively exclude 
any targets that are located behind the forward surface of a partition 
or bulkhead * * * . We believe it is neither practical nor beneficial 
to require test target points that could not possibly be contacted by 
the head of an occupant seated forward of the partition.''

[[Page 3263]]

Agency Response
    The Alliance objected to the 600 mm limit because it ``can result 
in targets being located in cargo areas and/or behind and below seat 
backs and head restraints.'' The Alliance's comment suggesting that 
seat belts would reduce the risk of an occupant's head and torso being 
ejected in the area behind the seat back and head restraints is not 
consistent with this final rule's goal of reducing partial and full 
ejections of belted and unbelted occupants. Similarly, the suggested 
use of the HRMD to define the limit of the opening in the third row 
disregards that this final is intended to protect belted and unbelted 
occupants.
    It is correct that the 600 mm limit can result in target areas in 
the cargo area and/or behind and below the seat back. We chose that 
limit to address what can occur in the field. Our field data 
assessment, discussed in section IX.b. and in our technical report, has 
several cases where occupants were ejected rearward of their initial 
seated position. In RODSS case 5032 (SCI CA09061) a driver was 
completely ejected through the left 3rd row quarter panel window. In 
NASS case 2006-79-89 the driver was partially ejected from the left 2nd 
row window. In SCI case DS04016, an infant seated in the middle of the 
2nd row was ejected through the 3rd row quarter panel window.
    These cases demonstrate how rollovers, particularly of the long 
duration multiple quarter-turn variety, are chaotic events with complex 
vehicle and occupant kinematics that can result in occupants moving 
rearward of their seating position. In addition, rollovers can be 
preceded by planar impacts with a substantial rearward component, 
resulting in occupants moving towards the rear of the vehicle. The bulk 
of the benefits from this standard are for unbelted occupants. The 
limitations suggested by the vehicle manufacturers are not consistent 
with protecting this population. For the agency, the issue is not 
whether the standard will cover some area rearward of a seating 
position, but how far behind the seating position.
    We decline to adopt Honda's technical method for limiting the 
daylight opening. Our technical report explains that the Honda method 
would result in a smaller area of coverage and potentially fewer impact 
targets than the NPRM method. Briefly stated, a small part of the area 
described by Honda would actually be farther rearward than the NPRM 
limit. However, the Honda derived limit has a smaller area overall. For 
some large windows, using the Honda method results in only two targets 
fitting in the window opening, whereas the NPRM's method results in 
four impact locations. Further, the Honda method increases the 
complexity of the standard.
    Honda suggested that selection of a 600 mm rearward limit, to the 
extent that it is potentially based on FMVSS No. 201, may be too great 
a distance. We do not agree on this point. To the extent that FMVSS No. 
201 attempts to protect occupants from interior impact in all crash 
modes, including rollovers, we believe that FMVSS No. 226 should be no 
less expansive in its rearward coverage than FMVSS No. 201. Moreover, 
since rollovers make up the largest portion of the target population 
for FMVSS No. 226, and because rollovers result in more chaotic 
occupant motion than any other crash type, it is our view that FMVSS 
No. 201's coverage should not prescribe the limits of the coverage of 
FMVSS No. 226.
    The suggestions of the Alliance and Honda to reduce the 600 mm 
value will dampen the effectiveness of this final rule in protecting 
unbelted occupants in rollovers. Accordingly, we deny the requests. (We 
respond to NTEA's suggestion in the ``Vehicle Applicability'' section 
of this preamble.)
iii. Increasing 600 mm Limit for Vehicles With One or Two Rows of Seats
    The NPRM proposed to limit the requirement to provide side daylight 
opening coverage to an area bounded by a plane 600 mm behind either the 
SgRP of a seat in the last row (for vehicles with fewer than 3 rows) or 
the SgRP of a seat in the 3rd row (for vehicles with 3 or more rows). 
As a result, for a vehicle with only one or two rows and with a cargo 
area behind the seats, all or part of the cargo area daylight opening 
rearward of that 1st or 2nd row would have been excluded under the 
NPRM.
    After reviewing the comments from glazing manufacturers and 
Advocates and the updated field data showing the prevalence of 
ejections through side glazing in the area of the first three rows, we 
have reconsidered the proposed 600 mm limit for vehicles with less than 
3 rows. We have also reconsidered this issue after reflecting on AIAM's 
comment which asked for clarification on whether a vehicle having 
windows to the rear of the last row of seats (e.g., 2 rows of seats but 
a third side window next to the rear cargo area) would be subject to 
testing of the third side window.
Agency Response
    For vehicles with only one or two rows of seating, we have decided 
to increase the 600 mm distance to 1,400 mm, measured from the SgRP of 
the seat in the last row. By extending the distance to 1,400 mm, we are 
subjecting more area of glazing to testing, i.e., more of the glazing 
area in cargo area behind the 1st or 2nd row will need an ejection 
mitigation countermeasure. The window openings subject to testing under 
the 1,400 mm limit are those that would have been adjacent to a third 
row seat had the vehicle had a third row.
    There is a safety need to cover this cargo area. In the NPRM (see 
Tables 16 and 17 of the NPRM preamble), we provided the distribution of 
ejected occupants by ejection route for all crashes. In these data 
tables, we did not have a category for cargo area ejections because 
data were not available. For this final rule, we undertook a manual 
review of each case to update ejection route data provided earlier in 
this preamble. In that review, we found that 0.5 percent of ejections 
in all crashes (and target population crashes) were ejected through the 
cargo area behind the 2nd row.\119\ This is slightly more than the 
percentage for 3rd row ejections.
---------------------------------------------------------------------------

    \119\ There were no ejections through the cargo area windows 
behind any other row.
---------------------------------------------------------------------------

    Further, our field data assessment discussed in section IX.b 
included a number of cases where occupants were ejected rearward of 
their initial seated position. As described earlier, in RODSS case 5032 
(SCI CA09061), a driver was completely ejected through the left 3rd row 
quarter panel window. In NASS case 2006-79-89, the driver was partially 
ejected from the left 2nd row window. In SCI case DS04016, an infant in 
the middle of the 2nd row was ejected through the 3rd row quarter panel 
window. These cases demonstrate how rollover crashes are complex 
turbulent events that can propel unbelted occupants rearward in the 
vehicle. Rollovers involving planar impacts having a substantial 
rearward component can thrust an unbelted occupant rearward toward the 
rear window openings in a manner unlike other crash types.
    Vehicles are already being produced that have side air bag curtains 
covering rows 1, 2 and 3 row windows (e.g., the MY 2005 Honda Odyssey, 
MY 2006 Mercury Monterey, MY 2007 Chevrolet Tahoe, MY 2007 Ford 
Expedition, MY 2007 Jeep Commander, MY 2008 Dodge Caravan, MY 2008 Ford 
Taurus X, and MY 2008 Toyota Highlander). The designs typically use a 
single curtain

[[Page 3264]]

covering tethered at the A- and D-pillars.\120\ Since there are designs 
that provide three rows of coverage, we believe that covering the cargo 
area behind the 1st or 2nd row of a vehicle up to window openings 
adjacent to where a third row would have been, offers no more of a 
technical challenge than manufacturers face in covering all openings 
adjacent to the 3rd row for vehicles with three rows.
---------------------------------------------------------------------------

    \120\ The MY 2007 Chevrolet Tahoe uses a separate curtain to 
cover the 3rd row window.
---------------------------------------------------------------------------

    Our FRIA calculates the cost effectiveness of extending a two-row 
curtain to cover the cargo area behind the second row and finds that it 
has a similar level of cost effectiveness as 3rd row coverage.\121\ 
Accordingly, it is reasonable and appropriate for this final rule to 
include impact targets in window openings in the cargo area behind the 
1st and 2nd row for vehicles with one or two rows of seating, if the 
window openings are located where they would have been adjacent to a 
third row seat had the vehicle had a third row.
---------------------------------------------------------------------------

    \121\ These cost effectiveness estimates are based on the cargo 
area and/or 3rd row area coverage alone. If they were to be lumped 
together with the first 2 rows of coverage, they become even more 
cost effective.
---------------------------------------------------------------------------

    We have determined that a third row seat would have been 
encompassed in an area bounded by a transverse plane 1,400 mm behind 
the rearmost SgRP of a first row seat (for vehicles with only one row 
of seats) or a second row seat (for vehicles with two rows of seats). 
Thus, we are extending the NPRM limit for these vehicles that have a 
cargo area behind the first or second row and no other row of seats, by 
800 mm. We arrived at the 1,400 mm value through a small study of 
curtain coverage length of late model 3 row vehicles beyond the 2nd row 
SgRP. This study included 14 of the MY 2006 to MY 2009 vehicles that 
were in the agency impactor testing program. These vehicles had 3rd row 
rollover curtains or curtains covering the cargo area behind the second 
row. Our measurements indicated that a 1,400 mm dimension rearward from 
the 2nd row SgRP would cover the entire daylight opening area for all 
except one of the vehicles.\122\
---------------------------------------------------------------------------

    \122\ More details of this study can be found in the technical 
report supporting this final rule.
---------------------------------------------------------------------------

    The final rule will maintain the 600 mm value for vehicles with 3 
or more rows.
3. Answers to Questions About Method for Determining Three-Row Area
    i. AIAM and Hyundai asked: (a) Is the targeting procedure done on 
the entire daylight opening and then the targets are limited to those 
that are in the area forward of the 600 mm line; or (b) is the 
targeting procedure done only on the area forward of the 600 mm line. 
In addition, if (a) above is the answer, Hyundai sought clarification 
on whether the entire target outline needs to be located in the 
daylight opening or just the center of the target outline.
    Our response is that the targeting procedure is performed on just 
the area forward of the 600 mm line (the second answer above), for a 3 
row vehicle. (As indicated above, this final rule specifies this 
dimension as 1,400 mm for vehicle with fewer rows.) Proposed 
S5.2.4.2(a) stated in part that ``the transverse vertical vehicle plane 
defines the rearward edge of the daylight opening for the purposes of 
determining target locations.'' The regulatory text adopted by this 
final rule (at S5.2.1.2(a)) slightly modifies the proposed text by 
indicating that the transverse vertical plane defines the rearward edge 
of the offset line (rather than the daylight opening) for the purposes 
of the targeting procedure performed on the daylight opening. To 
reiterate, the wording does not specify that the targeting procedure is 
performed on the entire opening and then only the targets forward of 
the 600 mm limit are used.
    ii. NTEA asked if side daylight openings behind occupants of side 
facing seats would be subject to the standard since the SgRP is 
parallel to the opening. Similarly, for rear facing seats, NTEA asked 
whether the side opening associated with such a seat is tested and 
would glazing on the opposite side of the vehicle be tested. Finally, 
NTEA asked if there was a lateral distance from any side glazing to the 
SgRP of a forward or rear-facing seating location, beyond which the 
requirements for the testing would not apply.
    Our answer is that daylight openings adjacent to both side and rear 
facing seats are potentially required to be targeted if they are part 
of the first three rows of seating. The definition of ``row'' adopted 
by the standard is still applicable. If these seats are fixed in a side 
or rear facing direction, the SgRP is not used to determine the 
rearward limit of the daylight opening. Rather, the limit is determined 
by the location of a vertical lateral vehicle plane located behind the 
rearmost portion of the rearmost seat. See proposed S5.2.4.2(a) and 
(b), and S5.2.1.2(a) and (b) in this final rule.
    Daylight openings on either side of the vehicle are subject to 
testing even if the seat or seats in that row are on the opposite side 
of the vehicle. There is no limit on lateral distance from a seat to a 
daylight opening that would exclude an opening from coverage. Crash 
data from the field have shown that an occupant on one side of a 
vehicle can be ejected out of an opposite side window. These provisions 
are to reduce the likelihood of such ejections.

e. How We Are Testing The Ability Of These Side Windows To Mitigate 
Ejections

1. What is a ``Window Opening''?
    The NPRM proposed to define ``side daylight opening'' as--

other than a door opening, the locus of all points where a 
horizontal line, perpendicular to the vehicle vertical longitudinal 
plane, is tangent to the periphery of the opening, including the 
area 50 millimeters inboard of the window glazing, but excluding any 
flexible gasket material or weather stripping used to create a 
waterproof seal between the glazing and the vehicle interior.
i. 50 mm Inboard of the Glazing
    Reference to the area 50 mm inboard from the window glazing was 
intended to account for interior vehicle structure that might be in the 
vicinity of the daylight opening, which could restrict the size of the 
opening through which an occupant could be ejected. In other words, we 
wanted to include, as part of the opening, vehicle structures that were 
within 50 mm of the window opening, if those structures could restrict 
ejection through the opening.
    The Alliance generally agreed with the proposed definition of 
daylight opening, except the commenter suggested extending the distance 
from the inside of the window glazing from 50 mm to 200 mm. The 
Alliance believed that the proposed 50 mm value ``may result in 
structures or trim proximal to the daylight opening to be removed to 
gain access to a target location. Removal of these structures or trim 
could result in an unintended consequence of laboratory performance 
reduction of the ejection mitigation countermeasures.''
    AIAM did not request a change in the 50 mm value, but rather asked 
for clarification about the inclusion of ``items of trim such as grab 
handles [that] may extend into the window area, potentially interfering 
with the motion of the impactor during a test.'' AIAM suggested that 
the standard specify one of the following: removing the trim item prior 
to the test, adjusting the target location so that the trim item is not 
engaged during impactor movement, conducting the test notwithstanding 
the interference of the trim item, or eliminating the target from 
testing requirements. Similarly, Honda and Hyundai requested guidance 
on

[[Page 3265]]

positioning and/or removal of interior components, such as sun visors, 
the instrument panel, interior and exterior mirrors, and grab handles. 
Hyundai stated ``certain interior structures which do not restrict the 
size of the daylight opening could still interfere with the linear 
travel of the impactor headform in the area 50 millimeters or more 
inboard toward the vehicle centerline from the window glazing interior 
surface.''
    Nissan asked that testing be performed without the headliner. It 
stated: ``Nissan does not anticipate the headliner affecting 
performance of the side curtain air bag system. Though the headliner 
might affect the initial trajectory of the deploying side curtain air 
bag, the proposed delay times of 1.5 seconds and 6 seconds ensure 
sufficient time for full deployment, allowing the curtain air bag to 
correctly position itself prior to contact with the impactor. Replacing 
the headliner between tests would unnecessarily increase test 
complexity and could result in lab error.''
Agency Response
    We believe the Alliance's request that the definition for side 
daylight opening be modified to increase the 50 mm distance inside the 
window has some merit. We have examined interior trim components, such 
as panels covering the vehicle pillars, and found that surfaces that 
should be considered as part of the outline of the daylight opening can 
be more than 50 mm inside the window glazing. Figure 12 is a schematic 
showing the cross-section of a hypothetical door panel and glazing 
whose horizontal tangent is 60 mm inside the glazing. Based on the 
vehicles we examined, we believe that increasing the distance to 100 mm 
will be sufficient to encompass interior borders and other components 
around the daylight opening that might not be easily removed and whose 
removal may have an unknown effect on the performance of the 
countermeasure. These components could have a positive effect on 
ejection mitigation, so our decision is that the determination of the 
side daylight opening should be made with the components in place.
[GRAPHIC] [TIFF OMITTED] TR19JA11.018

    We will not increase the distance to 200 mm, however. A 200 mm 
distance is excessive and potentially includes more vehicle components 
in the determination of the window opening periphery than necessary. 
Although the linear impactor travels along a lateral horizontal path, 
during a rollover, people moving towards the window opening would not. 
Objects 200 mm from the window opening may have no ability to limit the 
potential for ejection. The Alliance did not provide a rationale 
justifying a 200 mm limit.
    One concern we had relative to increasing the inboard distance from 
50 mm to 100 mm was that even the 100 mm distance increases the 
possibility of including inappropriate vehicle components in the 
determination of the periphery of the window opening. The components 
should not be included because they are not relevant to the actual 
ejection portal, i.e., they are unlikely to have a positive effect in 
mitigating ejection.
    One of these components is the vehicle seat. In S6.3 of the 
proposed regulatory text, we expressly specified that the seat may be 
removed to conduct the test in an uncomplicated manner. Relatedly, in 
view of our increasing the inboard distance defining the opening to 100 
mm, the final rule at S3 will specifically exclude seats from 
consideration in the definition of daylight opening.
    Similarly, the agency also believes that we should expressly list 
grab handles as components that will not be included in the 
determination of a ``side daylight opening.'' Both Hyundai and AIAM 
asked for clarification of the treatment of grab handles. Hyundai's 
comments showed two examples of grab handles that were both outside of 
the 50 mm limit (108 mm and 75 mm) proposed in the NPRM. At a distance

[[Page 3266]]

limit of 100 mm, one of these grab handles would be included, unless 
specifically called out for exclusion.
    We believe grab handles should be excluded from contributing to the 
daylight opening for several reasons. First, we think it unlikely that 
they will contribute anything positive to ejection mitigation. Second, 
we believe there is a possibility that grab handles could interfere 
with the ejection impactor in the test. The final rule will add them to 
the definition of side daylight opening in S3 as an item that is 
excluded from consideration in the definition of the daylight opening 
(and to S6.3 as an item that can be removed if it obstructs the path of 
the travel).
ii. Conducting the Test With Various Items Around the Window Opening
    The comments from AIAM, Honda, and Hyundai also extend to items of 
interior structure, aside from grab handles, that are not included in 
the definition of the daylight opening (because they have no potential 
for mitigating occupant ejection), but could restrict the travel of the 
impactor headform. AIAM suggested multiple ways of handling these items 
other than their removal, i.e., changing the target position, 
eliminating a target, or performing the test with the item in place. In 
the NPRM, S6.3 specifically allowed for the removal of seats and the 
steering wheel. Our goal was to make sure the testing could be 
performed, even if these items need to be removed, as these items would 
provide no impediment to ejection in the real world.
    We agree with AIAM, Honda, and Hyundai that there is a need to 
provide more specificity in this part of the standard (S6.3 and S6.4 of 
the final rule). One item mentioned by commenters was the exterior 
mirror. We believe this component is worthy of specific mention in the 
regulatory text as being an item that should be removed or adjusted so 
as not to impede the motion of the headform beyond the vehicle. As 
indicated by the National Forensic Engineers in its comments, exterior 
mirrors may break off during rollovers and are unlikely to have a role 
in mitigating ejection.
    In the final rule, S6.3 will now specify that steering wheels, 
seats, grab handles and exterior mirrors may be removed or adjusted to 
facilitate testing and/or provide an unobstructed path for headform 
travel through and beyond the vehicle. In addition, we have added the 
steering column to the list since it is attached to the steering wheel 
and may be the means by which the steering wheel is removed or 
adjusted.
    Beyond these components mentioned in S6.3, there are others that 
may obstruct the impactor path. For example, one could conceive of a 
rear drop-down entertainment center that blocks the upper targets. To 
address these items, S6.4 in the final rule will indicate that other 
vehicle components or structures may be removed or adjusted to provide 
an unobstructed path for the headform to travel through and beyond the 
vehicle.
    Nissan requested that the final rule allow testing on a ``cut 
body'' and not a fully trimmed vehicle. It also requested that testing 
be done without the headliner since Nissan believes that the headliner 
will not affect the test results, but may instead result in laboratory 
error. Similarly, TRW wanted testing on a buck to be allowed.
    We decline to make these changes requested by Nissan and TRW in the 
final rule. Manufacturers are free to conduct certification testing 
without the headliner, or on a cut body or test buck, as long as they 
are assured that the vehicle would meet FMVSS No. 226 when tested by 
NHTSA in the manner specified in the standard. We particularly 
understand why manufacturers might want to test on a cut body or buck 
during developmental testing. However, the agency prefers to test a 
vehicle in as near the as-manufactured condition as practicable, to 
better ensure that the performance we witness in the compliance 
laboratory is representative of the performance of the vehicle in the 
real world.
    However, we recognize that there are practical difficulties of 
testing the ejection mitigation countermeasure in a laboratory. We have 
decided that S6.4 in the final rule will include language specifying 
the adjustment or removal of vehicle structure that interferes with the 
ejection propulsion mechanism and headform travel, but only to the 
extent necessary to allow positioning of the ejection propulsion 
mechanism and unobstructed path for the headform to travel. It has been 
our experience that for daylight openings that are not located in 
doors, there may be limited access on the opposite side of the vehicle 
to pass the impactor propulsion mechanism through. This may then 
require removal of a fixed window and or cutting of sheet metal to 
allow access on the non-tested side of the vehicle. These modifications 
will not affect the results of the impact testing.
iii. Removing Flexible Gasket Material For the Purpose of Determining 
the Daylight Opening
    To keep the test area as large as possible, the proposed ``daylight 
opening'' definition excluded any flexible gasket material or weather 
stripping used to create a waterproof seal between the glazing and the 
vehicle interior. Flexible material is unlikely to impede occupant 
ejection through the opening.
    Honda stated that while it understood the agency's desire to 
exclude gasket material from the daylight opening definition, it was 
concerned about the material being difficult to remove or damaged 
during removal for determination of the opening. Honda proposed an 
alternative where the gasket material is included in the daylight 
opening, but the 25 mm offset line defined in proposed S5.2.1(b), is 
decreased. It stated that this ``retains the intention of addressing 
occupant ejection through side glazing, but test repeatability and 
validity are better assured.'' Similarly, TRW recommended that the 
opening be measured considering any gasket/weather stripping as 
potentially defining the opening, but the offset line be 20 mm from the 
opening rather than 25 mm. Honda stated that manufacturers would not 
enlarge the gasket material to reduce the daylight opening because of 
``styling, appearance and consumer acceptance.'' Nissan stated that 
``removing this [gasket] material prior to the test could expose the 
side curtain air bag system to sharp edges on the vehicle that it would 
not normally be exposed to during deployment and adversely affect 
system performance.''
    Both the AORC and TRW recommended that the agency obtain CAD data 
from the vehicle manufacturers and use this to determine the daylight 
opening and offset line. They believed that this would obviate the need 
for removal and reinstallation of the gasket/weather stripping, which 
they believed could lead to potential test variability.
    Guardian, a glazing supplier, commented that: ``The NPRM defines a 
window opening as the `daylight opening' (page 63204). We believe the 
opening should include all related trim and gaskets that could be 
removed with the glass in a rollover situation.''
    In contrast, Takata indicated agreement with the proposed method of 
determining the target location.
Agency Response
    We disagree with commenters that wish to allow gasket material or 
weather stripping to have a part in defining the opening. We continue 
to believe that this has the potential of causing an unnecessary 
reduction in the size of the opening, which may reduce the stringency 
of the test.

[[Page 3267]]

    Most commenters wishing to include gasket material in the 
definition were concerned about potential test problems associated with 
removal and reinstallation of this gasket material or weather stripping 
in order to determine the daylight opening. We address the issue of 
testing with this material in the next section. In summary, we do not 
share this concern.
    Both AORC and TRW suggested that CAD information submitted by 
manufacturers could be used by the agency to define the daylight 
opening, rather than removing any gasket material. It is certainly true 
that the agency can ask for information from manufacturers and this has 
been done for other FMVSSs \123\ and is a part of FMVSS No. 226's 
framework concerning the rollover sensor.\124\ However, we do not 
believe such a requirement is needed regarding the measurement of the 
window opening. We prefer to have a test procedure within the 
regulatory text of the standard that we can use to independently assess 
factors used in the compliance test, such as the size of the window 
opening, rather than depend upon information provided by the 
manufacturers.
---------------------------------------------------------------------------

    \123\ For example, S22.4.1.2 of FMVSS No. 208 requires knowledge 
of the volumetric center of the static fully inflated air bag. The 
agency requires this information from vehicle manufacturers.
    \124\ The agency can ask the manufacturer to provide information 
about the rollover sensor's deployment capabilities. See proposed 
S4.2.4, Technical Documentation.
---------------------------------------------------------------------------

    TRW and Honda suggested a reduction in the offset line distance, 
defined in proposed S5.2.1(b), if the agency chooses to include gasket 
material in measuring the daylight opening. Honda did not suggest a 
value, but TRW recommended a reduction from 25 mm to 20 mm. No data 
were provided to indicate that the 5 mm reduction would compensate for 
reduction in the size of the opening that would occur from inclusion of 
the gasket material. There could still be a risk that measuring the 
size of the opening with gasket material in place could artificially 
reduce the testable area in a manner not in the best interest of 
safety. Given our decision to exclude the gasket material, we are not 
reducing the offset line distance.
    On the other hand, we do believe that a small change in the 
definition of side daylight opening is necessary as it relates to 
gasket material and weather stripping. The NPRM referred to ``flexible 
gasket material or weather strip[p]ing used to create a waterproof seal 
between the glazing and the vehicle interior.'' During our research, it 
became apparent that gasket material, in addition to sealing the 
glazing, may also provide a weather-tight seal between the door and the 
door frame. For purposes of defining the window opening, this gasket 
material should be treated the same as gasket material used for sealing 
glazing, because if it were not, it could artificially reduce the size 
of the daylight opening. Accordingly, S3 in this final rule excludes 
flexible gasket material or weather stripping used to create a 
waterproof seal between the glazing and the vehicle interior and the 
door and the door frame from the definition of daylight opening.
iv. Testing With Flexible Gasket Material In Place
    In the section above, we stated that the final rule will continue 
to define the daylight opening without considering flexible gasket 
material or weather stripping. Thus, this material may, on some 
vehicles, need to be temporarily removed. However, this does not mean 
that the testing will be performed without this material. The NPRM 
proposed that the headform test be conducted with the flexible gasket 
material or weather stripping in place.\125\
---------------------------------------------------------------------------

