U.S. Department
`Of Transportation
`
`PRELIMINARY REGULATORY IMPACT ANALYSIS
`
`Notice of Proposed Rulemaking
`FMVSS No. 226
`Ejection Mitigation
`
`Office of Regulatory Analysis and Evaluation
`November 2009
`
`IPR 2016-01790
`American Vehicular Sciences
`Exhibit 2016
`
`

`

`
`
`TABLE OF CONTENTS
`
`Executive Summary …………………………………………………………….….
`
`I.
`
`II.
`
`III.
`
`IV.
`
`V.
`
`Introduction …………………………………………………………………
`
`Background …………………………………………………………..……..
`
`Test Data ……………………..……………………………………………..
`
`Benefits ……………………………………………………………..………
`
`Costs. ……………………………………………………………………….
`
`VI.
`
`Cost Effectiveness & Benefit-Cost Analyses ………………………………
`
`E-1
`
`I-1
`
`II-1
`
`III-1
`
`IV-1
`
`V-1
`
`VI-1
`
`VII. Sensitivity Analyses ….……………………………………………………..
`
`VII-1
`
`VIII. Alternatives ….……………..………………………………………………..
`
`VIII-1
`
`IX. Regulatory Flexibility Act and Unfunded Mandates Reform Act Analysis ...
`
`IX-1
`
`
`
`
`
`APPENDIX
`
`
`A-1
`A. Belted Dummy with Selected Interior Impact Objects….…………………
`B-1
`B. Unbelted Dummy with Selected Interior Impact Objects …………………
`C-1
`C. 201 Headform HIC Results…………….…………………………………
`D-1
`D. Winnicki’s Effectiveness Rates ……………………………………………
`E-1
`E. Estimated Benefits with Different Assumptions ……………………………
`F-1
`F. Comprehensive Costs and Relative Value Factors …………………………
`G. Distribution of Target Population by Vehicle Type ………………………… G-1
`H. Lives Saved with 100% Observed Safety Belt Use Rate …………………… H-1
`I. Estimated Number of Lives Saved Excluding Alcohol Related Fatalities …..
`I-1
`J. ELS Broken-Out by Belt Use and Level of Ejection ………………………
`J-1
`K. Excluding A1 from Meeting Head Form Requirements ……………………… K-1
`
`
`
`
`
`
`
`

`

`
`
` E- 1
`
`EXECUTIVE SUMMARY
`
`This Preliminary Regulatory Impact Analysis (PRIA) analyzes the potential impacts of new
`
`performance requirements and test procedures for ejection mitigation systems in rollover and
`
`certain side crashes. The intent of the rulemaking is to protect both belted and unbelted
`
`occupants from partial or complete ejection through side windows in vehicle crashes.
`
`
`
`
`
`Test Requirements
`
`The proposed rule requires that the occupant containment countermeasure be tested by impact
`
`from a guided 18 kg featureless head form traveling laterally and horizontally. The performance
`
`criterion is a displacement limit, measured by the impactor, of 100 mm beyond the inside surface
`
`of the window at the target location being tested. It requires that each side window, for up to
`
`three vehicle rows, be impacted at any of four locations referenced to the edges of the window
`
`opening at two impact velocities (16 and 24 km/h). The 16 km/h impact will occur 6 seconds
`
`after air bag deployment and the 24 km/h impact will occur 1.5 seconds after air bag deployment.
`
`
`
`Countermeasures
`
`The agency believes that curtain air bags will be used to pass the test. We believe that most
`
`manufacturers will have to make changes to the air bags that have been or will be installed in
`
`vehicles in response to the recent pole test upgrade of FMVSS No. 214.1 Side curtain air bags
`
`will be made wider or combination (combo) air bags will be replaced with a curtain to pass the
`
`impactor test. Vehicle manufacturers would install a single-window curtain for each side and
`
`these window curtains are assumed to provide protection for both front and rear seat occupants.
`
`
`1 72 FR 51908
`
`

