DOT HS 809 833 October 2004

Technical Report

Lives Saved by the Federal Motor Vehicle

Safety Standards and Other Vehicle Safety

Technologies, 1960-2002

Passenger Cars and Light Trucks

With a Review of 19 FMVSS and their Effectiveness in

Reducing Fatalities, Injuries and Crashes

This document is available to the public from the National Technical Information Service, Springfield, Virginia 22161
The United States Government does not endorse products or 

manufacturers. Trade or manufacturers’ names appear only 

because they are considered essential to the object of this report. 
 Technical Report Documentation Page 

1. Report No. 

DOT HS 809 833

2. Government Accession No. 3. Recipient’s Catalog No. 

5. Report Date 

October 2004

4. Title and Subtitle 

Lives Saved by the Federal Motor Vehicle Safety Standards and 

Other Vehicle Safety Technologies, 1960-2002 – Passenger Cars and 

Light Trucks – With a Review of 19 FMVSS and their Effectiveness 

in Reducing Fatalities, Injuries and Crashes

6. Performing Organization Code 

7. Author(s) 

Charles J. Kahane, Ph.D.

8. Performing Organization Report No. 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

Evaluation Division; National Center for Statistics and Analysis 

National Highway Traffic Safety Administration 

Washington, DC 20590

11. Contract or Grant No. 

13. Type of Report and Period Covered 

NHTSA Technical Report

12. Sponsoring Agency Name and Address 

Department of Transportation 

National Highway Traffic Safety Administration 

Washington, DC 20590

14. Sponsoring Agency Code 

15. Supplementary Notes 

 

16. Abstract 

The National Highway Traffic Safety Administration (NHTSA) began to evaluate its Federal Motor 

Vehicle Safety Standards (FMVSS) in 1975. By October 2004, NHTSA had evaluated the effectiveness 

of virtually all the life-saving technologies introduced in passenger cars, pickup trucks, sport utility 

vehicles and vans from about 1960 up through the later 1990’s. A statistical model estimates the number 

of lives saved from 1960 to 2002 by the combination of these life-saving technologies. Fatality Analysis 

Reporting System (FARS) data for 1975-2002 document the actual crash fatalities in vehicles that, 

especially in recent years, include many safety technologies. Using NHTSA’s published effectiveness 

estimates, the model estimates how many people would have died if the vehicles had not been equipped 

with any of the safety technologies. In addition to equipment meeting specific FMVSS, the model tallies 

lives saved by installations in advance of the FMVSS, back to 1960, and by non-compulsory 

improvements, such as the redesign of mid and lower instrument panels. FARS data have been available 

since 1975, but an extension of the model allows estimates of lives saved in 1960-1974. 

Vehicle safety technologies saved an estimated 328,551 lives from 1960 through 2002. The annual 

number of lives saved grew quite steadily from 115 in 1960, when a small number of people used lap 

belts, to 24,561 in 2002, when most cars and light trucks were equipped with numerous modern safety 

technologies and belt use on the road achieved 75 percent.

17. Key Words 

FARS; statistical analysis; evaluation; benefits; 

effectiveness; fatality reduction; injury reduction; 

crashworthiness; crash avoidance

18. Distribution Statement 

Document is available to the public through the 

National Technical Information Service, 

Springfield, Virginia 22161

19. Security Classif. (Of this report) 

Unclassified

20. Security Classif. (Of this page) 

Unclassified

21. No. of Pages 

 422

22. Price 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

TABLE OF CONTENTS 

Executive summary.................................................................................................................... ix 

Framework for the analysis..........................................................................................................1 

Basic analysis method..........................................................................................................2 

What is included and what is excluded? ..............................................................................3 

List of FMVSS, safety technologies and effectiveness evaluations....................................4 

Estimating lives saved by safety technologies, 1960-2002 ...............................................12 

Part 1: Review of 19 FMVSS and their effectiveness in reducing fatalities, injuries 

and crashes for passenger cars and light trucks.................................................................15 

103 Windshield defrosting and defogging systems..........................................................17 

Rear window defrosting and defogging systems.......................................................17 

105 Hydraulic and electric brake systems ........................................................................20 

 Dual master cylinders ................................................................................................20 

 Front disc brakes........................................................................................................23 

 Rear-wheel antilock (RWAL) brake systems for light trucks ...................................25 

Four-wheel antilock brake systems (ABS) for passenger cars and light trucks ........27 

Electronic stability control (ESC) systems (preliminary evaluation) ........................31 

108 Lamps, reflective devices, and associated equipment ...............................................34 

 Side marker lamps......................................................................................................34 

Center High Mounted Stop Lamps (CHMSL)...........................................................37 

Retroreflective tape on heavy trailers........................................................................41 

201 Occupant protection in interior impact ......................................................................46 

Redesign of mid and lower instrument panels with improved occupant protection..46 

 Head injury protection upgrade (not yet evaluated) ..................................................51 

Head air bags (not yet evaluated)...............................................................................52 

 202 Head restraints ...........................................................................................................53 

Head restraints for front-outboard seats.....................................................................53 

203 Impact protection for the driver from the steering control system ............................59 

204 Steering control rearward displacement 

 Energy-absorbing and telescoping steering assembly ...............................................59 

205 Glazing materials.......................................................................................................65 

High-Penetration Resistant (HPR) windshields.........................................................65 

 Glass-plastic windshields...........................................................................................68 

206 Door locks and door retention components...............................................................70 

Stronger locks, latches and hinges for side doors......................................................70 

iii
207 Seating systems..........................................................................................................73

Seatback locks for 2-door cars with folding front seatbacks.....................................73 

208 Occupant crash protection..........................................................................................77 

209 Seat belt assemblies 

210 Seat belt assembly anchorages 

Lap belts for front-seat occupants..............................................................................80 

Lap belts for back-seat occupants..............................................................................85 

Manual 3-point lap-shoulder belts for front-seat occupants......................................87 

 3-point lap-shoulder belts for back-seat occupants....................................................98 

Automatic safety belts..............................................................................................101 

Pretensioners and load limiters for safety belts (not yet evaluated) ........................103 

 Frontal air bags ........................................................................................................104 

On-off switches for passenger air bags in pickup trucks.........................................115 

1998-99 redesign of air bags (not yet evaluated).....................................................118 

Advanced air bags (not yet evaluated).....................................................................118 

212 Windshield mounting...............................................................................................120 

Adhesive windshield bonding..................................................................................120 

213 Child restraint systems.............................................................................................125 

225 Child restraint anchorage systems 

 Child safety seats.....................................................................................................125 

Upper tethers and anchorages (not yet evaluated)...................................................131 

LATCH (lower anchors and tethers for children – not yet evaluated) ....................131 

Riding in the back seat.............................................................................................132 

214 Side impact protection .............................................................................................136 

Side door beams.......................................................................................................136 

Voluntary (pre-1994) TTI(d) improvements in 2-door cars....................................140 

Dynamic test standard, passenger cars (not yet evaluated)......................................143 

Side air bags (not yet evaluated)..............................................................................144 

216 Roof crush resistance ...............................................................................................145 

Redesign of true hardtops as pillared hardtops or sedans........................................145 

301 Fuel system integrity................................................................................................149 

1975-77 upgrade: rollover, rear-impact and lateral-impact tests.............................149 

NCAP New Car Assessment Program............................................................................153 

Frontal NCAP-related improvements in cars without air bags................................153 

Frontal NCAP in vehicles with air bags (not yet evaluated) ...................................156 

Side NCAP (not yet evaluated)................................................................................157 

 Rollover-resistance NCAP (not yet evaluated)........................................................157 

Summary tables for Part 1................................................................................................158 

Table 1-2: Estimates of fatality-reducing effectiveness..........................................159 

Table 1-3: Estimates of injury-reducing effectiveness and benefits.......................164 

Table 1-4: Estimates of crash-avoidance effectiveness and benefits......................170 

iv
Part 2: Lives saved by the FMVSS and other vehicle safety technologies, 1960-2002 .........173 

Summary of the estimation method .................................................................................173 

Findings............................................................................................................................185 

Estimate of lives saved.............................................................................................185 

Net effectiveness for car/LTV occupants ................................................................187 

Car/LTV occupant fatalities per 100,000,000 VMT................................................194 

Estimates of lives saved by each FMVSS................................................................197 

Benefits for occupants of passenger cars.................................................................204 

Benefits for occupants of LTVs...............................................................................227 

Benefits for pedestrians, bicyclists and other non-occupants..................................244 

Benefits for motorcyclists........................................................................................244 

Effect of air bags by seat position, occupant age and on-off switch availability.....249 

References................................................................................................................................257 

Appendix A: SAS programs used to estimate lives saved by the FMVSS and 

other vehicle safety technologies, 1960-2002..................................................................277 

 Overview..........................................................................................................................277 

Description of the main analysis program LS2004..........................................................281 

Description of the postprocessor program OLDFA24.....................................................357

Appendix B: Summaries of published evaluation reports ......................................................397

v
LIST OF ABBREVIATIONS 

ABS Antilock brake system

ACIR Automotive Crash Injury Research, a crash data file of the 1950’s and 60’s 

ACTS Automotive Coalition for Traffic Safety (before 1999, American Coalition for 

Traffic Safety) 

AIS Abbreviated Injury Scale

AMC American Motors Corporation 

ANPRM Advance Notice of Proposed Rulemaking 

ANSI American National Standards Institute 

BMW Bayerische Motoren Werke 

CATMOD Categorical models procedure in SAS 

CHMSL Center high mounted stop lamp

CRASH Calspan reconstruction of accident speeds on the highway 

CY Calendar year 

DMV Department of Motor Vehicles 

ESC Electronic stability control 

FARS Fatality Analysis Reporting System (a census of fatal crashes in the United States 

since 1975) 

FHWA Federal Highway Administration 

FMCSA Federal Motor Carrier Safety Administration 

FMH Free-Motion Headform for testing upper interior components 

FMVSS Federal Motor Vehicle Safety Standard 

GM General Motors 

vi
GSA General Services Administration of the Federal government 

GVWR Gross Vehicle Weight Rating (specified by the manufacturer, equals the vehicle’s 

curb weight plus maximum recommended loading) 

HIC Head Injury Criterion 

HPR High penetration resistant windshield 

HSL Highway Safety Literature, an on-line literature database that is a subfile of the 

automated Transportation Research Information Service (TRIS) file, accessible at 

http://199.79.179.82/sundev/search.cfm

IIHS Insurance Institute for Highway Safety 

LATCH Lower anchors and tethers for children 

LTV Light trucks and vans (includes pickup trucks, SUVs, minivans and full-sized 

vans) 

MCOD Multiple Cause of Death file, a supplement to FARS in 1987-98, listing causes of 

death from the occupant’s death certificate 

MDAI Multidisciplinary Accident Investigations (a file of in-depth crash investigations 

conducted by NHTSA and others, 1967-78) 

MDB Moving deformable barrier 

mph Miles per hour 

MVMA2D Motor Vehicle Manufacturers’ Association’s 2-dimensional computer simulation 

of the occupant’s motion in a frontal crash 

MY Model year 

NASS National Automotive Sampling System (a probability sample of police-reported 

crashes in the United States since 1979, investigated in detail) 

NCAP New Car Assessment Program (consumer information supplied by NHTSA on the 

safety of new cars and LTVs, based on test results, since 1979) 

NCSA National Center for Statistics and Analysis, NHTSA 

NCSS National Crash Severity Study (a probability sample of police-reported towaway 

crashes in seven multi-county areas, 1977-79, investigated in detail) 

vii
NHTSA National Highway Traffic Safety Administration 

NOPUS National Occupant Protection Use Survey (statistics for the United States, since 

1994, from a national observational survey based on a probability sample) 

NPRM Notice of Proposed Rulemaking 

NTSB National Transportation Safety Board 

RF Right-front 

RSEP Restraint Systems Evaluation Project (a probability sample of police-reported 

towaway crashes involvements of model year 1973-75 cars in five urban or multicounty areas, 1974-75, investigated in detail) 

RWAL Rear-wheel antilock brake system

SAE Society of Automotive Engineers 

SAS Statistical analysis software produced by SAS Institute, Inc.