    \125\ 74 FR 63205
---------------------------------------------------------------------------

    The air bag suppliers commenting on this issue supported testing 
with weather stripping. TRW stated ``the weather stripping must be 
present to provide representative inflatable countermeasure deployment, 
and occupant interaction with the countermeasure. Further, the absence 
of weather stripping during the test, could expose edges which could 
damage the countermeasure, affecting test performance.'' Takata stated 
that they ``agree with the NHTSA's proposal to determine the target 
location and carry out the testing with [the gasket] materials.''
    As indicate in the previous section, most commenters wishing to 
include gasket material or weather stripping in defining the daylight 
opening were concerned about potential test problems associated with 
removal and reinstallation. We have not experienced difficulty or 
complexity in dealing with the gasket material in our testing. It has 
been our experience that gasket material, due to its flexible nature, 
can be moved aside to allow access to the vehicle surfaces that create 
the daylight opening. If the gasket covers the relevant vehicle surface 
that defines the daylight opening and needs to be removed temporarily 
to allow access to that area, once the measurement is made removal of 
the gasket need not be done again to define the opening. No data was 
submitted to indicate such a single removal and reinstallation or, for 
that matter, multiple removals and reinstallations, would have any 
effect on test results. We do not believe that removing and 
reinstalling the gasket will have any notable effect relative to other 
factors influencing test variability, such as normal manufacturer 
build-to-build variability.
    We also agree with commenters who suggest that testing without this 
material may unnecessarily expose the air bag to sharp surfaces. In 
addition, the agency prefers to test a vehicle in as near the as-
manufactured condition as practicable. Thus, in the final rule we have 
not added any regulatory text that indicates that flexible gasket or 
weather stripping will be removed during testing, as we have done in 
S6.3 for other parts of the vehicle.
v. Metal Dividers in Glazing
    Hyundai requested clarification on how potentially non-structural 
steel dividing elements in a window opening should be handled. Our 
answer is such elements would serve to define the daylight opening 
since they do not consist of glazing. We currently have no reasonable 
way to exclude these dividing elements based on the extent to which 
they may or may not add structural integrity to the vehicle.
2. How We Determine Impactor Target Locations In An Objective And 
Repeatable Manner
i. Testing in ``Any'' Location
    The Alliance, AIAM, Honda, Hyundai, AORC, TRW and Takata all 
requested that the final rule maintain defined locations for the impact 
targets as opposed to allowing any point in the window opening to be 
targeted. The Alliance AIAM, Honda, and Hyundai suggested that testing 
at any target point in the window opening would increase the testing 
burden for manufacturers without providing any meaningful information, 
and would introduce uncertainty in the certification process. The 
Alliance stated that ``[t]he proposed up to 4 targets (without `target 
reconstitution') achieves NHTSA's stated goal to `assess how well the 
curtain covers the perimeter of the window opening' (FR 63204).'' 
(Emphasis in text). AORC stated that ``four impact points per window 
opening sufficiently represents the `worse case' * * * .'' TRW also 
agreed with the view that the NPRM ``adequately cover[s] the window 
opening by requiring that the most demanding locations of the opening 
be tested.'' Honda stated, in reference to

[[Page 3268]]

target points such as A1, that ``coverage of these most challenging 
points by FMVSS No. 226 will successfully provide ejection mitigation 
with the adoption of this regulation.'' Both TRW and Takata suggested 
that the specification of exact target points supports a high level of 
repeatability, reproducibility and robustness of testing. In contrast, 
Advocates stated that the fixed target method limits the areas to be 
tested and performance outside of those areas will not be known.
Agency Response
    We have decided to use the methodology of the NPRM to define the 
target points. First, we agree with the Alliance that the procedure 
using four defined targets achieves the agency's goal of assessing the 
coverage of the ejection mitigation countermeasure. We also agree with 
Honda's comment that the fixed target method will test or come very 
close to testing the worst case locations.
    In response to Advocates, in developing the final rule's test 
procedure, we sought to achieve a full and robust assessment of side 
window opening coverage. We intentionally selected target locations 
that we believed will provide the greatest challenge to the ejection 
countermeasure. Based on our test data to date, we remain confident 
that this is the case with our current target selection method. If we 
were to test at any location, manufacturers will have less certainty in 
the certification process. Whether this would result in increased test 
burden is not clear. Although the concept of testing the window opening 
at any potential impact point has merit, we do not believe it is 
necessary for this standard to reduce certainty, since testing at 
defined target points will achieve our safety objectives.
ii. Methodology
    The Alliance believed that the target locations should be 
determined in a manner consistent with the methods utilized by GM and 
Ford, which are based on occupant seating positions and ``up and out'' 
occupant kinematics in rollover events. The Alliance stated that GM 
uses three target points per window adjacent to a row of seating: (1) 
Upper rear; (2) centroid of window opening; and (3) head position of 
5th percentile female with the seat back at a 10-degree rearward 
incline from vertical and the head position projected forward 30 
degrees to the lateral axis. The Alliance indicated that, contrary to 
what was stated by the agency in the NPRM, for some vehicles, the lower 
forward GM target does not align with position A1. It stated that Ford 
uses three in the front window and two in the rear windows. Ford's 
front window locations are the same as GM's except that the target 
corresponding to the 5th percentile female position is projected 
forward from the lateral axis at 15 degrees rather than 30 degrees. For 
rear windows, Ford eliminates the 5th percentile female head target 
location.
    The Alliance also requested that the rear window targets be 
reversed, i.e., the mirror image from that proposed by the agency. It 
stated that this would provide a ``more consistent protocol'' because 
the front window and rear window targets would be located in the same 
way, while achieving the stated goal of assessing ``how well the 
curtain covers the perimeter of the windows opening.''
    The Alliance disagreed with the proposed method to add back a 
target (reconstitution). It believed that ``[t]he combination of FMVSS 
214 and FMVSS 226 requirements renders testing at any point and `target 
reconstitution' unnecessary and redundant to provide enhanced side 
curtain coverage.''
    Batzer and Ziejewski indicated that ``two impacts against the upper 
half of the glazing should be adequate.'' The commenter stated that for 
the bottom half of the window, the use of a headform is inappropriate. 
The commenter stated that known occupant danger for this region of the 
glass is arm and leg excursion and suggested that ``a new device that 
simulates a forearm or calf/foot can, and should, be developed to 
validate the side curtain airbag against this mode of excursion. This 
need not be a 10 mph impact, but merely an excursion test.''
Agency Response
    The agency has decided not to reduce the number of target locations 
as requested by the Alliance and Batzer and Ziejewski. As expressed in 
Honda's comment, coverage of the most challenging points like A1 are 
necessary for FMVSS No. 226 to successfully ensure that adequate 
ejection mitigation is provided. The same level of ejection mitigation 
performance is not assured by the suggested alternative procedures.
    We believe that three target locations are insufficient (and more 
so for the two locations resulting from the Ford procedure for rear 
windows) to test the entire perimeter of the daylight opening. The 
Alliance indicated that the GM and Ford target points are consistent 
with the assumption of ``up and out'' rollover occupant 
kinematics.\126\ However, such an assumption ignores the possibility 
that during long duration, multiple quarter-turn rollovers, occupants 
can move to openings after impacting the ejection countermeasure, and 
impact the countermeasure multiple times. In addition, the GM and Ford 
impact locations seem to be most relevant to the belted occupant 
situations. As we have stated many times, the bulk of the benefits of 
this final rule come from unbelted occupants. The suggestion of Batzer 
and Ziejewski for two impacts near the upper part of the window is not 
well defined. It is not clear to us if the commenter is requesting two 
impact locations or two impacts on the same countermeasure. The latter 
would only be possible for a glazing-only countermeasure. If it is the 
former, it is unsatisfactory for the same reasons that we have 
expressed about the Ford procedure. We know from our own testing of 
vehicle systems that testing point A1 is vital to determine if the 
countermeasure provides full and robust coverage.
---------------------------------------------------------------------------

    \126\ The commenter did not define the meaning of ``up and 
out.'' Based on the context of the Alliance's use of the ``up and 
out'' terminology, we assume that the term means that occupants 
would be ejected near their longitudinal vehicle location at the 
time of the rollover.
---------------------------------------------------------------------------

    We are also declining the Alliance request to modify the target 
locations for rear windows such that they are the reverse of that 
proposed in the NPRM for rear windows. In Figure 13 below, illustrating 
the suggested Alliance targeting, it is shown that the Alliance 
procedure targeting can provide a large gap for daylight openings with 
a forward rake. It is our experience that, to the extent that the rear 
windows have a rake, this rake is forward. For rear window openings, 
matching the front window pattern creates a large gap of coverage, as 
shown in Figure 13. Further, the Alliance methodology crowds the 
targets closer together, raising the potential for forcing the 
elimination of targets based on the target reduction methodology. We 
are not aware of any reason why it is important to have consistency 
between the protocol used in the front and rear windows. Accordingly, 
we are denying the Alliance and Batzer and Ziejewski requests.

[[Page 3269]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.019

iii. Reorienting the Targets
    The Alliance, Hyundai, AORC, TRW, NTEA and Pilkington were all 
opposed to reorienting the impactor headform.\127\ The Alliance stated 
that ``[if a daylight opening is such that the headform cannot fit with 
25 mm clearance when oriented with a vertical long axis, then NHTSA's 
goal to reduce the risk of head and upper torso ejection has already 
been achieved by the architectural characteristics of the vehicle, 
particularly when combined with belt usage.''
---------------------------------------------------------------------------

    \127\ This is the same as saying they did not want to rotate the 
targets, because the impactor headform orientation is aligned with 
the target orientation.
---------------------------------------------------------------------------

    Hyundai stated that they ``found that the side daylight opening of 
some vehicles with high belt-lines \128\ could not fit the outline of 
the impactor headform within the 25 millimeter offset line of the 
window opening.'' \129\ Nonetheless, Hyundai opposed the rotation of 
the headform by 90 degrees for windows with small vertical dimensions 
where no targets will fit with the typical impactor orientations. It 
stated ``these windows are unlikely exit portals.'' TRW believed that 
``revising the orientation of the headform for certain window shapes, 
while not doing so for others, does not appear to be based on any real 
world rationale.'' The Alliance, AORC and TRW raised testing concerns 
related to reorienting the impactor. The Alliance stated: ``Arbitrary 
deviations from [the NPRM] approach introduce unnecessary setup 
variation and also increase the complexity of the impactor design.''
---------------------------------------------------------------------------

    \128\ The beltline of a vehicle is a term used in vehicle design 
and styling referring to the nominally horizontal imaginary line 
below the side glazing of a vehicle, which separates the glazing 
area from the lower body.
    \129\ NHTSA-2009-0183-0044, p. 6.
---------------------------------------------------------------------------

    The agency has decided that the final rule will allow the 
reorientation of the targets and the associated reorientation of the 
impactor headform, under specific conditions. We believe that, all 
things being equal, the size of an uncovered side window has some 
correlation to the risk of ejection. A gap in coverage of a small 
window could be an ejection portal, just as it could be for a large 
window. If the test procedure in the final rule does not allow for 
rotation of the headform, it could allow large gaps in the window 
coverage that could provide an ejection portal.
    We examined two issues in investigating whether the headform should 
be reoriented. The first issue involved reviewing the number and 
location of impact targets for vehicles with relatively long and narrow 
side daylight openings (high beltline vehicles) under the NPRM 
targeting procedure. The second issue involved the pluses and minuses 
of systematically rotating the target outline in small increments in 
order to fit a single target in a window opening that would otherwise 
not accommodate a target.
    In an April 15, 2010 meeting with NHTSA, Ford showed the impact 
locations for many of their current and future vehicles.\130\ One of 
the vehicles was a MY 2010 Ford Taurus. In Table 40, we have summarized 
the number of impact targets in each daylight opening for many of the 
Ford vehicles, as provided by Ford.
---------------------------------------------------------------------------

    \130\ Docket No. NHTSA-2009-0183-47.1

     Table 40--Number of Targets per Daylight Opening for Ford Models, According to the NPRM Test Procedure
----------------------------------------------------------------------------------------------------------------
               MY                        Model                Type            Row 1        Row 2        Row 3
----------------------------------------------------------------------------------------------------------------
2010............................  Taurus.............  PC................            1            1           NA
2010............................  Lincoln MKS........  PC................            2            2           NA
2010............................  Lincoln MKT........  SUV...............            2            4           NA
2010............................  F150 Crew Cab......  PU................            4            4           NA
2010............................  F150 Super Cab.....  PU................            4            2           NA
2010............................  F150 Regular Cab...  PU................            4           NA           NA
2010............................  Flex...............  SUV...............            4            4            4
2010............................  Mustang............  PC................            3            0           NA
2011............................  Fiesta.............  PC................            3            2           NA
2012............................  Focus..............  PC................            2            2           NA
2012............................  Future SUV.........  SUV...............            3            3           NA
                                  Next Gen. Full Size  Van...............            4            4            4
                                   Van.
----------------------------------------------------------------------------------------------------------------

    This table indicates that, without target rotation, more than half 
[\7/12\] of the vehicles on the list would have fewer than four targets 
in the row 1 windows. Similarly, for the second row windows, seven of 
11 would have fewer

[[Page 3270]]

than four targets. This level of target reduction is much greater than 
we have seen in our research testing. There are several potential 
reasons for this emerging picture. First, manufacturers initially 
focused their introduction of rollover curtains on SUVs and pickups, 
which typically have larger windows. Second, the trend towards higher 
beltlines has reduced the height of windows.
    The question then becomes, how extensive is the window opening 
coverage for windows with fewer than four vertically oriented targets? 
To help answer this question we also examined a partial side view of a 
MY 2010 Chevrolet Camaro. This view is shown in the technical report 
for this final rule. In Figure 14 below, we drew the outline of the 
daylight opening and the associated 25 mm offset line for illustration 
purposes. (These are approximations given the resolution of the image 
and given that we did not know the dimensions of the flexible gasket 
material around the opening. Also, we could not determine the exact 
outline at the forward lower corner because the view was obscured by 
the outside mirror. However, to the extent this drawing differs from 
the actual image of the vehicle, the differences would not be 
significant for the purposes of discussion in this section.)
    If the targeting procedure defined in the NPRM is followed, the 
four initial target locations (primary and secondary targets) are as 
shown in the top graphic in Figure 14. (The procedure is explained in 
detail in the NPRM at 74 FR at 63205-63211.) Under the NPRM procedure, 
if the horizontal distance between target centers is less than 135 mm 
and the vertical distance between target centers is less than 170 mm, 
the targets are considered to be significantly overlapping and are 
eliminated. At the end of the process, only a single target would 
remain. See middle graphic of Figure 14(b). The forward edge of this 
target is 464 mm from the forward edge of the daylight opening outline, 
which would leave a large opening forward of the target untested. 
Occupant ejection could occur through that opening. Further, if the 
daylight opening were less than 1 mm smaller (a vertical dimension of 
less than 276.1 mm), under the NPRM procedure, there would be no 
targets in the window opening.
    If we perform the same targeting procedure as defined in the NPRM 
except with a horizontally-oriented target outline (the long axis 
oriented horizontally), the result is the four targets shown in the 
bottom graphic of Figure 14. The forward edge of the most forward 
target was 173 mm from the forward edge of the daylight opening.

[[Page 3271]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.020

    It appears that, if the target outline were to be kept only 
vertical, there would be an artifact in the test that could result in 
the exclusion of entire or large parts of some window openings from 
being tested, while not excluding a window that differed only by a few 
millimeters in dimension. For a long narrow window, the number of 
targets can jump from zero to four with an increase in vertical 
dimension of the window opening of only about 15 mm. If a long, narrow 
window had a vertical dimension of 277 mm, the NPRM procedure would 
result in no targets on the window opening. If the window vertical 
dimension were increased by only 5 percent, from 277 mm to 290 mm, 
under the NPRM procedure the targets would go from zero to four.
    Figure 15 shows the result of the NPRM's targeting process with the 
vertical dimension of the daylight opening increased by 3 percent (from 
277 mm to 285 mm). The four initial vertical target locations are shown 
in the top graphic. The target elimination process results in the two 
middle targets being removed but under the target reconstitution 
process a target is reconstituted between them; the final number of 
vertical targets is three, as shown in the middle graphic of the 
figure. The forward edge of the most forward target is 348 mm from the 
forward edge of the daylight opening, which is a substantial area. If 
we perform the targeting procedure with a horizontally oriented target 
outline, the four targets shown in the bottom graphic of Figure 15 
result. The forward edge of the most forward target is 159 mm from the 
forward edge of the daylight opening.
BILLING CODE 4910-59-P

[[Page 3272]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.021

    Figure 16 compares the horizontal coverage (dimension from leading 
edge of most forward target to the trailing edge of the most rearward 
target) of the daylight opening using the vertical and horizontal 
target outlines. The vertical targets show a great deal of sensitivity 
to the height of the daylight opening as opposed to the horizontal 
targets, which are very insensitive to opening height.

[[Page 3273]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.022

    The second issue we explored involved the pluses and minuses of 
systematically rotating the target outline in small increments in order 
to fit a single target in a window opening that would otherwise not 
accommodate a target. Figure 17 depicts a daylight opening that is too 
small to fit a vertically oriented target outline within the offset 
line. Under the NPRM targeting procedure, such a daylight opening would 
not be impacted. However, rotating the target in increments of 5 
degrees, from the initial vertical orientation, we find that the target 
outline will fit at an angle of 45 degrees.
[GRAPHIC] [TIFF OMITTED] TR19JA11.023

    We disagree with the Hyundai comment that suggested that, if there 
are no vertically oriented targets that can fit in a window under the 
NPRM procedure, it is unlikely to be a portal for ejection. We have no 
data that supports the view that occupants maintain a vertical 
orientation when ejected through a window in a rollover. Given the 
chaotic nature of rollovers, we do not expect this to be the case. We 
know of no convincing reason why the target should not be rotated at 
the window opening, given that a simple and small rotation will enable 
us to test a countermeasure in a satisfactory manner and ensure that 
the ejection mitigation device fully covers the window opening.
    If we specified that the targets may be reoriented (rotated) in a 
systematic manner, we could eliminate an artifact in the proposed 
procedure. In the section above, we saw that for a long

[[Page 3274]]

narrow window, the number of targets can jump from zero to four with an 
increase in vertical dimension of the window opening of about 15 mm. 
This is not desirable that a daylight opening would go from zero to 4 
targets when the vertical dimension of the opening is above or below 
276.1 mm. These artifacts of the combination of the window opening 
geometry and the orientation of the impactor under the NPRM are 
unacceptable, given that the standard would not assess the ability of 
the countermeasure installed at the window opening to prevent partial 
or complete ejections.
    Contrary to the Alliance comments that rotating the headform is an 
``[a]bitrary deviation'' of the test procedure, the agency believes 
that, for certain situations, to leave the headform in the vertical 
orientation would result in arbitrary results, not consistent with the 
need for daylight opening coverage. Similarly, we disagree with the TRW 
comment that implied that target reorientation needlessly complicates 
the test procedure. Rotating the target outlines would add little if 
any complexity to the standard. To the extent the procedure is more 
complicated, the need is justified.
    Accordingly, the agency has decided that this final rule will allow 
the reorientation of the targets and the associated reorientation of 
the impactor headform, under specific conditions. The conditions are 
discussed below.
    From the examples shown in the technical analysis above, any 
situation where fewer than four vertical targets can be placed in the 
daylight opening would allow for unacceptably large gaps in coverage. 
As shown in Figure 15, supra, the 3 vertically-oriented targets had 279 
mm less horizontal window coverage than did the 4 horizontally oriented 
targets and the forwardmost horizontal target was 189 mm more forward 
than the vertical target.
    Yet, the agency has chosen not to change the orientation of the 
impactor from vertical to horizontal when the same number of targets 
can be placed in the daylight opening in either orientation. This is so 
even though in some cases, it is possible that the horizontal targets 
provide more horizontal coverage of the window opening. There are 
several reasons for this decision.
    First, regardless of target orientation, if the same number of 
targets can be placed within the window opening then the area being 
impacted in both cases would be essentially the same. For example, 
looking at Figure 18 below, the target outlines impact approximately 
the same amount of area in the window opening. What differs is the 
distribution of the targets within the opening, which is solely a 
function of the opening shape. The horizontal targets cover more of the 
window opening towards the bottom of the A-pillar and the vertical 
targets more fully cover more of the remaining areas of the window.
[GRAPHIC] [TIFF OMITTED] TR19JA11.024


[[Page 3275]]


    Second, the bulk of our test data to date and the test data 
submitted by comments are with the impactor in the vertical 
orientation. This includes data that indicates that the proposed 
requirements are practicable. Without more test data with a horizontal 
orientation, we are reluctant to change the impactor orientation for 
all window openings. Notwithstanding that most of our testing was done 
with the impactor in the vertical orientation, when the number of 
targets is fewer because the target is oriented vertically, we believe 
that the importance of fuller window opening coverage outweighs all 
other considerations.
    Third, there are window openings that would otherwise not 
accommodate a target unless the target outline is rotated to some 
oblique angle. See Figure 17. We find it objectionable not to specify 
that the impactor may be rotated.
    We find no reasonable argument that would compel us not to allow 
rotation of the impactor beyond the vertical or horizontal 
configurations given that this might result in such a window not being 
covered by any countermeasure. To say that an occupant's head or some 
other body part cannot reorient itself during the rollover event, 
including the head or body part of a belted occupant, is not logical.
    The conditions for the rotation of the targets and impactor 
headform by 90 degrees to a horizontal orientation are specified in the 
final rule regulatory text at S5.2.5.2 and S5.6.2, respectively. The 
conditions for the incremental 5 degree rotation of the targets and 
impactor headform are specified in final rule regulatory text S5.2.5.3 
and S5.6.3, respectively. The 5 degree increment reorientation is about 
the y axis of the target and achieved by rotating the target's positive 
z axis toward the vehicle's positive x axis.\131\ At each increment of 
rotation, an attempt is made to fit the target within the offset line 
of the side daylight opening. At the first increment of rotation where 
the target will fit, the target is placed such that its center is as 
close as possible to the geometric center of the side daylight opening.
---------------------------------------------------------------------------

    \131\ Looking at the left side of the vehicle from the outside, 
the rotation is counterclockwise and looking at the right side of 
the vehicle, the rotation is clockwise.
---------------------------------------------------------------------------

iv. Suppose Even by Rotating the Headform the Vehicle Has No Target 
Locations
    AIAM and VSC requested that the regulatory text expressly state 
that vehicles without any target locations are excluded from the 
standard. Hyundai suggested that any window not having targets 
according to the proposed requirement should be excluded.
Agency Response
    We have added text to S4.2 of the standard to state that if a side 
daylight opening contains no target locations, the impact test is not 
performed on that opening.
    The vehicle is not excluded from FMVSS No. 226, however. There are 
a number of requirements in section S4.2 of the standard that apply to 
vehicles that have an ejection mitigation countermeasure that deploys 
in the event of a rollover. Paragraph S4.2.2 requires the vehicles to 
have a monitoring system with a readiness indicator meeting certain 
specifications. Paragraph S4.2.3 requires the vehicle owner's manual to 
have written information about the ejection mitigation system and the 
readiness indicator. Paragraph S4.2.4 requires the manufacturer of the 
vehicle to make available to the agency, upon request, certain 
information about the rollover sensor system. Vehicles that have an 
ejection mitigation countermeasure that deploys in the event of a 
rollover are subject to these requirements even if side daylight 
openings contain no target locations. Since the vehicle is subject to 
FMVSS No. 226, the vehicle may be counted as a vehicle that meets the 
ejection mitigation requirements of the standard for phase-in and 
advanced credit purposes.
v. Decision Not To Test Target of Greatest Displacement
    Vehicle manufacturers were supportive of a method to reduce the 
number of tests. However, not all supported the alternative presented 
in the NPRM to test at the 24 km/h impact speed at only the target 
location with the greatest displacement during the 16 km/h impact. 
Hyundai stated that ``no significant additional information would be 
gained by testing all of the lesser displacement locations.'' The 
Alliance alternatively suggested a single impact speed and time delay 
for all target locations (16 km/h with a 3.4 second delay). The 
Alliance opined that ``[d]eployment of side curtain airbags is highly 
dependent on placement of garnish trim and performance of attachments 
in the vehicle body. If a subsequent test needs to be performed [on] 
one side of a vehicle after an airbag is deployed, a new airbag and new 
garnish trim will have to be installed.'' \132\ They mentioned that 
this reinstallation may not be representative of factory installation. 
In addition, it alleges that attachment points may wear or deform after 
multiple tests.
---------------------------------------------------------------------------

    \132\ NHTSA-2009-0183-0029, p. 30.
---------------------------------------------------------------------------

    AIAM stated that ``[t]here would be no reduction in test burden 
unless the agency were to require manufacturers to identify which 
impact location had the largest displacement in their low speed 
certification testing, so that the agency could perform its high speed 
test at the same location. Otherwise, the manufacturer could be 
required to conduct high speed tests at all impactor locations, to 
assure that it has test data for the same location that the agency 
tests.''
    Air bag suppliers were mixed in their responses on this topic. TRW 
recommended ``keeping all four impact tests at both impact speeds. This 
is because NHTSA testing could identify a different `worst point' than 
is identified by the OEM in their tests. Therefore, vehicle 
manufacturers would likely need to test more extensively than NHTSA. 
Thus while the compliance testing burden may be slightly lowered, 
testing at the manufacturer [sic] will probably not be diminished 
significantly.'' Takata suggested the alternative of testing all target 
locations at the 24 km/h-1.5 second test, then performing the 16 km/h-6 
second test only at the location experiencing the greatest displacement 
in the first series. Takata believed that ``it is important to test all 
the locations at the high energy level to ensure structural integrity 
of the countermeasure device. This approach identifies a robust design 
and also reduces the number of tests.''
Agency Response
    After considering the comments, we have determined that the final 
rule will require that all target locations be impacted at the higher 
and lower impact velocities rather than just impacting one target 
location at the higher speed test. This adopts the regulatory text 
option presented in proposed S5.5(2A) (except, as discussed earlier in 
this preamble, the higher speed will be 20 km/h rather than 24 km/h).
    We found the comments from AIAM, TRW, and Takata to be informative 
and persuasive. We agree with AIAM and TRW that there is unlikely to be 
a significant reduction of test burden to the industry by only 
requiring a 1.5 second-high speed test at the location that yields the 
greatest displacement at the 6 second-low speed test. This is because 
our ejection mitigation side air curtain test data indicates that there 
is typically no clear distinction between the displacements of several 
of the target points in a vehicle window

