3212 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

DEPARTMENT OF TRANSPORTATION 

National Highway Traffic Safety 

Administration 

49 CFR Parts 571 and 585 

[Docket No. NHTSA–2011–0004] 

RIN 2127–AK23 

Federal Motor Vehicle Safety 

Standards, Ejection Mitigation; PhaseIn Reporting Requirements; 

Incorporation by Reference 

AGENCY: National Highway Traffic 

Safety Administration (NHTSA), U.S. 

Department of Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: This final rule establishes a 

new Federal Motor Vehicle Safety 

Standard No. 226, ‘‘Ejection Mitigation,’’ 

to reduce the partial and complete 

ejection of vehicle occupants through 

side windows in crashes, particularly 

rollover crashes. The standard applies to 

the side windows next to the first three 

rows of seats, and to a portion of the 

cargo area behind the first or second 

rows, in motor vehicles with a gross 

vehicle weight rating (GVWR) of 4,536 

kilogram (kg) or less (10,000 pounds (lb) 

or less). To assess compliance, the 

agency is adopting a test in which an 

impactor is propelled from inside a test 

vehicle toward the windows. The 

ejection mitigation safety system is 

required to prevent the impactor from 

moving more than a specified distance 

beyond the plane of a window. To 

ensure that the systems cover the entire 

opening of each window for the 

duration of a rollover, each side window 

will be impacted at up to four locations 

around its perimeter at two time 

intervals following deployment. 

The agency anticipates that 

manufacturers will meet the standard by 

modifying existing side impact air bag 

curtains, and possibly supplementing 

them with advanced glazing. The 

curtains will be made larger so that they 

cover more of the window opening, 

made more robust to remain inflated 

longer, and made to deploy in both side 

impacts and in rollovers. In addition, 

after deployment the curtains will be 

tethered near the base of the vehicle’s 

pillars or otherwise designed to keep the 

impactor within the boundaries 

established by the performance test. 

This final rule adopts a phase-in of the 

new requirements, starting September 1, 

2013. 

This final rule advances NHTSA’s 

initiatives in rollover safety and also 

responds to Section 10301 of the Safe, 

Accountable, Flexible, Efficient 

Transportation Equity Act: A Legacy for 

Users (SAFETEA–LU). That section 

directs NHTSA to initiate and complete 

rulemaking to reduce complete and 

partial ejections of vehicle occupants 

from outboard seating positions, 

considering various ejection mitigation 

systems. 

DATES: Effective date: The date on 

which this final rule amends the Code 

of Federal Regulations (CFR) is March 1, 

2011. The incorporation by reference of 

certain publications listed in the 

standard is approved by the Director of 

the Federal Register as of March 1, 2011. 

Petitions for reconsideration: If you 

wish to petition for reconsideration of 

this rule, your petition must be received 

by March 7, 2011. 

Compliance dates: This final rule 

adopts a phase-in of the new 

requirements. The phase-in begins on 

September 1, 2013. By September 1, 

2017, all vehicles must meet the 

standard, with the exception of altered 

vehicles and vehicles produced in more 

than one stage, which are provided 

more time to meet the requirements. 

Manufacturers can earn credits toward 

meeting the applicable phase-in 

percentages by producing compliant 

vehicles ahead of schedule, beginning 

March 1, 2011 and ending at the 

conclusion of the phase-in. 

ADDRESSES: If you wish to petition for 

reconsideration of this rule, you should 

refer in your petition to the docket 

number of this document and submit 

your petition to: Administrator, 

National Highway Traffic Safety 

Administration, 1200 New Jersey 

Avenue, SE., West Building, 

Washington, DC 20590. 

The petition will be placed in the 

docket. Anyone is able to search the 

electronic form of all documents 

received into any of our dockets by the 

name of the individual submitting the 

comment (or signing the comment, if 

submitted on behalf of an association, 

business, labor union, etc.). You may 

review DOT’s complete Privacy Act 

Statement in the Federal Register 

published on April 11, 2000 (Volume 

65, Number 70; Pages 19477–78). 

For access to the docket to read 

background documents or comments 

received, go to http:// 

www.regulations.gov and follow the 

online instructions for accessing the 

docket. You may also visit DOT’s 

Docket Management Facility, 1200 New 

Jersey Avenue, SE., West Building 

Ground Floor, Room W12–140, 

Washington, DC 20590–0001 for on-line 

access to the docket. 

FOR FURTHER INFORMATION CONTACT: For 

non-legal issues, you may contact Mr. 

Louis Molino, NHTSA Office of 

Crashworthiness Standards, telephone 

202–366–1740, fax 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 


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1The 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). 

2NHTSA 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. 

3NHTSA 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. 