SCI Special Crash Investigations, NHTSA National Center for Statistics and Analysis 

SID Side impact dummy 

SSF Static stability factor (Half of the vehicle’s track width divided by the height of its 

center of gravity) 

SUV Sport utility vehicle 

TTI Thoracic Trauma Index 

TTI(d) Thoracic Trauma Index for the dummy in a side-impact test 

UMTRI University of Michigan Transportation Research Institute 

VIN Vehicle Identification Number 

VMT Vehicle Miles of Travel 

VW Volkswagen 

viii
EXECUTIVE SUMMARY 

The National Highway Traffic Safety Administration (NHTSA) began to evaluate the 

effectiveness of its Federal Motor Vehicle Safety Standards (FMVSS) in 1975. By October 

2004, NHTSA had evaluated virtually all the life-saving technologies introduced in passenger 

cars and in LTVs (light trucks and vans – i.e., pickup trucks, sport utility vehicles, minivans and 

full-size vans) from about 1960 up through the later 1990’s. The agency is now ready to 

estimate the number of lives saved from 1960 to 2002, year-by-year, by the combination of all 

these life-saving technologies, and by each individual technology. 

Past evaluation reports estimated the effectiveness of a safety technology – a percentage 

reduction of fatalities – by statistically analyzing crash data on vehicles produced just before vs. 

just after a make-model received that technology. Effectiveness, if accurately estimated, should 

not change much over time. But the benefits of a technology – the absolute number of lives 

saved in a year – readily change from year to year depending on the number of vehicles equipped 

with the technology, their mileage and the crash-involvement rate of the driving population 

(exposure). This report will: 

• Review the effectiveness estimates in past evaluations of safety technologies for cars and 

LTVs, describing how they work, and the history of the FMVSS that regulate them. 

• Develop a model that uses Fatality Analysis Reporting System (FARS) data and these 

past effectiveness estimates to calculate how many lives the following technologies have 

saved, individually and in combination, in each year from 1960 to 2002: 

Heavy

FMVSS: Safety Technologies Cars LTVs Trucks 

105: Dual master cylinders & front disc brakes1

 X X 

108: Conspicuity tape for heavy trailers X2

(201) Voluntary mid/lower instrument panel improvements X X 

203/204: Energy-absorbing steering assemblies X X 

206: Improved door locks X X 

208: Lap belts X X 

 3-point belts X X 

 2-point automatic belts X 

Voluntary NCAP-related improvements for belted occs. X 

 Frontal air bags X X 

212: Adhesive windshield bonding X X 

213: Child safety seats X X 

214: Side door beams X X 

Voluntary (pre-1994) side impact protection in 2-door cars X 

216: Roof crush strength (eliminate true hardtops) X 

 

1

 Applied to cars and LTVs, but also saves pedestrians, bicyclists and motorcyclists not hit by these cars and LTVs. 2

 Applied to heavy trailers, but also saves occupants of cars and LTVs that avoid collisions with these trailers. 

ix
In addition to safety equipment installed to meet specific FMVSS, the model tallies lives saved 

by installations in advance of the FMVSS, and by non-compulsory improvements, as shown in 

the preceding list, such as the redesign of mid and lower instrument panels and modifications to 

improve performance on the New Car Assessment Program. The model includes car/LTV 

occupants saved by car/LTV technologies or child safety seats (99 percent of the total), plus 

pedestrians/bicyclists/ motorcyclists saved by car/LTV brake improvements, and car/LTV 

occupants saved by conspicuity tape on heavy trailers. 

The model does not include technologies so recent that NHTSA has not yet evaluated them

based on statistical analysis of crash data, such as the dynamic-test standard for side impact 

protection (1994-97 phase-in), or head air bags. The study is limited to technologies in cars and 

LTVs, or that save lives of car/LTV occupants; for example, motorcycle helmets are not 

included. It is limited to vehicle technologies. It does not estimate the effects of behavioral 

safety programs (such as the reduction of impaired driving) – except, of course, to the extent that 

programs to increase belt use have contributed greatly to the number of lives saved by belts; 

roadway and traffic engineering improvements; and shifts in the vehicle fleet – e.g., from large to 

small cars, or from cars to LTVs. The model is limited to estimating fatality reduction by the 

safety technologies: NHTSA does not have enough “building blocks” (evaluation results) to 

develop estimates for the numbers of nonfatal injuries prevented over the years. 

How the model works Consider 1,000 cases of driver fatalities in directly frontal multivehicle 

crashes in cars with 1960 technology: no energy-absorbing steering columns, all drivers 

unbelted, no air bags. A NHTSA evaluation estimates that energy-absorbing columns reduce 

fatalities of drivers in frontal crashes by 12.1 percent. Thus, if these cars had been equipped with 

them, there would have been only 879 fatalities, a saving of 121 lives. Another evaluation 

estimates that 3-point belts, in cars with energy-absorbing columns, reduce drivers’ fatality risk 

by 42 percent in these types of crashes. If the cars had been equipped with 3-point belts in 

addition to energy-absorbing columns, and the drivers had buckled up, the 879 fatalities would 

have diminished to 510, saving another 369 lives. A third evaluation estimates that air bags 

reduce fatality risk by 25.3 percent for belted drivers in these types of crashes, in cars with 

energy-absorbing columns. Air bags would have cut the 510 fatalities down to 381, saving 

another 129 lives. 

The model uses 1975-2002 FARS data and performs the same calculations in reverse order: e.g., 

there might be 381 actual FARS cases of 3-point-belted driver fatalities in directly frontal 

multivehicle crashes in model year 1999 cars, all of which are equipped with air bags and 

energy-absorbing columns. If air bags, the most recent (1990’s) safety technology, had been 

removed from the cars, fatalities would have increased to 510. In other words, there must have 

been 129 potentially fatal collisions in these model year 1999 cars that did not become FARS 

cases because air bags saved the driver’s life. If the 3-point belts, a 1970’s technology, had also 

been removed from the cars, and the drivers had been unbelted, the fatalities would have 

increased to 879. Finally, if the energy-absorbing columns, a 1960’s technology, had been 

replaced by rigid columns, degrading these cars all the way back to a 1960 level of safety, 

fatalities would have increased to 1,000. The three technologies, in combination, saved 619 

lives: 129 by air bags, 369 by 3-point belts and 121 by energy-absorbing columns. In summary, 

FARS cases of fatalities in vehicles equipped with modern safety technologies constitute 

x
evidence of an even larger number of fatalities that would have occurred without those 

technologies. This approach, based on “reverse chronological order” is not the only one that 

could have been used in the model; however, alternative approaches would have generated the 

same estimate of overall lives saved in 1960-2002, differing only in how they allocated that total 

among the individual safety technologies. 

FARS data have been available since 1975, but the FMVSS date back to January 1, 1968, and 

some technologies were introduced before that. An extension of the model allows estimates of 

lives saved in 1960-1974. 

Lives saved in 1960-2002 Safety technologies saved an estimated 328,551 lives from 1960 

through 2002. Table 1 shows that the annual number of lives saved grew quite steadily from 115 

in 1960, when a small number of people used lap belts, to 24,561 in 2002, when most cars and 

LTVs were equipped with numerous modern safety technologies and belt use on the road 

achieved 75 percent. (Safety belt use continued to increase after 2002, and reached 80 percent in 

2004.) 

Figure 1 tracks the benefits of vehicle safety technologies. Fewer than 1,000 lives per year were 

saved in 1960-67. Starting in 1968, vehicles incorporating most of the safety improvements of 

the 1960’s superseded older vehicles; lives saved reached 4,000 in 1978, but remained at that 

level for 6 years as belt use temporarily declined. The greatest increase, from 4,835 in 1984 to 

11,265 in 1988, came with buckle-up laws. Since 1988, continued increases in belt use, air bags 

and other recent technologies, and a steadily escalating “base” of more vehicles and more VMT 

(vehicle miles of travel) have helped the fatality reduction grow steadily, exceeding 15,000 in 

1994 and 20,000 in 2000, reaching 24,561 in 2002. 

xi
TABLE 1: LIVES SAVED BY VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

(Car and LTV occupants saved, 

plus non-occupants and motorcyclists saved by car/LTV brake improvements) 

 LIVES 

 CY SAVED 

 1960 115 

 1961 117 

 1962 135 

 1963 160 

 1964 203 

 1965 251 

 1966 339 

 1967 509 

 1968 816 

 1969 1,179 

 1970 1,447 

 1971 1,774 

 1972 2,226 

 1973 2,576 

 1974 2,518 

 1975 3,058 

 1976 3,240 

 1977 3,671 

 1978 4,040 

 1979 4,299 

 1980 4,539 

 1981 4,455 

 1982 4,057 

 1983 4,248 

 1984 4,835 

 1985 6,389 

 1986 8,523 

 1987 9,973 

 1988 11,265 

 1989 11,487 

 1990 11,711 

 1991 12,194 

 1992 12,483 

 1993 13,796 

 1994 15,154 

 1995 16,117 

 1996 17,813 

 1997 18,560 

 1998 19,380 

 1999 19,942 

 2000 21,789 

 2001 22,605 

 2002 24,561 

 =========== 

 328,551 

xii
FIGURE 1: LIVES SAVED BY VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

 ‚ 

25000 ˆ 

 ‚ belt use O 

 ‚ keeps 

 ‚ increasing O 

 ‚ O 

 ‚ + air bags 

 ‚ 

20000 ˆ + more vehicles O 

 ‚ and VMT O 

 ‚ O 

 ‚ O 

 ‚ 

 ‚ O 

 ‚ 

15000 ˆ O 

 ‚ 

 ‚ O 

 ‚ 

 ‚ O O 

 ‚ O O O 

 ‚ 

10000 ˆ O BUCKLE 

 ‚ 

 ‚ O UP 

 ‚ 

 ‚ LAWS 

 ‚ O 

 ‚ 

 5000 ˆ O 

 ‚ energy O O O O O O 

 ‚ crisis O O declining belt use 

 ‚ O O O 

 ‚ O early non-belt 

 ‚ O O O technologies phase in 

 ‚ O O 

 0 ˆO O O O O O O 

 ______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

xiii
Car/LTV occupants: actual fatalities, potential fatalities and percent saved Among the 328,551 

lives saved in 1960-2002, 326,371 were occupants of cars and LTVs. (The remaining 2,180 

were pedestrians, bicyclists and motorcyclists who avoided fatal impacts by cars or LTVs 

because dual master cylinders or front disc brakes improved the car or LTV’s braking 

performance.) The sum of the actual fatalities and the lives saved is the number of fatalities that 

potentially would have happened if cars and LTVs still had 1960 safety technology and nobody 

used safety belts. Table 2 shows 1,443,030 actual car/LTV occupant fatalities in 1960-2002; 

without the 326,371 lives saved, there would have been 1,796,401 potential fatalities. Actual car 

and LTV occupant fatalities only increased from 28,183 in 1960 to 32,737 in 2002. Without the 

vehicle safety technologies and increases in belt use, they would have more than doubled, from

28,298 in 1960 to 57,242 in 2002. 