[[Page 3276]]

opening. There sometimes is no clear distinction that a certain target 
is the ``weakest,'' showing the most displacement in the 16 km/h-6 
second test. Agency testing of production vehicles set forth earlier in 
this preamble indicates that the weakest target location is not obvious 
across data from the 24 km/h-1.5 second test, 20 km/h-1.5 second test, 
or the 16 km/h-6 second test. Based on limited data from our new 
impactor, we found that there is less difference in displacement 
between the 20 km/h-1.5 second and 16 km/h-6 second tests. (See rank of 
the displacement by target location for the second row testing of the 
MY 2008 Highlander, Tables 10-18, supra.) Thus, vehicle manufacturers 
might not be assured from their data which target location will be the 
weakest in a NHTSA test. Accordingly, they may end up testing all of 
the targets to all of the impact speeds.
    We also agree with Takata's comments that all target locations must 
be tested at the higher impact speed to assure that the testing 
determines the robustness of the designs. However, not only must the 
robustness of design be assessed at the top impact speed of 20 km/h, 
performance at 6 seconds must also be determined. The agency can only 
assure this by impacting all locations at 16 km/h with a 6 second 
delay.
    AORC suggested that the standard could specify that manufacturers 
will pronounce to us which target point should be tested at the higher 
speed. We do not agree with the logic of binding the agency to only 
impact target locations deemed by the manufacturer to have the greatest 
displacement in the 16 km/h test. Such an approach would be an 
unacceptable limitation of the agency's ability to independently 
determine how to test a vehicle.
    We also did not find compelling the comments expressed by the 
Alliance. We have already discussed and rejected the commenter's 
suggestion that FMVSS No. 226 should have only a single impact speed 
and time delay for all target locations (16 km/h with a 3.4 second 
delay).
    With regard to the commenter's suggestion that there should be only 
one 16 km/h test due to wear and tear on and effect of trim components 
on testing, we decline this suggestion also. There was no showing that 
issues related to trim components justify reducing the tests to a 
single impact speed. Moreover, the Alliance's concerns about trim 
components appear inconsistent with Nissan's comment. Nissan indicated 
that it would like the final rule to allow testing on an untrimmed 
``cut body'' and that the headliner would not be expected to affect 
performance of the side curtain air bag system. This indicates to us 
the possibility that trim components generally might not have a 
significant effect on curtain performance. The Alliance's comments 
about trim components are not substantiated and do not justify reducing 
the number of tests to one.
    This final rule does reduce a test burden on manufacturers of 
vehicles that use only non-movable (fixed) glazing as the ejection 
mitigation countermeasure to meet FMVSS No. 226, without use of a 
deployable ejection mitigation countermeasure. We have written the 
standard to apply only the 20 km/h-1.5 second test to the daylight 
opening with the non-movable glazing, and not the 16 km/h-6 second 
test. If the displacement limit can be met at the window opening in the 
20 km/h-1.5 second test, we will not subject the window opening to the 
16 km/h-6 second test. This is because the 20 km/h test would be 
redundant. If the displacement limit is met in the high speed test, we 
believe the limit will be met in the low speed test.
vi. Reconstitution of Targets
    The Alliance disagreed with the proposed method to add back a 
target (reconstitution). It believed that ``[t]he combination of FMVSS 
214 and FMVSS 226 requirements renders testing at any point and `target 
reconstitution' unnecessary and redundant to provide enhanced side 
curtain coverage.''
Agency Response
    We disagree with the Alliance's position that target reconstitution 
is unnecessary and redundant. A large space between two impact 
locations in a daylight opening is not consistent with our desire for 
full window coverage. Reconstituting (adding back) a target back 
between two distantly-spaced targets helps to meet our goal. We note 
that both the Ford and GM internal ejection test procedures have an 
impact location at the geometric center of the window. For many window 
shapes assessed under the procedures of this final rule, the target at 
the center of the window would be close to the location that would be 
covered by the middle target reconstituted. Thus, the Ford and GM 
procedures appear to recognize the merits of testing for full window 
coverage.

f. Glazing Issues

    The NPRM proposed to allow movable windows made from advanced 
glazing to be in position (up and closed) for the compliance test, but 
pre-broken by a specified test procedure to simulate the breakage of 
glazing during a rollover. Tempered (non-advanced) glazing shatters 
when broken, so for tempered glazing, we proposed that we would conduct 
the glazing breaking procedure and shatter the glazing, remove the 
glazing, or retract the glazing, at the manufacturer's option.
1. Positioning the Glazing
    The NPRM discussed the pros and cons of advanced glazing for 
ejection mitigation. Advanced glazing may enhance the performance of 
current air bag curtain designs. Vehicles tested by NHTSA showed an 
average displacement reduction across target locations and test types 
of 51 mm.\133\ However, the updated target population data show that 31 
percent of front seat ejections and 28 percent of all target population 
ejections are through windows that were partially or fully open prior 
to the crash. Further, the agency was concerned that in the real world, 
advanced glazing would not be as effective as an ejection 
countermeasure due to vehicle structural deformation and the effects of 
inertial loading of the window mass.
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    \133\ We stated in the NPRM that we believed that incorporation 
of advanced glazing for ejection mitigation would be relatively 
expensive compared to the implementation of air bags. The PRIA 
showed that the proposed requirements would add about $33 per light 
vehicle at a total cost of $568 million for the full curtain 
countermeasure. A partial curtain plus advanced glazing would have 
an incremental and total cost of $88 and $1,494 million, 
respectively.
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    The NPRM requested comments on several alternatives, including the 
alternative of testing all movable windows removed or retracted, 
regardless of whether the window is laminated or tempered; fixed 
laminated windows would be permitted to be kept in place, but pre-
broken.
Comments
    Commenters were divided in their views of how Standard No. 226 
should test vehicles that have advanced glazing covering a side 
daylight opening.
    Vehicle manufacturers and air bag suppliers did not support testing 
with advanced glazing in place. Ford stated that ``[s]ide glazing 
retention, regardless of construction-type (e.g., laminated or 
tempered), in real-world rollover crashes is random and 
unpredictable.'' Ford stated that side glazing retention ``is dependent 
on the unique characteristics of that particular crash (e.g., number of 
quarter turns, vehicle roll rate and deceleration, objects contacted, 
occupant loading, vehicle deformations, etc.).'' The commenter

[[Page 3277]]

referred to an SAE paper from Kramer, et al.\134\ in which the authors 
stated ``there is information from the field (FARS and other individual 
collisions) that document ejections through laminated side glass.'' 
Ford recommended \135\ that--
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    \134\ Kramer et al. ``A Comparative Study of Automotive Side 
Window Occupant Containment Characteristics for Tempered and 
Laminated Glass,'' SAE Paper 2006-01-1492.
    \135\ NHTSA-2009-0183-0020, p. 4.

the eventual requirements of FMVSS 226 be focused on rollover 
activated side curtain technology, with consideration of the 
associated capabilities of this 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.

    Honda had a similar view, stating that ``a vehicle with movable 
windows, being operated with a laminated glazing even partially open, 
could result in the window falling out of the window frame due to body 
deformation resulting from the crash or subsequent ground contact 
during a rollover event.'' It stated that because the pre-breaking 
procedure allows the window to be in the full up position it ``may not 
fully simulate real world conditions.'' Honda suggested that all 
testing should be done with the windows ``removed or retracted prior to 
the impact test instead of allowing pre-breaking for movable windows.'' 
For fixed laminated windows, the commenter said that ``the concerns 
mentioned above would not apply and pre-breaking would be a suitable 
method of simulating real world conditions * * *.''
    AORC and TRW expressed concerns about testing glazing with the 
window up. They suggested that the agency could test without any 
glazing present, but either increase the amount of allowable excursion, 
or reduce the energy level (i.e. reduce the impactor velocity) for 
impact locations which have advanced glazing, to reflect the enhanced 
performance expected if the advanced glazing were present.
    In contrast, glazing suppliers stated that all testing should be 
performed with the advanced glazing in place because they believed that 
the NPRM provided strong support of advanced glazing in reducing 
impactor displacement.
    Consumer groups overall supported the use of advanced glazing. IIHS 
described roof crush and side impact testing it did on several vehicles 
with front row laminated glazing. IIHS stated that all the laminated 
glazing remained intact within the window frame. IIHS suggested NHTSA 
provide an incentive to vehicle manufacturers to use advanced glazing, 
such as by testing all vehicles without the glazing in place but allow 
a higher displacement for vehicles equipped with laminated glazing. In 
contrast, Advocates suggested NHTSA should test with both air curtains 
and advanced glazing and require a much reduced displacement limit. 
Public Citizen wanted the final rule to specifically disallow the use 
of advanced glazing on a vehicle unless it was in combination with side 
curtain air bags. Public Citizen stated there is a lack of evidence 
that laminated glazing will perform well enough on its own.
Agency Response
    This final rule does not allow the use of movable glazing as the 
sole means of meeting the displacement limit of the standard (i.e., 
movable glazing is not permitted to be used without a side curtain air 
bag). It also specifies that if a vehicle has movable advanced glazing, 
the 16 km/h-6 second test will be performed with the glazing retracted 
or removed from the daylight opening. Our decision is based on the 
following factors.
    First, field data already evidence an incongruity between the 
glazing countermeasure and the foreseeable use of it by the public. The 
updated target population data show that 31 percent of front seat 
ejections and 28 percent of all target population ejections are through 
windows that were partially or fully open prior to the crash. We have 
no small concerns about a countermeasure that can be easily, totally 
and most likely unknowingly counteracted by motorists by the simple and 
everyday act of opening a window. As crash data show, many in the 
target population already operate their vehicles in a manner that 
negates the efficacy of the countermeasure. Any benefits accruing from 
advanced glazing will not be achieved if the window were partially or 
fully down.
    Second, in contrast to IIHS's roof crush and side impact laboratory 
test findings, the field data of real-world performance of advanced 
glazing are showing that even when movable advanced glazing is 
initially up, such glazing may not be present as an effective 
countermeasure beyond the initial phase of a rollover. Rollovers are 
one of the most severe and unpredictable vehicle crash events. Based on 
an analysis of field data and the comments on the NPRM, we are not 
confident at this time that movable advanced glazing used alone, 
without an ejection mitigation side air curtain to supplement it, will 
be a viable countermeasure throughout a rollover crash. The following 
illustrates some real world examples of the un-predictable nature of 
advanced glazing in rollovers.
    In NASS CDS case 2001-43-190, a MY 2000 Audi A8 experienced a left 
leading, four quarter-turn rollover.\136\ This vehicle did not have 
side curtain air bags. The unbelted driver was completely ejected 
through the sunroof. The belted front passenger was not ejected. The 
technical report accompanying this final rule shows the interior views 
of the passenger and driver sides of the vehicle, respectively. The 
passenger side laminated glazing has completely detached from the first 
and second row windows. However, the first and second row driver side 
windows are in place. The first row driver side window was coded as 
being partially open prior the crash. It remained so after the crash, 
although it was extensively damaged. The second row driver side window 
was in place and undamaged.
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    \136\ Although the NASS coding indicates that the first 2 rows 
of side windows were tempered glass, we determined this to be 
incorrect from the photographic evidence.
---------------------------------------------------------------------------

    In SCI case CA09063 (RODSS 7242), a MY 2003 Lincoln Aviator with 
laminated glass in the driver's side window sustained a head-on 
collision followed by a three quarter-turn rollover. This vehicle had 
rollover deployable curtain air bags, but they did not deploy. The 
driver and right front passenger were belted. There were no ejections. 
Both laminated driver and front row passenger windows detached from the 
window opening.
    In SCI Case CA10006 (RODSS 8289), a MY 2003 Lincoln Aviator 
experienced an eight quarter-turn rollover. This vehicle had rollover 
deployable curtain air bags, which deployed. The driver and right front 
passenger were belted. The belted driver was killed due to partial 
ejection of her head. Both laminated driver and front row passenger 
windows vacated the window opening. The passenger side window glazing 
is shown in the foreground of a photograph of the scene, completely 
detached from the vehicle.
    In these examples, it is not possible from the visual evidence to 
determine when in the rollover event the advanced glazing detached from 
the window opening, nor the cause(s) of the separation. In all except 
one of the cases there was a belted occupant adjacent to the window 
that detached from its opening. In these cases, occupant interaction 
may have been a factor. The rear passenger side window of the Audi did 
not have an adjacent occupant, so

[[Page 3278]]

occupant contact was not likely the cause of the window vacating the 
opening. Other potential causes are structural deformation and inertial 
forces due to impact or vehicle rotation.
    We found compelling the Ford and Honda comments discussing the 
potential for advanced glazing to detach from the window opening in 
real-world rollovers. We agree with Ford that the retention of advanced 
glazing, particularly movable glazing, can be a function of the random 
and unpredictable nature of rollovers. We also believe there is merit 
to the Honda contentions that movable advanced glazing could vacate the 
window frame due to vehicle body deformation resulting from crash 
dynamics or ground contact, even when the window is partially up, and 
that the pre-breaking procedure performed in a full-up position may not 
fully simulate these conditions. We found their comments to be 
consistent with the information presented above, which shows examples 
of field performance of advanced glazing (specifically laminated 
glazing) in several rollover and combination crashes (rollover in 
combination with planar impacts). Particularly interesting is the Audi 
A8 rollover, where the glazing on one side of the vehicle vacated, but 
the windows on the other side did not.
    Ejection is a major cause of death and injury in rollover crashes. 
As stated in our discussion of the safety need for this rulemaking, 
according to 2000-2009 FARS data, about half of the occupants killed in 
rollovers were completely ejected from their vehicle. 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. The ejection countermeasures that should be installed in 
response to this final rule are those which have been shown to perform 
well in keeping occupants in the vehicle in rollover crashes. We are 
unable, at this time, to assert our confidence in the ability of 
advanced glazing to retain occupants throughout a multiple quarter-turn 
rollover when used alone in movable window applications.
    We have learned from the comments about ways to improve FMVSS No. 
226's ability to distinguish between countermeasures. We saw that the 
test procedure should be enhanced to ensure that the vehicle will 
provide ejection mitigation protection throughout a multiple quarter-
turn real-world rollover. The proposed impactor test of ejection 
countermeasures is appropriate and worthwhile, but we have learned that 
to better replicate real-world conditions, it is imperative to remove 
any kind of glazing on a movable window when preparing for the 16 km/h-
6 second test. Since there is a reasonable possibility that the movable 
window glazing will vacate the vehicle in the later stages of the 
crash, by removing the glazing in the test we better replicate the 
real-world condition. Removing such glazing, and expressly stating in 
the standard that vehicles are not allowed to use movable glazing as 
the sole means of complying with the standard, assure that movable 
advanced glazing will be used with an ejection mitigation side curtain 
air bag or other deployable safety system. These provisions assure that 
the movable glazing will have to be supplemented by a side curtain air 
bag or other countermeasure, thus assuring a minimal level of safety in 
the event the window is partially or fully rolled down or vacates the 
window opening due to the dynamics of the crash.
    It is possible that there could be modifications to the designs of 
the window frame that may improve the ability of movable advanced 
glazing to remain within the window opening during a rollover.\137\ 
However, the agency currently does not have the information to make 
this determination. We assume that this is what the AORC meant when it 
stated that a single integrity test for laminated glazing could be 
established to verify retention. Unfortunately, we did not learn of 
these potential test parameters from the comments.
---------------------------------------------------------------------------

    \137\ The agency researched such window frame modifications 
during the research into advanced glazing as a standalone ejection 
mitigation countermeasure. ``Ejection Mitigation Using Advanced 
Glazings: A Status Report,'' November 1995, DOT DMS NHTSA-1996-1782-
3, pp. 4-7 to 4-10. Results indicated that adequate retention was 
maintained in the area of encapsulation, but that the unsupported 
(nonencapsulated) top edge was subject to large deflections. (pg. 7-
29).
---------------------------------------------------------------------------

    Some glazing manufacturers indicated that the problem of the open 
window could be mitigated by newer vehicle safety technology that rolls 
windows up prior to a crash. It is our understanding that at least some 
of these systems are initiated when the ESC is activated.\138\ ESC 
would activate in only a portion of the rollover events that make up 
our target population, i.e., most likely single vehicle rollover 
crashes. The remainder would not be covered. Moreover, the 
effectiveness, cost and practicability of an automatic roll up system 
in achieving the benefits of ejection mitigation throughout a multiple 
quarter-turn rollover has not been demonstrated.
---------------------------------------------------------------------------

    \138\ Mercedes offers this feature and calls it Pre-Safe.
---------------------------------------------------------------------------

    Accordingly, for the 16 km/h-6 second test, if a vehicle has 
movable advanced glazing as all or part of the ejection countermeasure, 
the test will be performed with the glazing retracted or removed from 
the daylight opening. Based on the 28 percent of the target population 
ejected through windows open prior to the crash and uncertainties about 
the field performance of the current movable advanced glazing, we 
cannot agree to the request that all impact testing be performed with 
the movable advanced glazing in place.
    If the advanced glazing is fixed in place, we will not remove it in 
the 16 km/h-6 second test. It is reasonable to assume that glazing 
permanently fixed in the up position will be up when the vehicle is on 
the road. We will pre-break the fixed glazing, to replicate the state 
of the glazing during the stages of a rollover event, but we will not 
remove it. Likewise, if the glazing is fixed, we will pre-break it but 
will not remove it in the 20 km/h-1.5 second test. Thus, it remains 
technically possible under the standard to have fixed advanced glazing 
as the standalone countermeasure. This provides an incentive to 
manufacturers to use advanced glazing.
    Movable advanced glazing will not be removed in the 20 km/h-1.5 
second test. This test will be performed with the advanced glazing in 
place, but the glazing will be pre-broken to replicate the state of the 
glazing at the outset of a rollover event. Although advanced glazing 
could vacate the opening late in the crash event after many quarter-
turns, we have more confidence that advanced glazing will not be 
dislodged early in the rollover event represented by the 20 km/h-1.5 
second test. This is because vehicle structural deformation and 
inertial effects resulting from ground contacts contributing to glazing 
being dislodge will be cumulative, i.e., increase as the rollover event 
continues.
    IIHS's tests also showed that the advanced glazing on some of the 
vehicles it tested remained within the frame in roof crush and side 
impact testing. Allowing movable advanced glazing to be in position in 
the high speed (20 km/h-1.5 second) test will provide an incentive to 
vehicle manufacturers to use advanced glazing to meet the standard's 
requirements or enhance ejection mitigation performance of side 
curtains.
    We decline the suggestions to provide an incentive for advanced 
glazing by increasing or decreasing the allowable displacement of 100 
mm. TRW and AORC suggested increasing the allowed

[[Page 3279]]

displacement, or decreasing the impact speed, at places on the window 
opening that had advanced glazing. We cannot agree to lessen the 
severity of the test for advanced glazing as this would reduce the 
protection of the motorists, particularly those who may have the window 
partially or fully rolled down. Advocates suggested decreasing the 
displacement limit below 100 mm for combined advanced glazing plus 
curtain air bag. As explained earlier in this preamble, the 100 mm 
limit strikes the appropriate balance between stringency and 
practicability.
    Advocates also stated that vehicle structural deformation will 
reduce the effectiveness of the curtain air bags and advanced glazing 
will increase roof strength.\139\ It presented no data to substantiate 
these claims. NHTSA is not aware of a technical or engineering basis 
for the view that side curtain air bag performance will be reduced by 
structural deformation.
---------------------------------------------------------------------------

    \139\ The relevance of the Advocates comment about advanced 
glazing increasing roof strength is not clear to us. In the May 12, 
2009, FMVSS No. 216 final rule, the agency stated that we had 
investigated the contribution of tempered side windows to roof 
strength and found that it had limited effect (74 FR 22371). We have 
no reason to believe that there would not be similar results from 
advanced laminates.
---------------------------------------------------------------------------

    Our concerns about the performance of advanced glazing also extend 
to the deformation of the window opening. Because of its mass, advanced 
glazing will be much more susceptible to inertial loading from vehicle 
rotation and vehicle ground contact than will curtain air bags. That 
was the point of our statement in the NPRM (74 FR at 63213) about 
advanced glazing having greater mass compared to an air bag curtain. In 
response to comments from some glazing suppliers, we did not mean to 
imply that laminates had a weight penalty when compared to tempered 
glazing.
2. Window Pre-Breaking Specification and Method
    We have determined that there is a safety need to have a glazing 
breaking procedure applied to both the interior and exterior sides of 
the glazing. We are slightly modifying the proposed procedure, to adopt 
use of a 75 mm offset pattern to reduce the glazing preparation time.
NPRM
    In the NPRM, we proposed specifications and a method that called 
for punching holes in the glazing in a 50 mm horizontal and vertical 
matrix (``50 mm matrix'') on both sides of the glazing. A spring-loaded 
automatic center punch was to be used to make the holes. The punch has 
approximately a 5 mm diameter before coming to a point. The spring on 
the punch was adjusted such that 150 N <plus-minus>25 N of force \140\ 
was required for activation. The details of the procedure were 
described in the NPRM. When punching a hole, we placed a 100 mm by 100 
mm piece of plywood on the opposite side of the glazing as a reaction 
surface against the punch. In testing glazing that will disintegrate 
under the procedure (e.g., tempered glazing), the vehicle manufacturer 
could opt to remove or completely retract the tempered glazing and 
thereby bypass the window breaking process.
---------------------------------------------------------------------------

    \140\ This force level worked well for the samples of advanced 
glazing tested by the agency.
---------------------------------------------------------------------------

    We also noted that we would be continuing research into window pre-
breaking methods, specifically, a variation of the 50 mm matrix hole 
punch method where the holes on either side of the glass are offset by 
25 mm. Initial indications at the time of the NPRM were that this 
variation exhibits the potentially positive attribute of lessening the 
chances of penetrating the inner membrane between the glass layers. 74 
FR at 63215.
Comments
    The Alliance said that use of different punches and punch settings 
can produce differing amounts of penetration and potential damage to 
the plastic laminate. The commenter also believed that the tolerance 
for the punch activation force is too large (17% of nominal value), and 
that the ``rigid'' backing material needs to be specified, as does the 
pressure/force applied to the backing material. The AORC supported 
offsetting the breaking pattern by 25 millimeters from the inside to 
the outside of the window, to reduce the potential that a punch 
impacting the same point from both sides of the window would produce a 
hole through the laminate. Guardian, EPGAA and Solutia believed that 
the 50 mm pre-breakage procedure was excessive and not consistent with 
real-world conditions, particularly breakage of the interior side of 
the glazing. Guardian commented that at a minimum the pre-breaking 
procedure be altered to offset the punch locations on either side of 
the glazing. Exatec asked about the suitability of the procedure for 
non-glass advanced glazing material.
Agency Response
    We disagree with the comments from the vehicle manufacturers and 
air bag suppliers that the proposed pre-breaking procedure was too time 
consuming, onerous, or impractical. Nonetheless, the procedure we adopt 
today calls for less than half the number of punched holes, reducing 
the glazing preparation time.
    We have performed well over 100 tests with advanced laminated 
glazing using various methods of pre-breaking. About 30 of these tests 
have been performed using a 50 mm matrix. We estimate that it takes our 
laboratory technicians about 30 minutes to mark the 50 mm grid pattern 
and punch all the holes for a relatively large front row side window. 
The time it takes to mark the holes per glazing pane can be 
significantly shortened by laying an unmarked pane on top of an already 
marked pane. If a subsequent test is to be performed (as might be the 
case during research and development) and the door trim is installed, 
it takes approximately 20 to 60 minutes to replace the glazing. Often 
this is done in parallel with preparations for other aspects of the 
test, so the overall test time is not affected appreciably. This 
procedure is not difficult or onerous to conduct.\141\
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    \141\ When testing with tempered glass, if the glass pane does 
not move completely out of the window opening into the door, it must 
be removed by opening the door trim. This glass pane removal takes 
about 20 to 60 minutes as well, due to the removal and 
reinstallation of door trim.
---------------------------------------------------------------------------

    Nor is the procedure gratuitous. To the contrary, the pre-breakage 
procedure is crucial to ensuring that advanced glazing will perform as 
intended in the field. Advanced glazing is weakened when pre-broken; 
the more breakage of the glazing, generally the more displacement of 
the impactor. See Table 23 of the NPRM, 74 FR at 63215. The pre-
breakage procedure is intended to condition the glazing to mimic the 
degree of breakage that is occurring in the field. Crash information 
and the results of impact testing corroborate the necessity of the 
proposed procedure.
    In the technical report accompanying this final rule, we have 
images from several rollover crashes. The first was a MY 2000 Audi A8 
that underwent four quarter-turns. The second was a MY 2003 Lincoln 
Aviator that was exposed to a frontal impact followed by a three 
quarter-turn rollover. The last vehicle was also a 2003 Aviator that 
experienced an eight quarter-turn rollover. The technical report also 
shows a close-up of the driver side window laminated glazing of the 
Aviator that rolled eight quarter-turns. In all of the cases, the crash 
scene photographs show the degree to which both sides of the glazing 
have been disintegrated, especially for those laminates that have 
vacated the window

[[Page 3280]]

opening. This finding that advanced glazing experienced severe damage 
to both inside and outside surfaces and detached from the vehicle 
supports our belief that pre-breaking the advanced laminate should be 
aggressive. The technical report also has a view of the driver's 
advanced glazing in a 2000 Audi A8 from NASS case 2001-43-190. The 
glazing remained in the window. Some areas appear more highly damaged 
than others.
    Accordingly, we are adopting the glazing breaking procedure, with 
slight changes that reduce the number of punched holes.
    In the NPRM preamble (74 FR at 63215), we stated that that the 
agency was contemplating using a method for glazing pre-breaking that 
takes the 50 mm matrix and offsets the holes horizontally on each side 
of the glazing by 25 mm. Initial indications were that this variation 
exhibits the potentially positive attribute of lessening the chances of 
penetrating the inner membrane between the glass layers. Our research 
since the NPRM has been focused on this and another alternative offset 
method. This alternative uses a 75 mm by 75 mm hole punch pattern on 
both sides of the glazing. However, the matrix on the inside of the 
glazing is offset by 37.5 mm [75 mm/2] horizontally. A 75 mm matrix 
pattern is used to reduce the number of breakage points from the 50 mm 
matrix, and as stated before, the offset reduces the chances of 
completely penetrating the material sandwiched between the glazing 
layers. The technical report provides a schematic of the 50 and 75 mm 
offset patterns.
    Our new results are consistent with our previous results. See the 
technical report for this final rule. We found that the method of pre-
breaking the laminated window has a discernable effect on the test 
results. We compared the 50 mm offset pattern to the 75 mm offset 
pattern. When these treatments were able to be compared statistically, 
there were no significant differences between the 50 and 75 mm offset 
hole punch pattern as it relates to impactor displacement. Moreover, 
given that finding and the finding that the 75 mm offset has less than 
half the number of punched holes, reducing the glazing preparation 
time, this final rule adopts the use of the 75 mm offset pattern.
    In response to Exatec, the final rule will clarify that it is only 
necessary to attempt to make the holes in the glazing and to not 
actually succeed. However, we will not change the procedure to stop 
after the first row is attempted. We have no firm basis at this time to 
treat one type of advanced glazing any differently than another. It is 
conceivable that the punches might not break the material, but could 
produce stress concentrations that weaken it.
    Finally, we decline all but one of the Alliance's requests because 
we do not believe that the procedure is not repeatable or reproducible 
and no information to the contrary was provided by the commenter. We 
believe that the tolerances and values for center punch angle, 
activation force and punch tip diameter are sufficient. We will 
specifically call out the material for the 100 mm x 100 mm reaction 
surface, rather than simply indicate that it should be rigid. The final 
rule will specify the use of plywood with a minimum thickness of 18 mm 
(standard \3/4\ inch), which is the material we used during our 
testing. Although we believe any sufficiently rigid material will 
adequately perform this function, for simplicity we will specify 
plywood.