`

`
`
`
`
` E- 2
`
`Although the majority of vehicles tested met the linear impactor head form (headform) test
`
`requirement at the upper portion of the window opening, none of the vehicles met the
`
`requirement at all impact points. For current OEM ejection countermeasures, a particularly
`
`difficult point to meet the test is the front lower corner of the front window near the A-pillar (test
`
`point A1).
`
`
`
`We examined two different types of countermeasures that are designed to meet the proposed
`
`headform impact requirements. One approach is to cover the opening with a wider curtain air
`
`bag (called “full curtain” in the PRIA). However, we believe that even if the window is
`
`completely covered with a header-mounted curtain air bag and limited the headform
`
`displacement to some value less than 100 mm, some partial ejections could occur through a
`
`potential gap along the bottom of the air bag between the air bag and vehicle’s window sill. As
`
`an alternative to this design approach, manufacturers may install laminated glazing in the
`
`window opening (called “partial curtain plus laminated glazing”) to prevent ejections through
`
`test point A1 and the lower gap. There is still a question whether a window curtain and
`
`laminated glazing could pass Point A1 at 24 km/h (15 mph). In this PRIA, we explore the
`
`implications of the agency lowering the test speed at Point A1 to 20 km/h (12 mph) in the 1.5-
`
`second test and how manufacturers would design an ejection mitigation system under such a
`
`condition (a third countermeasure called “A1 full curtain”).2
`
`
`2 As discussed, the goal is to cover the whole window opening. As part of the rulemaking effort, the agency tested a
`prototype curtain ejection mitigation system developed by TRW in a dynamic rollover fixture (DRF). The test
`results showed that in a near worst case ejection condition an unrestrained small child could be ejected through a
`small window opening (target position A1) when the area is not fully covered, even when initially aimed at another
`part of the window (target position A2). For additional discussion, see a report titled “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. These benefits estimates are based on lateral rollovers. We do not
`
`

`

` E- 3
`
`
`
`
`
`Benefits
`
`The agency estimates benefits for both partially and completely ejected occupants in rollovers
`
`and certain side crashes. The agency’s annualized injury data from 1997 to 2005 National
`
`Automotive Sampling System (NASS) Crashworthiness Data System (CDS) and fatality counts
`
`adjusted to 2005 Fatal Analysis Reporting System (FARS) levels show that there are 6,174
`
`fatalities and 5,271 Maximum Abbreviated Injury Scale (MAIS) 3+ non-fatal injuries for
`
`occupants ejected through side windows. The potential benefits estimated in the 214-FRIA for
`
`the upgrade to FMVSS No. 214 were excluded from the ejection mitigation benefits. After
`
`adjusting for assumed full compliance with Electronic Stability Control (ESC) penetration in the
`
`model year (MY) 2011 vehicle fleet and current compliance with the proposed rule, we
`
`estimated that the proposed rule being met by the full curtain would save 390 to 402 lives and
`
`prevent 296 to 310 serious injuries, annually.3 For the estimated benefits, we assumed that the
`
`belt use rate observed in 2005 remains unchanged. The majority of the benefits are for unbelted
`
`occupants but the analysis shows that 13 percent of the benefits would be from belted occupants:
`
`10 percent from rollovers and about 3 percent from side crashes considered.
`
`
`
`Costs
`
`Potential compliance costs for the linear impactor headform test vary considerably and are
`
`dependent upon the types of the FMVSS No. 214-head/side air bags that will be installed by
`
`know the effectiveness of these bags in other rollover events, such as end-to-end or more complex rolls. We suspect
`that the effectiveness would decrease noticeably in non-lateral rollovers.
`3 The benefit estimate was made based on particular assumptions used in the analysis. The range of potential
`benefits is due to different assumptions about where in the opening occupants are ejected. The benefit chapter in the
`PRIA discuses the assumptions used for occupant ejections. In addition, when inputs that affect the analysis are
`uncertain, the agency makes its best judgment about the range of values that will occur through sensitivity analyses,
`as discussed in Chapter VII.
`
`