Figure 2 compares the trends in actual and potential fatalities. Up to the early 1980’s, both trend 

lines were fairly close together, and both moved up or down in response to baby boomers 

starting to drive (1960’s), energy crisis (1970’s) and recession (early 1980’s). From the mid 

1980’s, vehicle safety made a big difference. Potential fatalities kept rising as registered vehicles 

and VMT increased in an affluent society. But increased belt use, air bags and other vehicle 

safety technologies held the line on actual fatalities at about 32,000 a year. 

The overall, combined effectiveness of the vehicle safety technologies is the percent of potential 

fatalities that were saved, as shown in the right column of Table 2. The effectiveness grew in 

every year from 1960 to 2002, from a humble 0.40 percent in 1960 to a very substantial 42.81 

percent fatality reduction in 2002. Figure 3 charts the trend, showing: 

• Not much effect before the FMVSS. 

• Steady growth in the early-to-mid 1970’s as the early FMVSS phased in. 

• A slowdown in 1978-82, when belt use declined prior to national buckle-up campaigns. 

• The largest gains came with the buckle-up laws in the mid-to-late 1980’s. 

• Steady progress since the late 1980’s thanks to continued increases in belt use, air bags 

and other recent FMVSS. 

xiv
TABLE 2: ACTUAL OCCUPANT FATALITIES, POTENTIAL FATALITIES WITHOUT 

THE VEHICLE SAFETY TECHNOLOGIES, AND LIVES SAVED IN CARS/LTVs 

 CAR+LTV OCCUPANT FATALITIES 

 W/O SAFETY LIVES PERCENT 

 CY ACTUAL TECHS. SAVED SAVED 

1960 28,183 28,298 115 0.40 

1961 28,087 28,204 117 0.41 

1962 30,544 30,679 135 0.44 

1963 32,664 32,823 159 0.49 

1964 35,603 35,805 202 0.56 

1965 36,518 36,767 249 0.68 

1966 39,130 39,465 334 0.85 

1967 39,327 39,826 499 1.25 

1968 41,019 41,818 799 1.91 

1969 42,117 43,273 1,156 2.67 

1970 39,556 40,972 1,415 3.45 

1971 38,916 40,651 1,735 4.27 

1972 40,103 42,281 2,178 5.15 

1973 38,739 41,258 2,520 6.11 

1974 31,145 33,608 2,463 7.33 

1975 31,361 34,355 2,995 8.72 

1976 32,222 35,398 3,176 8.97 

1977 33,173 36,772 3,599 9.79 

1978 34,988 38,951 3,964 10.18 

1979 35,108 39,325 4,217 10.72 

1980 35,097 39,554 4,456 11.27 

1981 33,911 38,284 4,373 11.42 

1982 29,855 33,834 3,979 11.76 

1983 29,209 33,384 4,176 12.51 

1984 30,177 34,935 4,758 13.62 

1985 30,044 36,357 6,314 17.37 

1986 32,380 40,827 8,447 20.69 

1987 33,306 43,203 9,898 22.91 

1988 34,217 45,407 11,190 24.64 

1989 33,709 45,127 11,418 25.30 

1990 32,830 44,470 11,640 26.18 

1991 30,928 43,060 12,131 28.17 

1992 29,542 41,966 12,424 29.60 

1993 30,182 43,917 13,735 31.27 

1994 30,979 46,075 15,096 32.76 

1995 32,057 48,113 16,056 33.37 

1996 32,534 50,289 17,755 35.31 

1997 32,501 51,003 18,502 36.28 

1998 31,940 51,263 19,323 37.69 

1999 32,151 52,038 19,887 38.22 

2000 32,234 53,968 21,734 40.27 

2001 32,009 54,558 22,548 41.33 

2002 32,737 57,242 24,506 42.81 

 =========== =========== =========== 

 1,443,030 1,769,401 326,371 

xv
FIGURE 2: ACTUAL VS. POTENTIAL CAR/LTV OCCUPANT FATALITIES 

(“A” = actual fatalities; “P” = potential fatalities without the vehicle safety technologies) 

 60000 ˆ 

 ‚ 

 ‚ potential P 

 55000 ˆ fatalities P 

 ‚ P 

 ‚ P P P 

 50000 ˆ P keep rising 

 ‚ P 

 ‚ P 

 45000 ˆ P P P 

 ‚ P P P P 

 ‚ A A P P P P 

 40000 ˆ P A A P A P P P FMVSS start to 

 ‚ baby- A A A P P make a big difference 

 ‚ boomers A energy P recession P 

 35000 ˆ start A crisis P P A A A P A 

 ‚ A P A A P P A A A A A A 

 ‚ driving A A A A A A A A A A A 

 30000 ˆ A A A A A A A 

 ‚A A 

 ‚ The FMVSS hold the line! 

 25000 ˆ 

 ‚ 

 ‚ 

 20000 ˆ 

 ‚ 

 ‚ 

 15000 ˆ 

 ‚ 

 ‚ 

 10000 ˆ 

 ‚ 

 ‚ 

 5000 ˆ 

 ‚ 

 ‚ 

 0 ˆ 

 ‚ 

 ______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

xvi
FIGURE 3: PERCENT OF POTENTIAL FATALITIES SAVED BY VEHICLE SAFETY 

TECHNOLOGIES, 1960-2002 

 45 ˆ 

 ‚ 

 ‚ O 

 ‚ more belt use O 

 40 ˆ O 

 ‚ + air bags O 

 ‚ O 

 ‚ O 

 35 ˆ O 

 ‚ O 

 ‚ O 

 ‚ O 

 30 ˆ O 

 ‚ O 

 ‚ 

 ‚ O 

 25 ˆ O O 

 ‚ 

 ‚ O 

 ‚ O 

 20 ˆ 

 ‚ buckle-up 

 ‚ O laws 

 ‚ 

 15 ˆ 

 ‚ O 

 ‚ O 

 ‚ O O O O 

 10 ˆ O O declining belt use 

 ‚ O O 

 ‚ O early 

 ‚ O non-belt 

 5 ˆ O FMVSS 

 ‚ O O phase in 

 ‚ O O 

 ‚ O O O 

 0 ˆO O O O O 

 ‚ 

 ______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

xvii
Estimates of lives saved by each FMVSS Car/LTV safety technologies saved an estimated 

24,561 lives in 2002, comprising 14,175 car occupants, 10,331 LTV occupants and 56 

pedestrians, bicyclists and motorcyclists saved by car/LTV braking improvements. Table 3 

shows how many lives were saved by the individual FMVSS – i.e., by the technologies 

associated with each FMVSS: 

• Safety belts are by far the most important occupant protection, saving an estimated 

14,570 lives3

: over half the total of 24,561. The estimate includes safety belts of all types 

(3-point, lap-only, automatic), at all designated seat positions. Safety belts are designed 

to keep occupants within the vehicle and close to their original seating position, provide 

“ride-down” by gradually decelerating the occupant as the vehicle deforms and absorbs 

energy, and, if possible, prevent occupants from contacting harmful interior surfaces or 

one another (however, NHTSA recommends correctly installed, age-appropriate safety or 

booster seats for child passengers until they are at least 8 years old, unless they are at 

least 4’9" tall). Safety belts are especially important in LTVs, where a large proportion 

of unrestrained fatalities are ejections and/or rollover crashes; belts saved 6,872 lives in 

LTVs, nearly two-thirds of the 10,331 LTV occupants saved. 

• Frontal air bags saved 2,473 lives in 20024

, when 63 percent of cars and LTVs on the 

road were equipped with driver or dual air bags. Benefits can be expected to grow in 

future years as the on-road fleet approaches 100 percent air bag equipped. Air bags have 

significant benefits in frontal and partially frontal impacts for nearly all occupants age 13 

and older, including the oldest drivers and passengers, by providing energy absorption 

and ride-down and by preventing head contacts with the windshield or windshield header. 

Risk from air bags to child passengers age 12 and younger can be eliminated by riding in 

the back seat, correctly restrained – or by turning off the on-off switch in pickup trucks 

where children cannot ride in a back seat correctly restrained. 

• Energy-absorbing steering assemblies meeting FMVSS 203 and 204 are an important 

“built-in” safety technology that saved an estimated 2,657 lives in 2002. In the 1960’s, 

they were the first basic protection for drivers in frontal crashes, designed to cushion their 

impact into the steering assembly. Today, the combination of energy-absorbing columns, 

safety belts and air bags provides far better protection for the driver in frontal crashes. 

• Improvements to door locks, latches and hinges, generally implemented by manufacturers 

in the 1960’s and regulated by industry standards subsequently incorporated into FMVSS 

206, saved 1,398 lives in 2002. They reduce the risk of occupant ejection by keeping 

doors closed in rollover crashes. 

 

3

 NHTSA’s official estimate in Traffic Safety Facts 2002 – Occupant Protection, is 14,164 lives saved by safety 

belts. This report uses slightly different computational procedures as it estimates the lives saved by all vehicle 

safety technologies, not just belts, air bags and safety seats. 4

 NHTSA’s official estimate in Traffic Safety Facts 2002 – Occupant Protection, is 2,248 lives saved by air bags. 

xviii
TABLE 3: ESTIMATES OF LIVES SAVED BY SAFETY TECHNOLOGIES IN 2002 

Pedestrians

FMVSS & Car LTV Bicyclists Safety Technology Occupants Occupants Motorcyclis105: Dual master cylinders & front disc brakes 288 194 56 108: Conspicuity tape for heavy trailers 91 68 201: Voluntary mid/lower instrument panel improvements 631 299 203/204: Energy-absorbing steering assemblies 1,660 997 206: Improved door locks 704 694 208: Safety belts – all types, all seat positions 7,699 6,872 208: Frontal air bags 1,642 831 212: Adhesive windshield bonding 229 118 213: Child safety seats 223 112 214: Side door beams & voluntary (pre-1994) TTI(d) reductions 848 146 216: Roof crush strength (eliminate true hardtops) 161 ______ __ TOTAL 14,175 10,331 56 * NHTSA’s official estimates of lives saved by safety belts (14,164), air bags (2,248) and child restraints (376), published in Traffic SafOccupant Protection, were computed by a similar method. This report’s estimates are not identical; slightly different computational pr

estimate the lives saved by all vehicle safety technologies, not just belts, air bags and safety seats. 

xix
• Side door beams in cars and LTVs meeting the original static crush test of FMVSS 214, 

plus modifications to 2-door cars in anticipation of the dynamic test requirement later 

added to FMVSS 214 saved 994 lives in side impacts. Side door beams are primarily 

effective in side impacts with fixed objects, such as trees or poles. 

• Improvements to mid- and lower instrument panels, not actually required by FMVSS 201 

but historically and functionally associated with that standard to some extent, saved an 

estimated 930 right-front passengers in frontal crashes in 2002. Instrument panels were 

redesigned, using energy-absorbing materials, to decelerate occupants at a safe rate and 

keep them in an upright position during frontal crashes. 

• Car/LTV braking improvements directly or indirectly associated with FMVSS 105 

include dual master cylinders and front disc brakes. By eliminating brake failure or 

helping cars and LTVs stop more effectively, they saved 538 lives in 2002, including 56 

pedestrians, bicyclists or motorcyclists 

• Adhesive windshield bonding saved 347 lives in 2002 by keeping the windshield attached 

to the vehicle in severe impacts and preventing occupant ejection via the windshield 

portal. FMVSS 212 regulates windshield mounting. 