g. Test Procedure Tolerances

    The proposed regulatory text had tolerances on various test 
parameters of the proposed test procedure. For example, the proposed 
text specified that the target outline must be aligned within <plus-
minus>1 degree of the vehicle longitudinal plane when determining the 
proper target location. Tolerances were selected such that they would 
not affect the test results, yet not be so small as to be unusable. In 
some instances, we based tolerances on those of other FMVSSs because 
those tolerances have been practicable and useful. For example, the 
tolerance on the impactor alignment with the vehicle lateral axis was 
based on a similar linear impactor tolerance in S5.2.5(c) of FMVSS No. 
202a, ``Head Restraints.'' Tolerance selection was based on test 
experience and engineering judgment. Comments were requested on whether 
the tolerances assure an objective, repeatable and practical test 
procedure.
Comments
    1. The Alliance ``requested that impactor specification be updated 
to clarify that the long axis of the impactor headform is to maintain a 
vertical orientation throughout the full stroke of the impact event. 
This approach is recommended in an effort to maximize repeatability and 
reproducibility of test results.'' The Alliance stated that they had 
observed some impactors that constrain this motion and others that do 
not.
Agency Response
    We agree with the request. The headform should not be able to 
freely rotate during the impact test. Both our original and new test 
devices have a specific mechanism to constrain them from rotation about 
their axis of travel. Thus, we have added a specification that the 
ejection impactor is inspected after the test, to make sure that it is 
still within the <plus-minus> 1 degree tolerance required at launch.
    2. TRW and AORC expressed concern about the <plus-minus> 0.1 second 
tolerance on the impact times of 1.5 and 6 seconds. They suggested a 
tolerance of <plus-minus> 0.05 seconds to reduce the amount of test 
variability due to air bag pressure changes. The AORC also would like 
the agency to clarify the time delay such that it would be the period 
of time the ``unimpeded impactor would arrive at the target location.''
Agency Response
    We are declining these requests. To answer the questions, it is 
important to keep in mind that under the test procedures, the impactor 
is to strike the countermeasure at the specified speeds and time 
delays.
    The target location is found by projecting the daylight opening on 
a vehicle vertical longitudinal plane and then projecting the target 
onto that plane. There are an infinite number of parallel vertical 
longitudinal planes, or alternatively, the vertical longitudinal plane 
can be thought of as having any lateral location. Assembling all the 
planes, each with a projection of the target, creates a three 
dimensional projection of the target, which crosses the vehicle 
laterally. Or, in other words, imagine the 2 dimensional target being 
translated along the transverse vehicle axis, creating a path the 
impactor headform should be setup to travel along.
    If the countermeasure is an air bag, it is deployed, and the 
ejection impactor is to strike the countermeasure (air bag) at the 
impact target location, at the specified speed and time delay. The 
trigger for the time delay is the activation of the countermeasure. For 
a curtain air bag, that would be the time at which the deployment is 
activated. The speed and time of impact of the impactor are measured at 
contact with the countermeasure (air bag) and must both be within the 
specified tolerances. To make it clear that it is the countermeasure 
that must be contacted at the specified time intervals, we have added 
text to S5.5(a).
    Since the agency anticipates that its tests will involve testing 
side curtain air bags, we need to account for the effect of the air bag 
on the impactor's timing. The calibration testing of our new impactor 
indicates that the impactor would meet the timing tolerance

[[Page 3281]]

reduction recommended by commenters if the target were at a static 
location. However, although our experience has been that curtain air 
bags deploy in a very consistent and repeatable manner, the fact is 
they are not static. Also, we determine contact time on a curtain 
through video analysis. All in all, because of the variables and 
calculations needed to establish contact time with the countermeasure, 
we believe it is more reasonable to maintain the <plus-minus> 0.1 
second impact time tolerance.
    3. The AORC suggests the procedure specify that contact with the 
countermeasure occurs when the impactor is beyond the influence of the 
propulsion system.
Agency Response
    We agree and have modified S5.5 of the regulatory text by adding a 
statement that the specified ejection impactor velocities must be 
achieved after propulsion has ceased.
    4. Honda asked if the agency has any intention of specifying the 
interval between each impact test. It also stated that the impactor 
speed might decrease after propulsion, so it requested that ``NHTSA 
clarify the position (by time) that the impact speed should be 
measured.'' Honda also asked how contact with the countermeasure is 
determined, and requested that we clearly state the speed and 
displacement measurement methods. Honda further requested that NHTSA 
provide the accuracy, sampling time, and filtering of each sensor.
Agency Response
    We do not agree with the suggestion to specify an interval between 
multiple tests. We do not know of a reason to rest the equipment 
between tests. We have no reason to believe that the amount of time 
between tests would have any effect on the test results.
    As explained above in answering TRW and AORC, the speed and time of 
impact are measured at contact with the countermeasure and must both be 
within the specified tolerances. We have made these measurements during 
our research testing, in several ways. As indicated above, one method 
we have used to determine time of contact within a resolution of about 
5 ms is video analysis. Another method is to know prior to the test the 
approximate location of the impactor stroke where contact will occur. 
In either case, the velocity versus time output of the ejection 
impactor can then be used to determine if the contact time and velocity 
parameters were met.
    There is no need to provide in the standard a specification for 
velocity and displacement measurement. There are multiple ways of 
measuring impactor displacement and velocity. The output of 
displacement-based instruments such as Linear Variable Differential 
Transformers (LVDTs) or string potentiometers can be used directly for 
displacement or differentiated to give velocity. Accelerometer output 
can be integrated once for velocity and twice for displacement. A 
light-based speed trap can be used for velocity measurement as well. 
The agency has used all of these methods. We believe it would be 
counterproductive to specify a single method in the regulatory text in 
that this may limit our flexibility in conducting compliance testing. 
We note also that we found that our new impactor loses very little 
speed over large ranges of stroke. If the speed is correctly set, it is 
not difficult to meet the <plus-minus>0.5 km/h speed tolerance.

h. Impactor Test Device Characteristics

    The agency proposed certain characteristics that the impactor 
should be calibrated to meet in order to enhance the repeatability of 
the test, i.e., to increase the likelihood that the headform will be 
delivered to the countermeasure and interact with it in a repeatable 
manner. One was a 20 mm limit on static deflection when the impactor is 
loaded by a 27 kg mass. There were two specifications to limit the 
amount of energy the impactor may lose due to friction. The proposal 
specified that the ejection impactor must not lose more than 10 and 15 
percent of the 24 and 16 km/h impact velocity, respectively, in 300 mm 
of unobstructed dynamic travel. Second, it must not require more than 
an average of 570 N of force to push the impactor rearward with a 27 kg 
mass attached to it. Finally, we required that impactor be able to 
deliver the center of the headform through a theoretical cylindrical 
shape.
    The agency stated that the research test device used to develop the 
proposal had not been optimized for compliance test purposes (74 FR at 
63216, footnote 81.). Thus, we stated our belief that tighter 
tolerances on the calibration characteristics could be attained with an 
optimized design. Id. Nonetheless, the agency's impactor was found to 
meet the percentage velocity reduction, on an average basis.
Comments
    Honda asked that the agency indicate in the regulatory text where 
the static deflection of the impactor headform should be measured. With 
respect to the targeting accuracy requirement, Honda wanted to know 
``if it is necessary to verify accuracy of the actual contact position 
after each impact test, as long as the test device satisfies the 
specifications.'' It stated that with testing of an air bag it would 
not seem to be possible to verify whether the targeting accuracy was 
achieved during the test. Also with respect to this targeting accuracy 
requirement, it wished to have the agency specify a calibration method.
    TRW believed that the performance attributes of the impactor are 
adequately covered by the AORC impactor specifications, as presented at 
the 2009 SAE Government/Industry meeting. These specifications are 
provided below in Table 41, for the convenience of the reader.
---------------------------------------------------------------------------

    \142\ Stein, Doug, ``Linear Impactor Performance Characteristics 
for Ejection Mitigation Testing,'' SAE Government/Industry Meeting, 
February 6, 2009, Washington DC. File Impactor--Charaterization.ppt, 
available at http://www.aorc.org/coep.asp.

       Table 41--AORC Recommendations for Impactor Performance 142
------------------------------------------------------------------------
                                                          Preliminary
            Variable               Maximum variance     recommendation
------------------------------------------------------------------------
Velocity........................  <plus-minus> 0.75   <plus-minus> 0.25
                                   km/h.               km/h.
Deflection......................  >> 25 mm..........  < 10 mm.
Time Delay to Impact............  400 ms............  < 100 mm (or
                                                       redefine time to
                                                       contact).
Excursion Accuracy..............  <plus-minus> 4.6    <plus-minus> 2 mm.
                                   mm.
Dynamic Friction................  2.62..............  < 0.25.
Design Margin...................  - 20% (TYP).......  TBD.
------------------------------------------------------------------------


[[Page 3282]]

    The AORC commented that NHTSA should adopt similar specifications 
for impactor performance as used by the agency in their solicitation 
for a new impactor (Solicitation Number DTNH22-09-Q-00071).
    The highlights of that solicitation are provided in the bullets 
below. An asterisk notes that the solicitation requirement matches the 
AORC recommendation.
    <bullet> The ejection mitigation impactor must be capable of 
measuring the displacement of the moving impactor mechanism throughout 
the entire stroke, with an accuracy of <plus-minus>2 mm.*
    <bullet> The maximum radial deflection of the ejection mitigation 
impactor must not exceed 10 mm.*
    <bullet> When the ejection mitigation impactor assembly is used in 
conjunction with the support frame, it must have a vertical radial 
deflection of no more than 15 mm.
    <bullet> The maximum dynamic coefficient of friction of the 
ejection mitigation impactor must not exceed 0.25.*
    <bullet> The moving impactor mechanism must be designed for use at 
peak velocities between 15 km/h and 25 km/h, with a tolerance within 
the range of <plus-minus>0.25 km/h; a range of <plus-minus>0.15 km/h or 
less is preferred.*
    <bullet> When used with an appropriate propulsion system, the time 
from the signal to deploy the air curtain to the peak velocity of the 
moving impactor mechanism (minus any pre-programmed delay time) must 
not exceed 100 milliseconds for any velocity within the range of 15 km/
h to 25 km/h. These velocities must also be achieved prior to the 
impactor making contact with deployed air curtains of current 
production.*
    <bullet> When the headform is fired at 24 km/h, point P must remain 
within cylinder C from the position at which the moving impactor 
mechanism achieves peak velocity to the position 100 millimeters beyond 
the position of peak velocity. Point P is the geometric center of the 
headform on the outer surface of the headform, and cylinder C is a 20-
millimeter diameter cylinder, centered on point P and parallel to the 
headform's direction of motion.
Agency Response
    Many provisions of the impactor test device calibration have been 
modified to make them consistent with some of the calibration 
procedures suggested by AORC and others. The static deflection 
provision has been changed from 20 mm under a 27 kg load, to 20 mm 
under a 981 N force applied in four orthogonal directions, with the 
device in a test-ready configuration. The final rule will require a 
limit on the dynamic coefficient of 0.25, measured in four orientations 
with the shaft loaded with a 100 kg mass. We believe this provision 
will fulfill the requirement previously specified by the unobstructed 
velocity test and obstructed push force tests.
    In response to Honda, we have added text to S7.2 in the final rule 
to indicate that the movement of the ejection impactor targeting point 
in the x-z plane (vehicle vertical-longitudinal plane) should be 
measured. In other words, looking along the y axis (direction of 
travel), the center of the headform face should not deflect more than 
the specified value. We have also added additional detail to this 
section to indicate that this static deflection test is to be performed 
with the impactor attached to the propulsion mechanism, including any 
support frame connecting it to the floor. In addition, the force is now 
applied in four orthogonal directions, rather than just downward. This 
is an acknowledgement that loading on the impactor can be in any 
direction.
    Since the test is performed on the device in a test-ready 
configuration, the allowable displacement is 20 mm rather than the 10 
mm recommended by the AORC in Table 41. The 10 mm value would be more 
appropriate for a test that excludes the supporting frame of the test 
device, as did the AORC recommendation.
    There is no reason to specify the displacement measurement accuracy 
for the impactor since we will use a method sufficiently accurate to 
determine that the displacement limit has been exceeded or not. There 
is also no reason to specify a minimum time from launch until the 
impact speed is obtained; how long it takes the impactor is irrelevant 
to the test as long as it arrives at the specified delay times of 1.5 
<plus-minus>0.1 seconds and 6.0 <plus-minus>0.1 seconds.
    A very important impactor characteristic is dynamic friction. We 
have indicated in S7.3 of the standard that the dynamic friction must 
not exceed 0.25. This matches the AORC recommendation. In the technical 
report for this final rule, we provided these dynamic friction 
measurements for the agency's new impactor and how the agency 
determined dynamic friction characteristics.
    We note that the dynamic friction test differs from the static 
deflection test in that it need not be done on the support frame that 
would connect to the impactor in a test-ready configuration. We believe 
this is acceptable since it is not likely that the static deflection of 
the entire frame will influence the dynamic friction determination. We 
also think it is acceptable that the perpendicular loading for the 
dynamic friction testing is achieved through gravity and rotation of 
the impactor and bearings rather than by pulling in four orthogonal 
directions, as is done in the static deflection tests. Practically 
speaking, there is no other way to perform the test.
    We believe that this detailed dynamic friction test in S7.3 of the 
standard will fulfill the purpose of the requirements previously 
specified in the NPRM for unobstructed velocity (proposed S7.2.1) and 
obstructed push force (proposed S7.2.2). We have reduced the maximum 
allowable dynamic coefficient of friction of the test device by a 
factor of 5 from 1.29 (NPRM) to 0.25 (final rule). In addition, S7.2.1 
allowed as much as a 15 percent velocity loss over a range of impactor 
stroke. Testing of the new impactor found about a 1 percent loss in 
impactor speed over a stroke of more than 150 mm. Thus, we conclude 
that proposed S7.2.1 can be removed with no negative effect on the test 
procedure.
    We understood Honda's comments on the issue of targeting accuracy 
(see S7.4 in the final rule) as seeking clarification as to when the 
accuracy is to be determined, i.e., would the tester need to know that 
for any particular impact test the ejection impactor targeting point 
was within the required cylindrical targeting zone shown in Figure 16 
of the NPRM. The answer to Honda's question is provided in S7 of the 
standard, where it is stated: ``[t]he ability of a test device to meet 
these specifications may be determined outside of the vehicle.'' That 
is, it is necessary that the test device being used meet the 
characteristics in S7, but these need not and cannot be determined 
during the test. We cannot see that it would be feasible to perform 
these calibration measurements during a vehicle test. Honda requested 
the agency specify how often and/or when these calibration tests should 
be done. We cannot make such a pronouncement in the regulatory text. 
Frequency of calibration is a test device and due care-specific issue 
and must be determined case by case.
    Honda also wanted to know how targeting accuracy would be measured 
by the agency. On our new impactor, we made this determination through 
analysis of high speed video. We found that the impactor met the 
required accuracy. We can envision other measurement techniques that 
utilize witness marks on stationary targets, or that make witness marks 
on the headform.

i. Readiness Indicator

    NHTSA proposed a requirement for a monitoring system with a 
readiness

[[Page 3283]]

indicator for ejection mitigation systems that deploy in a rollover, 
such as that required for frontal air bags in S4.5.2 of FMVSS No. 208. 
74 FR at 63218.
    No comments were received opposing the proposal. Accordingly, the 
proposal is adopted for the reasons discussed in the NPRM.

j. Other Issues

1. Rollover Sensors
    The NPRM did not require vehicle manufacturers to provide a sensor 
that deploys the ejection countermeasure in a rollover or side impact 
crash, and did not dictate the performance of any supplied sensor. We 
were concerned as to whether specifying performance features for the 
sensor could satisfactorily capture the myriad of rollovers occurring 
in the real-world. Moreover, we explained that ejection mitigation air 
bag curtains are now being designed, developed, and implemented by 
industry and are deploying satisfactorily in the field.
    We believed there would be no incentive for manufacturers to 
provide an ejection mitigation side curtain designed to meet the 
standard without providing the sensor to deploy it in a rollover crash. 
In addition, under the proposed requirements of the standard, 
manufacturers would be required to provide written information to 
NHTSA, upon the agency's request, explaining the basic operational 
characteristics of their rollover sensor system. We also proposed to 
deploy the side curtain in our compliance testing only if the owner's 
manual or other written material informs the owner that the vehicle is 
equipped with an ejection mitigation countermeasure that deploys in the 
event of a rollover.
    The NPRM also discussed alternatives considered by the agency to 
the approach proposed, such as requiring that the rollover sensors be 
provided as a piece of equipment and defining such a piece of 
equipment, or specifying a test that would assure the presence of a 
rollover sensor on the vehicle. Advantages and disadvantages of the 
approaches were presented.
Comments
    Nearly all comments from vehicle manufacturers and air bag 
suppliers supported the NPRM's not establishing specific rollover 
sensor requirements or performance tests. The Alliance concurred with 
the NPRM that sensors are performing well in the field. GM stated its 
support for only deploying air bags ``during the compliance test that 
have been identified in the owner's manual as rollover-enabled. This is 
a practicable and reasonable approach.'' GM agreed that manufacturers 
would have no incentive to misidentify an air bag system as rollover 
capable. AIAM stated that manufacturers have their own test and 
calibration processes for crash sensors, so adding any tests in the 
final rule would only add complexity to manufacturers' test plans for 
little or no benefit. AIAM believed that the definition of sensor 
deployment requirements is vehicle specific due to the different nature 
of such factors as mass distribution, center of gravity height and use 
of stability systems. Therefore, AIAM believed that setting a generic 
test requirement would not be feasible.
    On the other hand, Honda believed that ``some manner of performance 
criteria may be necessary for rollover sensors required for deployment 
of such countermeasures.'' The commenter encouraged NHTSA to establish 
basic performance criteria ``consistent with other elements of the test 
procedure for FMVSS No. 226, if possible.'' Honda suggested a 
definition for ``rollover sensor'' and suggested that NHTSA ``establish 
a minimum requirement for the system configuration.''
    Advocates and Public Citizen requested that the final rule place 
requirements on sensors that would deploy the ejection countermeasures 
rather than leave it to the discretion of the manufacturer. Advocates 
believed that NHTSA should specify requirements for sensors to ensure 
sustained inflation throughout the long event of a rollover with 
multiple quarter-turns. Public Citizen recommended a dynamic test that 
``would allow the agency to measure both the presence and the 
performance of rollover sensors.''
    IIHS stated that while it understood the agency's reluctance to 
specify performance requirements for sensors that may not capture the 
scope of real-world rollover crash scenarios, NHTSA should continue 
monitoring field data to determine the adequacy of the agency's 
approach.
Agency Response
    This final rule adopts the approach of the NPRM and does not 
specify direct rollover sensor specifications. The agency is not aware 
of any repeatable rollover test that replicates the breadth of real-
world rollovers addressed by this rulemaking. Current dynamic tests, 
such as the 208 Dolly test, do not allow the agency to determine how 
well the sensor will perform in the field. The 208 Dolly test offers 
little challenge to the sensor and, according to Viano and 
Parenteau,\143\ represents a very small portion of rollover crashes. 
See the NPRM, 74 FR at 63218, for additional discussion of dynamic 
rollover testing.
---------------------------------------------------------------------------

    \143\ Viano D, Parenteau C., ``Rollover Crash Sensing and Safety 
Overview,'' SAE 2004-01-0342.
---------------------------------------------------------------------------

    With respect to Honda's comment on specification of ``some manner 
of performance criteria'' and/or a definition for ``rollover sensor,'' 
this concept is very similar to an option discussed in the NPRM 
preamble (Equipment Definition Option) (74 FR at 63218). We indicated 
in that analysis that this option was problematic for several reasons. 
We stated that such an option has the--

limitation of having to definitively specify the item of equipment 
it would be requiring, which might necessitate adopting and applying 
an overly restricted view of what a deployable rollover is and 
perhaps what it is not. For example, we can contemplate rollovers 
that have such an extremely slow roll rate when it would not be 
necessary or desirable for the countermeasure to deploy. That being 
the case, a reasonable definition of a rollover sensor might include 
a roll rate specification as a function of roll angle. Developing 
such a definition requires vehicle roll angle versus rate data, 
which are not readily available to NHTSA. Another potential drawback 
of this option is that without a test or tests to assess compliance 
with the definition, enforcement of the requirement could be 
restricted. An approach for a compliance test could be for NHTSA to 
remove the sensor from the vehicle and subject the sensor to a 
performance test to assess whether a specified performance 
requirement is achieved, but the agency has limited information at 
this time on which to develop performance parameters or a compliance 
test.

Id.

    As Honda's comments did not address the shortcomings of this 
option, the agency continues to have concerns. We thus decline to 
implement Honda's request in this final rule.
    In view of the determination to adopt the approach of the NPRM, and 
after reviewing the comments, we conclude that it is critical that 
written information be provided in the owner's manual that describes 
how the ejection mitigation countermeasure deploys in the event of a 
rollover (see regulatory text of S4.2.3(a) of this final rule) \144\ 
and how

[[Page 3284]]

system readiness is monitored (see S4.2.3(b)). It is also important 
that the test procedure not deploy the ejection countermeasure if this 
information is not provided (see S5.5(c)). We also adopt the 
requirement that the final rule require manufacturers to provide more 
detailed technical information to the agency upon request (see S4.2.4).
---------------------------------------------------------------------------

    \144\ Ford provided excerpts from the owner's manual of a 
vehicle with a rollover curtain air bag, and asked if the 
information would meet the requirements of S4.2.3(a), ``Written 
information.'' (NHTSA-2009-0183-0047, p. 20.) Ford's excerpt stated 
in part: ``The Safety Canopy system is designed to activate when the 
vehicle sustains lateral deceleration sufficient to cause the side 
crash sensor to close an electrical circuit that initiates Safety 
Canopy inflation or when a certain likelihood of a rollover event is 
detected by the rollover sensor.'' Our answer is yes.
---------------------------------------------------------------------------

    Field data on vehicles with rollover sensors continue to indicate 
that curtains are deploying in rollovers when they should. Of the 21 
RODSS cases, four NASS cases and 48 SCI cases believed to involve 
vehicle rollover crashes and presumed to have rollover deployable 
curtains, five were determined not to have deployed.
    We conducted an in-depth review of these five cases. Four of the 
five cases had a significant frontal impact that preceded the rollover. 
These impacts may have destroyed the vehicle battery and thus 
eliminated the primary power source for deploying the rollover curtain. 
There is also some question as to whether one of these vehicles was 
definitely equipped with a rollover sensor, since the system was an 
option on this vehicle. In one case, the vehicle's kinematics were very 
complex and may have included some motion not typical of a lateral 
rollover.
    After reviewing the five non-deployment cases, it was not apparent 
to us that there was a problem with the rollover sensor that would have 
been identified by a test for a sensor, such as the Equipment 
Definition test or Presence test discussed in the NPRM (74 FR at 
63218). We cannot make a finding that in these cases, the rollover 
curtains' non-deployment was unrelated to the initial frontal impacts. 
A presence test that only addressed whether the curtain will deploy, 
that did not account for a significant initial frontal impact, might 
not have made any difference on the deployment of these rollover 
curtains.
    We have become interested, however, after reviewing the field data, 
as to whether ejection mitigation systems could have a backup power 
source, such as a capacitor, that can provide the power for curtain 
deployment within some short time period after primary power is lost. 
It is our understanding that generally vehicles currently have such 
energy storage systems, but these systems may not have the ability to 
deploy rollover curtains when the rollover is subsequent to a frontal 
impact causing the loss of power. There were only a handful of cases on 
hand. We would like to learn more about this issue.
    We are not ready to specify in this final rule some sort of 
requirement related to the ability to deploy the curtain after loss of 
primary power. For one thing, we believe that this issue is outside of 
the scope of notice of the NPRM. Moreover, NHTSA would like to gain 
more knowledge in this area. We would like to analyze the vehicle 
kinematics that result when a frontal crash is followed by a rollover 
to better understand the amount of time secondary power is, and should 
be, available. Data available from event data recorders may provide a 
starting point for the analysis of this issue. We have begun a review 
of the EDR data available to the agency and will continue to monitor 
data as it becomes available. We would like to find out if there is a 
problem in the field and seek to know more about the amount of storage 
time capacitors typically have vis-[agrave]-vis their ability to deploy 
the curtain after power is lost.
2. Quasi-Static Loading
    We requested comments on the need for an additional test that would 
impose quasi-static loading on the ejection countermeasure. Films of 
occupant kinematics in vehicle rollover testing and in DRF testing 
indicate that ejection mitigation countermeasures can be exposed to 
quasi-static loading during a rollover, in addition to short-duration 
impacts that the headform test replicates. Quasi-static loading can 
occur when an occupant contacts the countermeasure and loads it 
throughout or nearly throughout an entire rollover event.
Comments
    AIAM commented that in the absence of data demonstrating that 
countermeasures designed to meet the proposed requirements are not 
adequate to address quasi-static loading, there is no basis for 
adopting such a test requirement at this time.
Agency Response
    We are not adopting a requirement at this time. Instead, we plan to 
pursue some limited testing in the near term to see how an ejection 
mitigation countermeasure that performs well to the requirements in the 
final rule performs in a quasi-static test. At this time, there are no 
data available to the agency. Therefore, we cannot determine the 
consistency, or lack thereof, between quasi-static performance and 
impact test performance.
3. Full Vehicle Test
    The NPRM explained the agency's position that the component test of 
FMVSS No. 226 would not only distinguish 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 
would ensure 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.
    The NPRM further noted that 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. 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 
correlated eight different tests to six rollover definitions from NASS-
CDS. 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 208 Dolly test. 
74 FR at 63185.
    The NPRM also discussed our belief that 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. Id. A single full vehicle rollover test 
could narrowly focus on only certain types of rollover crashes 
occurring in the field. We noted in the NPRM our concern that a 
comprehensive assessment of ejection mitigation countermeasures through 
full vehicle dynamic testing may only be possible if it were to involve 
multiple crash scenarios. Such a suite of tests imposes test burdens 
that could be lessened by a component test. We also noted that a 
comprehensive suite of full-vehicle dynamic tests would likely involve 
many more years of research, which would delay the rulemaking