`

`
`
` E- 4
`
`vehicle manufacturers to comply with the oblique pole test requirements. For vehicles with two
`
`rows of seats to be covered with a curtain air bag, we estimate an ejection mitigation system
`
`(consisting of 2 window curtains, 2 thorax air bags for the front seat occupants only, 2 side
`
`impact sensors and 1 rollover sensor) would cost about $299.44, when compared to a vehicle
`
`with no side air bags. This is $49.97 more than a vehicle with a side air bag system designed to
`
`meet the FMVSS No. 214 pole and MDB tests. The estimated MY 2011 sales show that 25% of
`
`light vehicles will have a third row seat. When the first through 3rd row are covered with a
`
`curtain air bag, we estimated the cost per vehicle will increase by $61.92, when compared to a
`
`vehicle equipped with a FMVSS No. 214-curtain system.
`
`
`
`The manufacturers’ plans for MY 2011 head air bag sales show that about 1%, 44% and 55% of
`
`vehicles would be equipped with combination air bags, curtain air bags without rollover sensor
`
`and with rollover sensors, respectively. Thus, manufacturers are planning to provide 55% of the
`
`MY 2011 vehicles with an expensive part of the cost of meeting the ejection mitigation test, the
`
`rollover sensor which is estimated to cost $38.02. Our analysis shows that most vehicles that are
`
`equipped with combination air bags would be convertibles (about 1%). The agency asks for
`
`comments on the feasibility of installing countermeasures other than header mounted air bag
`
`curtains such as door-mounted ejection mitigation curtains in convertibles on a widespread basis
`
`and the associated costs and benefits. Given that 25% of light trucks have 3 rows of seats, we
`
`estimate the average cost per vehicle would increase by $54 if there were no voluntary
`
`compliance by manufacturers for MY 2011.4 Manufacturers’ plans for MY 2011 indicate at
`
`least $20 per vehicle of costs toward this proposal. Thus, compared to the manufacturers’ plans
`
`4 We estimated that a total cost of $920 million when all light vehicles are equipped with rollover ejection curtains.
`For the $920M, $583M would be a result of the final rule and the remaining $337M would be resulting from
`voluntarily installed rollover curtain bags.
`
`

`

`
`
` E- 5
`
`this proposal will add about $34 per light vehicle at a total cost of $583 million for the full
`
`curtain countermeasure.
`
`Costs
`
`Total and Average Vehicle Costs*
`($2007)
`Weighted MY 2011
`Manufacturers’ Plans
`$20
`$337million
`
`Ejection Mitigation
`System
`$54
`$920 million
`
`Per Vehicle Costs
`Total Costs
`(17 million vehicles)
`* The system costs are based on vehicles that are equipped with the 214-curtain system. According to vehicle
`manufacturers, 98.7% of MY 2011 vehicles will be equipped with curtain air bags and 55% of vehicles with curtain
`air bags will be equipped with a roll sensor.
`
`
`
`Incremental Costs
`
`$34
`$583 million
`
`Cost per Equivalent Life Saved and Net Benefits
`
`Estimates were made of the net costs per equivalent life saved. For the full curtain
`
`countermeasure5, the low end of the range is $1.57 million per equivalent life saved, using a 3
`
`percent discount rate. The high end of the range is $2.04 million per equivalent life saved, using
`
`a 7 percent discount rate.
`
`
`
`Net benefit analysis differs from cost effectiveness analysis in that it requires that benefits be
`
`assigned a monetary value, and that this value is compared to the monetary value of costs to
`
`derive a net benefit. When we assume that the percentage of MY 2011 air bag sales remain
`
`unchanged (i.e., 1%, 44% and 55% of vehicles would be equipped with combination air bags,
`
`curtain air bags without rollover sensor and with rollover sensors, respectively), it resulted in
`
`$1,605 to $1,680 million net benefits using a 3 percent discount rate, and $1,158 to $1,217
`
`
`5 The cost equivalent and net benefits analyses showed that the full curtain would have a cost per equivalent of
`$1.57M and $1.98M discounted at 3% and 7%, respectively, when the weighted risk of distribution method is used.
`When the uniform distribution method is used, the full curtain would have a cost equivalent of $1.63M and $2.04M
`discounted at 3% and 7%, respectively. For the “A1 full cover” curtain, we estimated $1.61M and $2.02M
`discounted at 3% and 7%, respectively, with the weighted distribution method and $1.70M and $2.14M discounted
`at 3% and 7%, respectively, with the uniform distribution method
`
`