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. 

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 wideranging 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. 

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 computercontrolled 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. 

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. 

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. 

Today’s final rule launches a new 

phase in occupant protection and 

ejection mitigation. It builds on and 


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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. 

6This 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. 

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. 

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 quarterturns 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. 

Under today’s final rule, vehicle 

manufacturers must provide 

information to NHTSA upon request 

that describes the conditions under 

which ejection mitigation air bags will 

deploy. There is no presently 

demonstrated need for us to specify in 

the standard the conditions dictating 

when the sensors should deploy; field 

data indicate that rollover sensors are 

overwhelmingly deploying effectively in 

the real world. We will keep monitoring 

field data to determine whether future 

regulatory action is needed in this area. 

This chapter in occupant protection 

will achieve tremendous benefits at 

reasonable costs. We estimate that this 

rule will save 373 lives and prevent 476 

serious injuries per year (see Table 1 

below). The cost of this final rule is 

approximately $31 per vehicle (see 

Table 2). The cost per equivalent life 

saved is estimated to be $1.4 million (3 

percent discount rate)–$1.7 million (7 

percent discount rate) (see Table 3 

below). Annualized costs and benefits 

are provided in Table 4. 

TABLE 1—ESTIMATED BENEFITS

Fatalities ............................... 373 

Serious Injuries ..................... 476 

TABLE 2—ESTIMATED COSTS* 

[2009 economics] 

Per Vehicle ........................... $31. 

Total Fleet (16.5 million vehicles).$507 Million 

* The system costs are based on vehicles 

that are equipped with an FMVSS No. 214 

curtain system. According to vehicle manufacturers’ projections made in 2006, 98.7 percent 

of Model Year (MY) 2011 vehicles will be 

equipped with curtain bags and 55 percent of 

vehicles with curtain bags will be equipped 

with a rollover sensor. 

TABLE 3—COST PER EQUIVALENT LIFE

SAVED

3% Discount rate 7% Discount rate 

$1.4M $1.7M 


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7These data are updated from the 1998 to 2007 

FARS data reported in the NPRM. 8The 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). 

9The data combines partially-ejected and unejected occupants together, because partial ejection 

is sometimes difficult to determine and the PARgenerated 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). 

11The 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. 

13All crash types are included, but the counts are 

restricted to ejected occupants who were injured. 

TABLE 4—ANNUALIZED COSTS AND BENEFITS

[In millions of $2009 dollars] 

Annual costs Annualized 

benefits Net benefits 

3% Discount Rate ........................................................................................................................ $507M $2,279M $1,773 

7% Discount Rate ........................................................................................................................ 507M 1,814M 1,307 

Accompanying today’s final rule is a 

Final Regulatory Impact Analysis (FRIA) 

analyzing the costs, benefits, and other 

impacts of this final rule, and a 

technical report the agency has prepared 

that presents a detailed analysis of 

engineering studies, and other 

information supporting the final rule. 

Both documents have been placed in the 

docket for this final rule. The 

documents can be obtained by 

contacting the docket by the means 

specified at the beginning of this 

document or by downloading them at 

www.regulations.gov. 

II. Safety Need 

Rollover crashes are a significant and 

a particularly deadly safety problem. As 

a crash type, rollovers are second only 

to frontal crashes as a source of fatalities 

in light vehicles. Data from the last 10 

years of Fatal Analysis Reporting 

System (FARS) files (2000–20097) 

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

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

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 

years11 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. 

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. 

TABLE 5—OCCUPANT INJURY AND FATALITY COUNTS BY EJECTION ROUTE IN ALL CRASH TYPES

[Annualized 1997–2008 NASS and FARS] 

Ejection route MAIS 1–2 MAIS 3–5 Fatal 

Windshield ....................................................................................................................... 1,517 1,400 1,078 

First-Row Windows .......................................................................................................... 14,293 4,980 5,589 

Second-Row Windows ..................................................................................................... 1,700 641 796 


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3216 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

TABLE 5—OCCUPANT INJURY AND FATALITY COUNTS BY EJECTION ROUTE IN ALL CRASH TYPES—Continued 

[Annualized 1997–2008 NASS and FARS] 

Ejection route MAIS 1–2 MAIS 3–5 Fatal 

Third-Row Windows ......................................................................................................... 279 88 27 

Fourth-Row Windows ...................................................................................................... 0 0 39 

Fifth-Row Window ............................................................................................................ 0 0 7 

Cargo Area Rear of Row 2 .............................................................................................. 342 17 52

Backlight .......................................................................................................................... 1,621 1,364 495 

Roof Panel or Glazing ..................................................................................................... 1,000 367 324 

Roof Other ....................................................................................................................... 420 105 81 

Multiple Windows ............................................................................................................. 0 19 0 

Not Glazing ...................................................................................................................... 2,848 2,207 1,814 

Subtotals: ............................ ............................ ............................