• Child safety seats meeting FMVSS 213 saved an estimated 335 young passengers in 

2002.1

 Child safety seats are the basic protection system for passengers who are too 

small to obtain full benefits from safety belts. Newborns should start with rear-facing 

infant seats, graduate to forward-facing toddler seats, booster seats and, finally, when 

they are at least 9 years old or 4’9” tall, to adult safety belts. 

• FMVSS 216, roof crush strength, is associated with the redesign of true hardtops as 

pillared hardtops or sedans during the 1970’s. True hardtops had no B-pillars to support 

the roof, making it more susceptible to crush in a rollover. If cars were still built that way 

there would have been 161 additional fatalities in 2002. 

• FMVSS 108 requires red-and-white conspicuity tape on heavy truck trailers. The tape

reflects another vehicle’s headlights strongly and it is highly visible in the dark. 

Although this device is furnished on heavy trailers, not cars or LTVs, it is the occupants 

of cars and LTVs who primarily benefit by avoiding collisions with the trailers. The tape 

saved an estimated 159 car and LTV occupants in 2002. 

Table 4 shows cumulative lives saved from 1960 through 2002: 232,255 car occupants and 

94,117 LTV occupants, plus 2,180 pedestrians, bicyclists and motorcyclists saved by car/LTV 

braking improvements, for an estimated total of 328,551. Safety belts (168,524) accounted for 

more than half the total. Air bags, one of the most recent technologies, had saved 12,074 lives 

by the end of 2002, and child safety seats, 5,954. The “built in” non-belt technologies regulated 

by the remaining nine FMVSS in Table 4 (105, 108, 201, 203/204, 206, 212, 214 and 216) add 

 

1

 NHTSA’s official estimate in Traffic Safety Facts 2002 – Occupant Protection, is 376 lives saved by child

restraints. 

xx
TABLE 4: ESTIMATES OF LIVES SAVED BY SAFETY TECHNOLOGIES IN 1960-200

Pedestrians

FMVSS & Car LTV Bicyclists Safety Technology Occupants Occupants Motorcyclis105: Dual master cylinders & front disc brakes 7,993 2,880 2,180 108: Conspicuity tape for heavy trailers 683 422 201: Voluntary mid/lower instrument panel improvements 16,670 4,373 203/204: Energy-absorbing steering assemblies 41,545 11,472 206: Improved door locks 19,504 9,398 208: Safety belts – all types, all seat positions 109,519 59,004 208: Frontal air bags 8,770 3,304 212: Adhesive windshield bonding 5,248 1,462 213: Child safety seats 4,854 1,100 214: Side door beams & voluntary (pre-1994) TTI(d) reductions 14,002 701 216: Roof crush strength (eliminate true hardtops) 3,466 ______ _____ 

TOTAL 232,255 94,117 2,180 

xxi
up to 142,000 lives saved; energy-absorbing steering assemblies, improved door locks, and 

voluntary instrument panel improvements saved the most lives. 

Comments on some assumptions in the model The effectiveness estimates used in the model 

derive from past NHTSA evaluations. Estimates were based on statistical analyses of crash data, 

comparing fatality risk in vehicles built just before and just after make-models were equipped 

with the technology; the reductions were statistically significant, and the analyses attempted to 

statistically control for factors other than the technology by using double-pair comparison, 

control groups, logistic regression, or other techniques. However, in the preparation of this 

report, the estimates in past evaluations were generally not updated with data that subsequently 

had become available. 

The basic assumption of the model is that FARS fatality cases with a safety technology are 

evidence of additional crashes where that technology saved lives: if there are 100 belted fatalities 

in a type of crash where statistical analysis shows 50 percent belt effectiveness, there must have 

been another 100 people in potentially fatal crashes who were saved by the belt. This is a leap of 

faith to the extent that we cannot identify those 100 specific crashes were occupants were “saved 

by the belt” – we assume they must exist, based on our effectiveness estimate. 

The model simulates “removing” safety equipment from a modern vehicle one piece at a time, 

starting with the most recent technology and working backward. Some of these technologies 

were introduced at about the same time, and it is not always obvious which was first: for some of 

the earliest ones, there is limited written information, and the people who worked on them have 

long since retired. A case could be made for changing the order of “removing” the technologies. 

The model would still produce the same estimate of overall lives saved, but the allocation among 

the FMVSS could change. 

The model assumes that the belt use of fatally injured occupants (not survivors) on FARS is 

accurately reported. NHTSA has long believed this to be true, based on statistical analyses 

comparing FARS data with belt use observed in surveys. In the future, conceivably, event data 

recorders could provide more direct evidence on belt use in crash data files. 

Finally, when the model says vehicle safety technology saved 328,551 lives, it means there 

would have been that many additional fatalities in 1960-2002 if everything else had stayed the 

same: the same increase in VMT from 1960-2002, the same driving behaviors. It is somewhat of 

a paper estimate. If safety belts and the other modern vehicle safety technologies had never been 

invented, and if occupant fatalities had continued climbing toward 57,000 instead of remaining 

near 32,000, as shown in Table 2, the public might have demanded much stronger regulation of 

drivers (e.g., licensing) or the infrastructure (e.g., speed limits). Consumers might purchase a 

different mix of vehicles (e.g., larger cars) and some people might be more reluctant to travel 

during the riskiest hours (e.g., weekend nights). Those measures might have prevented at least 

some of the additional 328,551 fatalities – but surely not as efficiently, and with as little 

impairment of driving enjoyment and mobility as the vehicle safety technologies. 

xxii
LIVES SAVED BY THE FEDERAL MOTOR VEHICLE SAFETY STANDARDS 

AND OTHER VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

FRAMEWORK FOR THE ANALYSIS 

The National Highway Traffic Safety Administration (NHTSA) began to evaluate the 

effectiveness of the Federal Motor Vehicle Safety Standards (FMVSS) in 1975, well before 

Executive Order 12291 (February 1981), Executive Order 12866 (October 1993) or the 

Government Performance and Results Act of 1993 required Federal agencies to evaluate their 

existing regulations. By October 2004, NHTSA had issued 48 evaluations of individual safety 

standards, programs or technologies.1

 

A typical evaluation estimates the effectiveness of a safety technology – a percentage reduction 

of fatalities, injuries and/or crashes – by statistically analyzing crash data on vehicles produced 

just before vs. just after receiving the technology. It estimates the benefits of that technology – 

absolute numbers of lives saved, injuries avoided, or crashes avoided per year – by applying 

effectiveness estimates to baseline numbers of annual fatalities, injuries or crashes. “Baselines” 

have typically been the year that a report was written. 

NHTSA has evaluated all the major crashworthiness standards and several crash avoidance 

standards for passenger cars and LTVs (light trucks and vans – i.e., pickup trucks, sport utility 

vehicles, minivans and full-size vans). The agency has studied consumer information on vehicle 

safety such as the New Car Assessment Program and safety technologies that are not mandatory 

for cars under Federal regulations, such as the redesign of mid and lower instrument panels. 

By now, the agency has evaluated virtually all the life-saving technologies introduced in cars and 

LTVs from about 1960 up through the later 1990’s. Having estimated the lives saved by each 

individual standard, we are now ready to assess the overall effect of vehicle safety improvements 

by essentially adding up the individual estimates. “Building up an estimate one standard at a 

time” is the most empirical and defensible way to estimate how many lives are saved by all the 

vehicle safety technologies. It is preferable to a complex statistical analysis of the long-term

reduction in overall fatality rates per 100,000,000 vehicle miles of travel (VMT) that attempts to 

tease out the relative effects of vehicle, behavioral, roadway and demographic factors. 

Estimating the combined net lives saved by the vehicle safety technologies, as well as the lives 

saved by each individual technology in each year, has been a long-term goal for NHTSA. The 

agency’s evaluation plan of 1998 proposed to start it in the near future, and the current 

evaluation plan of 2004-2007 says it is underway and describes the proposed approach.2

 

1 “Executive Order 12291 – Federal Regulation," Federal Register 46 (February 19, 1981): 13193; “Executive Order 

12866 – Regulatory Planning and Review," Federal Register 58 (October 4, 1993): 51735; Government

Performance and Results Act of 1993, Public Law 103-62, August 3, 1993; National Highway Traffic Safety 

Administration Evaluation Program Plan, Calendar Years 2004-2007, NHTSA Report No. DOT HS 809 699, 

Washington, 2004, pp. 37-47; www.nhtsa.dot.gov/cars/rules/regrev/evaluate/Summaries.html . 2 Evaluation Program Plan, 1998-2002, NHTSA Report No. DOT HS 808 709, Washington, 1998, p. 12; NHTSA

Evaluation Program Plan, Calendar Years 2004-2007, pp. 2-3. 

1
Basic analysis method 

We will rely on the individual effectiveness estimates (percentage reductions) developed in past 

NHTSA evaluations. But it is not as simple as merely adding up past reports’ estimates of lives 

saved per year. The absolute estimates in the various reports are not directly comparable, and are 

no longer accurate today, because they involve many different, past baselines. 

Instead, a process is needed that applies the effectiveness estimates in a consistent manner and to 

a consistent “baseline” number of fatalities. The Fatality Analysis Reporting System (FARS) 

data serve as the starting point, indicating the actual number of fatalities during 1975-2002 in the 

fleet of cars and LTVs that was on the road. It is a mix of vehicles, some built recently and 

meeting many of the FMVSS, others quite old and pre-FMVSS. 

Each 100 actual fatality cases on FARS represent a potentially even greater number of fatalities 

that could have happened if the vehicles had not met any of the FMVSS. The process begins 

with the actual FARS fatality cases and computes how many additional fatalities there would 

have been if the vehicles had not been equipped with any safety technologies. The computations 

rely on the effectiveness estimates from past evaluations. For example, given that 3-point belts 

reduce fatality risk by 45 percent in cars, 100 belted FARS fatality cases are equivalent to 

100/(1 - .45) = 182 fatalities without belts – i.e., there must have been 182 belted occupants 

involved in crashes that would have been potentially fatal without belts, but 82 of them did not 

become FARS cases, because the belts saved the occupant’s life. The process is repeated for 

other FMVSS and safety technologies until all of them have been “removed” from the vehicle – 

until the vehicle has been degraded to a level of safety performance characteristic of the 1950’s 

rather than its actual model year. The technologies are removed in the reverse chronological 

order that they were historically introduced into vehicles. At each step into the past, the model 

tallies the lives saved by the latest safety technology – i.e., the additional fatalities that would 

have occurred if that technology had been removed. This is the process that NHTSA already 

uses to estimate the number of lives saved by air bags and safety belts, but expanded to also 

count the benefits of the other FMVSS.3

 “Reverse chronological order” is not the only approach 

that could have been used in the model; alternative approaches are considered in Part 2 of this 

report (Summary of the Estimation Method). However, the various techniques would have 

generated the same estimate of overall lives saved in 1960-2002, differing only in how they 

allocated that total among the individual safety technologies. 

The model produces unbiased estimates of the lives saved by the various technologies, and it is 

not an exercise in double counting, because the effectiveness estimates in past evaluations are 

based on analyses of vehicles produced just after vs. just before the FMVSS in question. They 

estimate the incremental effect of that FMVSS on a vehicle that already meets all the earlier 

FMVSS. For example, NHTSA’s evaluation of air bags was a study of cars, some without air 

bags and some with air bags, but all equipped with 3-point belts and energy-absorbing columns. 