`

`
`
` E- 6
`
`million using a 7 percent discount rate. Both of these are based on a $6.1 million cost per life,6
`
`as shown below:
`
`
`
`Analysis of Alternatives
`
`The following tables show the estimated benefits, costs, cost per equivalent life saved, and net
`
`benefits for the three alternative countermeasures considered.
`
`Countermeasure
`
`Full Curtain
`A1 Full Curtain
`Partial Curtain plus Laminated Glazing
`
`Incremental Benefits
`Weighted risk of ejection
`method
`Serious Injuries
`310
`301
`391
`
`Fatalities
`402
`391
`494
`
`Uniform risk of ejection
`method
`Serious Injuries
`296
`286
`386
`
`Fatalities
`390
`377
`490
`
`
`Cost per Equivalent Life Saved and Net Benefits, with two methods
`Countermeasure Total
`with Weighted Distribution (in $M) with Uniform Distribution me (in $M)
`Cost
`Cost per
`Net Benefits
`Cost per
`Net Benefits
`Equivalent Life
`Equivalent Life
`Saved
`Saved
`3%
`7%
`3%
`7%
`$1.57
`$1.98
`$1.63
`$2.04
`$583
`$1.62
`$2.03
`$1.68
`$2.11
`$583
`$1,494 $3.27
`$4.12
`$3.30
`$4.14
`
`Full Curtain
`A1 full Curtain
`Partial Curtain
`plus Laminated
`Glazing
`
`3%
`$1,680
`$1,615
`$1,293
`
`7%
`$1,217
`$1,166
` $720
`
`3%
`$1,605
`$1,534
`$1,271
`
`7%
`$1,158
`$1,101
`$706
`
`
`6 The Department of Transportation has determined that the best current estimate of the economic value of
`preventing a human fatality is $5.8 million (“Treatment of the Economic Value of a Statistical Life in Departmental
`Analyses,” Tyler D. Duval, Assistant Secretary for Transportation Policy, February 5, 2008. The $6.1 million
`comprehensive cost was based on the $5.8 million statistical life.
`7 The “full curtain” and the “A1 full curtain” cover the window opening area fully. Since the incremental costs are
`based on the increase in material cost, we assumed that the incremental costs are the same for these two full-cover
`bags. Accordingly, we believe that the “A1 curtain” bag could be re-designed, without additional materials, to meet
`the proposed 24 km/h requirement at the lower impact point, A1.
`
`Countermeasure
`Full Curtain
`A1 full Curtain7
`Partial Curtain plus Laminated Glazing
`
`Total (in millions)
` $583
` $583
`$1,494
`
`
`Incremental Costs
`Cost (in 2007 economics)
`Per Average Vehicle
`$34
`$34
`$88
`
`

`

`
`
` E- 7
`
`
`The estimated benefits from the ejection mitigation systems considered show that the partial
`
`curtain plus laminated glazing system would result in most benefits (494 lives saved) followed
`
`by the full curtain and the partial curtain. However, the curtain plus glazing system would be the
`
`most costly system ($1,494 million) followed by the full curtains. When the comprehensive
`
`saving (for preventing a statistical life) was considered, the net benefit analysis showed that the
`
`full curtain would result in the lowest cost per equivalent life saved and the highest net benefits.
`
`

`

`
`
` I- 1
`
`I. INTRODUCTION
`
`General: As a crash type, rollovers are second only to frontal crashes in the annual number of
`
`fatalities in light vehicles. Figure I-1 shows the distribution of fatalities by crash type from 1992
`
`to 2004 in the Fatal Analysis Reporting System (FARS). Although frontal crash fatalities have
`
`remained fairly steady at around 12,000 per year, going back to 1992, rollover fatalities have be
`
`steadily increasing from 8,600 in 1992 to 10,600 in 2004. In 2004, 33% of fatalities were in
`
`rollover crashes.
`
`Fatalities by Crash Type
`
`Rear Planar
`Side Planar
`Frontal Planar
`Rollover
`
`35,000
`
`30,000
`
`25,000
`
`20,000
`
`15,000
`
`10,000
`
`5,000
`
`0
`
`Occupants Killed
`
`1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
`Year
`
`
`
`Figure I-1 Fatalities by Crash Type – 1992 to 2004 FARS
`
`The National Automotive Sampling System (NASS) General Estimates System (GES) can be
`
`used to determine the frequency of particular crash types as documented by police accident
`
`reports (PARs). Dividing the number of fatalities in each crash type by the frequency of the
`
`