Rows 1–3 .......................................................................................................... 16,272 5,709 6,412 

4th, 5th Row and Cargo .................................................................................... 342 17 98 

Total .......................................................................................................................... 24,020 11,188 10,302 

Table 6, below, provides the 

percentage of the total at each injury 

level. The injuries and fatalities 

resulting from ejections through the first 

three rows of windows constitute 68 

percent of MAIS 1–2 injuries, 51 percent 

of MAIS 3–5 injuries, and 62 percent of 

all ejected fatalities. 

TABLE 6—OCCUPANT INJURY AND FATALITY PERCENTAGES BY EJECTION ROUTE IN ALL CRASH TYPES

[Annualized 1997–2008 NASS and FARS] 

Ejection route MAIS 1–2 MAIS 3–5 Fatal 

Windshield ....................................................................................................................... 6.3% 12.5% 10.5% 

First-Row Windows .......................................................................................................... 59.5% 44.5% 54.2% 

Second-Row Windows ..................................................................................................... 7.1% 5.7% 7.7% 

Third-Row Windows ......................................................................................................... 1.2% 0.8% 0.3% 

Fourth-Row Windows ...................................................................................................... 0.0% 0.0% 0.4% 

Fifth-Row Window ............................................................................................................ 0.0% 0.0% 0.1% 

Cargo Area Rear of Row 2 .............................................................................................. 1.4% 0.2% 0.5% 

Backlight .......................................................................................................................... 6.8% 12.2% 4.8% 

Roof Panel or Glazing ..................................................................................................... 4.2% 3.3% 3.1% 

Roof Other ....................................................................................................................... 1.7% 0.9% 0.8% 

Multiple Windows ............................................................................................................. 0.0% 0.2% 0.0% 

Not Glazing ...................................................................................................................... 11.9% 19.7% 17.6% 

Subtotals: ............................ ............................ ............................

Rows 1–3 .......................................................................................................... 67.7% 51.0% 62.2% 

4th, 5th Row and Cargo .................................................................................... 1.4% 0.2% 1.0% 

Total .......................................................................................................................... 100.0% 100.0% 100.0% 

Since the countermeasure covering 

side window openings will be made 

more effective in preventing ejections, 

this rulemaking will also reduce the 

number of complete and partial 

ejections of occupants in side impacts. 

These benefits go beyond those 

achieved in the rulemaking adopting an 

oblique pole test into FMVSS No. 214 

(Phase 1 FMVSS No. 214 rulemaking) 

because a side air bag installed to meet 

FMVSS No. 214 is not necessarily wide 

or robust enough to effectively contain 

occupants in certain side impacts. In 

fact, NHTSA found that FMVSS No. 

214’s requirements could be met by a 

seat-mounted head/torso side air bag or 

a side head protection curtain air bag 

together with a seat-mounted or doormounted 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 (DV) 

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. 


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

Ejection degree Belted 

Row 1 Row 2 Row 3 

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

Ejection degree Belted 

Row 1 Row 2 Row 3 

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% 


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3218 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

14When 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. 

15Paragraph (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. 

16One 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. 

17This fatality reduction does not double-count 

benefits from ESC and the recent FMVSS No. 214 

upgrade. 

18For 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. 

TABLE 9—DISTRIBUTION OF FATALITIES AND INJURIES OF FIRST 3 ROWS SIDE WINDOW EJECTED OCCUPANTS BY

VEHICLE TYPE—Continued 

[Annualized 1997—2008 NASS and FARS] 

Vehicle MAIS 1–2 MAIS 3–5 Fatal MAIS 1–2 MAIS 3–5 Fatal 

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

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

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. 

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. 

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 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3219 

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. 

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 performanceoriented 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

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 prebroken, 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 


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3220 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

20The 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). 

21AIAM 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. 

22 VSC states: ‘‘Vehicle Services Consulting, Inc. 

assists numerous small volume vehicle 

manufacturers with US certification-related 

matters.’’ 

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. 

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. 

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 


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23NTEA describes itself as a ‘‘trade association 

representing distributors and manufacturers of 

multi-stage produced, work related trucks, truck 

bodies and equipment.’’ 

24Takata 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. 

25AORC 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. 

26Advocates 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.’’ 

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. 

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. 

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 pretest 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 threeyear phase-in period to meet the 

proposed requirements. 

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 


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3222 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

27Ejection mitigation glazing systems have a 

multi-layer construction with three primary layers. 

There is usually a plastic laminate bonded between 

two pieces of glass. 