The evaluation of 3-point belts was based on older cars equipped with energy-absorbing columns 

but not yet with air bags. The evaluation of energy-absorbing columns was based on even older 

cars without air bags or 3-point belts. These effectiveness estimates are incremental, and they 

 

3 Traffic Safety Facts 2002 – Occupant Protection, NHTSA Publication No. DOT HS 809 610, Washington, 2003. 

2
may be applied in sequence to estimate the total fatality reduction for the combination of the 

three technologies.4

What is included and what is excluded? 

This will be a study of the lives saved in 1960-2002 by vehicle safety technologies that were 

implemented in cars or LTVs from approximately 1960 until the later 1990’s, or that were 

implemented in other vehicles but benefited occupants of cars and LTVs. The short explanation 

for limiting the study to vehicle safety technologies in general, and to these vehicles and 

timeframe in particular, is that they are the technologies that have been evaluated by NHTSA5

 – 

inclusively enough to add up the lives saved by the individual technologies and say, “Here is the 

net impact of the vehicle program.” 

The benefits of roadway improvements or behavioral safety programs, such as the effort to 

prevent drunk driving are not explicitly included here. One exception: the benefits of safety 

belts, a vehicle technology, would not be anywhere near what they are today without all the 

behavioral programs that have increased belt use; the benefits of the behavioral “occupant 

protection program” are implicitly and inseparably part of the benefit of safety belts. Unlike the 

FMVSS, there are generally no easy statistical methods to estimate the effectiveness of 

individual behavioral or roadway programs. NHTSA does not have a comprehensive set of 

effectiveness estimates for behavioral or roadway programs, based directly on statistical analysis 

of crash data, corresponding to what it has for the vehicle programs. 

NHTSA has thoroughly evaluated the life-saving benefits of FMVSS and other technologies for 

passenger cars. The set of estimates for LTVs is almost as complete, and where there are some

gaps, estimates can in most cases be plausibly inferred from the results for cars. The list of 

evaluations for motorcycles, heavy trucks and buses is not so complete (although this is a future 

priority for NHTSA). 

The timeframe of vehicle technologies is as up-to-date as feasible. However, some of the rules 

or technologies introduced in the mid-to-late 1990’s, and anything more recent than that cannot 

be included because NHTSA is only now acquiring, or has not yet acquired enough crash data to 

evaluate their effectiveness in production vehicles. 

For the beginning of the timeframe, it seems most logical to start with the technologies more or 

less directly regulated by the initial FMVSS of January 1, 1968. Many of these technologies, 

however, were actually introduced some years before 1968. For a full picture of the benefits of 

the FMVSS-era technologies, it makes sense to take the analysis back to 1960, as long as we 

keep separate accounts of lives saved in pre-standard and post-standard vehicles. The oldest 

technologies more or less directly regulated by the initial FMVSS include lap belts, introduced in 

 

4 Kahane (1996), pp. 7-9; Kahane, C.J., Fatality Reduction by Safety Belts for Front-Seat Occupants of Cars and

Light Trucks, NHTSA Technical Report No. DOT HS 809 199, Washington, 2000, pp. 5-10; Kahane, C.J., An 

Evaluation of Federal Motor Vehicle Safety Standards for Passenger Car Steering Assemblies, NHTSA Technical 

Report No. DOT HS 805 705, Washington, 1981, pp. 197-203. 5 NHTSA Evaluation Program Plan, Calendar Years 2004-2007, pp. 37-47; 

www.nhtsa.dot.gov/cars/rules/regrev/evaluate/Summaries.html . 

3
the late 1950’s and early 1960’s; improvements to door locks throughout the 1960’s; and many 

effective devices introduced in 1965-67. There does not seem to be much point in going back 

before 1960 or attempting to predict how many fatalities there would be today if cars still had, 

say, 1905 technology; in any case, NHTSA has not evaluated safety improvements that long 

precede the FMVSS era, such as enclosed, metal car bodies, hydraulic brakes, safety glass, or 

electric headlamps. 

One feature of the estimation model in Part 2 of this report is that estimates for the later 

technologies (such as air bags or 3-point belts) are unaffected by the inclusion or exclusion of 

any technology that preceded them. Thus, readers have the option of just subtracting the benefits 

for the earliest technologies on the list (e.g., lap belts or the 1960’s improvements to door locks) 

if, in their opinion, they ought not have been included in this report. 

NHTSA is also preparing a summary report of its past evaluations of the cost of individual 

FMVSS, and estimates of the cost per car or LTV of all the FMVSS, by model year.6

 It will be a 

companion to this report. A supplement to these two reports will compare overall lives saved 

and costs on a substantial “core” group of FMVSS for which NHTSA has evaluated 

effectiveness as well as costs. 

List of FMVSS, safety technologies and effectiveness evaluations

Part 1 of this report is a review of 19 FMVSS, plus the New Car Assessment Program (NCAP) 

that provides consumers with information about vehicle safety performance. Part 1 is grouped 

into 16 chapters. These FMVSS either regulate cars and/or LTVs, or they regulate other 

vehicles/equipment but result in benefits to occupants of cars and LTVs. Part 1 reviews 31 

individual safety technologies directly or indirectly associated with FMVSS/NCAP that NHTSA 

has evaluated based on statistical comparisons of the crash experience of vehicles built before 

and after the introduction of those technologies. 

Historically, the FMVSS have had numbers. The 100-series are crash avoidance standards; the 

200-series, crashworthiness; and the 300-series, post-crash fire prevention. Within each series, 

the numbering is chronological. 

Each chapter of Part 1 presents the rationale for a FMVSS, the safety problem it addresses, and 

its regulatory history, including major Federal Register citations. For each safety technology, 

Part 1 summarizes what was added or changed in vehicles and how this equipment works, when 

it was introduced and by whom, and why it was expected to reduce fatalities, injuries or crashes. 

The data and statistical methods of NHTSA’s evaluations are summarized, with examples if 

possible, and so are the principal findings on effectiveness, benefits, and side effects (if any). 

For technologies that require some action by drivers or other occupants (e.g., safety belts, on-off 

switches for air bags, ABS, head restraints), Part 1 describes how to use them most effectively. 

 

6 NHTSA Evaluation Program Plan, Calendar Years 2004-2007, pp. 3-4. 

4
Table 1-1 lists the safety technologies reviewed in Part 1, grouped by chapter (FMVSS). It 

summarizes the effectiveness of each technology in reducing fatalities, injuries or crashes (100-

series only) of cars and LTVs: 

• Yes = NHTSA’s evaluation found a statistically significant reduction 

• No = the evaluation did not find a significant reduction, despite ample data. 

• (Yes), (No) = LTV results inferred by analogy from the passenger car results 

• Mixed results = significant reduction on some crash types, significant increase on others. 

• Unknown = NHTSA has not performed an evaluation 

• N/A = the safety technology was not installed on this type of vehicle. 

NHTSA’s evaluations demonstrated significant benefits of some type – if not a fatality reduction 

then at least a reduction of injuries, crashes or fires – for 28 of the 31 technologies: all except 

rear window defoggers, seat back locks and glass-plastic windshields (and of these three, only 

seat back locks are required by a FMVSS). 

Almost all the effectiveness estimates in Part 1 may be found in published NHTSA reports. 

Those NHTSA publications are cited in footnotes and listed in the References at the end of this 

report. Moreover, Appendix B provides capsule summaries of 48 evaluations published as of 

October 2004, in chronological order. The only new analyses performed especially for this 

report are: fatality reduction by front-seat lap belts, injury reduction by air bags, and fatality 

reduction for riding in the back seat. 

For many technologies, NHTSA has published only one evaluation, statistically comparing 

vehicles just before vs. just after that technology was introduced, based on crash data for a 

number of calendar years after introduction. The report assumes the effectiveness, in specific 

crash types, has stayed about the same in subsequent years. It can be difficult to estimate the 

effectiveness of a technology in later model-year vehicles. However, NHTSA has completed or 

plans follow-up evaluations of: 

• Technologies that have changed over the years, such as frontal air bags or child safety 

seats. 

• Front-seat 3-point belts, because of their exceptional importance. 

• Crash avoidance technologies whose effectiveness may change over time as a result of

drivers’ response, such as ABS or Center High Mounted Stop Lamps. 

5
TABLE 1-1: SAFETY TECHNOLOGIES EVALUATED BY NHTSA 

Effectiveness 

 Cars FMVSS SAFETY TECHNOLOGY Fatals Injuries Crashes Fatals 103: Windshield defrosting and defogging  Rear-window defoggers Unknown Unknown No Unknown U105: Hydraulic brake systems 

Dual master cylinders Yes Yes Yes Yes Front disc brakes Yes Yes Yes Yes 

Rear-wheel ABS for LTVs N/A Mix4-wheel antilock brake systems (ABS) Mixed results MixElectronic stability control (ESC)1 Yes (Yes) Yes Yes 

108: Lamps, reflective devices 

Side marker lamps No Yes Yes No Center High Mounted Stop Lamps No Yes Yes No Retroreflective tape on heavy trailers2 Yes Yes Yes Yes 

1 Preliminary evaluation; injury reduction inferred from the crash reduction and the fatality reduction.2 Tape installed on heavy trailers is effective in preventing cars and LTVs from hitting those trailers. 

6
TABLE 1-1 (continued): SAFETY TECHNOLOGIES EVALUATED BY NHTSA 

Effectiven

Cars 

FMVSS SAFETY TECHNOLOGY Fatals Injuries 201: Occupant protection in interior impact 

Voluntary mid and lower instrument panel improvements Yes Yes 

202: Head restraints 

Head restraints for front-outboard occupants No Yes 

203: Impact protection from the steering control 204: Steering control rearward displacement 

Energy-absorbing steering assemblies Yes Yes 

205: Glazing materials  High-penetration resistant (HPR) windshields No Yes  Glass-plastic windshields No No 206: Door locks 

Improved locks, latches and hinges for side doors4 Yes (Yes) 

3 Result for LTVs inferred from the evaluation of cars. 4 Injury reduction and LTV fatality reduction inferred from the fatality reduction in cars. 

7
TABLE 1-1 (continued): SAFETY TECHNOLOGIES EVALUATED BY NHTSA 

Effectiven

Cars 

FMVSS SAFETY TECHNOLOGY Fatals Injuries 207: Seating systems 

Seatback locks for 2-door cars No No 

208: Occupant crash protection 209: Seat belt assemblies 210: Seat belt assembly anchorages 

Lap belts for front-seat occupants Yes Yes Lap belts for back-seat occupants Yes Yes Manual 3-point belts for front-seat occupants Yes Yes 3-point belts for back-seat occupants Yes Yes Automatic safety belts Yes Unknown 

 Frontal air bags Yes6 Yes 

On-off switches for passenger air bags in pickup trucks N/A N/A 

5 “(Yes)” indicates result for LTV injuries inferred from the results for passenger car injuries and LTV fatalities. 6 Except that fatalities increased for certain groups of child passengers in cars and LTVs. 

8
TABLE 1-1 (continued): SAFETY TECHNOLOGIES EVALUATED BY NHTSA 

Effectiven

Cars 

FMVSS SAFETY TECHNOLOGY Fatals Injuries 212: Windshield mounting 

Adhesive windshield bonding Yes Yes 

213: Child restraint systems 225: Child restraint anchorage systems  Child safety seats Yes Yes 

Riding in the back seat Yes Unknown U

214: Side impact protection 

Side door beams Yes Yes Voluntary (pre-1994) TTI(d) improvements in 2-door cars Yes Unknown 

216: Roof crush resistance 

Redesign of true hardtops as pillared hardtops or sedans Yes Unknown 

7 “(Yes)” indicates results for LTVs inferred from corresponding results for cars. 