`

`
`
` I- 2
`
`crash type gives a measure of the relative risk of fatality for each crash type. Figure I-2
`
`graphically represents this relative risk. This data clearly shows the deadly nature of rollover
`
`crashes. An occupant is 14 times more likely to be killed in a rollover than in a frontal crash.
`
`Fatality Risk per 1000 Occupants Exposed to Each Crash Type
`(Avg. 1992 - 2004)
`
`25.9
`
`1.9
`
`1.8
`
`0.3
`
`30.0
`
`25.0
`
`20.0
`
`15.0
`
`10.0
`
`5.0
`
`0.0
`
`Occupants Killed per 1000 Exposee
`
`Rollover
`
`Rear Planar
`
`Frontal Planar
`
`Side Planar
`
`
`Figure I-2 Fatality Risk per 1000 Occupants Exposed to Each Crash Type (Avg. 1992 – 2004
`FARS)
`As stated above, rollover fatalities have been increasing for many years, with the number in 2004
`
`about 2,000 more than in 1992. The main reason for this has been an increase in rollover
`
`fatalities in the sport utility vehicle (SUV) segment. Figure I-3 shows the rollover fatalities by
`
`vehicle type, over time. There were approximately 800 SUV rollover fatalities in 1992 as
`
`compared to approximately 2,900 in 2004. So, the increase in SUV rollover fatalities accounts
`
`for the overall increase in rollover fatalities.
`
`
`
`
`
`

`

`
`
` I- 3
`
`Rollover Fatality by Vehicle Type
`
`Utility
`Pickup
`Van
`Car
`
`
`
`1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
`Year
`
`12,000
`
`10,000
`
`8,000
`
`6,000
`
`4,000
`
`2,000
`
`0
`
`Occupants Killed
`
`Figure I-3 Rollover Fatalities by Vehicle Type- 1992 to 2004 FARS
`
`Using FARS data shown in Figure I-4 we see that over the last 13 reporting years about half of
`
`the occupants killed in rollovers are completely ejected from the vehicle. Note that in this graph
`
`the FARS data lumps partially ejected and un-ejected occupants together. This is because
`
`partially ejection is sometimes difficult to determine and we do not expect the PAR generated
`
`FARS data to have an accurate representation of partially ejected occupant fatalities.
`
`

`

`
`
` I- 4
`
`Rollover Fatalities by Ejection Status
`
`No or Partial Ejection
`Total Ejection
`
`12,000
`
`10,000
`
`8,000
`
`6,000
`
`4,000
`
`2,000
`
`Occupants Killed
`
`0
`1992
`
`1993
`
`1994
`
`1995
`
`1996
`
`1997
`
`1999
`1998
`Years
`
`2000
`
`2001
`
`2002
`
`2003
`
`2004
`
`
`
`Figure I-4 Rollover Fatalities by Ejection Status-1992 to 2004 FARS
`
`The FARS data in Figure I-4 can be used in conjunction with NASS GES data to determine the
`
`relative risk of being killed in a rollover as a function of whether or not the occupant is fully
`
`ejected. Figure I-5 shows this risk averaged over the period of 1992 to 2004. There are 317
`
`fully ejected occupants killed for every 1,000 fully ejected occupants in rollover crashes or a
`
`32% probability of being killed if fully ejected. By comparison 14 of every 1,000 occupants not
`
`fully ejected are killed in rollover crashes or a 1.4% probability of being killed. Thus, an
`
`occupant is 23 times more likely to be killed if fully ejected. This clearly shows the benefit of
`
`preventing complete ejections in rollovers.
`
`
`
`
`
`
`
`
`
`

`

` I- 5
`
`Fatality Risk per 1000 Rollover Occupants in Each Ejection
`Category (Avg. 1992 - 2004)
`
`316.6
`
`13.7
`
`350.0
`
`300.0
`
`250.0
`
`200.0
`
`150.0
`
`100.0
`
`50.0
`
`0.0
`
`Occupants Killed per 1000
`
`
`
`
`
`Total Ejection
`
`No or Partial Ejection
`
`
`Figure I-5 Fatality Risk per 1000 Rollover Occupants in Each Ejection Category
`(Avg. 1992 – 2004 FARS)
`
`Injuries and Fatalities by Rollover Severity: The majority of occupants exposed to rollover
`
`crashes are in vehicles that roll 2 ¼-turns or less. However, the distribution of ejected occupants
`
`who are seriously injured (maximum abbreviated injury scale (MAIS) 3+) and killed is skewed
`
`towards rollovers with higher degrees of rotation, as shown in Figure I-6. The graph was
`
`generated from NASS CDS data of occupant exposed to a rollover crash from 1988 to 2005. All
`
`rollover crashes were included irrespective of whether it was coded as the most harmful event.
`
`Note that half of all fatal complete ejections occurred in crashes with 5+ ¼-turns.
`
`
`
`
`
`