28Tempered 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. 

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 prebreaking 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

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. 


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30See 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. 

32NHTSA developed the DRF to produce fulldummy 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 Bpillar. 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. 

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. 

34Two 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. 

35Since these were experimental systems, they 

were not deployed through pyrotechnic or invehicle 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. 

36HIC36 is the Head Injury Criterion computed 

over a 36 msec duration. HIC36 = 1,000 represents 

an onset of concussion and brain injury. 

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

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. 

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. 

In the tests of the experimental 

inflatable devices, the air bags were predeployed 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. 

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 HIC3636 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 


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3224 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

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. 

38 Id. 

39 ITS systems were originally introduced by 

BMW as a side impact countermeasure. 

40The ‘‘ejection impactor’’ is the moving mass that 

strikes the ejection mitigation countermeasure. It 

consists of an ejection headform attached to a shaft. 

41The ejection mitigation test device consists of 

an ejection impactor and ejection propulsion 

mechanism. 

42The ‘‘ejection propulsion mechanism’’ is the 

component that propels the ejection impactor and 

constrains it to move along its axis or shaft. 

system) and 1020 N (5th percentile 

female tested with laminate only). 

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-yearold 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

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 prebroken advanced glazing with the TRW 

system managed to contain the dummy 

inside the test buck in all tests.38

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. 

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 Apillar. 

4. Insights 

The DRF research provided the 

following insights into ejection 

mitigation curtains: 

• Inflatable devices prevented 

ejection of test dummies in simulated 

rollover tests, but design differences 

accounted for differences in 

performance; 

• Gaps in the inflatable device’s 

coverage of the window opening at the 

sill and A-pillar allowed partial ejection 

of adult dummies and full ejection of a 

6-year-old child dummy; 

• Adding pre-broken advanced 

glazing to an air bag system enhanced 

the ability of the system to contain the 

dummy; and, 

• To optimize ejection mitigation 

potential, a performance test should 

ensure that the countermeasure has full 

coverage of the window opening. 

c. Comparable Performance in 

Simulated Rollovers and ComponentLevel 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. 

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 Apillar 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 


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43Testing was restricted to the extreme corners of 

the window due to limited availability of this 

system. 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. 

47The 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. 

48http://media.ford.com/ 

article_display.cfm?article_id=6447 (Last accessed 

October 8, 2010.) 

49The 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. 

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.) 

52http://www.autodeadline.com/detail?source=

Honda&mid=HON2004083172678&mime=ASC. 

(Last accessed October 5, 2010.) 

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. 

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’’). 

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. 

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). 

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. 

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. 

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 


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53 Ibid. 54Who Benefits From Side and Head Airbags?’’ 

(http://www.edmunds.com/ownership/safety/

articles/105563/article.html), supra. 

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

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. 

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 


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TABLE 10—FRONT ROW WINDOW, 24 KM/H IMPACT, 1.5 SECOND DELAY—Continued 

Vehicle N/O* Pos. A1 Pos. A2 Pos. A3 Pos. A4 

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) 


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TABLE 11—FRONT ROW WINDOW, 20 KM/H IMPACT, 1.5 SECOND DELAY—Continued 

Vehicle N/O* Pos. A1 Pos. A2 Pos. A3 Pos. A4 

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 


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TABLE 13—SECOND ROW WINDOW, 24 KM/H IMPACT, 1.5 SECOND DELAY—Continued 

Vehicle N/O* Pos. B1 Pos. B2 Pos. B3 Pos. B4 

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 


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TABLE 15—SECOND ROW WINDOW, 16 KM/H IMPACT, 6 SECOND DELAY—Continued 

Vehicle N/O* Pos. B1 Pos. B2 Pos. B3 Pos. B4 

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. 


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


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55 In some cases average values were used to 

calculate the differences. 

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. 

The CX9 was the only vehicle that 

was impacted multiple times at the 

same targets by both the old and new 


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56The 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. 

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. 

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 

Test Vel. 

(km/h) 

A1 A3 

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/h1.5 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/h1.5 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

Vehicle Test 

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 


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57The 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. 

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 ttest 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. 

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 nonejected, 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.’’ 


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TABLE 24—FORD SCI ROLLOVER

CASES (PRESENTED IN THE NPRM) 

Case Make Model MY 

Occupants 1⁄4 Rot. Deploy 

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, 

2NR†.

1R, 

2NR†.

5 .......... Yes ...... Unknown Unknown 

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. † One NR 2nd and 3rd row occupant ejected (total of 2 ejected). 


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3236 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

58A 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. 

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. 

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 nondeployment 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

Curtain 

deployment Drivers Passengers 

All 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. 