9
TABLE 1-1 (concluded): SAFETY TECHNOLOGIES EVALUATED BY NHTSA 

Effectiven

Cars 

FMVSS SAFETY TECHNOLOGY Fatals Injuries 301: Fuel system integrity 

1975-77 upgrade: rollover, rear- and lateral-impact tests No Yes8 

NCAP: New Car Assessment Program 

Frontal NCAP-related improvements, vehicles w/o air bags Yes Unknown U

8 Significant reduction of crashes with post-crash fires. 

10
Part 1 also summarizes the vehicle modifications and rationale for 12 safety technologies that are 

already available in production vehicles cars and LTVs, but are still too new for NHTSA to have 

completed an evaluation based on statistical analysis of crash data. The agency’s evaluation plan 

of 2004-20071

 outlines these ongoing and future studies: 

• FMVSS 201 – head impact protection upgrade 

• Head air bags

• Pretensioners and load limiters for safety belts 

• 1998-99 redesign of air bags 

• Advanced air bags 

• Upper tethers and anchorages for child safety seats 

• LATCH (lower anchors and tethers for children) 

• FMVSS 214 – side impact protection, dynamic test standard for passenger cars 

• Side air bags 

• Frontal NCAP-related modifications in vehicles with air bags 

• Side NCAP-related modifications 

• Rollover resistance NCAP-related modifications 

The agency’s evaluation plan of 2004-2007 also outlines two ongoing, but not completed studies 

of safety technologies for heavy trucks that will likely prevent collisions with cars/LTVs or 

reduce injury risk to the car/LTV occupants (but the technologies are not discussed in Part 1 of 

this report): 

• FMVSS 121 – Antilock Brake Systems for vehicles with air brakes 

• FMVSS 223/224 – Rear impact guards for heavy trailers 

In addition to the 19 FMVSS listed in Table 1-1, there are 24 other FMVSS (in effect as of April 

2004) that regulate new cars, new LTVs, or car/LTV components that have not been evaluated 

by NHTSA. The following FMVSS definitely or quite possibly resulted in tangible changes to 

vehicles, but were not evaluated because existing or potentially available data do not adequately 

identify what vehicles were modified; or because the type of crashes/injuries mitigated by the 

FMVSS cannot be singled out in available data (or cannot be identified at all); or because there is 

no hope of obtaining enough data for a statistically meaningful analysis of the limited effect, if 

any, that could reasonably be expected for that FMVSS: 

• 114: Theft protection 

• 116: Motor vehicle brake fluids 

• 118: Power-operated windows 

• 124: Accelerator control systems 

• 125: Warning devices 

• 129: New non-pneumatic tires for passenger cars 

• 219: Windshield zone intrusion 

• 302: Flammability of interior materials 

 

1

 NHTSA Evaluation Program Plan, Calendar Years 2004-2007, op. cit. 

11
The following standards have not been evaluated even though they may regulate vehicle 

subsystems that are important for safety (e.g., tires, mirrors). The agency believes they by and 

large did not result in extensive changes to those subsystems, or does not know if they have 

resulted in changes. In many cases, the FMVSS may have largely incorporated other 

organizations’ standards or industry-wide practices that vehicles had already been meeting for 

quite some time before 1968: 

• 101: Controls and displays 

• 102: Transmission shift lever sequence 

• 104: Windshield wiping and washing systems 

• 106: Brake hoses 

• 109: New pneumatic tires 

• 110: Tire selection and rims

• 111: Rearview mirrors 

• 113: Hood latch systems 

• 117: Retreaded pneumatic tires 

• 119: New pneumatic tires for vehicles other than passenger cars 

• 120: Tire selection and rims for vehicles other than passenger cars 

The following standards went into effect recently. NHTSA has not yet begun an evaluation, or

proposed one in its 2004-2007 evaluation plan: 

• 135: Passenger car brake systems 

• 303: Fuel system integrity of compressed natural gas vehicles 

• 304: Compressed natural gas fuel container integrity 

• 305: Electric-powered vehicles: electrolyte spillage and electrical shock protection 

• 401: Interior trunk release 

Part 1 ends with Tables 1-2, 1-3 and 1-4 summarizing the effectiveness of safety technologies: 

their estimated percentage reductions in fatalities, nonfatal injuries and crashes (always 

specifying to what group of crashes/injuries these percentages apply). Tables 1-3 and 1-4 also 

summarize the estimated annual benefits of nonfatal injury reduction and crash avoidance, as 

stated in NHTSA’s evaluation reports. However, those estimates of benefits, in general, are not 

directly comparable and do not add up to the overall crash avoidance and injury reduction by all 

the FMVSS in, say, 2002. NHTSA does not have enough “building blocks” to develop models 

for overall crash avoidance and injury reduction comparable to the analysis of fatal crashes in 

Part 2 of this report. 

Estimating lives saved by safety technologies, 1960-2002 

Part 2 of this report focuses on the safety technologies that have significantly reduced fatality 

risk. The individual effectiveness estimates and the basic analysis method, described above, are 

applied to FARS data to estimate how many lives were saved in 1960-2002. The tables in Part 2 

also estimate how many lives were saved: 

12
• In each calendar year 

• By each individual safety technology, and grouped by FMVSS 

• By vehicle type: 

o Car occupants 

o LTV occupants 

o Pedestrians and motorcyclists saved by car/LTV braking improvements 

• Distinguishing between lives saved by a FMVSS in effect and “voluntary” saves such as: 

o Improvements introduced before the effective date of a FMVSS 

o Technologies not required for meeting any FMVSS, although perhaps indirectly 

associated with a FMVSS because they address the same general safety problem 

Part 2 compares the actual number of fatalities in 1960-2002, or in any specific year to the 

number that potentially would have occurred, given the same driving exposure, if none of the 

cars and LTVs had been equipped with any of the safety technologies. It computes the 

percentage of the potential fatalities that were saved by the technologies. Part 2 also compares 

the trends in fatalities per 100,000,000 VMT – with and without the vehicle safety technologies. 

Every life-saving technology in Table 1-1 is included in Part 2 except electronic stability control 

(ESC) systems and “riding in the back seat.” ESC systems began to appear in the late 1990’s, 

and NHTSA has so far only conducted a preliminary evaluation. The back seat is not a new 

technology of the FMVSS era, but has been available since the early days of the automobile. 

The FMVSS 213 chapter of Part 1 only discusses the fatality reduction for riding in the back seat 

because it is highly relevant to the child passenger safety issue. Just as Part 2 does not count 

lives saved by the recent shift from front to back seats among the “benefits of the FMVSS,” it 

does not count the effects of other market shifts between existing vehicle types, such as between: 

• 2-door cars and 4-door cars 

• Large cars and small cars 

• Passenger cars and LTVs 

While these shifts can and do affect the number of fatalities, they cannot be considered benefits 

of new safety technologies of the FMVSS era. Part 2 considers only their implicit effects on the 

year-to-year changes in actual and potential fatalities. 

13

PART 1 

REVIEW OF 19 FEDERAL MOTOR VEHICLE SAFETY STANDARDS 

AND THE NEW CAR ASSESSMENT PROGRAM 

COMPRISING 43 SAFETY TECHNOLOGIES 

AND THEIR EFFECTIVENESS IN REDUCING FATALITIES, INJURIES AND 

CRASHES FOR PASSENGER CARS AND LIGHT TRUCKS 

Following the review of the FMVSS and NCAP, Tables 1-2, 1-3 and 1-4 summarize the fatality-, 

injury- and crash-reducing effectiveness (percentage reductions) of the safety technologies. 

Tables 1-3 and 1-4 also summarize annual benefits of individual technologies: injuries and 

crashes avoided per year. Part 2 of this report estimates the annual fatality reduction, for each 

technology individually and for all of them together. 

15

FMVSS 103: Windshield defrosting and defogging systems

A vehicle modification whose safety benefits have been evaluated by NHTSA is grouped with 

this standard merely because the functions are similar: 

• Rear window defrosting and defogging systems

FMVSS 103 only regulates windshield defrosting and defogging. One of NHTSA’s initial safety 

standards, effective on January 1, 1968, it required passenger cars and SUVs to have windshield 

defroster/defoggers and it set performance requirements for them, incorporating SAE 

Recommended Practices dating back to 1964. Cars and LTVs had windshield 

defroster/defoggers well before 1968. They remained unchanged during the mid-to-late 1960’s.1

FMVSS 103 has never required, or proposed to require rear-window defoggers. Their 

development has been voluntary on the part of the industry, in response to customer demand. 

Drivers obviously want a clear rear window, and they like a device that clears it for them 

automatically, so they don’t have to wipe or scrape it repeatedly. 

History of rear window defoggers Ward’s Automotive Yearbooks (Ward’s Publications, Detroit) 

began to include rear window defoggers in MY 1973 among their statistics for factory-installed 

equipment in domestic cars by make-model. In that year, 16 percent of new cars were equipped 

with them; presumably, they were offered in smaller numbers some years before that. 

Installations grew steadily in the 1970’s and 1980’s. By 1992, over 90 percent of new cars were 

equipped with them. By MY 2001, they were standard equipment on most cars, SUVs and 

minivans, but not pickup trucks or full-size vans; 94 percent of new cars were equipped with 

them.

2

How they work Current rear-window defoggers are grids of electric wires attached to the rear 

window. The wires are thin enough not to obstruct vision. Controlled by a switch on the 

instrument panel, they heat up to evaporate condensation or melt ice and snow. The switch 

automatically turns off after a certain number of minutes, in order to save wear and tear on the 

system, and the driver has to turn it back on if the window is not clear. During the 1970’s some

defoggers consisted of an electric heater and blower-motor. That type was gone by 1982. 

Two things must happen for rear-window defoggers to “work”: (1) There has to be some

environmental factor such as rain, snow or cold that fogs or ices up the window; (2) The driver 

has to be aware of the problem and turn on the switch. In warm, dry, sunny conditions, windows 

are normally clear and defoggers are not needed. The situations that might put condensation, 

snow or ice on the window include any kind of precipitation; early morning hours when water 

vapor in the outside air condenses as dew; and very cold weather that can make water vapor 

inside the vehicle condense on windows. Whereas rear-window defoggers rapidly dispel 

condensation, they cannot melt large amounts of ice, but they make it easier to scrape off. 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.103; Federal 

Register 32 (February 3, 1967): 2414. 2

 Morgan, C., Evaluation of Rear Window Defrosting and Defogging Systems, NHTSA Technical Report No. DOT

HS 809 724, Washington, 2004, pp. 1-4.

17
Expected benefits Rear-window defoggers might help prevent collisions by allowing a driver to 

see through the back window, either directly or via the inside rear-view mirror – but only when 

there are environmental conditions that are fogging or icing up the windows, and when the driver 

has activated the defoggers. Specifically, there are two maneuvers where a driver must know, or 

at least ought to know what is behind the vehicle. The maneuvers could result in rear-impact 

collisions if performed in an unsafe manner: 

• Backing up: obviously, the driver needs to know what is directly behind the vehicle, and 

that is much easier if he or she can look through a rear window that has been cleared by 

a defogger. Without a defogger, the driver’s alternative strategies would be relying on 

outside mirrors, getting out of the car to look around/wipe the window, or just backing 

up a short distance very slowly and hoping for the best. 

• Changing lanes: good, defensive driving includes periodic scanning to the rear of the 

vehicle to know if it will be safe to change lanes should it suddenly become necessary. 