[[Page 3285]]

action and the potential for incorporating life-saving technologies. 
The agency stated that such a delay appears unwarranted, given that 
NHTSA believes the component test will be an effective means of 
determining the acceptability of ejection countermeasures.
Comments
    AIAM agreed with the agency's view that a dynamic full vehicle test 
should not be pursued at this time. The commenter concurred that it is 
not clear how the agency could represent the wide range of rollover 
crash scenarios with a single test mode, and that manufacturer 
certification using a series of test modes would be unduly burdensome. 
AIAM also stated, ``Making a dynamic rollover test adequately 
repeatable for regulatory purposes would also be a very significant 
challenge.'' AIAM supported continued research on developing a 
practicable dynamic test approach that provides additional safety 
benefits.
    In contrast, Batzer and Ziejewski recommended that in addition to 
an impact test, NHTSA should ``mandate that all manufacturers perform 
at least one FMVSS-208 style dolly rollover test.'' Advocates believed 
that the FMVSS No. 226 impact test does not account for ``door-window 
frame distortion that can occur in rollover crashes'' and that this 
could result in reduced curtain air bag effectiveness. Public Citizen 
also supported a whole vehicle dynamic test. Public Citizen stated that 
further delays needed to develop a dynamic test would ``benefit 
occupants in rollover crashes, if a dynamic rollover test resulted in a 
better standard that was more representative of real world crash 
conditions.'' The commenter also stated that the agency ``cannot simply 
add up the sum of the target populations identified in each of its 
rollover rulemakings and claim to have protected occupants.''
Agency Response
    For the reasons discussed in the NPRM, the final rule will not 
contain a full vehicle dynamic test to evaluate ejection mitigation.
    We understand the appeal of a dynamic test for ejection mitigation 
as well as all aspects of rollover protection, a complement of sorts to 
frontal and side protection offered by the dynamic tests in FMVSS Nos. 
208 and 214, respectively. As a matter of fact, the agency is currently 
pursuing a research program looking at the development of a dynamic 
test to address roof strength. In addition, the agency has been 
pursuing laboratory research on restraint system (e.g., seat belt 
system) optimization for rollover crashes.
    As it happens, however, a full vehicle dynamic test for rollover 
crashworthiness systems is not available. An FMVSS No. 208 (frontal 
impact) or No. 214 (side impact) test presents different challenges 
than a rollover test. Frontal and side impacts, while deadly, are less 
complex by comparison to a rollover crash. As explained in the NPRM, 
rollover crash tests have a high degree of variability in vehicle and 
occupant kinematics. There are many types of rollover crashes, and 
within each crash type the vehicle speed, roll rate, roll axis and 
other parameters can vary widely. In contrast, the critical parameters 
for planar crashes can be captured by the direction of impact and 
[Delta]V. It is a relatively simple matter to develop a test(s) (i.e., 
a vehicle into barrier or object into vehicle) that results in the 
desired vehicle [Delta]V in the desired direction.
    Nor might a full vehicle dynamic test be available as an outgrowth 
of the agency's roof crush and seat belt system research. The vehicle 
kinematics involved in assessing enhanced protection of the occupant 
within the vehicle (studied in the roof crush and belt system programs) 
may be significantly different from those involved in mitigating the 
risks of occupant ejection to belted and unbelted occupants. A dynamic 
test that is appropriate for assessing roof crush and seat belt 
performance may not necessarily provide the same kind of challenge to 
ejection mitigation.
    It may or may not be suitable to have a single rollover test to 
assess roof crush and seat belt performance. For ejection mitigation, 
it is unlikely that a single rollover test would be sufficient to 
address the many types of rollovers that occur in the field.\145\ We 
would want the dynamic test to assure that an ejection mitigation 
countermeasure constrains belted and unbelted occupants in all types of 
rollover crashes. However, at this time there is no archetype rollover 
crash that can be replicated in laboratory testing.\146\
---------------------------------------------------------------------------

    \145\ We have already discussed our determination that the 208 
Dolly test is not suitable for ejection mitigation testing. See, 
e.g., 74 FR at 63185. The 208 Dolly test represents less than 1 
percent of real-world rollovers. Further, some recent experience 
with the 208 Dolly test makes problematic its implementation as a 
replacement for the impact test or an additional test. During recent 
tests in our rollover restraints research program, we attempted to 
subject a MY 2007 Ford Expedition to the 208 Dolly procedure. 
However, two out of five attempts failed to initiate a roll of even 
one quarter-turn. We acknowledge that the above was not a typical 
result of 208 Dolly testing within the agency's experience, but it 
does highlight testing issues.
    \146\ A full vehicle dynamic test would presumably involve the 
use of anthropomorphic test devices (ATDs). There is some question 
whether the currently available ATDs offer an acceptable level of 
biofidelity with respect to occupant ejection. For example, the hip 
articulation for the Hybrid III dummies is limited, which may alter 
their ability to replicated real world occupant kinematics. An 
appropriate ATD for use in the test would have to be explored.
---------------------------------------------------------------------------

    We stated in the NPRM preamble, ``a comprehensive assessment of 
ejection mitigation countermeasures through full vehicle dynamic 
testing may only be possible if it were to involve multiple crash 
scenarios. Such a suite of tests imposes test burdens that could be 
assuaged by a component test such as that proposed today.'' 74 FR at 
63186. We hope that in the future, a full vehicle dynamic test, or a 
suite of tests, could be developed that is appropriate for use in FMVSS 
No. 226. However, at this time, there is not a viable full vehicle 
rollover test procedure to evaluate ejection mitigation. In response to 
Public Citizen, we strongly disagree that a delay of this rulemaking to 
develop a dynamic test would be justified. This final rule will save 
over 370 lives a year. Each year delayed to develop what is now an 
indefinable full vehicle test will have a substantial human cost.
    Public Citizen also commented that the agency ``cannot simply add 
up the sum of the target populations identified in each of its rollover 
rulemakings and claim to have protected occupants.'' The agency takes 
great care when doing the benefits assessment to not double count lives 
saved. If we assume a specific population is saved by one of our 
standards, we do not count them again when determining the benefits for 
another. In this way, our estimates are conservative.
4. Minor Clarifications to the Proposed Regulatory Text
    In preparing the final rule regulatory text, we made some changes 
to make the text clearer and easier to understand. The changes were not 
meant to alter the requirements of the proposal. Below we provide a 
listing of the more noteworthy of these minor changes and a brief 
rationale for the change.
    S3. Ejection Impactor--Deleted ``It consists of an ejection 
headform attached to a shaft'' and moved it to S7.1. This was done 
because this descriptive information is consistent with the type of 
information provided in S7.1.
    S3. Ejection propulsion mechanism--Deleted ``specified in S7.2 of 
this Standard No. 226.'' This was deleted because S7.2 (New S7.3) does 
not really

[[Page 3286]]

provide information specific to the propulsion mechanism.
    S3. Target Outline--Eliminated the term ``target outline'' and 
replace it with ``target'' throughout the regulatory text. This does 
not result in any substantive change in the standard, since in the NPRM 
these terms were defined to be interchangeable in the regulatory text.
    S3. Walk-in van--Deleted the second sentence indicating that the 
seating position must be forward facing and edited the first sentence 
to indicate the only seating position is the driver. This was done to 
eliminate redundancy in the definition.
    S4.1.1--Added text to the first sentence referencing S8. This was 
done to provide clarity and similarity with other standards.
    S5.1--The wording of the third sentence was modified to clarify 
that the countermeasure was being struck at the defined target 
locations.
    New S5.2.1.1 (NPRM S5.2.1(a)), S5.5.5, S5.4.1.1--All occurrences of 
``daylight opening'' were replaced with ``side daylight opening.''
    New S5.2.1.1 (NPRM S5.2.1(a)), second sentences--Added the word 
``projection'' after ``side daylight opening.''
    New S5.2.2(a) (NPRM S5.2)--Deleted ``and the x-z plane of the 
target outline within <plus-minus>1 degree of a vehicle vertical 
longitudinal plane.'' This was a redundant constraint. However, text 
was added to indicate that the y axis of the target points outboard.
    New S5.2.3.3 (NPRM S5.2.2.3)--Revisions were made to the structure 
of this section to clarify the determination of primary targets.
    S5.5(a)--The sentence was modified to make it clear that it was the 
countermeasure that must be impacted at the specified time.
    S5.5(a) and (b)--Replaced ``velocity'' with ``speed.''
    S6.1--Added text to clarify how the vehicle attitude is to be 
adjusted.

k. Practicability

    NHTSA believed that meeting the proposed requirements as they 
applied to the side windows at the first three rows was practicable. 
There were a number of vehicles with side air bag curtains that cover 
the windows adjacent to rows 1, 2, and 3, such as the 2005-2007 MY 
Honda Odyssey, 2006 Mercury Monterey, 2007 Chevrolet Tahoe, and 2007 
Ford Expedition.\147\ The agency also believed it was practicable to 
produce vehicles that would meet the proposed performance requirements.
---------------------------------------------------------------------------

    \147\ Since that time the following vehicles with three rows of 
coverage have been tested: MY 2007 Jeep Commander, MY 2008 Dodge 
Caravan, MY 2008 Ford Taurus X, and MY 2008 Toyota Highlander.
---------------------------------------------------------------------------

    The NPRM had a proposed 24 km/h-1.5 second test, which has been 
reduced in this final rule to 20 km/h-1.5 second. Some of the current 
production vehicles tested during the development of the NPRM came 
close to meeting the 100 mm displacement limit at all target locations 
and impact speeds. The most challenging target location was A1, with A4 
being the least challenging. For the 2nd row windows, the limited data 
indicated target location B1 was more challenging than B4. Only two 
vehicles were tested at the 3rd row. For these systems, C4 was more 
challenging than C1.
    The agency stated that the primary parameters that determine the 
stringency of the test were: (a) The impactor dimensions and mass; (b) 
the displacement limit; (c) impactor speed and time of impact; and (d) 
target locations. Comments focused on (c) above, specifically impactor 
speed, to argue for reducing the stringency of the test based on 
practicability grounds.
    We discussed in an earlier section of this preamble our decision to 
reduce the impactor speed from 24 km/h-1.5 second (400 J) to 20 km/h-
1.5 second (278 J), based on a reanalysis of the research data used for 
the NPRM. We believe this reduction in test velocity resolves many of 
the comments, described below, that raised concerns about the 
practicability of meeting a 24 km/h-1.5 second test. However, we wish 
to address the concerns about practicability to explore any remaining 
questions about the practicability of meeting a 20 km/h-1.5 second 
requirement. Further, we would like to discuss issues relating to the 
practicability and cost of meeting a 24 km/h-1.5 second requirement.
Comments
    All comments relating to practicability were submitted by vehicle 
manufacturers. The comments were focused on side curtain air bags as 
the sole countermeasure for the FMVSS No. 226 requirements. The 
comments did not appear to dispute the potential of manufacturing side 
curtain air bag systems that could meet the NPRM; rather they expressed 
concerns with the potential negative trade-offs associated with such 
systems for both side impact and OOP occupants.
    Honda referred to agency statements in the NPRM that indicated that 
two methods of improving the ejection mitigation performance of curtain 
air bags were to make them thicker and to increase their internal 
pressure. Honda provided data on the relationship between internal 
pressure and impactor displacement. Honda argued that increasing tank 
pressure of an air bag design to meet the proposed requirements (to 
produce less displacement of the impactor) results in notable increases 
in Nij and neck compression measures. Honda believed that if 200 J is 
set as the impact energy limit (17 km/h impact), ``the primary 
objective of the side curtain airbag of occupant protection can be 
balanced with the proposal for occupant ejection mitigation without 
significant change to current side curtain airbag designs for some 
vehicles.''
    VW also provided information showing the relationship between 
impactor displacement and air bag pressure. It estimated that the 
initial internal pressure would need ``to be increased 2-3 times 
depending on the actual kinetic energy of the impactor and the NPRM's 
required excursion limits.'' VW stated that ``the above mentioned 
pressure increase for the ejection mitigation test will result in a 
detuning of the airbag and in deterioration of the side crash test 
results'' relevant to NCAP and IIHS consumer information programs. VW 
believed there would be a reduction of overall fleet star ratings and a 
reduction in occupant safety in conventional side crashes.
    The Alliance provided research performed by Toyota that the 
Alliance believed ``illustrates the increased OOP risk associated with 
the high impact energy (400 Joule impact) and limited excursion (100 
mm) requirements proposed in the NPRM.'' In this research, two SUVs and 
two passenger cars were tested to the 24 km/h-1.5 second impact test 
and subsequently to OOP testing using the Technical Working Group (TWG) 
Recommended Practice with an inboard facing 5th percentile adult female 
dummy.\148\ When changes were made to the side curtain air bag systems 
by increasing internal pressure and coverage to meet a 160 mm 
displacement limit when tested at 24 km/h-1.5 seconds, the Alliance 
reported that OOP values increased from approximately 80 percent of 
IARVs to about 105 percent of IARVs.
---------------------------------------------------------------------------

    \148\ The TWG Recommended Procedures were developed to evaluate 
the risk of side air bags to children who are out-of-position. 
Through a voluntary agreement with NHTSA, vehicle manufacturers 
consented to meet the TWG. The agency requests the results of 
testing through the Buying a Safer Car program and publishes the 
data annually.

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[[Page 3287]]

Agency Response
    It appears from the comments that if the impact speed was 24 km/h, 
some manufacturers would have to increase the air pressure in their 
side curtain air bags to meet the requirement. We estimate that this 
approach to meet a 24 km/h test would add $7.53 to the $31 incremental 
cost of meeting a 20 km/h test. This added cost is for a larger 
capacity inflator. Some manufacturers have commented that increasing 
air bag pressure in current bags to meet a 24 km/h-1.5 second test 
increases HIC values measured in a side impact test and IARVs measured 
in OOP tests. If manufacturers were attempting to bring a curtain air 
bag into compliance that was well outside of the 100 mm limit by only 
increasing internal pressure, the air bag would likely become more 
rigid. Whether those increased HIC values and IARVs in OOP tests from 
increased air bag pressure pose an unreasonable safety risk has not 
been shown, but so-called ``negative trade-offs'' concern the agency in 
any rulemaking.
    New side curtain air bag designs appear to be evolving that show 
promise in meeting the 100 mm limit of impactor displacement when 
tested to a 24 km/h-1.5 second condition, without undesirably affecting 
side impact and OOP test results.
    However, if these systems require significantly more air bag 
volume, they may be more costly than a system that meets a 24 km/h 
requirement by increased air pressure. We estimate that, for a vehicle 
with an air bag system that uses higher volume and more material to 
meet the 24 km/h requirement, $37.87 would be added to the $31 
incremental cost of a system that meets a 20 km/h requirement.\149\
---------------------------------------------------------------------------

    \149\ A curtain air bag with more volume will require more air 
bag material and may also utilize an extra inflator if a single 
inflator is not sufficient. An extra inflator adds significant cost 
to a curtain air bag system.
---------------------------------------------------------------------------

    Air bag supplier Takata met with the agency on July 28, 2009, to 
discuss its effort at designing an ejection mitigation system to meet a 
December 2006 NHTSA ejection mitigation research test procedure at a 
displacement limit of 100 mm at 24 km/h-1.5 second impact.\150\ Takata 
explained that it believed there were two potential ways of meeting the 
requirement: By way of retaining a strong membrane over the window 
opening, or by absorbing the impactor energy. For the first approach, 
Takata stated that the strong membrane could be achieved by laminated 
glazing or a high stiffness/pressure curtain. The second energy 
absorption method could be achieved by air bags of increased volume or 
air bags of a different shape to increase impactor stroke. Takata said 
it chose this second approach, to develop an air bag of a different 
shape.\151\
---------------------------------------------------------------------------

    \150\ Docket NHTSA-2006-26467-0019.
    \151\ We note that Takata claimed that it achieved the necessary 
performance by a change in shape, rather than an increase in 
pressure or volume.
---------------------------------------------------------------------------

    Takata stated that a new air bag design it has developed was 
integrated into a sedan and tested to the 24 km/h-1.5 second and 16 km/
h-6 second impacts, and to TWG OOP requirements using both the 5th 
percentile adult female and 6-year-old (6YO) child dummies. The 
greatest displacement for the 24 km/h-1.5 second test was approximately 
82 mm at A1. The greatest displacement at the 16 km/h-6 second test was 
approximately 79 mm at B1. The air bag pressure at time of impact was 
reported as 30 kPa.
    The results from the TWG testing are shown in Takata's docket 
submission. The 5th percentile adult female results have a maximum 
value of approximately 55 percent of the IARVs. For the 6YO child 
dummy, no injury measure exceeded 20 percent of the IARVs.
    Takata determined that its new shape curtain could meet the 100 mm 
displacement limit without advanced glazing with a sufficient 
compliance margin in a sedan design. At the time of the presentation, 
Takata indicated that it was working on increasing the compliance 
margin for a sport utility vehicle (SUV) design and working with a 
vehicle manufacturer to introduce the technology to the market.
    In its comment to the NPRM, the Alliance stated that NHTSA should 
not interpret information about the performance of innovative side air 
bag design concepts developed in an attempt to meet the NPRM to mean 
that ``the requirements of the NPRM are practicable.'' \152\ The 
Alliance claimed that the air bag supplier design evaluations have not 
addressed the following areas: The ability of the air bags to be 
deployed in time for a side impact and provide adequate side impact 
protection; the ability to integrate these bags with FMVSS No. 201 
countermeasures; the ability to function in a complete vehicle 
environment; and the ability to implement this technology across 
vehicle architectures.
---------------------------------------------------------------------------

    \152\ NHTSA-2009-0183-0029, p. 20.
---------------------------------------------------------------------------

    We understand that integrating a component into a full vehicle 
design involves many factors. However, the Alliance did not provide a 
convincing discussion as to why NHTSA should not consider a system such 
as Takata's an indication of the practicability of meeting a 24 km/h-
1.5 second impact test.
    The Alliance and others questioned whether innovative systems could 
be packaged in a vehicle to meet FMVSS No. 201 requirements. The 
commenters did not explain how new ejection mitigation side air 
curtains would pose unique design problems that would impede the 
ability to certify to FMVSS No. 201, when current vehicles with 
rollover side air curtains already are certified to that standard. 
There was no showing that changes to the air curtains or to the 
inflator will present insurmountable problems in packaging the 
equipment to FMVSS No. 201. It also appears that Takata is now working 
on implementing its system across vehicle architectures. Takata has 
indicated that its new system has been successfully integrated into a 
passenger car \153\ and is in the midst of SUV integration. Takata did 
not provide cost data.
---------------------------------------------------------------------------

    \153\ The Toyota data provided by the Alliance indicated that it 
was more difficult to meet TWG guidelines in the passenger 
environment than in SUVs.
---------------------------------------------------------------------------

    The proposed 24 km/h-1.5 second impact has been reduced to 20 km/h-
1.5 second in this final rule after our reanalysis of the technical 
basis for the energy requirement and our FRIA analysis showing a 20 km/
h requirement to be more cost effective. With this reduction in 
impactor speed, vehicles will be able to meet the final rule's 
requirements with fewer changes to existing designs. Data from agency 
testing of production vehicles presented earlier in this preamble 
demonstrate the practicability of the requirements of this final rule. 
The MY 2007 Mazda CX9 was able to meet the performance tests in the 
final rule (20 km/h), without modification. This vehicle had a 5-star 
side impact rating in the 2007 NCAP program.
    We recognize that most side curtains will need design changes to 
various degrees to meet the requirements of this final rule. As Takata 
indicated in its 2009 meeting, there are several ways to possibly 
improve performance in the ejection mitigation test. Manufacturers will 
have to decide what suits their particular situation best. 
Manufacturers could increase air bag internal pressure to make the air 
bag stiffer and/or increase the volume to make the air bag thicker. 
They could possibly change the air bag shape, such as Takata has done, 
reducing the need for drastic changes in pressure and volume. They 
might decide to use advanced glazing to

[[Page 3288]]

supplement ejection mitigation side air curtain performance in meeting 
the 20 km/h-1.5 second test. In addition, the availability of lead time 
and a phase-in schedule and advanced credits will provide manufacturers 
time and flexibility to implement design changes to meet the standard.
    Lastly, the Alliance referred to data presented to NHTSA by Ford in 
a September 10, 2008 meeting \154\ obtained by a load cell Ford placed 
on the impactor shaft behind the headform. The Alliance believed that 
``[p]reliminary testing has shown the need to further research energy 
and excursion targets to ensure a `balanced approach' between excursion 
and curtain stiffness (load cell measurement) in order to avoid 
unintended consequences.'' In response, to our knowledge, no one has 
established the biomechanical relevance of a uniaxial load measurement 
on the shaft of an ejection impactor to occupant injury. Until and 
unless such a relationship can be established, the agency has no 
reasonable way to judge such data.
---------------------------------------------------------------------------

    \154\ NHTSA-2006-26467-0016.
---------------------------------------------------------------------------

l. Vehicle Applicability

    This standard applies to passenger cars, multipurpose passenger 
vehicles (MPVs), trucks and buses with a GVWR of 4,536 kg (10,000 lb) 
or less, except as noted in this section. Manufacturers are installing 
or plan to install side impact air bag window curtains in many of these 
vehicles. These side air bag window curtains are capable of meeting 
FMVSS No. 214's pole test requirements, which apply to passenger cars, 
MPVs, trucks and buses with GVWR of 4,536 kg or less. An FMVSS No. 214 
air bag window curtain system can be augmented for use as an ejection 
mitigation window curtain system.
1. Convertibles
    The NPRM tentatively determined that the standard should apply to 
convertibles. We requested comments on the practicability of certifying 
convertibles to the proposed performance test with door-mounted 
ejection mitigation curtains and/or advanced glazing.
Comments
    All comments from vehicle manufacturers and air bag manufacturers 
opposed the inclusion of convertibles in FMVSS No. 226 for 
practicability reasons. Many stated that there was no technology that 
would allow a convertible to meet the proposed requirements. The AIAM 
explained that although convertibles can meet FMVSS No. 214's pole test 
using a door-mounted upwardly deploying air bag, the inflated bag does 
not have a door frame to which the curtain can be tethered to achieve 
the lateral stiffness needed for ejection mitigation. Further, the 
curtains need to be retained by the convertible top, which may not have 
the same retention capability as the door trim of conventional 
vehicles.
    The Alliance informed the agency that the agency was incorrect in 
thinking that research from Porsche indicated the feasibility of a 
door-mounted air bag system for ejection mitigation. The Alliance 
explained that Porsche meant to describe a ``technologically neutral 
solution'' for a coupe, ``which unlike a convertible, can be fitted 
with framed windows.'' The Alliance stated that it believed that 
``advanced glazing, with or without a door[hyphen]mounted airbag, does 
not constitute a practicable compliance solution for convertibles.'' 
AORC stated that its members have been working on this technology but 
have not yet verified performance relative to this specification.
    Comments from Pilkington and from Public Citizen supported 
including convertibles in the applicability of the standard.
Agency Response
    We have decided that the standard will not apply to convertibles. 
We found compelling the practicability concerns raised by vehicle 
manufacturers and air bag suppliers related to the near-term technical 
challenges involved with producing a compliant convertible.
    In NPRM preamble, we mentioned Porsche's development of door-
mounted curtains that would deploy upward toward the vehicle roof in a 
rollover. Comments from the Alliance to the NPRM indicated that Porsche 
was not developing this curtain for ejection mitigation of 
convertibles, but rather for a coupe.
    We sought comments on the feasibility of a door-mounted upwardly-
deploying curtain for ejection mitigation of convertibles. Comments 
from vehicle manufacturers and air bag suppliers indicated that current 
air bag designs are not effective for ejection mitigation purposes in 
vehicles without a window frame because the air bag cannot be tethered 
at the leading edge of the curtain without a firm door frame to which 
to attach. We concur that an ejection mitigation side curtain air bag 
must be sturdily tethered in order to meet the displacement limits of 
this final rule. At this time, convertibles lack the rigid door frame 
or door pillar to which the ejection mitigation side curtain air bag 
could be tethered. We agree that current ejection mitigation side 
curtain air bag designs cannot be used on convertibles, and we are not 
aware of information indicating the feasibility of developing designs 
that could be used on convertibles in the foreseeable future.
    Advanced glazing will not be an available countermeasure for use in 
convertibles to meet the standard. Honda and others stated that the 
advanced glazing on a convertible door is likely to fall out in a 
rollover crash due to the lack of roof structure and rigid structure 
around the window opening. In our review of field data on advanced 
glazing, we found sufficient evidence of glazing vacating the window 
opening in real world rollover crashes that we decided not to allow 
movable advanced glazing to be the sole countermeasure used to meet the 
displacement limits of the standard. Also, movable glazing cannot be 
present during the 16 km/h-6 second test. With these changes, the 
glazing-only countermeasure is no longer viable for a movable window 
opening. A convertible would have to pass the 16 km/h-6 second test 
with just the door mounted ejection mitigation side curtain air bag. As 
previously discussed, we do not believe it is practicable for 
convertibles to meet the test with only an air bag at this time.
    In response to a comment from the Alliance, our reasons for 
excluding convertibles from the standard are not based on FMVSS No. 
216's exclusion of convertibles from roof crush resistance 
requirements. However, we acknowledge that convertibles can pose unique 
challenges related to the roof. As shown previously in this preamble, 
there were 16 fatalities and 18 MAIS 3+ injuries due to ejections 
through a convertible roof closed prior to the crash. For convertibles 
where the roof was open, the fatalities and MAIS 3+ injuries were 31 
and 84, respectively. This indicates that about half of the ejection 
fatalities through the roof area occurred even when the roof was closed 
before the crash. (These estimates are based on an extremely small 
sample size.) These data reflect the problematic nature of convertible 
ejection protection.
2. Original Roof Modified
    NHTSA proposed to exclude vehicles whose original roof was 
replaced, raised or otherwise modified. A definition of ``modified 
roof'' was adopted. No commenter opposed the proposal. NTEA commented 
in support of it. This final rule adopts the proposed exclusion and 
definition.