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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. 

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 Apillar tether detached. It is not possible 

to know if these instances of curtain 

damage occurred during the rollover or 

post-crash due to extrication. 


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3238 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

59Both 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). 

TABLE 28—RODSS, NASS CDS AND SCI CASES WITH OCCUPANTS WHO WERE EJECTED THROUGH SIDE WINDOWS

PROTECTED BY ROLLOVER CURTAINS

Case ID Year/Make/Model 1/4 

Turns 

Curt. 

depl. 

Seat 

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. 

8289 * ................ 03 Lincoln Aviator ‡ .............................. 8+ Yes ...... 12 Yes ...... 28y No ....... NA .......... Serious. 

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

‡ These seating positions had laminated glazing adjacent to them. 

Non-Deployed Rollover Curtains in 

Rollover Crashes 

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 nondeployment 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 DV 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

Case ID Year/Make/Model Quarter 

turns 

Curt. 

depl. 

Seat 

pos. Belt use Age Eject. Route Injury/ MAIS 

RODSS 

5032 * ................ 04 Lincoln Aviator ‡ .............................. 3 No ....... 11 No ....... 68y Comp. Row 2 R Fatal. 

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. 

7242 * ................ 03 Lincoln Aviator ‡ .............................. 3 No ....... 13 Yes ...... 26y No ....... NA .......... Serious. 

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

‡ These seating positions had laminated glazing adjacent to them. 


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60These 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). 

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. 

62Since 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. 

X. Response to Comments and Agency 

Decisions 

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. 

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


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63 ‘‘Technical Analysis in Support of a Notice of 

Proposed Rulemaking for Ejection Mitigation,’’ 

supra. 

64The 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). 

65O’Brian-Mitchell, Bridget M., Lange, Robert C., 

‘‘Ejection Mitigation in Rollover Events— 

Component Test Development,’’ SAE 2007–01– 

0374. 

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. 

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. 

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. 

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. 


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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 windowbreaking 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 prebreaking 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 


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66There were only some slight variations in target 

locations. 

67The 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. 

68The 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/. 

69O’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. 

71This is aside from commenters who want the 

agency to use a completely different test method, 

i.e., full vehicle dynamic rollover. 

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. 

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

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. 

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.69 70 Displacement is measured 

perpendicular to this excursion plane. 

Thus, the allowable GM displacement is 

approximately 100/cos(q) mm, with q 

being the angle with the vertical of the 

exterior plane, if other aspects of the test 

were identical to those of the NPRM. If 

q 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. 

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. 

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 


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72Honda’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. 

excursion plane by 100 mm along a line normal to the excursion plane, rather 

than 150 mm laterally. 

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. 

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. 


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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. 

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 Alliancerecommended 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 (D 

excursion plane) and the 150 mm 


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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. 

additional displacement to the 

maximum excursion plane.73

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 D 

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). 


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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 


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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. 

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 


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74 74 FR 63193. 

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. 

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 


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75NHTSA–2009–0183–0022, p. 3. 76Each impact takes place on a test specimen 

(e.g., a curtain) that was not previously subject to 

an impact test. 77 ‘‘Ejection Mitigation Using Advanced Glazings: 

A Status Report,’’ November 1995, Docket NHTSA– 

1996–1782–3. Pg. 6–1. 

78The 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. 

80MADYMO user’s manual V5.1, TNO, 1994. 

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. 

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 postimpact 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. 

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. 

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 quarterturn for Corolla and Jetta) in the rollover 

event. 


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81These 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 30—HEAD AND TORSO VELOCITIES OF A HYBRID III 50TH PERCENTILE MALE DUMMY IN 3 ROLLOVER SIMULATIONS

Vehicle Vehicle 1⁄4

turns 

1⁄4 Turns at 

complete 

ejection 

Restraint use 

Head to 

opening 

(km/h) 

Head to 

glazing 

(km/h) 

Torso to 

glazing 

(km/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 mid1980s 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. 

TABLE 31—NHTSA FULL VEHICLE ROLLOVER TESTING FILM ANALYSIS

Test # Make Model MY Test type Tilt angle 

(deg.) 

Roll axis 

(deg.) 

Vehicle 

speed 

(km/h) 

1⁄4 Turns Total time 

(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 


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83The 50 percent point in the cumulative 

distribution occurs between 5 and 6 quarter turns. 

84 Duffy, S., ‘‘Test Procedure for Evaluating 

Ejection Mitigation Systems,’’ 2002 SAE 

Government/Industry Meeting. 

85For 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. 

86As mentioned earlier, just less than half of the 

complete ejection fatalities occur when the vehicle 

rolls up to 5 quarter-turns. 