`

`
`
` I- 6
`
`Cummulative Percentage of Rollover Occupants by Number of
`1/4 Turns and Injury Outcome - 1988 to 2005 NASS CDS
`
`All Rollover Occupants
`Fatal Partial Ejections
`MAIS 3+ Partial Ejections
`Fatal Complete Ejections
`MAIS 3+ Complete Ejections
`
`100%
`
`90%
`
`80%
`
`70%
`
`60%
`
`50%
`
`40%
`
`30%
`
`20%
`
`10%
`
`0%
`
`Cummulative Percentage
`
`1
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`10
`9
`8
`Quarter Turns
`
`11
`
`12
`
`13
`
`14
`
`15
`
`16
`
`17
`
`
`
`Figure I-6 Cumulative Percentage of Rollover Occupants by Number of 1/4 Turns and Injury
`Outcome - 1988 to 2005 NASS CDS
`
`Ejection Routes in All Crashes: In this section, we used annualized injury data from 1997 to
`
`2005 NASS CDS and fatality counts adjusted to 2005 FARS levels to analyze ejection routes.
`
`All unknowns have been distributed and all crash types are included. However, the counts are
`
`restricted to ejection occupants that were injured. In addition, in NASS CDS the ejection route
`
`for side windows is only explicitly coded for the front (Row 1 Window) and rear (Row 2
`
`Window). The third and further rearward side window ejections should be coded as “other
`
`glazing.” This is because there are specific codes available for coding roof glazing, windshield
`
`and backlight. However, when extracting NASS cases of known ejections through “other
`
`glazing,” we observed 17 unweighted occupants. A hard copy review of these cases showed that
`
`9 were known 3rd row side window ejections, but five cases were miscoded. Four were actually
`
`

`

`
`
` I- 7
`
`backlight ejections and one was a sunroof ejection. The known 3rd row ejections were recoded
`
`as “Row 3 Window” ejections.
`
`
`
`Table I-1 shows the MAIS 1-2, MAIS 3+ and fatality distribution of ejected occupants by eight
`
`potential ejection routes. Table I-2 gives the percentage of the total at each injury level.
`
`Ejection through side windows makes up the greatest part of the ejection problem. There are
`
`6,174 fatalities, 5,271 MAIS 3+ injuries, and 18,353 MAIS 1-2 injuries for occupants ejected
`
`through side windows. These make up 61%, 47% and 68% of all ejected fatalities, MAIS 3+
`
`injuries, and MAIS 1-2 injuries, respectively.
`
`Table I-1
`Occupant Injury and Fatality Counts by Ejection Route in All Crash Types
`(Annualized 1997 – 2005 NASS, 2005 FARS)
`Ejection Route
`MAIS 1-2 MAIS 3+ Fatal
`Row 1 Window
`15,797
`4,607
`5,209
`Row 2 Window
`2,533
`621
`906
`Row 3 Window
`23
`43
`59
`Windshield
`1,923
`1,565
`1,155
`Backlight
`1,625
`1,677
`515
`Sun Roof
`1,127
`305
`237
`Other Window
`1
`51
`0
`Not Window
`3,870
`2,411
`2,068
`
`All Side Windows
`Total
`
`6,174
`5,271
`11,280 10,149
`
`18,353
`26,899
`
`
`
`
`
`
`
`
`
`
`
`
`
`

`

` I- 8
`
`Table I-2
`Occupant Injury and Fatality Percentages by Ejection Route in All Crash Types
`(Annualized 1997 – 2005 NASS, 2005 FARS)
`Ejection Route
`MAIS 1-2 MAIS 3+ Fatal
`Row 1 Window
`58.7%
`40.8% 51.3%
`Row 2 Window
`9.4%
`5.5%
`8.9%
`Row 3 Window
`0.1%
`0.4%
`0.6%
`Windshield
`7.1%
`13.9% 11.4%
`Backlight
`6.0%
`14.9%
`5.1%
`Sun Roof
`4.2%
`2.7%
`2.3%
`Other Window
`0.0%
`0.5%
`0.0%
`Not Window
`14.4%
`21.4% 20.4%
`
`All Side Windows
`Total
`
`46.7% 60.8%
`68.2%
`100.0% 100.0% 100.0%
`
`
`
`
`
`The crash data show that most of ejections occurred through side window in rollovers. (Note
`
`that some of the rollovers are preceded by side crashes. These side-then-roll crashes were
`
`analyzed separately in the benefit chapter.) There are 4,128 fatalities, 4,095 MAIS 3+ injuries,
`
`and 12,229 MAIS 1-2 injuries for occupants ejected through side windows in rollovers.
`
`Table I-3
`Occupant Injury and Fatality Counts by Ejection Route in Rollovers
`Ejection Route
`MAIS 1-2
`MAIS 3+
`Fatal
`Row 1 Window
`10,618
`3,660
`3,470
`Row 2 Window
`1,589
`421
`620
`Row 3 Window
`22
`14
`38
`total
`12,229
`4,095
`4,128
`
`87%
`13%
`<1%
`100%
`
`
`
`89%
`10%
`1%
`100%
`
`84%
`15%
`1%
`100%
`
`