[[Page 3289]]

3. Multi-Stage Manufacture of Work Trucks
    NTEA asked that NHTSA exclude work trucks built in two or more 
stages (``multi-stage vehicles'') from FMVSS No. 226. NTEA stated that 
it expects that if ejection mitigation side curtain air bags are 
installed by a chassis manufacturer to meet FMVSS No. 226, ``this 
manner of compliance by the chassis manufacturers will result in 
restrictive or non-existent pass-through compliance guidance for multi-
stage manufacturers of work trucks.'' The commenter believed that the 
purchasers of these vehicles require an extensive variety of end 
designs, ``including bulkheads and partitions to protect the driver 
from loose cargo in the back of the vehicle,'' and that the design of 
most vehicles will almost certainly affect the performance of the 
chassis manufacturers' side curtain air bag systems. The commenter 
believed that ``pass-through compliance will prohibit any completions 
or alterations that could affect the vehicle's center of gravity thus 
potentially affecting the sensor(s) that control side curtain bag 
deployment. Also expected to be prohibited for pass-through compliance 
would be any changes to the trim or headliner around any of the 
regulated window space.'' \155\
---------------------------------------------------------------------------

    \155\ NHTSA-2009-0183-0017, p. 3.
---------------------------------------------------------------------------

    NHTSA is declining the request for a blanket exclusion of all work 
trucks built in two or more stages from FMVSS No. 226. To provide 
relief to multi-stage manufacturers and alterers, we have already 
excluded vehicles whose original roof was removed, in part or in total, 
by an alterer or final stage manufacturer. That exclusion addresses 
designs that will specifically affect side curtain air bag coverage or 
inflators for which pass-through guidance might not be available.
    A final-stage manufacturer can either stay within the incomplete 
vehicle document (IVD) furnished by the incomplete vehicle manufacturer 
(which are typically large vehicle manufacturers, such as GM or Ford), 
or the final-stage manufacturer can work with incomplete vehicle 
manufacturers to enable the final-stage manufacturer to certify to the 
new standard.\156\ The final-stage manufacturer can also certify to the 
standard using due care based on an assessment of the information 
available to the manufacturer.
---------------------------------------------------------------------------

    \156\ For a discussion of NHTSA's certification regulations for 
final stage manufacturers, see 71 FR 28168, May 15, 2006, Docket No. 
NHTSA-2006-24664, Response to petitions for reconsideration of a 
final rule implementing regulations pertaining to multi-stage 
vehicles and to altered vehicles. The Background section of that 
document provides concepts and terminology relating to the 
certification of multi-stage vehicles.
---------------------------------------------------------------------------

    NTEA contended that work-performing vehicles should be excluded 
from the standard because producing these vehicles may involve changing 
the vehicle's center of gravity, which the commenter stated could 
potentially affect the sensor(s) that control side curtain air bag 
deployment. The standard adopted today does not specify any 
requirements for the rollover sensor. In the compliance test, we 
manually deploy the ejection mitigation side curtain air bags with the 
stationary vehicle set up in the test laboratory. Changing the center 
of gravity of the vehicle would not affect our ability to manually 
deploy the side curtain air bags in the laboratory test. Likewise, 
lowering the vehicle floor would not affect the ability to manually 
deploy the side curtain air bags in the test.
    Since no certification requirement exists with regard to the 
sensor, the IVD will not have center of gravity restrictions regarding 
sensor performance. We have no sound reason to exclude multi-stage work 
vehicles from the standard based on possible restrictions relating to 
sensor performance.
    Furthermore, we do not believe that changing the center of gravity 
of the vehicle will affect whether or not an ejection mitigation side 
curtain air bags deploys in a real world rollover. We believe that 
incomplete vehicle manufacturers will be able to develop rollover 
detection technology that can address variability in the vehicle's 
center of gravity.\157\ Sensors that are based on roll angle and roll 
rate can be made to deploy the air bag when the vehicle rolls, despite 
changes to the center of gravity of the vehicle involved in installing 
bulkheads, partitions, etc., to which NTEA alludes. However, such 
changes may have an effect on the optimization of the sensor for the 
particular vehicle, which could result in the systems deploying earlier 
or later than would otherwise be the case. Nonetheless, even without 
sensor optimization, work vehicles with ejection mitigation side 
curtain air bags would continue to provide ejection protection to their 
occupants. If these vehicles were excluded because of center of gravity 
changes, they would offer no ejection protection in rollovers and no 
protection against ejection in side impacts.
---------------------------------------------------------------------------

    \157\ Mercedes' comment to the NPRM indicated that vehicle 
manufacturers will work toward developing rollover detection 
technology for use in large vehicles with center of gravity 
different than those of passenger cars.
---------------------------------------------------------------------------

    Some modifications made by a final-stage manufacturer or alterer to 
the interior of the vehicle could affect the vehicle's compliance with 
FMVSS No. 226. An example of this is installing a partition. NTEA 
sought to exclude multi-stage manufactured vehicles with bulkheads and 
partitions from FMVSS No. 226 since installation of a bulkhead or 
partition ``will almost certainly affect the performance of the chassis 
manufacturers' side curtain air bag systems.''
    We decline to adopt a blanket exclusion of multi-stage vehicles 
with bulkheads or partitions in work vehicles.\158\ Such an exclusion 
would be unreasonably broad. Bulkheads and partitions can be installed 
so as not to interfere with the deployment of ejection mitigation side 
curtain air bags. Bulkheads and partitions can be designed to allow for 
sufficient clearance to allow the air bags to deploy, or may have 
break-away features to allow a curtain air bag to deploy.\159\ The 
incomplete vehicle manufacturers will be able to provide the 
appropriate guidance to allow for pass-through certifications. Even if 
the IVD does not provide guidance, the final-stage manufacturer will be 
able to ascertain the clearance needed to install the bulkhead or 
partition. The bulkhead and partition designs will enable the final 
customer to purchase a vehicle certified to FMVSS No. 226 and to 
provide the protection of side curtain air bags to their employees who 
will be occupying the vehicle.
---------------------------------------------------------------------------

    \158\ As discussed later in this section, we are allowing a 
limited exclusion of ``security partitions'' in multi-stage 
manufactured or altered law enforcement vehicles, correctional 
institution vehicles, taxis and limousines.
    \159\ See 75 FR 12123, 12128-12131, March 15, 2010, for a 
discussion of approaches that are available to multi-stage 
manufacturers enabling them to certify to FMVSS No. 214's pole test 
using side impact curtain air bags in vehicles with partitions.
---------------------------------------------------------------------------

    We disagree with the Alliance's comment that the National Traffic 
and Motor Vehicle Safety Act precludes the agency from applying FMVSS 
No. 226 to vehicles with partitions. Partitioned vehicles are not a 
vehicle type. In any event, it is not impracticable to meet the 
standard with a partition. Manufacturers will be able to determine how 
to provide a clearance for the ejection mitigation side curtain air 
bags and/or design and position the partition to take advantage of the 
shape of the air bag.
    NTEA also expressed concerns related to testing cost for those 
multi-staged vehicles for which pass-through would not be available. It 
stated that it received estimates for testing costs ``from $9,000 to 
$25,000 for 1-3 rows at 5 tests per

[[Page 3290]]

window, and $14,000 to $40,000 for 1-3 rows at 8 tests per window 
(assuming new airbags and glass for each impact.'' We do not believe 
those estimates are accurate. In the PRIA, the agency estimated testing 
costs would consist of $100 for labor, $300 for an air bag and $400 for 
advanced glazing.\160\ For a 3 row vehicle, assuming testing every 
target at both test speeds; this would result in a testing cost 
estimate of $19,200.
---------------------------------------------------------------------------

    \160\ PRIA, pg. V-21.
---------------------------------------------------------------------------

    NTEA also questioned the potential availability of testing 
facilities to fulfill the need of the multi-stage manufacturers. We 
believe testing facilities will be able and willing to provide the 
market demand for testing. The agency purchased a state-of-the-art 
ejection mitigation test device for about $150,000 and received 
delivery in 4\1/2\ months.
    In addition, multi-stage manufacturers have an additional year 
after the phase-in is completed to certify compliance to FMVSS No. 226. 
This leadtime available to multi-stage manufacturers will provide 
enough time for the manufacturers to work with incomplete vehicle 
manufacturers to address pass-through certification guidance or perform 
whatever testing they deem is necessary for certification purposes, 
including the basis for certifying vehicles with a partition or 
bulkhead.
    NTEA noted that it expected any change to the trim or headliner 
around any of the window space to be prohibited by the IVD for pass-
through compliance. We do not agree. In its comment, Nissan stated that 
it did not anticipate the headliner would affect performance of the 
side curtain air bag system. NTEA did not provide information showing 
otherwise. Further, the multi-stage manufacturers have ample lead time 
to work with incomplete vehicle manufacturers to develop acceptable 
trim and headliner changes or to work with test laboratories themselves 
to assess what changes to the trim or headliner can be made that will 
not affect the performance of the ejection mitigation system.
    We are adopting a suggestion of NTEA with regard to partitions. One 
of NTEA's comments related to vehicles with partitions or bulkheads 
that separate areas of the vehicle with and without seating positions. 
It stated that to the extent the proposed standard applied to multi-
stage produced trucks, ``NHTSA [should] consider adopting testing 
parameters similar to those found in FMVSS 201 to effectively exclude 
any targets that are located behind the forward surface of a partition 
or bulkhead * * *. We believe it is neither practical nor beneficial to 
require test target points that could not possibly be contacted by the 
head of an occupant seated forward of the partition.'' \161\
---------------------------------------------------------------------------

    \161\ This provision is found in S6.3(b) of FMVSS No. 201. 
Footnote added.
---------------------------------------------------------------------------

    We find merit in this suggestion to be consistent with FMVSS No. 
201. If there is a permanent partition or bulkhead that separates areas 
of the vehicle with designated seating positions (DSgPs) from areas 
that do not have DSgPs, we believe there is no sensible reason to 
target daylight openings in the latter area. The likelihood of an 
occupant being ejected from an opening in an area without a DSgP is 
low. However, to reduce the likelihood an occupant would be in the area 
without a DSgP, the partition or bulkhead must be fixed to the vehicle 
and not provide access for an occupant to pass through it. A partition 
with a door would not be considered as separating the occupant space 
from non-occupant space.
    This final rule makes a limited exclusion of security partitions in 
multi-stage manufactured or altered law enforcement vehicles, 
correctional institution vehicles, taxis and limousines. The Alliance 
and Volvo commented that police vehicles, taxis and limousines with 
partitions between the first and second rows should be excluded from 
FMVSS No. 226. The Alliance claimed that any partition installed in a 
way to not interfere with curtain deployment would leave ``a 
significant gap between the outboard edge of the partition and the 
inboard surface of the vehicle trim thus rendering it unable to provide 
either complete security or privacy.'' The Alliance believed that 
upwardly-deploying air bags are not feasible. Volvo believed that 
installing a partition is ``always done by a third party and is, for 
this reason, beyond the vehicle manufacture[r]'s control. To take this 
potential adaptation into consideration during design, development, and 
testing would not be possible.''
    Considering that law enforcement vehicles are more likely to be 
involved in risky driving operations than other passenger vehicles, 
NHTSA prefers that the vehicles provide ejection mitigation 
countermeasures. However, we agree to exclude some vehicles from the 
standard under certain circumstances due to practical considerations.
    Security partitions (e.g., prisoner partitions) are necessary for 
the safety and security of law enforcement officers. These partitions 
must be flush against the sides of the vehicle to prevent a rear seat 
occupant's hand or article from intruding into the officer's 
compartment. A partition installed by a final-stage manufacturer in an 
incomplete vehicle or by an alterer in a completed vehicle will 
interfere with the ejection mitigation side curtain air bags currently 
being produced. The curtains are tethered from the A-pillar to the C-
pillar, so a partition between the 1st and 2nd rows or between the 2nd 
and 3rd rows will prevent the curtain from properly covering the window 
opening.
    After considering the comments, we believe it would be difficult 
for incomplete vehicle manufacturers providing vehicles to the final 
stage manufacturers or alterers to have an alternative design which 
would be compatible with a security partition.\162\ Thus, we are 
excluding from the standard law enforcement vehicles, correctional 
institution vehicles, taxis and limousines, if they have a fixed 
security partition separating the 1st and 2nd or 2nd and 3rd rows, and 
if they are manufactured in more than one stage or are altered. We do 
not believe that compatible designs, such as a split curtain, are 
impossible. Rather, we believe compatible designs will need time to 
develop.
---------------------------------------------------------------------------

    \162\ In FMVSS No. 214, we do not exclude police and other 
vehicles from meeting the standard's pole test requirements. The 
pole test does not apply to rear seats. To meet the pole test, 
vehicles must provide head, thorax and pelvic protection. Side 
window curtains can be used to meet the pole test, but seat- and 
door-mounted air bags in the front seat are also available for use 
as well in meeting FMVSS No. 214. Thus, multi-stage manufacturers 
can work together such that the vehicle in which the partition is 
installed can meet FMVSS No. 214 with a front seat seat-mounted or 
door-mounted air bag. At this time there is no countermeasure 
available from incomplete vehicle manufacturers that could meet 
FMVSS No. 226 with a security partition flush to the side of the 
vehicle. A countermeasure only using advanced glazing for movable 
windows will not meet today's requirements because the 16 km/h test 
must be passed without glazing in place.
---------------------------------------------------------------------------

    We do not believe there is any technical barrier to designing 
curtain(s) to cover side windows that are separated by a partition with 
two separate curtains. The front of the first row curtain and rear of 
the second row curtain could be tethered to the A- and C-pillars, 
respectively. Each curtain could be separately tethered to the B-
pillar. We also believe that such a split curtain system could use a 
single inflator to feed both air bags. The trim on the B-pillar and on 
the header in front and behind the partition could be split to allow 
the two air bags to deploy independently. Development of such a vehicle 
specific curtain would likely require time, and the resources available 
to an incomplete vehicle manufacturer, i.e., a large vehicle 
manufacturer.

[[Page 3291]]

Because we believe incomplete vehicle manufacturers are able to develop 
a curtain design that is compatible with a partition, we are not 
extending this exclusion to law enforcement vehicles, correctional 
institution vehicles, taxis and limousines if they are built in a 
single stage. We believe it is practicable for such a vehicle to have a 
single design to meet the final rule and that manufacturers of such 
vehicles will be capable of applying the necessary resources to meet 
the standard.
4. Other Issues
i. Vehicles That Have No Doors and Walk-In Vans
    Comments were requested but none were received on whether vehicles 
are still being manufactured that have no doors, or exclusively have 
doors that are designed to be easily attached or removed so that the 
vehicle can be operated without doors. NHTSA proposed excluding the 
vehicles on practicability grounds. This final rule adopts the 
exclusion.
    We did not receive comments on the proposed exclusion of walk-in 
vans. This final rule excludes the vehicles on practicability grounds.
ii. Vehicles Over 4,536 kg
    A few commenters requested that the standard not be limited to 
vehicles under 4,536 kg (10,000 lb) GVWR. Batzer and Ziejewski stated 
that school buses over 4,536 kg offered ejection mitigation by virtue 
of the divider-bar requirement and, therefore, commercial vehicles over 
4,536 kg GVWR should be covered as well. The commenter stated that 
``[w]hile this could conceivably cause some manufacturers distress, 
they could be provided the opportunity to petition NHTSA for a waiver, 
and notify the purchaser that their vehicle does not fully comply with 
pertinent FMVSS regulations.'' \163\
---------------------------------------------------------------------------

    \163\ NHTSA-2009-0183-0009, p. 1.
---------------------------------------------------------------------------

    We did not propose to apply the standard to vehicles with a GVWR 
over 4,536 kg and did not discuss the possibility of this application 
of the standard or request comments on this issue. Thus, the requests 
are outside the scope of the rulemaking. Also, we note that the 
National Traffic and Motor Vehicle Safety Act provides very limited 
authority to NHTSA to grant exemptions to manufacturers from meeting 
the requirements of the Federal motor vehicle safety standards. General 
authority to grant waivers is not available.

m. Lead Time and Phase-In Schedules; Reporting Requirements

    Motor vehicle manufacturers will need lead time to develop and 
install ejection mitigation countermeasures and rollover sensors. 
Although inflatable side curtain air bags are being developed in new 
vehicles to meet the September 1, 2010 date that begins the phase-in of 
the FMVSS No. 214 final rule for the pole test, to meet the 
requirements adopted today, these side curtains will have to be made 
larger to cover more of the window opening, will have to be made more 
robust to remain inflated longer, and will have to be enhanced (by 
tethering and other means) to retain vehicle occupants within the 
vehicle. Moreover, rollover sensors will need to be installed to deploy 
the ejection mitigation countermeasures in rollover crashes, to augment 
the sensors needed to deploy the side curtains in side impacts.
    Our tests of vehicles to the NPRM's proposed requirements found 
that vehicle manufacturers were at different stages with respect to 
designing inflatable ejection mitigation side curtains that meet the 
requirements then-proposed. Vehicle manufacturers also face unique 
manufacturing constraints and challenges, e.g., each face differences 
in the technological advances incorporated in their current air bag 
systems, differences in engineering resources, and differences in the 
numbers and type of vehicles for which ejection mitigation systems will 
need to be incorporated. NHTSA believed that these differing situations 
can best be accommodated by phasing in the ejection mitigation 
requirements and by allowing the use of advanced credits.
    NHTSA proposed that the phase-in would be implemented in accordance 
with the following schedule: 20 percent of each manufacturer's vehicles 
manufactured during the first production year beginning three years 
after publication of a final rule (for illustration purposes, assuming 
the final rule is issued in January 2011, under the NPRM that effective 
date would have been September 1, 2014); 40 percent of each 
manufacturer's vehicles manufactured during the production year 
beginning four years after publication of a final rule; 75 percent of 
vehicles manufactured during the production year beginning five years 
after publication of a final rule; and all vehicles (without use of 
advanced credits) manufactured on or after the September 1st following 
six years after publication of a final rule.
    NHTSA also proposed to permit ``limited line'' manufacturers that 
produce three or fewer carlines the option of achieving full compliance 
when the phase-in is completed. The NPRM also proposed that 
manufacturers of vehicles manufactured in two or more stages and 
alterers would not be required to meet the phase-in schedule and would 
not have to achieve full compliance until one year after the phase-in 
is completed. NHTSA proposed reporting requirements to accompany the 
phase-in.
Comments
    The Alliance asked for an additional year of lead time, believing 
that it will take at least 12 months after publication of the final 
rule to obtain impactors meeting the specified performance 
requirements. Further, the Alliance stated that ``even after the 
devices have been acquired, they must be installed, pre[hyphen]tested 
and run[hyphen]in before they can produce consistent test results which 
are necessary prior to the initiation of a development process that 
will yield reproducible results. These logistical steps will 
unfortunately eliminate one[hyphen]third of the lead[hyphen]time 
intended by the NPRM and because manufacturers will utilize the 
impactor in the development process, this lost time will significantly 
impact manufacturers' ability to achieve compliance in the first year 
of the phase[hyphen]in as proposed.''
    The AIAM stated that an additional year of lead time is needed for 
vehicles not utilizing roof rail mounted curtain air bags to meet FMVSS 
No. 214. It claimed that these vehicles would need significantly 
greater redesign and that this work cannot begin until the final rule 
is issued.
    Several vehicle manufacturers asked for the application of advanced 
credits in the 100 percent certification year. The Alliance contended 
that manufacturers producing vehicles that do not meet FMVSS No. 214 by 
way of a side window air bag curtain will need to use credits in the 
100 percent year to be able to redesign vehicles to meet FMVSS No. 226. 
The commenter stated its belief that vehicles with a GVWR over 2,722 kg 
(6,000 lb) will need more lead time to install larger air bag cushions 
and inflators to cover the vehicles' larger windows. Porsche stated 
that compliance with future ejection mitigation requirements will 
necessitate significant changes to the body-in-white, greenhouse and 
interior fittings which can only be implemented with the launch of a 
new vehicle model. Mercedes commented that large vehicles, such as the 
Mercedes-Benz Sprinter, have large window openings

[[Page 3292]]

which Mercedes stated will require a completely new generation of large 
air bag curtains.
    In contrast, glazing manufacturers and consumer groups requested a 
one-year reduction in both the lead time and phase-in of the final 
rule. Advocates requested that the phase-in be changed to 40 percent, 
75 percent and 100 percent. Guardian stated that ``advanced glazing 
technology is available today.'' EPGAA stated ``many manufacturers' 
models already incorporate advanced glazing and airbags, and as NHTSA's 
testing shows, little or no changes are required to existing airbags to 
achieve compliance with the proposed standard.''
Agency Response
    To accelerate the ejection mitigation benefits provided by this 
final rule, the agency has decided to reduce the lead time by a year, 
to two years of lead time, and to require larger percentages of a 
manufacturer's fleet to meet the new standard in the first two years of 
the phase-in schedule than proposed. The overall timetable is 
comparable to the schedules in FMVSS Nos. 214 and 216, and with the 
Phase I advanced air bag implementation in FMVSS No. 208.
    We reject the argument of the Alliance that a lack of availability 
of impact testers will delay compliance. Many vehicle manufacturers and 
air bag manufacturers presented test data to the agency indicating they 
have access to impact testers and are able to perform the tests. The 
lead time and phase-in timetable provided will afford sufficient time 
to perform compliance tests.
    We reject the AIAM request for increased lead time for vehicles 
that do not or will not use curtains to meet the FMVSS No. 214 upgrade. 
If manufacturers need more time for such vehicles, they can address 
this through the flexibility offered by the phase-in and credits. AIAM 
indicated that the additional year was needed to ``fully separate the 
214 and ejection mitigation phase-in periods.'' We do not know of a 
reason why full separation is needed between completion of the phase-in 
of the FMVSS No. 214 upgraded requirements and the first year of the 
FMVSS No. 226 phase-in.
    The 24 km/h-1.5 second impact proposed in the NPRM has been reduced 
in this final rule to 20 km/h-1.5 seconds after our reanalysis of the 
technical basis for the energy requirement. With this reduction in 
impactor speed, it is expected that fewer changes will be needed to 
existing designs to meet the final rule's requirements. Data from 
agency testing of production vehicles presented earlier in this 
preamble showed that the MY 2007 Mazda CX9 was able to meet the 
performance tests in the final rule, without modification. Given this 
reduction in stringency of the test, fewer and/or less substantial 
vehicle design changes will be needed to meet the standard, and less 
lead time required to begin phasing in the requirements across the 
fleet. Accordingly, we believe that two years of lead time are 
sufficient prior to the phase-in. For the same reason, a greater 
percentage of vehicles will be able to meet the requirements in each of 
the phase-in years. Thus, we are slightly increasing the percentages of 
vehicles in the fleet that will need to meet the ejection mitigation 
standard during the first two years of the phase-in.
    However, vehicle manufacturers are at different stages with respect 
to designing ejection mitigation systems, and also face differences in 
the challenges they face and the resources available to them. To 
provide flexibility to manufacturers in managing their resources to 
meet this schedule, this final rule provides a multi-year phase-in 
period and allows credits to be used in the 100 percent phase-in year. 
The agency did allow the use of credits for the 100 percent year for 
the advanced air bag rulemaking in FMVSS No. 208. We generally agree 
with the comments from AIAM stating that credits allow for manufacturer 
flexibility and earlier safety benefits. The added flexibility of 
allowing credits in the 100 percent year will allow manufacturers a 
more seamless introduction of compliant vehicles while enhancing their 
ability to manage their engineering and manufacturing resources.
    We found particularly compelling the comments from Mercedes 
(regarding the Sprinter), Porsche (regarding the long product cycle of 
their sports cars), Volvo and other manufacturers. The use of advanced 
credits in the 100 percent year will provide relief to manufacturers of 
vehicles with very large windows, vehicles with very long product 
cycles, and vehicles that are not as far along having side curtain air 
bags as other vehicles.
    The comments showed that manufacturers have unique problems 
depending on factors such as organizational resources, product mix, and 
product life cycle. A manufacturer with many different models may have 
more flexibility in determining which vehicles to certify and in 
accruing credits. However, this larger portfolio may require greater 
effort to bring all vehicles into compliance. On the other hand, 
manufacturers with small portfolios may have less flexibility, but may 
be able to focus resources on a much smaller number of vehicles to 
upgrade. The final rule phase-in schedule, even with the added year of 
credit use, may result in some manufacturers needing to reassess and 
modify their plans. Nonetheless, we believe that the two-year lead time 
and the four-year phase-in correctly balances the manufacturers' needs 
for flexibility and the needs of the agency to limit the length of time 
for the phase-in to a reasonable period and achieve the safety benefits 
of the final rule as quickly as practicable.
    NHTSA has decided that the lead time and phase-in will continue to 
apply to all vehicles under 4,536 kg (10,000 lb).\164\ We have balanced 
the safety need to implement the requirements of this final rule as 
quickly as practicable with the realistic burdens of manufacture.\165\ 
We believe that the relief provided by the additional year to use 
credits will allow manufacturers the flexibility to address any 
specific problems associated with bringing heavier vehicles into 
compliance. Some vehicle manufacturers pointed to FMVSS Nos. 214 and 
216 as examples of standards where the certification schedule gave 
special treatment to heavier vehicles. For example, for FMVSS No. 214, 
the agency stated that more time was being provided for the pole test 
of vehicles with GVWR greater than 3,856 kg (8,500 lb) because the 
vehicles had never been regulated in FMVSS No. 214 and thus ``more 
redesign of the vehicle side structure, interior trim, and/or 
optimization of dynamically deploying head/side protection systems may 
be needed in these vehicles than in light vehicles.'' \166\ We do not 
find the analogy persuasive. The changes needed to meet FMVSS Nos. 214 
and 216 were primarily

[[Page 3293]]

structural. FMVSS No. 226 countermeasures for larger vehicles, as 
indicated by commenters, will likely be larger curtains and longer-
lasting inflators. The two-year lead time and phase-in timetable for 
FMVSS No. 226, and the use of credits in the 100 percent year, will 
provide the time needed to meet the standard.
---------------------------------------------------------------------------

    \164\ This does not include limited line manufacturers, 
manufacturers of multi-stage vehicles, and alterers. Those 
manufacturers are not required to achieve full compliance until one 
year after the phase-in is completed.
    \165\ The agency estimates that vehicles between the ranges of 
2,722 kg (6,000 lb) to 4,536 kg (10,000 lb) and 3,856 kg (8,500 lb) 
to 4,536 kg (10,000 lb) constitute 25 percent and 6 percent of the 
annual production of vehicles with a GVWR less than 4,536 kg (10,000 
lb). The 25 percent estimate can be found in the FRIA for the recent 
FMVSS No. 216 upgrade (Docket NHTSA-2009-0093). The 6 percent 
estimate is derived from MY 2010 submissions to the NCAP Buying a 
Safer Car program and Ward's 2009 Yearbook. We believe that to 
exclude 25 percent of vehicles less than 4,536 kg (10,000 lb) from 
meeting FMVSS No. 226 until the end of the phase-in, as would be the 
case for the 2,722 kg (6,000 lb) split, would be unacceptable in 
terms of the delayed safety benefits. We also believe that the 6 
percent of vehicles, represented by the 3,856 kg (8,500 lb) split, 
represents a number that can be accommodated with accrued advanced 
credits.
    \166\ 72 FR 51911.
---------------------------------------------------------------------------

    We do not agree with the commenters expressing concern that 
countermeasures for heavier vehicles may have more OOP issues and 
therefore, in general, need more time to comply. Toyota data submitted 
by the Alliance indicated that OOP concerns were actually greater for 
passenger cars than they were for larger vehicles. Further, there is 
the potential of using advanced glazing in these heavier vehicles, 
particularly for fixed windows.
    We take this opportunity to correct Public Citizen's apparent 
misinterpretation of the PRIA that led the commenter to believe that 
the agency estimated that 25 percent of MY 2011 vehicles would be able 
to comply with the NPRM. In the PRIA, we said that none of the curtain 
systems tested met the proposed 100 mm displacement limit. However, 
although none of the current curtain air bags met the displacement 
requirement, the non-compliant curtains would provide some amount of 
ejection mitigation. Since we do not want to double count the potential 
benefits of the rulemaking with the benefits that the non-compliant 
curtains already provide, these potential benefits were excluded from 
the benefits estimate.\167\ Thus, the 25 percent value quoted by Public 
Citizen is an adjustment factor, not a compliance rate.\168\
---------------------------------------------------------------------------

    \167\ For example, a curtain air bag that completely covers the 
front window opening and meets the 100 mm displacement requirement 
at A2, A3, and A4, but not A1. We assumed that the air bag system 
would provide some benefits, even if it failed to meet the 
displacement requirement at A1.
    \168\ The PRIA stated that current ejection mitigation curtain 
systems are only 46 percent effective in preventing occupants from 
ejection and that 55 percent of MY 2011 vehicles would be equipped 
with these non-compliant air bags.
---------------------------------------------------------------------------

Reporting Requirements
    The Alliance mentioned that the NPRM requires manufacturers to 
report advanced credits 60 days after the end of the production year. 
It stated that this means the first report would be due on August 31, 
2011. (Under the NPRM the first report would actually have to be filed 
60 days after the date of August 31, 2011, rather than on August 31.) 
It opined that ``[b]ecause the rule will likely not be finalized until 
2011 and the impactors complying with the specifications contained in 
the final rule may not be available to all manufacturers until the 2012 
timeframe, the Alliance recommended that section 585.105 of the 
regulation be revised so as to provide manufacturers up to one year 
after the end of the first advanced credit production period to file 
their advanced credit phase[hyphen]in report for that year.
    We disagree with this request. The commenter's rationale for 
putting off the filing of the report for a year was the same one it 
used to argue for an increase in lead time by one year, i.e., an 
alleged lack of availability of impact testers meeting the final rule 
requirements. We disagree with this reason because, as previously 
stated, many vehicle manufacturers and air bag manufacturers presented 
test data to the agency indicating they have access to impact testers 
and are able to perform tests. Further, allowing manufacturers one year 
after the end of the MY 2011 production period ends to report would 
lead to logistical difficulties for the agency's compliance testing 
program. At the time we would be purchasing vehicles for the MY 2011 
compliance testing, we would not know which vehicles to purchase for 
testing to FMVSS No. 226 without the reports. If the reports were not 
due until October 1, 2012, it might be difficult to procure the 
certified MY 2011 vehicles at that time.
    AIAM and VSC asked that small volume and limited line manufacturers 
be exempt from the phase-in reporting until the first year that they 
must comply or can earn credits. We agree with the comment. These 
entities are exempt from the phase-in requirements, so they should be 
exempt from reporting requirements as well.