87The 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 quarterturns may have 5–6 second roll times. 

88http://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). 

90NHTSA–2009–0183–0022, p. 12. 

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+ quarterturns, 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.) 

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. 

TABLE 32—DRF TESTING RESULTS

Dummy 

Far side 

impact 

time 

(sec.) 

Far side 

impact @ 

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 quarterturns. 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. 

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 quarterturns. 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

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. 

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. 

iii. Agency Response 

The agency declines to increase or 

decrease the time delay for the 1.5 

second and 6 second impacts. We also 


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91 74 FR 63196. 92 74 FR 63182. 

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. 

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 quarterturns. 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.) 

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

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 


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93The 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 

95 74 FR at 63197 

96The 24 km/h test imparts about 400 joules of 

energy, while the 16 km/h test imparts 

approximately 178 J. 

97O’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. 

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 quarterturns (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 161⁄4-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 

DV 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. 

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. 

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. 

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. 

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 = 1/2mv2; 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 


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99NHTSA–2009–0183–0002, p. VIII 18. 100NHTSA–2009–0183–0015, p. 2. 

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. 

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.) 

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 midsize 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 


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101Although the membrane had force 

measurement instrumentation at each corner, these 

measurements were not used in the analysis due to 

a ‘‘data integrity issue.’’ 

102 Docket No. NHTSA–2006–26467–0002. 103The 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. 

104 ‘‘Ejection Mitigation Using Advanced Glazing: 

A Status Report,’’ November 1995, Docket No. 

NHTSA–1996–1782–3. Pg. 7–10. 

105These have been entered as test Nos. 10282— 

10287 in the NHTSA Biomechanics Test Database. 

They are accessible at http://wwwnrd.nhtsa.dot.gov/database/aspx/biodb/ 

querytesttable.aspx. 

106Although 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. 

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. 

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). 

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. 

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 farreaching 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

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. 


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107We say ‘‘minimum’’ because by the nature of 

impact into foam, there were energy losses that 

would not be reflected in the estimated impact 

energy. 

108We 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. 

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.) 

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. 

Where: 

Fh = Force measured at head foam pad, 

assumed to be lateral force on dummy 

head. 

yh/s = 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. 

TABLE 33—ENERGY (EQ. 1) AND

FORCE ON THE ETHAFOAM PADDING

IN THE 24.1 KM/H SLED TEST

Maximum 

energy 

(J) 

Maximum 

force 

(N) 

Head ................. 97 .1 2,569 

Shoulder ........... 190 .1 3,220 

TABLE 33—ENERGY (EQ. 1) AND

FORCE ON THE ETHAFOAM PADDING

IN THE 24.1 KM/H SLED TEST—Continued 

Maximum 

energy 

(J) 

Maximum 

force 

(N) 

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. 


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109As 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). 

Where: 

EM = effective mass 

ay = 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). 

Where: 

Ei = Energy of impact 

Vy0 = 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). 

Where: 

Vyf = 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

V0 (m/s) 

Method of Effective Mass Determination (kg) 

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 preimpact 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


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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 freeflight 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). 

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. 

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 (tf) of minimum relative dummy to 

sled velocity (vyf) 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

Vo (m/s) EM (eq. 6.6.4) 

(kg) Energy (eq. 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). 


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110 Duffy, S., ‘‘Test Procedure for Evaluating 

Ejection Mitigation Systems,’’ 2002 SAE 

Government/Industry Meeting. 

111 Videos and electronic data from these tests 

have been placed in the NHTSA Component 

Database and can be accessed at wwwnrd.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. 

112An 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. 

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. 

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. 

TABLE 38—DRF TESTING PEAK VELOCITIES

Dummy 

Impact speed (km/h) Estimated impact energy (J) 

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. 

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 


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3260 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

114Some 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. 

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. 

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 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3261 

115These rankings exclude ejections through nonglazing areas. 116 It is important to emphasize that the RODSS 

data is not a statistically representative sample of 

field data. 

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. 

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

Assumed containment effectiveness 

Cost per ELS 

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. 

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. 


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3262 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

117These rankings exclude ejections through nonglazing areas. The second ranked fatal ejection route 

is the windshield, for both lateral rollovers and side 

impact crash populations. 118 74 FR 63201 

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. 

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. 

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.’’ 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3263 

119There were no ejections through the cargo area 

windows behind any other row. 

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. 

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 


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120The MY 2007 Chevrolet Tahoe uses a separate 

curtain to cover the 3rd row window. 

121These 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. 

122More details of this study can be found in the 

technical report supporting this final rule. 

covering tethered at the A- and Dpillars.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. 

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. 

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

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 


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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. 

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 


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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 asmanufactured 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. 