Obviously, this is easiest with a correctly positioned inside rear-view mirror and a clear 

window. Without them, the driver would have to rely more on outside mirrors, change 

lanes with less confidence that it is safe, or even forego lane changes unless they are 

absolutely necessary. 

Analysis of crash avoidance – passenger cars NHTSA’s study, published in 2004, used crash 

data from Michigan (1981-91) and Florida (1986-99). The basic analysis method was to 

compare the number of rear-impacts involving either of the pre-crash maneuvers where rearwindow defoggers might be effective – backing up or changing lanes – to the number of rearimpact involvements where the vehicle had been standing still for some time and was hit by 

somebody else. The latter are a control group, because the drivers did nothing to cause the crash, 

and rear-window defoggers would not have prevented it. Did the ratio of impacts while backing

up or changing lanes to impacts while standing still decrease with rear window defoggers – in the 

types of environmental conditions when defoggers might be in use (precipitation, early morning, 

winter)?3

This is a difficult statistical analysis. Neither the police-reported data elements nor the VIN 

included on the Michigan and Florida files indicate if any specific vehicle was equipped with 

rear-window defoggers. The VIN only identifies the make-model and the model year. Ward’s 

Automotive Yearbooks indicate the percent of vehicles with rear-window defoggers by makemodel and MY. However, unlike most other safety technologies that went from 0 to 100 or near100 percent of vehicles from one MY to the next, rear-window defoggers increased their market 

share of nearly all make-models gradually, a few percent more each year. That precluded a 

relatively simple 3-way contingency table analysis (yes/no defogger, impact type, environmental 

condition) and necessitated logistic regressions on each State’s data. The dependent variable was 

the type of rear impact (backing-up or changing-lanes vs. control group). The independent 

variables were the proportion of vehicles of that make-model and MY equipped with defoggers, 

the environmental conditions (precipitation, early morning or winter vs. none of the above), 

vehicle age, driver age/gender, calendar year, and the specific make-model. However, the key 

independent variable was the interaction term between rear-window defogger and adverse 

 

3 Ibid., pp. 9-14. 

18
environmental conditions. If defoggers are effective, there should be a significant reduction in 

backing-up/changing-lanes involvements under adverse environmental conditions.4

The statistical analyses showed little or no effect for defoggers in either State. The evaluation 

was unable to conclude that rear-window defoggers reduce police-reported crashes. It may be 

that the complexity of the analysis, necessitated by the data, made it harder to identify an effect. 

It may also be that rear-window defoggers are not that essential to bottom-line safety. As 

explained in “Expected Benefits,” drivers usually have alternative strategies to compensate for 

the absence of a defogger: more reliance on outside mirrors, getting out of the car to look around 

or wipe the window when that can be done safely, or simply backing up and changing lanes less 

frequently/more gradually. These alternatives are, at best, inconvenient and sometimes 

unnerving. Therefore, we would expect most drivers will continue wanting to have rear-window 

defoggers on their vehicles.5

 

4 Ibid., pp. 4-8 and 14-17. 5 Ibid., pp. v-vi and 18-27. 

19
FMVSS 105: Hydraulic and electric brake systems

NHTSA has evaluated five innovative braking technologies for passenger vehicles: 

• Dual master cylinders

• Front disc brakes

• Rear-wheel antilock (RWAL) brake systems for light trucks

• Four-wheel antilock brake systems (ABS) for passenger cars and light trucks

• Electronic stability control (ESC) systems (preliminary evaluation)

The goal of dual master cylinders is to provide dual hydraulic circuits, so that a fault in one 

hydraulic system will not lead to a catastrophic loss of all braking power. They have been 

standard equipment on most passenger cars since model year 1967. Front disc brakes enhance a 

driver’s control by providing a more linear pedal “feel” than drum brakes. They are also less 

prone to “fade” from overheating or exposure to water. They have been standard on most cars 

since model year 1977. Rear-wheel antilock (RWAL) brake systems are designed to prevent 

rear-wheel lockup and loss of control during braking. Four-wheel antilock brake systems (ABS) 

do what RWAL does and additionally allow drivers to keep control of a vehicle and steer it 

during severe braking. Since the mid-1990’s, antilock brakes have been installed as standard or 

optional equipment on approximately 60 percent of new cars (4-wheel) and light trucks (4-wheel 

or rear-wheel). Electronic stability control (ESC) systems detect when a vehicle is about to go 

out of control and automatically apply the brakes to individual wheels and/or reduce engine 

torque to help the driver stay on course. ESC systems were first offered on selected model year 

1997 cars, and they were installed on 7.4 percent of vehicles in model year 2003. 

FMVSS 105 regulated hydraulic brake systems until 2000-2002, when it was superseded by 

FMVSS 135.

1

 FMVSS 105 is a performance standard, specifying stopping distances or 

deceleration rates for a series of stopping tests under various conditions. It does not prescribe 

technologies. However, dual master cylinders satisfied the FMVSS 105 requirement for a dual 

or split braking system. Front disc brakes helped vehicles pass the fade and water-recovery tests 

added to FMVSS 105, effective September 1, 1975. Antilock brakes have never been required 

for vehicles with a GVWR less than 10,000 pounds, but Congress asked NHTSA in 1991 to 

consider an ABS requirement in FMVSS 105. Electronic stability control systems, likewise, 

have never been required on motor vehicles. NHTSA’s evaluations of these five technologies 

will now be discussed, one-by-one. 

Dual master cylinders 

Regulatory history Before it was superseded by FMVSS 135 in 2000-2002, FMVSS 105 

applied to all motor vehicles with hydraulic brakes. The first version of FMVSS 105 was one of 

NHTSA’s initial safety standards, with an effective date of January 1, 1968 for passenger cars. 

To a large extent, it incorporated SAE Recommended Practices dating back to 1966. FMVSS 

105 allows two alternatives for hydraulic brakes: (1) Vehicles may have a “split service brake 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Parts 571.105 and

571.135. However, after 2002, FMVSS 105 continued to apply to vehicles with a GVWR of 7,716 pounds or more. 

20
system” – i.e., “a brake system consisting of two or more subsystems actuated by a single 

control, designed so that a single failure in any subsystem (such as a leakage-type failure of a 

pressure component of a hydraulic subsystem...) does not impair the operation of any other 

subsystem” that enables the vehicle to stop within a specified distance even “in the event of any 

one rupture or leakage type of failure in any component of the service brake system.” Dual or 

tandem master cylinders met the requirement. (2) Alternatively, vehicles may have a single 

hydraulic circuit if they can meet even more stringent stopping tests in the partial failure mode.2

 

Dual master cylinders were installed on 9 percent of model year 1962 and 1963 cars, 7 percent of 

model year 1964 and 1965 cars, and most new cars from model year 1967 onwards. It is likely 

that dual master cylinders were also installed in LTVs at about the same time (although FMVSS 

105 was only extended to LTVs effective September 1, 1983).3

How dual master cylinders work Without dual master cylinders, a significant loss of pressure 

in the hydraulic system due to a leak can result in a complete, catastrophic loss of braking power. 

Moreover, when there is a slow leak that will eventually lead to a loss of pressure, the vehicle 

does not send an early warning that can be easily understood by the average driver. The Indiana 

Tri-Level Study of the Causes of Accidents suggested that approximately 2 percent of all 

accidents in cars with 1960’s technology were caused by some type of catastrophic brake failure, 

most commonly hydraulic failures.4

 

A dual braking system consists of two separate hydraulic circuits – typically split front-and-rear

in rear-wheel-drive cars, or diagonally in front-wheel-drive cars. Both circuits are activated by 

the brake pedal through one master cylinder that has two chambers, called a “dual master 

cylinder.” If one of the circuits fails, the other is still available. The car can be stopped from

high speeds, although of course not as quickly as when both circuits are intact. A second 

important feature is that the dual master cylinder has a sensor to detect the relative pressure in 

the chambers. If there is an imbalance, it activates a warning light on the instrument panel. It is 

an unambiguous early warning that the brake system needs repair.5

Expected benefits Dual master cylinders should prevent many of the crashes involving 

catastrophic brake failure, specifically those due to failures in the hydraulic system. Possible 

exceptions could include certain types of failure within the master cylinder or cases where the 

driver ignores the warning light. Since catastrophic brake failures can occur in fatal and injury 

crashes, dual master cylinders ought to have an effect on fatalities and injuries. Moreover, when 

brake failure in one vehicle results in a collision with another vehicle or pedestrian, preventing 

the brake failure in that one vehicle will prevent the fatalities or injuries of every crash partner, 

including the other vehicles’ occupants and pedestrians. 

 

2 Ibid., Part 571.105 S4, S5.1.2.1 and S5.1.2.2; Federal Register 32 (February 3, 1967): 2414; 1967 SAE Handbook, 

Society of Automotive Engineers, New York, 1967, pp. 856-857. 3

 Kahane, C.J., A Preliminary Evaluation of Two Braking Improvements for Passenger Cars, NHTSA Technical 

Report No. DOT HS 806 359, Washington, 1983, pp. 1-7; Federal Register 46 (January 2, 1981): 55. 4

 Treat, J.R. et al., A Tri-Level Study of the Causes of Traffic Accidents, Vol. 1, NHTSA Technical Report No. DOT

HS 805 085, Washington, 1977. 5

 The sensor in some vehicles also detects low fluid level in the master cylinder reservoirs. 

21
Crash avoidance – passenger cars NHTSA’s evaluation was published in 1983. It is based on 

crash data from North Carolina (1971-81) and Texas (1972,74,77).6

 The data allow comparison 

of the proportion of crash involvements in which “defective brakes” are a “contributing factor” 

for cars with single vs. dual master cylinders. However, it is important to control for vehicle age,

since the rate of brake defects increases strongly as a vehicle ages. The analysis method is linear 

regressions of the proportion of crash involvements (in a given model year and calendar year) in 

which defective brakes are a contributing factor, by percentage of cars with dual master 

cylinders, vehicle age, and other control variables. The regressions attributed an unequivocal, 

statistically significant reduction of brake defects upon the introduction of dual master cylinders. 

The effectiveness estimate is an 0.7 percent reduction of all police-reported crashes involving at 

least one car, when all cars are equipped with dual master cylinders.7

 The incidence of 

“defective brakes” was reduced by approximately 35 percent (0.7/2.0). Using 1979-80 as the 

“baseline” years, the evaluation estimated that dual master cylinders would prevent 40,000 

police-reported crashes per year when all cars on the road were equipped with them.

8

Injury reduction – passenger cars Estimates of injury reduction were obtained by limiting the 

preceding analyses of North Carolina and Texas data to injury-producing crashes – i.e., crashes 

where at least one occupant in any of the involved vehicles (not necessarily the vehicle equipped 

with a dual master cylinder) was injured.9

 The regression showed virtually the same

effectiveness in injury-producing crashes as in property-damage crashes. The evaluation 

estimated that dual master cylinders prevent 0.7 percent of injury-producing crashes, resulting in 

a reduction of 24,000 injuries per year.10

Fatality reduction – passenger cars The preceding regression analyses were also performed 

with 1975-81 FARS data.

11 They showed a statistically significant reduction for dual master 

cylinders, proportionately about the same as in the nonfatal crashes. The evaluation assumed 

that brake defects are a contributing factor in similar percentages of fatal and nonfatal crashes 

(i.e., 2 percent of crashes, in cars without dual master cylinders). It estimated that dual master 

cylinders prevent 0.7 percent of fatal crashes that involve passenger cars, saving 260 lives per 

year.12

Light trucks The 1983 evaluation addressed only passenger cars. However, FMVSS 105 also 

applies to light trucks. Both types of vehicles use fairly similar hydraulic braking technology. It 

seems likely that dual master cylinders could have about the same effect in LTVs as in cars: a 0.7 

percent reduction of crashes, injuries and fatalities. 