XI. Costs and Benefits

    The FRIA we have placed in the docket analyzes the impacts of this 
final rule. A summary of the FRIA follows.
    The agency believes that side curtain air bags will be used to pass 
the ejection mitigation test. We believe that most manufacturers will 
widen the side curtain air bags that they are providing to meet FMVSS 
No. 214's pole test requirements, or replace combination (combo) seat-
mounted side air bags with a curtain to pass the impactor test of the 
standard adopted today. We assume that for the most part vehicle 
manufacturers will install a single-window curtain for each side of the 
vehicle, and that these window curtains will provide protection for 
occupants of the first three rows.
    This final rule will save 373 lives and prevent 476 serious 
injuries per year (see Table 42 below). The cost of this final rule is 
approximately $31 per vehicle (see Table 43). 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 44 below). Annualized 
costs and benefits are provided in Table 45.

                      Table 42--Estimated Benefits
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Fatalities......................................................     373
Serious Injuries................................................     476
------------------------------------------------------------------------


                       Table 43--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 44--Cost per Equivalent Life Saved
------------------------------------------------------------------------
                  3% Discount rate                     7% Discount rate
------------------------------------------------------------------------
$1.4M...............................................               $1.7M
------------------------------------------------------------------------


                                     Table 45--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
----------------------------------------------------------------------------------------------------------------


[[Page 3294]]

    The agency received several comments about the PRIA's cost benefit 
analysis. Several glazing manufacturers commented that the agency's 
analysis underestimated air bag costs, did not adequately consider 
benefits of advanced glazing associated with enhanced security, UV 
shading, weight reduction, improved energy efficiency, etc., and 
overstated the cost of advanced glazing. Public Citizen stated that the 
agency underestimated the benefits of FMVSS No. 226 because we 
overestimated the effectiveness of ESC. Conversely, IIHS stated we 
overestimated the benefits of FMVSS No. 226 because we underestimated 
the benefits of FMVSS No. 216.
    In the FRIA, NHTSA responds to all relevant comments on the costs 
and benefits estimated by the NPRM and PRIA.

XII. Rulemaking Analyses and Notices

Executive Order 12866 (Regulatory Planning and Review) and DOT 
Regulatory Policies and Procedures

    The agency has considered the impact of this rulemaking action 
under Executive Order 12866 and the Department of Transportation's 
regulatory policies and procedures. This rulemaking is economically 
significant and was reviewed by the Office of Management and Budget 
under E.O. 12866, ``Regulatory Planning and Review.'' The rulemaking 
action has also been determined to be significant under the 
Department's regulatory policies and procedures. NHTSA has placed in 
the docket a Final Regulatory Impact Analysis describing the costs and 
benefits of this rulemaking action.

Regulatory Flexibility Act

    The Regulatory Flexibility Act of 1980, as amended, requires 
agencies to evaluate the potential effects of their proposed and final 
rules on small businesses, small organizations and small governmental 
jurisdictions. I hereby certify that this final rule will not have a 
significant economic impact on a substantial number of small entities. 
Small organizations and small governmental units will not be 
significantly affected since the potential cost impacts associated with 
this final rule will not significantly affect the price of new motor 
vehicles.
    The final rule could indirectly affect air bag manufacturers and 
suppliers. These entities do not qualify as small entities.
    The final rule will directly affect motor vehicle manufacturers. 
The FRIA discusses the economic impact of the final rule on small 
vehicle manufacturers, of which there are six. We believe that the 
final rule will not have a significant economic impact on these 
manufacturers. The standard will employ static testing of the ejection 
mitigation system. The test does not involve destructive crash testing. 
It only involves the replacement of certain components and small 
vehicle manufacturers can perform such testing themselves. They can 
certify compliance using a combination of their own engineering 
analyses and testing and component testing by air bag suppliers. 
Already much of the air bag development work for these small vehicle 
manufacturers is done by air bag suppliers. While typically, air bag 
suppliers will supply larger vehicle manufacturers during the lead time 
and phase-in period of this final rule, this rulemaking accounts for 
this limitation by allowing more time to small manufacturers and 
limited line manufacturers to comply with the upgraded requirements. 
They have a year past the end of the phase-in period to comply. This 
additional time provides flexibility to those entities and enough time 
to work with the air bag suppliers to meet their needs.
    Final-stage vehicle manufacturers buy incomplete vehicles and 
complete the vehicle. Alterers modify new vehicles, such as by raising 
the roofs of vehicles. In both cases, NHTSA concludes that the impacts 
of this final rule on such entities is not significant. Final-stage 
manufacturers and alterers engaged in raising the roofs of vehicles 
would not be affected by this final rule because the rule excludes 
vehicles with raised roofs from the ejection mitigation requirements.
    NHTSA believes that work vehicles can be produced in compliance 
with the standard. Partitions separating a driver from cargo can be 
installed to accommodate an ejection mitigation side curtain air bag by 
providing clearance for the air bag. This final rule accommodates 
partitions installed in police vehicles, limousines and taxis by final-
stage manufacturer and alterers by excluding those vehicles from the 
standard.

Executive Order 13132 (Federalism)

    NHTSA has examined today's final rule pursuant to Executive Order 
13132 (64 FR 43255, August 10, 1999) and concluded that no additional 
consultation with States, local governments or their representatives is 
mandated beyond the rulemaking process. The agency has concluded that 
the rulemaking would not have sufficient federalism implications to 
warrant consultation with State and local officials or the preparation 
of a federalism summary impact statement. The final rule would not have 
``substantial direct effects on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government.''
    NHTSA rules can preempt in two ways. First, the National Traffic 
and Motor Vehicle Safety Act contains an express preemption provision: 
When a motor vehicle safety standard is in effect under this chapter, a 
State or a political subdivision of a State may prescribe or continue 
in effect a standard applicable to the same aspect of performance of a 
motor vehicle or motor vehicle equipment only if the standard is 
identical to the standard prescribed under this chapter. 49 U.S.C. 
30103(b)(1). It is this statutory command by Congress that preempts any 
non-identical State legislative and administrative law addressing the 
same aspect of performance.
    The express preemption provision described above is subject to a 
savings clause under which ``[c]ompliance with a motor vehicle safety 
standard prescribed under this chapter does not exempt a person from 
liability at common law.'' 49 U.S.C. 30103(e) Pursuant to this 
provision, State common law tort causes of action against motor vehicle 
manufacturers that might otherwise be preempted by the express 
preemption provision are generally preserved. However, the Supreme 
Court has recognized the possibility, in some instances, of implied 
preemption of such State common law tort causes of action by virtue of 
NHTSA's rules, even if not expressly preempted. This second way that 
NHTSA rules can preempt is dependent upon there being an actual 
conflict between an FMVSS and the higher standard that would 
effectively be imposed on motor vehicle manufacturers if someone 
obtained a State common law tort judgment against the manufacturer, 
notwithstanding the manufacturer's compliance with the NHTSA standard. 
Because most NHTSA standards established by an FMVSS are minimum 
standards, a State common law tort cause of action that seeks to impose 
a higher standard on motor vehicle manufacturers will generally not be 
preempted. However, if and when such a conflict does exist--for 
example, when the standard at issue is both a minimum and a maximum 
standard--the State common law tort cause of action is impliedly 
preempted. See Geier v. American Honda Motor Co., 529 U.S. 861 (2000).

[[Page 3295]]

    Pursuant to Executive Order 13132 and 12988, NHTSA has considered 
whether this rule could or should preempt State common law causes of 
action. The agency's ability to announce its conclusion regarding the 
preemptive effect of one of its rules reduces the likelihood that 
preemption will be an issue in any subsequent tort litigation.
    To this end, the agency has examined the nature (e.g., the language 
and structure of the regulatory text) and objectives of today's rule 
and finds that this rule, like many NHTSA rules, prescribes only a 
minimum safety standard. As such, NHTSA does not intend that this rule 
preempt state tort law that would effectively impose a higher standard 
on motor vehicle manufacturers than that established by today's rule. 
Establishment of a higher standard by means of State tort law would not 
conflict with the minimum standard announced here. Without any 
conflict, there could not be any implied preemption of a State common 
law tort cause of action.

Executive Order 12778 (Civil Justice Reform)

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

Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 (UMRA) requires Federal 
agencies to prepare a written assessment of the costs, benefits and 
other effects of proposed or final rules that include a Federal mandate 
likely to result in the expenditure by State, local or tribal 
governments, in the aggregate, or by the private sector, of more than 
$100 million in any one year ($100 million adjusted annually for 
inflation, with base year of 1995). These effects are discussed earlier 
in this preamble and in the FRIA.
    UMRA also requires an agency issuing a final rule subject to the 
Act to select the ``least costly, most cost-effective or least 
burdensome alternative that achieves the objectives of the rule.'' The 
preamble and the FRIA discuss several alternatives we considered, and 
the resulting cost and benefits of various alternative countermeasures. 
The alternatives considered were: (a) Exclusion of the front lower 
corner of the front side window area (test point A1); (b) a component 
test consisting of a single headform impact at the center of the side 
window opening area; and, (c) a full-vehicle dynamic test to evaluate a 
countermeasure's retention capability instead of the headform component 
test. The countermeasures examined for alternatives (a) and (b) were 
various levels of partial window coverage (``partial curtain''). We 
also examined the potential countermeasure of a partial curtain in 
combination with the installation of laminated glazing in the front 
window openings to prevent ejections through test point A1 and the 
lower gap (``partial curtain plus laminated glazing''). However, as 
discussed in this preamble and in the FRIA, none of these alternatives 
achieved the objectives of the alternative adopted today. The agency 
believes that it has selected the least costly, most cost-effective and 
least burdensome alternative that achieves the objectives of the 
rulemaking.

National Environmental Policy Act

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

Plain Language

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

Paperwork Reduction Act (PRA)

    Under the PRA of 1995, a person is not required to respond to a 
collection of information by a Federal agency unless the collection 
displays a valid OMB control number. The final rule contains a 
collection of information, i.e., the phase-in reporting requirements, 
requirements to place consumer information about the readiness 
indicator and about the sensor in the vehicle owner's manual (S4.2.3), 
and requirements for providing information to NHTSA about a rollover 
sensor in a compliance test (S4.2.4). There is no burden to the general 
public.
    The collection of information would require manufacturers of 
passenger cars and of trucks, buses and MPVs with a GVWR of 4,536 kg 
(10,000 lb) or less, to annually submit a report, and maintain records 
related to the report, concerning the number of such vehicles that meet 
the ejection mitigation requirements of this FMVSS. The phase-in of the 
test requirements would be completed approximately seven years after 
publication of a final rule (eight years counting the 100 percent 
credit year). The purpose of the reporting requirements is to aid the 
agency in determining whether a manufacturer has complied with the 
ejection mitigation requirements during the phase-in of those 
requirements, including the manufacturer's use of advanced credits.
    Under the PRA, the agency must publish a document in the Federal 
Register providing a 60-day comment period and otherwise consult with 
members of the public and affected agencies concerning each collection 
of information. This was accomplished in the NPRM preceding this final 
rule (74 FR 63225). The Office of Management and Budget (OMB) has 
promulgated regulations describing what must be included in such a 
document. Pursuant to OMB's regulations (5 CFR 320.8(d)), NHTSA sought 
public comment on the following:
    (1) Whether the collection of information is necessary for the 
proper performance of the functions of the agency, including whether 
the information will have practical utility;

[[Page 3296]]

    (2) The accuracy of the agency's estimate of the burden of the 
proposed collection of information, including the validity of the 
methodology and assumptions used;
    (3) How to enhance the quality, utility, and clarity of the 
information to be collected; and,
    (4) How to minimize the burden of the collection of information on 
those who are to respond, including the use of appropriate automated, 
electronic, mechanical, or other technological collection techniques or 
other forms of information technology, e.g., permitting electronic 
submission of responses.
    We published our estimates of the burden to vehicle manufacturers, 
as follows:
    <bullet> NHTSA estimated that there are 21 manufacturers of 
passenger cars, multipurpose passenger vehicles, trucks, and buses with 
a GVWR of 4,536 kg (10,000 lb) or less;
    <bullet> NHTSA estimated that the total annual reporting and 
recordkeeping burden resulting from the collection of information is 
1,260 hours;
    <bullet> NHTSA estimated that the total annual cost burden, in U.S. 
dollars, will be $0. No additional resources would be expended by 
vehicle manufacturers to gather annual production information because 
they already compile this data for their own use.
    NHTSA did not receive any comments on the above. Therefore, we are 
submitting a request for OMB clearance of the collection of information 
required under today's final rule.

National Technology Transfer and Advancement Act

    Under the National Technology Transfer and Advancement Act of 1995 
(NTTAA) (Pub. L. 104-113), all Federal agencies and departments shall 
use technical standards that are developed or adopted by voluntary 
consensus standards bodies, using such technical standards as a means 
to carry out policy objectives or activities determined by the agencies 
and departments.
    Voluntary consensus standards are technical standards (e.g., 
materials specifications, test methods, sampling procedures, and 
business practices) that are developed or adopted by voluntary 
consensus standards bodies, such as the International Organization for 
Standardization (ISO) and the Society of Automotive Engineers. The 
NTTAA directs us to provide Congress, through OMB, explanations when we 
decide not to use available and applicable voluntary consensus 
standards.
    Commenters requested that the agency apply voluntary industry 
standards SAE J2568--Intrusion Resistance of Safety Glazing Systems for 
Road Vehicles or BSI AU 209--Vehicle Security. These industry standards 
specify that after testing there must not be separation within the 
glazing or between the glazing and vehicle body, which would allow for 
passage of a 40 mm diameter sphere (40 mm gap test).
    We studied the potential of applying these standards, but decided 
against adopting them for several reasons. These standards provide 
glazing intrusion resistance requirements from external impact 
(outside-in) as opposed to ejection mitigation (inside-out). 
Additionally, the requirements are not appropriate for vehicles with 
only side curtain air bags, given that there is a time dependence 
associated with a curtain's ejection mitigation performance. Once 
deployed, the pressure in the air bag continuously decreases. The 16 
km/h test is done at 6 seconds to assure that the pressure does not 
decrease too quickly. It does not seem that the 40 mm gap test could be 
done after the 6-second impact, in any timeframe which is related to 
rollover and side impact ejections.
    Further, there was no shown safety need for applying the suggested 
standards. We cannot show that ejections that would not be prevented by 
the primary 100-mm displacement requirement would be prevented by a 
secondary 40-mm requirement. Also, it seemed that the 40-mm requirement 
would indirectly require installation of advanced glazing. As discussed 
in this preamble, the costs associated with advanced glazing 
installations at the side windows covered by the standard adopted today 
are substantial in comparison to a system only utilizing rollover 
curtains. For these reasons, the agency did not accept the suggestions.

List of Subjects

49 CFR Part 571

    Imports, Incorporation by reference, Motor vehicle safety, 
Reporting and recordkeeping requirements, Tires.

49 CFR Part 585

    Motor vehicle safety, Reporting and recordkeeping requirements.

    In consideration of the foregoing, NHTSA amends 49 CFR parts 571 
and 585 as set forth below.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

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

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


0
2. Section 571.5(b) is amended by adding, in alphabetical order, an 
entry to the list of materials incorporated by reference, as follows:


Sec.  571.5  Matter incorporated by reference.

* * * * *
    (b) * * *

------------------------------------------------------------------------
 
------------------------------------------------------------------------
``Parts List; Ejection Mitigation       571.226, S7.1.1
 Headform Drawing Package,'' December
 2010; ``Parts List and Drawings;
 Ejection Mitigation Headform Drawing
 Package,'' December 2010. Copies may
 be obtained by contacting:
 Reprographics Technologies, 9000
 Virginia Manor Rd., Beltsville, MD
 20705, telephone (301) 210-5600.
------------------------------------------------------------------------

* * * * *

0
3. Section 571.226 is added to read as follows:


Sec.  571.226  Standard No. 226; Ejection Mitigation.

    S1. Purpose and Scope. This standard establishes requirements for 
ejection mitigation systems to reduce the likelihood of complete and 
partial ejections of vehicle occupants through side windows during 
rollovers or side impact events.
    S2. Application. This standard applies to passenger cars, and to 
multipurpose passenger vehicles, trucks and buses with a gross vehicle 
weight rating of 4,536 kg or less, except walk-in vans, modified roof 
vehicles and convertibles. Also excluded from this standard are law 
enforcement vehicles, correctional institution vehicles, taxis and 
limousines, if they have a fixed security partition separating the 1st 
and 2nd or 2nd and 3rd rows and if they are produced by more than one 
manufacturer or are altered (within the meaning of 49 CFR 567.7).
    S3. Definitions.
    Ejection impactor means a device specified in S7.1 of this standard 
that is a component of the ejection mitigation test device and is the 
moving mass that strikes the ejection mitigation countermeasure.
    Ejection impactor targeting point means the intersection of the y-
axis of the ejection headform and the outer surface of the ejection 
headform.

[[Page 3297]]

    Ejection mitigation countermeasure means a device or devices, 
except seat belts, integrated into the vehicle that reduce the 
likelihood of occupant ejection through a side window opening, and that 
requires no action by the occupant for activation.
    Ejection propulsion mechanism means a device that is a component of 
the ejection mitigation test device consisting of a mechanism capable 
of propelling the ejection impactor and constraining it to move along 
its axis or shaft.
    Limited-line manufacturer means a manufacturer that sells three or 
fewer carlines, as that term is defined in 49 CFR 583.4, in the United 
States during a production year.
    Modified roof means the replacement roof on a motor vehicle whose 
original roof has been removed, in part or in total.
    Row means a set of one or more seats whose seat outlines do not 
overlap with the seat outline of any other seats, when all seats are 
adjusted to their rearmost normal riding or driving position, when 
viewed from the side.
    Seat outline means the outer limits of a seat projected laterally 
onto a vertical longitudinal vehicle plane.
    Side daylight opening means, other than a door opening, the locus 
of all points where a horizontal line, perpendicular to the vehicle 
vertical longitudinal plane, is tangent to the periphery of the 
opening. The periphery includes surfaces 100 millimeters inboard of the 
inside surface of the window glazing and 25 mm outboard of the outside 
surface of the side glazing. The periphery excludes the following: any 
flexible gasket material or weather stripping used to create a 
waterproof seal between the glazing or door and the vehicle interior; 
grab handles used to facilitate occupant egress and ingress; and any 
part of a seat.
    Small manufacturer means an original vehicle manufacturer that 
produces or assembles fewer than 5,000 vehicles annually for sale in 
the United States.
    Target means the x-z plane projection of the ejection headform face 
as shown in Figure 1.
    Walk-in van means a special cargo/mail delivery vehicle that only 
has a driver designated seating position. The vehicle has a sliding (or 
folding) side door and a roof clearance that enables a person of medium 
stature to enter the passenger compartment area in an up-right 
position.
    Zero displacement plane means, a vertical plane parallel to the 
vehicle longitudinal centerline and tangent to the most outboard 
surface of the ejection headform when the headform is aligned with an 
impact target location and just touching the inside surface of a window 
covering the side daylight opening.
    S4. Phase-in, performance and other requirements.
    S4.1 Phase-in requirements.
    S4.1.1 Except as provided in S4.1.3 of this standard, a percentage 
of each manufacturer's vehicle production, as specified in S8 of this 
standard, manufactured on or after September 1, 2013 to August 31, 
2017, shall meet the requirements of S4.2. Vehicles that are not 
subject to the phase-in may be certified as meeting the requirements 
specified in this standard.
    S4.1.2 Except as provided in S4.1.3 of this section, each vehicle 
manufactured on or after September 1, 2017 must meet the requirements 
of S4.2 without use of advanced credits.
    S4.1.3 Exceptions from the phase-in; special allowances.
    (a) Vehicles produced by a small manufacturer and by a limited line 
manufacturer are not subject to S4.1.1 of this standard, but are 
subject to S4.1.2.
    (b) Vehicles that are altered (within the meaning of 49 CFR 567.7) 
before September 1, 2018, after having been previously certified in 
accordance with part 567 of this chapter, and vehicles manufactured in 
two or more stages before September 1, 2018, are not required to meet 
the requirements of S4.2. Vehicles that are altered on or after 
September 1, 2018, and vehicles that are manufactured in two or more 
stages on or after September 1, 2018, must meet the requirements of 
S4.2.
    S4.2 Performance and other requirements.
    S4.2.1 When the ejection propulsion mechanism propels the ejection 
impactor into the impact target locations of each side daylight opening 
of a vehicle according to the test procedures specified in S5 of this 
standard, the most outboard surface of the ejection headform must not 
displace more than 100 millimeters beyond the zero displacement plane.
    S4.2.1.1 No vehicle shall use movable glazing as the sole means of 
meeting the displacement limit of S4.2.1.
    S4.2.1.2 Vehicles with an ejection mitigation countermeasure that 
deploys in the event of a rollover must deploy the countermeasure for 
the side daylight opening being tested according to the procedure 
specified in S5 of this standard.
    S4.2.1.3 If a side daylight opening contains no target locations, 
the impact test of S4.2.1 is not performed on that opening.
    S4.2.2 Vehicles that have an ejection mitigation countermeasure 
that deploys in the event of a rollover must have a monitoring system 
with a readiness indicator. The indicator shall monitor its own 
readiness and must be clearly visible from the driver's designated 
seating position. The same readiness indicator required by S4.5.2 of 
FMVSS No. 208 may be used to meet the requirement. A list of the 
elements of the system being monitored by the indicator shall be 
included with the information furnished in accordance with S4.2.3.
    S4.2.3 Written information.
    (a) Vehicles with an ejection mitigation countermeasure that 
deploys in the event of a rollover must be described as such in the 
vehicle's owner manual or in other written information provided by the 
vehicle manufacturer to the consumer.
    (b) Vehicles that have an ejection mitigation countermeasure that 
deploys in the event of a rollover must include in written information 
a discussion of the readiness indicator required by S4.2.2, specifying 
a list of the elements of the system being monitored by the indicator, 
a discussion of the purpose and location of the telltale, and 
instructions to the consumer on the steps to take if the telltale is 
illuminated.
    S4.2.4 Technical Documentation. For vehicles that have an ejection 
mitigation countermeasure that deploys in the event of a rollover, the 
vehicle manufacturer must make available to the agency, upon request, 
the following information: A discussion of the sensor system used to 
deploy the countermeasure, including the pertinent inputs to the 
computer or calculations within the computer and how its algorithm uses 
that information to determine if the countermeasure should be deployed.
    S5. Test procedures.
    S5.1 Demonstrate compliance with S4.2 of this standard in 
accordance with the test procedures specified in this standard, under 
the conditions of S6, using the equipment described in S7. In the 
impact test described by these procedures, target locations are 
identified (S5.2) and the zero displacement plane location is 
determined (S5.3). The glazing is pre-broken, fully retracted or 
removed prior to the impact test (S5.4). The countermeasure is 
deployed, if applicable, and an ejection impactor (see S7.1) strikes 
the countermeasure at the impact target locations, at the specified 
speeds and times (S5.5). The lateral displacement of the ejection 
impactor beyond the zero displacement plane is measured.