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123For 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. 

124The agency can ask the manufacturer to 

provide information about the rollover sensor’s 

deployment capabilities. See proposed S4.2.4, 

Technical Documentation. 125 74 FR 63205 

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. 

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

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-tobuild 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 


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126The 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. 

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. 

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. 


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127This is the same as saying they did not want 

to rotate the targets, because the impactor headform 

orientation is aligned with the target orientation. 

128The 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. 

129NHTSA–2009–0183–0044, p. 6. 

130 Docket No. NHTSA–2009–0183–47.1 

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.’’ 

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.’’ 

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. 

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 .................................... Van ............................... 4 4 4 

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 


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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. 


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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 


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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. 


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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. 

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 


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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. 


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131Looking 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. 132NHTSA–2009–0183–0029, p. 30. 

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. 

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. 

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 


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133We 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. 

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 distantlyspaced 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. 

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 


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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. 

135NHTSA–2009–0183–0020, p. 4. 

136Although 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. 

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— 

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 prebreaking 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 unpredictable 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. 

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 


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3278 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

137The 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). 

138Mercedes offers this feature and calls it PreSafe. 

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. 

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. 

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 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3279 

139The 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. 

140This force level worked well for the samples 

of advanced glazing tested by the agency. 

141When 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. 

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. 

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 ±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. 

We also noted that we would be 

continuing research into window prebreaking 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 prebreakage 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 prebreaking 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

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 


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3280 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

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 ±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 ± 1 degree tolerance required 

at launch. 

2. TRW and AORC expressed concern 

about the ± 0.1 second tolerance on the 

impact times of 1.5 and 6 seconds. They 

suggested a tolerance of ± 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 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3281 

142Stein, 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. 

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 ± 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 ±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. 

TABLE 41—AORC RECOMMENDATIONS FOR IMPACTOR PERFORMANCE 142

Variable Maximum variance Preliminary recommendation 

Velocity .................................................................................... ± 0.75 km/h ............................................ ± 0.25 km/h. 

Deflection ................................................................................ >> 25 mm .............................................. < 10 mm. 

Time Delay to Impact .............................................................. 400 ms ................................................... < 100 mm (or redefine time to contact). 

Excursion Accuracy ................................................................. ± 4.6 mm ............................................... ± 2 mm. 

Dynamic Friction ..................................................................... 2.62 ........................................................ < 0.25. 

Design Margin ......................................................................... ¥ 20% (TYP) ........................................ TBD. 


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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. 

• The ejection mitigation impactor 

must be capable of measuring the 

displacement of the moving impactor 

mechanism throughout the entire stroke, 

with an accuracy of ±2 mm.* 

• The maximum radial deflection of 

the ejection mitigation impactor must 

not exceed 10 mm.* 

• 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. 

• The maximum dynamic coefficient 

of friction of the ejection mitigation 

impactor must not exceed 0.25.* 

• 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 ±0.25 km/h; a range of ±0.15 km/h or 

less is preferred.* 

• 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.* 

• 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 testready 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 ±0.1 

seconds and 6.0 ±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 carespecific 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 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3283 

143 Viano D, Parenteau C., ‘‘Rollover Crash 

Sensing and Safety Overview,’’ SAE 2004–01–0342. 

144Ford 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. 

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 realworld 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. 

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 


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3284 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

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). 

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 nondeployment 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-a`-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 nonrollover 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 fullvehicle dynamic tests would likely 

involve many more years of research, 

which would delay the rulemaking 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3285 

145We 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 realworld 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. 

146A 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. 

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 DV. 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 DV 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

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 


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147Since 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. 

148The 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. 

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 ±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. 

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. 


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149A 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. 

150 Docket NHTSA–2006–26467–0019. 

151We note that Takata claimed that it achieved 

the necessary performance by a change in shape, 

rather than an increase in pressure or volume. 

152NHTSA–2009–0183–0029, p. 20. 

153The Toyota data provided by the Alliance 

indicated that it was more difficult to meet TWG 

guidelines in the passenger environment than in 

SUVs. 

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 socalled ‘‘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

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

Takata stated that a new air bag 

design it has developed was integrated 

into a sedan and tested to the 24 km/h1.5 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. 

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. 

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 


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154NHTSA–2006–26467–0016. 

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. 

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-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 upwardlydeploying 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. 


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155NHTSA–2009–0183–0017, p. 3. 

156For 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. 

157Mercedes’ 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. 

158As 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. 

159See 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. 

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

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 finalstage manufacturer can also certify to 

the standard using due care based on an 

assessment of the information available 

to the manufacturer. 

NTEA contended that workperforming 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. 

Some modifications made by a finalstage 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. 