`

`
`
` I- 9
`
`Proliferation of Vehicles with Rollover Sensors: The availability of vehicles that offer inflatable
`
`side curtains that deploy in a rollover has increased since they first became available (Figure I-7).
`
`For the 2007 model year, rollover sensors are available on approximately 95 models with the
`
`system being standard equipment on about half. Rollover sensors are available predominantly on
`
`Vehicle Models With Rollover Sensors
`
`Optional
`Standard
`
`SUVs.
`
`70
`
`60
`
`50
`
`40
`
`30
`
`20
`
`10
`
`0
`
`Model Count
`
`2002
`
`2003
`
`2004
`
`2005
`
`2006
`
`2007
`
`Model Year
`
`
`
`
`
`Figure I-7 Vehicles with Rollover Sensors
`
`Current State and Future Direction of Ejection Countermeasures: The first generation of roof
`
`mounted inflatable curtain air bags were introduced in the U.S. in the late 1990s (1998 Volvo
`
`S80, Figure I-8). These inflatable curtains were designed to deploy in the event of a side impact
`
`crash to reduce the chance of head injury. During the 2002 MY, Ford introduced the first
`
`generation of side curtain air bag that were designed to deploy in the event of a rollover crash
`
`

`

`
`
` I- 10
`
`(Figure I-9). Ford introduced this rollover air bag curtain system as an option on the Explorer
`
`and Mercury Mountaineer and marketed it as the “Safety Canopy.”
`
`
`
`There are three important design differences between air bag curtains designed for rollover
`
`ejection mitigation as opposed to side impact protection. The first difference is longer inflation
`
`duration. The portion of a side impact crash when the air bag curtain can provide protection is
`
`less than a 0.1 seconds. By contrast, rollover with multiple full vehicle rotations can last many
`
`seconds. Ford claims that their “Safety Canopy” stay inflated for six seconds. GM claims that
`
`their side curtain air bags designed for rollover protection maintain 80% inflation pressure for 5
`
`seconds. The side curtains on the 2005 and later Honda Odyssey stay inflated for 3 seconds.
`
`Figure I-8 1999 Volvo S80
`
`
`
`

`

`
`
` I- 11
`
`
`
`
`Figure I-9 2002 Ford Explorer/Mercury Mountaineer
`The second important air bag curtain design difference between side impact and rollover
`
`protection is the size or coverage of the air bag curtain. GM claims that their curtains designed
`
`for rollover protection are larger than non-rollover curtains. One of the most obvious trends in
`
`newer vehicles is the increasing area of coverage for rollover curtains. Third, the rollover
`
`curtain must be tethered tightly the lower part of the air bag to vehicles’ A- and C-pillars.
`
`
`
`Figure I-10 shows the side curtain for the 2006 Ford Expedition/Navigator. For the 2003 to 2006
`
`models this was optional on the Expedition and standard on the Navigator. It is not much
`
`different from that of the original 2002 Explorer/Mountaineer. Ford claimed that these systems
`
`covered two-thirds to 80% of the first two rows of windows. Compare this to the 2007 Ford
`
`Expedition/Navigator system shown in Figure I-11, the coverage is much more complete in the
`
`new vehicles and extends to the third row. However, it still appears as if the second rollover
`
`curtain does not extend to the sill. The 2007 Chevrolet Tahoe has extensive coverage as well
`
`(Figure I-12).
`
`

`

`
`
`
`
` I- 12
`
`Figure I-10 2006 Ford Expedition/Navigator
`
`
`
`Figure I-11 2007 Ford Expedition/Navigator
`
`
`
`