[[Page 3298]]

    S5.2 Determination of impact target locations.
    S5.2.1 Boundary of target location.
    S5.2.1.1 Initial determination of offset line. Determine the 
location of an offset-line within the side daylight opening by 
projecting each point of the side daylight opening laterally onto a 
vehicle vertical longitudinal plane. Move each point by 25<plus-minus>2 
mm towards the center of the side daylight opening projection and 
perpendicular to a line tangent to the projection at that point, while 
maintaining the point on a vehicle vertical longitudinal plane.
    S5.2.1.2 Rearmost limit of offset line.
    (a) Seats fixed in a forward facing direction. Except as provided 
in S5.2.1.2(b), if an offset line extends rearward of a transverse 
vertical vehicle plane located behind the seating reference point at 
the distance specified in 5.2.1.2(a)(1) or (2), the transverse vertical 
vehicle plane defines the rearward edge of the offset line for the 
purposes of determining target locations.
    (1) For a vehicle with fewer than 3 rows--1,400 mm behind the 
rearmost SgRP.
    (2) For a vehicle with 3 or more rows--600 mm behind the 3rd row 
SgRP.
    (b) Seats not fixed in a forward facing direction. When the last 
row seat adjacent to the opening, in the case of a vehicle with fewer 
than 3 rows, or the 3rd row seat adjacent to the opening, in the case 
of a vehicle with 3 or more rows, is not fixed in the forward facing 
direction, the offset line may extend farther rearward than specified 
in S5.2.1.2(a) under the following conditions. With the seat in any 
non-forward facing orientation, the seat back set at an inclination 
position closest to the manufacturer's design seat back angle, and all 
other seat adjustments at any possible position of adjustment, 
determine the location of a vertical transverse vehicle plane located 
behind the portion of the seat rearmost in the vehicle, at the distance 
specified in 5.2.1.2(b)(1) and (2). The boundary of target locations 
extends to this vertical plane if it is farther rearward than the plane 
determined in S5.2.1.2(a).
    (1) For a vehicle with fewer than 3 rows--1,400 mm behind the 
portion of the seat rearmost in the vehicle.
    (2) For a vehicle with 3 or more rows--600 mm behind the portion of 
the seat rearmost in the vehicle, for a seat in the 3rd row.
    (c) Vehicles with partitions or bulkheads. If a vehicle has a fixed 
traverse partition or bulkhead through which there is no occupant 
access and behind which there are no designated seating positions, a 
vertical transverse vehicle plane 25 mm forward of the most forward 
portion of the partition or bulkhead defines the rearward edge of the 
offset line for the purposes of determining target locations when said 
plane is forward of the limiting plane defined in S5.2.1.2(a) or (b).
    S5.2.2 Preliminary target locations.
    (a) To identify the impact target locations, the following 
procedures are performed with the x and z axes of the target, shown in 
Figure 1 (provided for illustration purposes), aligned within <plus-
minus>1 degree of the vehicle longitudinal and vertical axes, 
respectively, and the target y axis pointing in the outboard direction.
    (b) Place targets at any location inside the offset-line where the 
target is tangent to within <plus-minus>2 mm of the offset-line at just 
two or three points (see Figure 2) (figure provided for illustration 
purposes).
    S5.2.3 Determination of primary target locations. Divide the side 
daylight opening into four quadrants by passing a vertical line and a 
horizontal line, in a vehicle vertical longitudinal plane, through the 
geometric center of the side daylight opening.
    S5.2.3.1 Front windows. For any side daylight opening forward of 
the vehicle B-pillar, the primary quadrants are the forward-lower and 
rearward-upper.
    S5.2.3.2 Rear windows. For any side daylight opening rearward of 
the B-pillar, the primary quadrants are the forward-upper and rearward-
lower.
    S5.2.3.3 If a primary quadrant contains only one target center, 
that target is the primary target for that quadrant (see Figure 3) 
(figure provided for illustration purposes). If there is more than one 
target center in a primary quadrant, the primary target for that 
quadrant is the lowest target in a lower quadrant and the highest 
target in an upper quadrant. If there is a primary quadrant that does 
not contain a target center, the target center closest to the primary 
quadrant outline is the primary target.
    S5.2.4 Determination of secondary target locations.
    S5.2.4.1 Front windows. Measure the horizontal distance between the 
centers of the primary targets. For a side daylight opening forward of 
the B-pillar, place one secondary target center rearward of the forward 
primary target by one-third of the horizontal distance between the 
primary target centers and tangent with upper portion of the offset-
line. Place another secondary target center rearward of the forward 
primary target by two-thirds of the horizontal distance between the 
primary target centers and tangent with the lower portion of the 
offset-line (see figure 4) (figure provided for illustration purposes).
    S5.2.4.2 Rear windows. For side daylight openings rearward of the 
B-pillar, place one secondary target center rearward of the forward 
primary target by one-third of the horizontal distance between the 
primary target centers and tangent with lower portion of the offset-
line. Place another secondary target center rearward of the forward 
primary target by two-thirds of the horizontal distance between the 
primary target centers and tangent with the upper portion of the 
offset-line (see Figure 4) (figure provided for illustration purposes).
    S5.2.5 Target adjustment.
    S5.2.5.1 Target elimination and reconstitution.
    S5.2.5.1.1 Target elimination. Determine the horizontal and 
vertical distance between the centers of the targets. If the minimum 
distance between the z axes of the targets is less than 135 mm and the 
minimum distance between the x axes of the targets is less than 170 mm, 
eliminate the targets in the order of priority given in steps 1 through 
4 of Table 1 (see Figure 5) (figure provided for illustration 
purposes). In each case, both the z axes of the targets must be closer 
than 135 mm and x axes of the targets must be closer than 170 mm. If 
the minimum distance between the z axes of the targets is not less than 
135 mm or the minimum distance between the y axes of the targets is not 
less than 170 mm, do not eliminate the target. Continue checking all 
the targets listed in steps 1 through 4 of Table 1.

 Table 1--Priority List of Target Distance To Be Checked Against Limits
------------------------------------------------------------------------
                                               Eliminate this target if
                                               distances between z axes
                   Measure distance from z     of targets and x axes of
      Step        axis to z axis and x axis    targets are less than 135
                 to x axis for these targets        mm and 170 mm,
                                                     respectively
------------------------------------------------------------------------
1..............  Upper Secondary to Lower     Upper Secondary.
                  Secondary.
2..............  Upper Primary to Upper or    Upper or Remaining
                  Remaining Secondary.         Secondary.

[[Page 3299]]

 
3..............  Lower Primary to Lower or    Lower or Remaining
                  Remaining Secondary.         Secondary.
4..............  Upper Primary to Lower       Upper Primary.
                  Primary.
------------------------------------------------------------------------

    S5.2.5.1.2 Target reconstitution. If after following the procedure 
given in S5.2.5.1.1, there are only two targets remaining, determine 
the absolute distance between the centers of these targets. If this 
distance is greater than or equal to 360 mm, place a target such that 
its center bisects a line connecting the centers of the remaining 
targets.
    S5.2.5.2 Target reorientation--90 degree rotation. If after 
following the procedure given in S5.2.5.1 there are less than four 
targets in a side daylight opening, repeat the procedure in 5.2 through 
5.2.5.1.2, with a modification to S5.2 as follows. Reorient the target 
by rotating it 90 degrees about the y axis of the target such that the 
target positive z axis is aligned within <plus-minus>1 degree of the 
vehicle longitudinal axis, pointing in the direction of the vehicle 
positive x axis. If after performing the procedure in this section, the 
remaining targets exceed the number of targets determined with the 
original orientation of the target, the reoriented targets represent 
the final target locations for the side daylight opening.
    S5.2.5.3 Target reorientation--incremental rotation. If after 
following the procedure given in S5.2.5.2 there are no targets in a 
side daylight opening, starting with the target in the position defined 
in S5.2.2.2(a), reorient the target by rotating it in 5 degree 
increments about the y axis of the target by rotating the target 
positive z axis toward the vehicle positive x axis. At each increment 
of rotation, attempt to fit the target within the offset line of the 
side daylight opening. At the first increment of rotation where the 
target will fit, place the target center as close as possible to the 
geometric center of the side daylight opening. If more than one 
position exists that is closest to the geometric center of the side 
daylight opening, select the lowest.
    S5.3 Determination of zero displacement plane. The glazing covering 
the target location of the side daylight opening being tested is intact 
and in place in the case of fixed glazing and intact and fully closed 
in the case of movable glazing. With the ejection impactor targeting 
point aligned within <plus-minus>2 mm of the center of any target 
location specified in S5.2, and with the ejection impactor on the 
inside of the vehicle, slowly move the impactor towards the window 
until contact is made with the interior of the glazing with no more 
than 20 N of pressure being applied to the window. The location of the 
most outboard surface of the headform establishes the zero displacement 
plane for this target location.
    S5.4 Window position and condition.Subject to S5.5(b), prior to 
impact testing, the glazing covering the target location must be 
removed from the side daylight opening, fully retracted, or pre-broken 
according to the procedure in S5.4.1, at the vehicle manufacturer's 
option.
    S5.4.1 Window glazing pre-breaking procedure.
    S5.4.1.1 Breakage pattern. Locate the geometric center of the side 
daylight opening, established in S5.2.3 of this standard. Mark the 
outside surface of the window glazing in a horizontal and vertical grid 
of points separated by 75<plus-minus>2 mm with one point coincident 
within <plus-minus>2 mm of the geometric center of the side daylight 
opening (see Figure 6) (figure provided for illustration purposes). 
Mark the inside surface of the window glazing in a horizontal and 
vertical grid of points separated by 75<plus-minus>2 mm with the entire 
grid horizontally offset by 37.5 <plus-minus> 2 mm from the grid of 
points on the outside of the glazing.
    S5.4.1.2 Breakage method.
    (a) Start with the inside surface of the window and forward-most, 
lowest mark made as specified in S5.4.1.1 of this standard. Use a 
center punch in this procedure. The punch tip has a 5 <plus-minus>2 mm 
diameter prior to coming to a point. The spring is adjusted to require 
150 <plus-minus>25 N of force to activate the punch. Only once at each 
mark location, apply pressure to activate the spring in the center 
punch in a direction which is perpendicular to the tangent of the 
window surface at the point of contact, within <plus-minus>10 degrees. 
Apply the pressure only once at each mark location, even if the glazing 
does not break or no hole results.
    (b) Use a 100 <plus-minus>10 mm x 100 <plus-minus>10 mm piece of 
plywood with a minimum thickness of 18 mm as a reaction surface on the 
opposite side of the glazing to prevent to the extent possible the 
window surface from deforming by more than 10 mm when pressure is being 
applied to the hole-punch.
    (c) Continue the procedure with the center punch by moving rearward 
in the grid until the end of a row is reached. When the end of a row is 
reached, move to the forward-most mark on the next higher row and 
continue the procedure. Continue in this pattern until the procedure is 
conducted at each marked location on the inside surface of the glazing.
    (d) Repeat the process on the outside surface of the window.
    (e) If punching a hole causes the glazing to disintegrate, halt the 
breakage procedure and proceed with the headform impact test.
    S5.5 Impact speeds and time delays. The ejection impactor speeds 
specified below must be achieved after propulsion has ceased.
    (a) Vehicles with or without an ejection mitigation countermeasure 
that deploys in a rollover. For a vehicle with an ejection mitigation 
countermeasure that deploys in a rollover, using the ejection 
propulsion mechanism, propel the ejection impactor such that it first 
strikes the countermeasure, while aligned with any target location 
specified in S5.2 of this standard, 1.5 <plus-minus>0.1 seconds after 
activation of the ejection mitigation countermeasure that deploys in 
the event of a rollover, and at a speed of 20 <plus-minus>0.5 km/h. For 
a vehicle without an ejection mitigation countermeasure that deploys in 
a rollover, propel the ejection impactor at any time such that it first 
strikes the countermeasure, while aligned with any target location 
specified in S5.2 of this standard, at a speed of 20 <plus-minus>0.5 
km/h.
    (b) Vehicles with an ejection mitigation countermeasure that 
deploys in a rollover. For a vehicle with an ejection mitigation 
countermeasure that deploys in a rollover, remove or fully retract any 
movable glazing from the side daylight opening. Using the ejection 
propulsion mechanism, propel the ejection impactor such that it first 
strikes the countermeasure, while aligned with any target location 
specified in S5.2 of this standard, 6.0 <plus-minus>0.1 seconds after 
activation of an ejection mitigation countermeasure that deploys in the 
event of a rollover, and at a speed of 16 <plus-minus>0.5 km/h.
    (c) An ejection mitigation countermeasure that deploys in the event 
of a rollover is described as such

[[Page 3300]]

in the vehicle's owner manual or in other written information provided 
by the vehicle manufacturer to the consumer.
    S5.6 Ejection impactor orientation.
    S5.6.1 If the targets for the side daylight opening being impacted 
were determined by the procedure specified in S5.2.2 through S5.2.5.1 
only, the ejection impactor orientation is as follows. At the time of 
launch of the ejection impactor the x, y and z axes of the ejection 
headform must be aligned within <plus-minus>1 degree of the vehicle 
longitudinal, transverse and vertical axes, respectively.
    S5.6.2 If the targets for the side daylight opening being impacted 
were determined by the procedure specified in S5.2.5.2, the ejection 
impactor orientation is as follows. At the time of launch the ejection 
impactor is rotated by 90 degrees about the ejection headform y axis, 
from the orientation specified in S5.6.1, resulting in the headform 
positive z axis pointing in the direction of the vehicle positive x 
axis.
    S5.6.3 If the targets for the side daylight opening being impacted 
were determined by the procedure specified in S5.2.5.3, the ejection 
impactor orientation is as follows. At the time of launch the ejection 
impactor is rotated about the y axis of the ejection headform by 
rotating the headform positive z axis towards the vehicle positive x 
axis, in the increment determined to be necessary in S5.2.5.3 to fit 
the target within the side daylight opening.
    S5.6.4 After any test, extend the ejection impactor to the zero 
plane and determine that x, y and z axes of the ejection headform 
remain aligned within <plus-minus>1 degree of its orientation at launch 
as specified in S5.6.1--5.6.3.
    S6 General test conditions.
    S6.1 Vehicle test attitude. The vehicle is supported off its 
suspension at an attitude determined in accordance with S6.1(a) through 
(e).
    (a) The vehicle is loaded to its unloaded vehicle weight.
    (b) All tires are inflated to the manufacturer's specifications 
listed on the vehicle's tire placard.
    (c) Place vehicle on a level surface.
    (c) Pitch: Measure the sill angle of the driver door sill and mark 
where the angle is measured.
    (d) Roll: Mark a point on the vehicle body above the left and right 
front wheel wells. Determine the vertical height of these two points 
from the level surface.
    (e) Support the vehicle off its suspension such that the driver 
door sill angle is within <plus-minus> 1 degree of that measured at the 
marked area in S6.1(c) and the vertical height difference of the two 
points marked in S6.1(d) is within <plus-minus> 5 mm of the vertical 
height difference determined in S6.1(d).
    S6.2 Doors.
    (a) Except as provided in S6.2(b) or S6.2(c), doors, including any 
rear hatchback or tailgate, are fully closed and latched but not 
locked.
    (b) During testing, any side door on the opposite side of the 
longitudinal centerline of the vehicle from the target to be impacted 
may be open or removed.
    (c) During testing, any rear hatchback or tailgate may be open or 
removed for testing any target.
    S6.3 Steering wheel, steering column, seats, grab handles, and 
exterior mirrors. During targeting and testing, the steering wheel, 
steering column, seats, grab handles and exterior mirrors may be 
removed from the vehicle or adjusted to facilitate testing and/or 
provide an unobstructed path for headform travel through and beyond the 
vehicle.
    S6.4 Other vehicle components and structures. During targeting and 
testing, interior vehicle components and vehicle structures other than 
specified in S6.2 and S6.3 may be removed or adjusted to the extent 
necessary to allow positioning of the ejection propulsion mechanism and 
provide an unobstructed path for the headform travel through and beyond 
the vehicle.
    S6.5 Temperature and humidity.
    (a) During testing, the ambient temperature is between 18 degrees 
C. and 29 degrees C., at any relative humidity between 10 percent and 
70 percent.
    (b) The headform specified in S7.1.1 of this standard is exposed to 
the conditions specified in S6.5(a) for a continuous period not less 
than one hour, prior to the test.
    S7. Ejection mitigation test device specifications. The ejection 
mitigation test device consists of an ejection impactor and ejection 
propulsion mechanism with the following specifications. The ability of 
a test device to meet these specifications may be determined outside of 
the vehicle.
    S7.1 Ejection impactor. The ejection impactor consists of an 
ejection headform attached to a shaft. The ejection impactor has a mass 
of 18 kg <plus-minus>0.05 kg. The shaft is parallel to the y axis of 
the headform.
    S7.1.1 Ejection headform dimensions. The ejection headform has the 
dimensions shown in Figure 1 and is depicted in the ``Parts List; 
Ejection Mitigation Headform Drawing Package,'' December 2010, and the 
``Parts List and Drawings; Ejection Mitigation Headform Drawing 
Package,'' December 2010 (incorporated by reference; see Sec.  571.5).
    S7.2 Static deflection. The ejection impactor targeting point must 
not deflect more than 20 mm in the x-z plane when a 981 N <plus-minus> 
5 N force is applied in a vehicle vertical longitudinal plane, through 
the y axis of the headform and no more than 5 mm rear of the posterior 
surface of the headform. The force is applied once in each of the 
following headform axes: +z, -z, +x, -x. The static deflection 
measurement is made with the ejection impactor extended 400 mm outboard 
of the theoretical point of impact with the countermeasure and attached 
to the ejection propulsion mechanism, including any support frame and 
anchors.
    S7.3 Frictional characteristics.
    (a) Measure the dynamic coefficient of friction of the ejection 
impactor and any associated bearings and bearing housing in a test 
ready orientation. Repeat the measurement in three more orientations 
with the ejection impactor and any associated bearings and bearing 
housing rotated 90, 180 and 270 degrees about the headform y axis. 
Perform the measurement five consecutive times at each orientation.
    (b) Measure the average force necessary to move the ejection 
impactor 200 mm rearward into the ejection propulsion mechanism at a 
rate of 50 (<plus-minus>13) mm per second, starting at a point 400 mm 
outboard of the theoretical point of impact with the countermeasure. 
Measure the force to an accuracy of <plus-minus>5 N. The measurement 
excludes the force measured over the first 25 mm of travel and is 
recorded at a minimum frequency of 100 Hz. During the test a 100 kg 
<plus-minus> 0.5 kg mass is attached to the impactor with its center of 
gravity passing through the axis of motion of the impactor and no more 
than 5 mm rear of the posterior surface of the headform.
    (c) Take the five force level averages made at each impactor 
orientation in S7.3(a) and average them. Take the maximum of the force 
average values and divide by 9.81 times the combined mass of the 
ejection impactor and mass added in S7.3(b). The resulting value must 
not exceed 0.25.
    S7.4 Targeting accuracy. Determine the distance ``D'' along the 
axis of travel of the ejection impactor from its launch point to the 
theoretical point of impact with the countermeasure, when moving at the 
speed specified in S5.5. Determine that the ejection mitigation test 
device can deliver the ejection impactor targeting point to within 
<plus-minus>10 mm of an axis normal to and passing through the target 
center, as the unobstructed impactor passes through a zone defined by 
vertical longitudinal

[[Page 3301]]

planes 50 mm forward and rearward of ``D.''
    S8 Phase-in Schedule for Vehicle Certification.
    S8.1 Vehicles manufactured on or after September 1, 2013 and before 
September 1, 2016. At anytime during the production years ending August 
31, 2014, August 31, 2015, and August 31, 2016, each manufacturer 
shall, upon request from the Office of Vehicle Safety Compliance, 
provide information identifying the vehicles (by make, model and 
vehicle identification number) that have been certified as complying 
with this standard. The manufacturer's designation of a vehicle as a 
certified vehicle is irrevocable.
    S8.2 Vehicles manufactured on or after September 1, 2013 and before 
September 1, 2014. Subject to S8.9, for vehicles manufactured on or 
after September 1, 2013 and before September 1, 2014, the number of 
vehicles complying with S4.2 shall be not less than 25 percent of:
    (a) The manufacturer's average annual production of vehicles 
manufactured in the three previous production years; or
    (b) The manufacturer's production in the current production year.
    S8.4 Vehicles manufactured on or after September 1, 2015 and before 
September 1, 2016. Subject to S8.9, for vehicles manufactured on or 
after September 1, 2015 and before September 1, 2016, the number of 
vehicles complying with S4.2 shall be not less than 75 percent of:
    (a) The manufacturer's average annual production of vehicles 
manufactured in the three previous production years; or
    (b) The manufacturer's production in the current production year.
    S8.5 Vehicles manufactured on or after September 1, 2016 and before 
September 1, 2017. Subject to S8.9, for vehicles manufactured on or 
after September 1, 2016 and before September 1, 2017, the number of 
vehicles complying with S4.2 shall be not less than 100 percent of the 
manufacturer's production in the current production year.
    8.6 Vehicles produced by more than one manufacturer. For the 
purpose of calculating average annual production of vehicles for each 
manufacturer and the number of vehicles manufactured by each 
manufacturer under S8.1 through S8.4, a vehicle produced by more than 
one manufacturer shall be attributed to a single manufacturer as 
follows, subject to S8.7.
    (a) A vehicle that is imported shall be attributed to the importer.
    (b) A vehicle manufactured in the United States by more than one 
manufacturer, one of which also markets the vehicle, shall be 
attributed to the manufacturer that markets the vehicle.
    S8.7 A vehicle produced by more than one manufacturer shall be 
attributed to any one of the vehicle's manufacturers specified by an 
express written contract, reported to the National Highway Traffic 
Safety Administration under 49 CFR part 585, between the manufacturer 
so specified and the manufacturer to which the vehicle would otherwise 
be attributed under S8.5.
    S8.8 For the purposes of calculating average annual production of 
vehicles for each manufacturer and the number of vehicles manufactured 
by each manufacturer under S8, do not count any vehicle that is 
excluded by this standard from the requirements.
    S8.9 Calculation of complying vehicles.
    (a) For the purposes of calculating the vehicles complying with 
S8.2, a manufacturer may count a vehicle if it is manufactured on or 
after March 1, 2011 but before September 1, 2014.
    (b) For purposes of complying with S8.3, a manufacturer may count a 
vehicle if it--
    (1) Is manufactured on or after March 1, 2011 but before September 
1, 2015 and,
    (2) Is not counted toward compliance with S8.2.
    (c) For purposes of complying with S8.4, a manufacturer may count a 
vehicle if it--
    (1) Is manufactured on or after March 1, 2011 but before September 
1, 2016 and,
    (2) Is not counted toward compliance with S8.2 or S8.3.
    (d) For purposes of complying with S8.5, a manufacturer may count a 
vehicle if it--
    (1) Is manufactured on or after March 1, 2011 but before September 
1, 2017 and,
    (2) Is not counted toward compliance with S8.2, S8.3, or S8.4.
    (e) For the purposes of calculating average annual production of 
vehicles for each manufacturer and the number of vehicles manufactured 
by each manufacturer, each vehicle that is excluded from having to meet 
this standard is not counted.

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0
4. The authority citation for part 585 continues to read as follows:

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


0
5. Part 585 is amended by adding Subpart K to read as follows:

PART 585--PHASE-IN REPORTING REQUIREMENTS

* * * * *
Subpart K--Ejection Mitigation Phase-in Reporting Requirements
585.100 Scope.
585.101 Purpose.
585.102 Applicability.
585.103 Definitions.
585.104 Response to inquiries.
585.105 Reporting requirements.
585.106 Records.

[[Page 3305]]

Subpart K--Ejection Mitigation Phase-in Reporting Requirements


Sec.  585.100  Scope.

    This part establishes requirements for manufacturers of passenger 
cars, and of trucks, buses and multipurpose passenger vehicles with a 
gross vehicle weight rating (GVWR) of 4,536 kilograms (kg) (10,000 
pounds (lb)) or less, to submit a report, and maintain records related 
to the report, concerning the number of such vehicles that meet the 
ejection mitigation requirements of Standard No. 226, Ejection 
Mitigation (49 CFR 571.226).


Sec.  585.101  Purpose.

    The purpose of these reporting requirements is to assist the 
National Highway Traffic Safety Administration in determining whether a 
manufacturer has complied with the requirements of Standard No. 226, 
Ejection Mitigation (49 CFR 571.226).


Sec.  585.102  Applicability.

    This part applies to manufacturers of passenger cars, and of 
trucks, buses and multipurpose passenger vehicles with a GVWR of 4,536 
kg (10,000 lb) or less. However, this subpart does not apply to 
vehicles excluded by Standard No. 226 (49 CFR 571.226) from the 
requirements of that standard. This subpart does not apply to 
manufacturers whose production consists exclusively of vehicles 
manufactured in two or more stages, to manufacturers whose production 
of motor vehicles for the United States market is less than 5,000 
vehicles in a production year, and to limited line manufacturers.


Sec.  585.103  Definitions.

    (a) All terms defined in 49 U.S.C. 30102 are used in their 
statutory meaning.
    (b) Bus, gross vehicle weight rating or GVWR, multipurpose 
passenger vehicle, passenger car, and truck are used as defined in 
Sec.  571.3 of this chapter.
    (c) Production year means the 12-month period between September 1 
of one year and August 31 of the following year, inclusive.
    (d) Limited line manufacturer means a manufacturer that sells three 
or fewer carlines, as that term is defined in 49 CFR 583.4, in the 
United States during a production year.


Sec.  585.104  Response to inquiries.

    At anytime during the production years ending August 31, 2014, 
August 31, 2015, August 31, 2016, and August 31, 2017, each 
manufacturer shall, upon request from the Office of Vehicle Safety 
Compliance, provide information identifying the vehicles (by make, 
model and vehicle identification number) that have been certified as 
complying with the ejection mitigation requirements of Standard No. 
226, Ejection mitigation (49 CFR 571.226). The manufacturer's 
designation of a vehicle as a certified vehicle is irrevocable.


Sec.  585.105  Reporting requirements.

    (a) Advanced credit phase-in reporting requirements. (1) Within 60 
days after the end of the production years ending August 31, 2011, 
through August 31, 2017, each manufacturer certifying vehicles 
manufactured during any of those production years as complying with the 
ejection mitigation requirements of Standard No. 226 (49 CFR 571.226) 
shall submit a report to the National Highway Traffic Safety 
Administration providing the information specified in paragraph (c) of 
this section and in Sec.  585.2 of this part.
    (b) Phase-in reporting requirements. Within 60 days after the end 
of each of the production years ending August 31, 2014, through August 
31, 2017, each manufacturer shall submit a report to the National 
Highway Traffic Safety Administration concerning its compliance with 
the ejection mitigation requirements of Standard No. 226 (49 CFR 
571.226) for its vehicles produced in that year. Each report shall 
provide the information specified in paragraph (d) of this section and 
in Sec.  585.2 of this part.
    (c) Advanced credit phase-in report content--(1) Production of 
complying vehicles. With respect to the reports identified in Sec.  
585.105(a), each manufacturer shall report for the production year for 
which the report is filed the number of vehicles, by make and model 
year, that are certified as meeting the ejection mitigation 
requirements of Standard No. 226 (49 CFR 571.226).
    (d) Phase-in report content--
    (1) Basis for phase-in production goals. Each manufacturer shall 
provide the number of passenger cars, multipurpose passenger vehicles, 
trucks, and buses, with a gross vehicle weight rating of 4,536 
kilograms (10,000 pounds) or less, manufactured in the current 
production year, or, at the manufacturer's option, in each of the three 
previous production years. A new manufacturer that is, for the first 
time, manufacturing these vehicles for sale in the United States must 
report the number of these vehicles manufactured during the current 
production year.
    (2) Production of complying vehicles. Each manufacturer shall 
report for the production year being reported on information on the 
number of passenger cars, multipurpose passenger vehicles, trucks, and 
buses, with a gross vehicle weight rating of 4,536 kilograms (10,000 
pounds) or less that meet the ejection mitigation requirements of 
Standard No. 226 (49 CFR 571.226). The manufacturer shall report the 
vehicles produced during the preceding years for which the manufacturer 
is claiming credits as having been produced during the production year 
being reported on.


Sec.  585.106  Records.

    Each manufacturer shall maintain records of the Vehicle 
Identification Number for each vehicle for which information is 
reported under Sec.  585.105 until December 31, 2020.

    Issued on January 5, 2011.
David L. Strickland,
Administrator.
[FR Doc. 2011-547 Filed 1-13-11; 8:45 am]
BILLING CODE 4910-59-P