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 


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160PRIA, pg. V–21. 

161This provision is found in S6.3(b) of FMVSS 

No. 201. Footnote added. 

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. 

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. 

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 41⁄2

months. 

In addition, multi-stage manufacturers 

have an additional year after the phasein 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 passthrough 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

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 multistage 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 upwardlydeploying 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. 

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 Bpillar. 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. 


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163NHTSA–2009–0183–0009, p. 1. 

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

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-tested and run-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-third of the lead-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-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-inwhite, 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 


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3292 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

164This 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. 

165The 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. 

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 phasein. 

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 phasein 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 


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Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 3293 

167For 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. 

168The 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. 

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. 

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 noncompliant 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

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-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] 

Annual costs Annualized 

benefits 

Net 

benefits 

3% Discount Rate ...................................................................................................... $507M $2,279M $1,773 

7% Discount Rate ...................................................................................................... 507M 1,814M 1,307 


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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 nonidentical 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). 


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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: 

• Have we organized the material to 

suit the public’s needs? 

• Are the requirements in the rule 

clearly stated? 

• Does the rule contain technical 

language or jargon that isn’t clear? 

• Would a different format (grouping 

and order of sections, use of headings, 

paragraphing) make the rule easier to 

understand? 

• Would more (but shorter) sections 

be better? 

• Could we improve clarity by adding 

tables, lists, or diagrams? 

• What else could we do to make the 

rule easier to understand? 

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; 


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(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: 

• 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; 

• NHTSA estimated that the total 

annual reporting and recordkeeping 

burden resulting from the collection of 

information is 1,260 hours; 

• 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 

■ 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. 

■ 2. Section 571.5(b) is amended by 

adding, in alphabetical order, an entry 

to the list of materials incorporated by 

reference, as follows: 

§ 571.5 Matter incorporated by reference. 

* * * * * 

(b) * * * 

‘‘Parts List; Ejection Mitigation 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.

571.226, S7.1.1 

* * * * * 

■ 3. Section 571.226 is added to read as 

follows: 

§ 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 walkin 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. 


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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 upright 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 prebroken, 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. 


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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±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 nonforward 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 ±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 ±2 mm of the offsetline 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 rearwardupper. 

S5.2.3.2 Rear windows. For any side 

daylight opening rearward of the Bpillar, 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 offsetline. 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 Bpillar, 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 offsetline. 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

Step Measure distance from z axis to z axis and x axis to x axis for 

these targets 

Eliminate this target if distances between z axes of targets and x 

axes of targets are less than 135 mm and 170 mm, respectively 

1 ......... Upper Secondary to Lower Secondary ............................................ Upper Secondary. 

2 ......... Upper Primary to Upper or Remaining Secondary .......................... Upper or Remaining Secondary. 


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TABLE 1—PRIORITY LIST OF TARGET DISTANCE TO BE CHECKED AGAINST LIMITS—Continued 

Step Measure distance from z axis to z axis and x axis to x axis for 

these targets 

Eliminate this target if distances between z axes of targets and x 

axes of targets are less than 135 mm and 170 mm, respectively 

3 ......... Lower Primary to Lower or Remaining Secondary .......................... Lower or Remaining Secondary. 

4 ......... Upper Primary to Lower Primary ..................................................... Upper 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 ±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 

±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±2 

mm with one point coincident within 

±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±2 

mm with the entire grid horizontally 

offset by 37.5 ± 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 ±2 mm 

diameter prior to coming to a point. The 

spring is adjusted to require 150 ±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 ±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 ±10 mm x 100 ±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 

±0.1 seconds after activation of the 

ejection mitigation countermeasure that 

deploys in the event of a rollover, and 

at a speed of 20 ±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 ±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 

±0.1 seconds after activation of an 

ejection mitigation countermeasure that 

deploys in the event of a rollover, and 

at a speed of 16 ±0.5 km/h. 

(c) An ejection mitigation 

countermeasure that deploys in the 

event of a rollover is described as such 


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3300 Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / Rules and Regulations 

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 ±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 ±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 ± 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 

± 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 

±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 § 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 ± 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 

(±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 ±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 ± 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 ±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 


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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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■ 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. 

■ 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. 


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Subpart K—Ejection Mitigation Phasein Reporting Requirements 

§ 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). 

§ 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). 

§ 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. 

§ 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 § 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. 

§ 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. 

§ 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 § 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 § 585.2 of this 

part. 

(c) Advanced credit phase-in report 

content—(1) Production of complying 

vehicles. With respect to the reports 

identified in § 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. 

§ 585.106 Records. 

Each manufacturer shall maintain 

records of the Vehicle Identification 

Number for each vehicle for which 

information is reported under § 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 


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