`

`
`
`
`
`
`
` I- 13
`
`Figure I-12 2007 Chevrolet Tahoe
`
`
`
`In the minivan vehicle category, the Honda Odyssey has been offering standard rollover
`
`protection with full three rows of coverage since 2005. Figure I-13 shows the second and third
`
`occupant seating rows. Note that the lower edge of the curtain extends beyond the sill. Figure I-
`
`14 shows the three row coverage of the standard equipment rollover curtain in the 2006 Mercury
`
`Monterey.
`
`
`
`

`

`
`
`
`
` I- 14
`1-14
`
`
`
`
`
`Figure I-13 2005 Honda Odyssey
`Figure 1-13 2005 Honda Odyssey
`
`

`

`
`
` II- 1
`
`II BACKGROUND
`
`Previous Agency Efforts on Rollover Mitigation:
`
`NHTSA has been active in rollover8 crash rulemaking and research for 30 years. The NHTSA
`
`Authorization Act of 1991 (part of the Intermodal Surface Transportation Efficiency Act)
`
`required the agency to address several vehicle safety subjects through rulemaking, including
`
`protection against unreasonable risk of rollovers of passenger cars and light trucks. In January
`
`1992, NHTSA published an ANPRM and a Technical Assessment Paper (57 FR 242). The
`
`ANPRM soliciting information concerning rollover crashes, to assist the agency in planning a
`
`course of action on several rulemaking alternatives, supplementing the ANPRM. The Technical
`
`Assessment Paper discussed testing activities, testing results, crash data collection, and analysis
`
`of the data.
`
`
`
`
`
`During the development of the ANPRM and after receiving and analyzing comments to the
`
`ANPRM, it became obvious that no single type of rulemaking could solve all, or even a majority
`
`of, the problems associated with rollover. Subsequently, a Rulemaking Plan titled "Planning
`
`Document for Rollover Prevention and Injury Mitigation Docket 91-68 No. 1" was published for
`
`public review on September 29, 1992, (57 FR 44721). The Planning Document gave an
`
`overview of the rollover problem and a list of alternative actions that NHTSA was examining to
`
`address the problem. Activities described in that document were:
`
`1) Crash avoidance research on vehicle measures for rollover resistance;
`
`2) Research on antilock brake effectiveness;
`
`
`8 As used in this document rollover refers to a lateral rollover or a vehicle rotation about its longitudinal axis.
`
`
`

`

`
`
` II- 2
`
`3) Rulemaking on upper interior padding to prevent head injury;
`
`4) Research into improved roof crush resistance to prevent head and spinal injury;
`
`5) Research on improved side window glazing and door latches to prevent occupant
`
`ejection; and
`
`6) Consumer information to alert people to the severity of rollover crashes and the
`
`benefits of safety belt use in this type of crash.
`
`In 1994, NHTSA terminated rulemaking to establish a minimum standard. In May 1996,
`
`NHTSA issued the “Status Report for Rollover Prevention and Injury Mitigation.” This
`
`document updated the progress of the programs discussed in the Planning Document.
`
`
`
`
`
`Side Window Area Ejection Mitigation by Glazing Use:
`
`NHTSA published two ANPRMs in 1988 announcing that the agency was considering the
`
`proposal of requirements for passenger vehicles intended to reduce the risk of ejections in
`
`crashes where the side protection of the vehicle was a relevant factor. One notice (53 FR 31712)
`
`dealt with passenger cars. The other notice (53 FR 31716) dealt with light trucks.
`
`
`
`
`
`The agency reported at the time, based on the 1982-1985 Fatality Analysis Reporting System
`
`(FARS), each year 19.5 percent of the occupant fatalities were the result of complete ejection
`
`through glazing and 4.3 percent were the result of partial ejection through glazing. Data
`
`presented indicated that a large percentage of these ejections were through the side windows and
`
`that ejected occupants were at greater risk of fatality or serious injury.
`
`
`
`

`

`
`
` II- 3
`
`NHTSA believed that new side window designs, incorporating different glazing/frames, had the
`
`potential to reduce the risk of ejections. At that time, NHTSA suggested that one performance
`
`approach would be to use an 18 kg (40 lb) glazing impact device, requiring that it not penetrate
`
`the plastic layer of a side window at 32 km/h (20 mph), an estimated typical contact speed.
`
`Numerous comments were received on the 1988 ANPRM. Major issues were raised concerning
`
`the proposal, primarily