 

6 Kahane (1983 Brakes), pp. 15-38. 7 Ibid., p. 43; 90% confidence bounds: 0.58 to 0.82 percent. 8 Ibid., pp. 55-57; 90% confidence bounds: 33,000 to 47,000 crashes prevented. 9 Ibid., pp. 28-29. 10 Ibid., pp. 55-57; 90% confidence bounds: 19,000 to 28,000 injuries prevented. 11 Ibid., pp. 38-40. 12 Ibid., pp. 55-57; 90% confidence bounds: 220 to 310 lives saved. 

22
Front disc brakes 

Regulatory history Front disc brakes began to appear on domestic passenger cars in model year 

1965. Consumers welcomed the new technology. It jumped from 13 percent of new cars in 

1968 to 86 percent by 1973. In 1970, NHTSA proposed FMVSS 105a, incorporating more 

stringent stopping distance, fade- and water-recovery tests than the original FMVSS 105, with a 

proposed effective date of October 1, 1972. After several revisions, this regulation took effect 

for passenger cars on January 1, 1976 and LTVs on September 1, 1983. Although some cars 

with four-wheel drum brakes could and did pass the new tests, it was easier to meet them with 

front disc brakes. Furthermore, the superior self-adjusting characteristics of disc brakes allowed 

for increased vehicle stability during the high-speed stopping tests in FMVSS 105. By model 

year 1978, most cars and LTVs produced for sale in the United States were equipped with front 

disc brakes. (FMVSS 105 or 135 have never been explicitly required disc brakes.)13

How front disc brakes work Disc brakes are calipers equipped with abrasive pads that squeeze 

rotors, metal plates parallel to the wheels that rotate with the wheels. Drum brakes are shoes 

with abrasive linings that press against the insides of drums that rotate with the wheels. Whereas 

drum brakes readily heat up from overuse or fill up with water upon immersion, resulting in 

losses of braking ability, disc brakes are ventilated to dissipate heat or shed water quickly. 

Furthermore, drum brakes have a “self-energizing capability” (friction building up more rapidly 

than pedal pressure) that makes drivers prone to lock the wheels. Disc brakes have a more linear 

relationship between pedal pressure and vehicle deceleration, making it easier for drivers to 

deliver just the right amount of pressure short of locking the wheels.14

Expected benefits Front disc brakes might prevent some crashes involving catastrophic brake 

failure, especially on mountain roads, where brakes could fade from overuse on the downhills, or 

on flooded roads, where water gets into the wheels. If drivers use the more linear pedal feel to 

advantage, that could manifest itself in two ways in the crash data: if locking the wheels is 

reported as “defective brakes,” a reduction in lockup could result in fewer reported brake defects. 

If drivers can better optimize their deceleration rate short of lockup, they will stop in a shorter 

distance, possibly reducing the risk of frontally hitting other vehicles in the rear. Since brake 

failures/defects can occur in fatal and injury crashes, front disc brakes could have an effect on 

fatalities and injuries. Moreover, when brake failure in one vehicle results in a collision with

another vehicle or pedestrian, preventing the brake failure in that one vehicle will prevent the 

fatalities or injuries of every crash partner, including the other vehicles’ occupants and 

pedestrians. 

Crash avoidance – passenger cars NHTSA’s 1983 evaluation has several analyses of the 

proportion of crash involvements in which “defective brakes” are a “contributing factor” for cars 

with drum vs. front disc brakes. The most reliable one is based on North Carolina data (1971-

 

13 Ibid., p. 7; Federal Register 35 (November 11, 1970): 17345, 37 (September 2, 1972): 17970, 38 (May 18, 1973): 

13017, 39 (February 22, 1974): 6708, 40 (June 9, 1975): 24525, 46 (January 2, 1981): 55; Ward’s Automotive 

Yearbook, Ward’s Communications, Detroit, 1975-79. 14 Ibid., pp. 6-10; Ballard, C. and Andrade, D., Systems and Hardware Effects of FMVSS 105-75, Paper No. 760216, 

Society of Automotive Engineers, Warrendale, PA, 1976; Kahane, C.J. and Ichter, K.D., Statistical Evaluation of

Brake Safety Improvements for Passenger Cars, Paper No. 841236, Society of Automotive Engineers, Warrendale, 

PA, 1984. 

23
81). It subdivides the data by make-model as well as model year, since front disc brakes were 

introduced earlier in some models than in others.15 The analysis method is a linear regression of 

the proportion of crash involvements (in a given make-model, model year and calendar year) in 

which defective brakes are a contributing factor, by percentage of cars with front disc brakes, 

vehicle age, and other control variables. The regressions attributed a statistically significant 

reduction of brake defects upon the introduction of front disc brakes, equivalent to an 0.17 

percent reduction of all police-reported crashes involving at least one car.16 Using 1979-80 as 

the “baseline” years, the evaluation estimated that front disc brakes would prevent 9,800 policereported crashes per year when all cars on the road were equipped with them.

17 Other analyses 

of North Carolina data showed reductions of “defective brake” crashes on hilly and wet roads 

with front disc brakes, but not necessarily greater reductions than on other roads.18 The analysis 

of front-to-rear crashes attributed to front disc brakes a 0.2 percent reduction in the likelihood of 

being the striking car, but this was not statistically significant.19

Injury reduction – passenger cars Estimates of injury reduction were obtained by limiting the 

preceding analysis of North Carolina data (by make-model) to injury-producing crashes.20 The 

regression showed virtually the same effectiveness in injury-producing crashes as in propertydamage crashes. The evaluation estimated that front disc brakes prevent 0.17 percent of injuryproducing crashes, resulting in a reduction of 5,700 injuries per year.21

Fatality reduction – passenger cars Regression analyses of 1975-81 FARS data (not subdivided 

by make-model) attributed a statistically significant 0.55 percent reduction of “defective brake” 

involvements to front disc brakes.22 However, the evaluation estimated, more conservatively, 

that front disc brakes would have proportionately the same effect in fatal as in nonfatal crashes: a 

0.17 percent reduction of fatal crashes that involve passenger cars, saving 64 lives per year.23

Light trucks The 1983 evaluation addressed only passenger cars. However, front disc brakes 

have superseded front-wheel drum brakes in light trucks as well as in passenger cars. Both types 

of vehicles use fairly similar hydraulic braking technology. It seems likely that front disc brakes 

could have about the same effect in light trucks as in cars: a 0.17 percent reduction of crashes, 

injuries and fatalities. 

 

15 Kahane (1983 Brakes), pp. 26-28. 16 Ibid., p. 44; 90% confidence bounds: 0.10 to 0.24 percent. 17 Ibid., pp. 55-57; 90% confidence bounds: 5,800 to 13,800 crashes prevented. 18 Ibid., pp. 29-31. 19 Ibid., pp. 45-47. 20 Ibid., pp. 28-29. 21 Ibid., pp. 55-57; 90% confidence bounds: 3,400 to 8,100 injuries prevented. 22 Ibid., pp. 38-40. 23 Ibid., pp. 55-57; 90% confidence bounds: 38 to 90 lives saved. 

24
Rear-wheel antilock (RWAL) brake systems for light trucks

Regulatory history and voluntary installations No type of antilock brake system (ABS) has 

ever been required for passenger vehicles with GVWR less than 10,000 pounds. However, the 

Highway Safety Act of 1991, Section 2507 instructed NHTSA to consider requiring ABS in 

passenger vehicles. NHTSA published an ANPRM at the beginning of 1994 asking for 

information about the effectiveness and potential benefits of ABS technologies.24 Based on 

responses to the 1994 ANPRM, including statistical studies by NHTSA and others that failed to 

show significant net benefits for voluntarily installed ABS, NHTSA issued a second ANPRM in

1996 deferring indefinitely the ABS requirement.25

Rear-wheel antilocks were installed as standard equipment in 1987 Ford F-Series pickup trucks, 

Bronco and Bronco II. In 1988-90, they were phased into most domestic pickup trucks and 

SUVs as well as many vans, as standard equipment. During the 1990’s, RWAL was increasingly 

superseded by 4-wheel ABS; by model year 2001, only 8 percent of new domestic LTVs were 

equipped with RWAL.26

How RWAL works The fundamental safety problem addressed by any ABS system is that few 

drivers are able to modulate pressure on the brake pedal optimally, given a sudden emergency 

situation or unexpectedly slippery surface. If excess pedal pressure locks the rear wheels, the 

vehicle can lose control. Light trucks are especially prone to rear-wheel lockup when they are 

not heavily loaded, and especially crash-prone once they are out of control. RWAL senses if any 

of the rear wheels have locked, and if so, quickly releases the brakes on that wheel and lets it 

start rolling again. Cycles of releasing, holding and reapplying brakes are repeated many times 

per second. RWAL, however, will not prevent front-wheel lockup or assure steering control 

during braking. If the front wheels lock while the rear wheels turn, the truck will just slow down 

on a straight line, without yawing. NHTSA conducted stopping tests on five surfaces with 

RWAL-equipped trucks, and also for the same trucks with the RWAL disabled. RWAL 

substantially but not completely reduced the frequency and severity of yawing in spike stops. 

That benefit, however, was offset by a slight (6 to 18 percent) increase in stopping distances on 

four of the surfaces.27

Expected benefits If RWAL prevents or substantially reduces yawing, it will help keep trucks 

from running off a straight road. By keeping the truck on the road, it may prevent the rollovers 

or impacts with fixed objects or pedestrians that can occur after a vehicle has left the road. Side 

impacts with fixed objects are especially characteristic of vehicles that have yawed out of 

control. RWAL would be less effective if the driving task requires steering as well as braking 

(e.g., on a curved road). It will not affect yawing caused by reasons other than brake-induced 

 

24 Federal Register 59 (January 4, 1994): 281. 25 Federal Register 61 (July 12, 1996): 36698. 26 Kahane, C.J., Preliminary Evaluation of the Effectiveness of Rear-Wheel Antilock Brake Systems for Light Trucks, 

NHTSA Docket No. 70-27-GR-026, Washington, 1993, p. 15; 2002 Ward’s Automotive Yearbook, Ward’s

Communications, Detroit, 2002, p. 333. 27 Kahane (1993 RWAL), pp. 7-14; Hiltner, E., Arehart, C. and Radlinski, R., Light Vehicle ABS Performance 

Evaluation, NHTSA Technical Report No. DOT HS 807 813, Washington, 1991; Arehart, C., Radlinski, R. and 

Hiltner, E., Light Vehicle ABS Performance Evaluation – Phase II, NHTSA Technical Report No. DOT HS 807 924,

Washington, 1992. 

25
rear-wheel lockup (e.g., going around a curve too quickly). To the extent that RWAL is 

associated with a slight increase in stopping distances, there could be an adverse effect on 

multivehicle crashes that require a truck to stop in time to avoid hitting another vehicle. 

 

Crash avoidance NHTSA’s preliminary evaluation was published in 1993. It is based on crash 

data from Florida (1990-91), Michigan (1990-91), and Pennsylvania (1989-91). These data 

show consistent, statistically significant reductions of nonfatal rollovers and side impacts with 

fixed objects in trucks equipped with RWAL.28 Involvements in rollovers or fixed-object 

collisions are compared to a control group: crash involvements in which the truck, standing still 

or moving 5 mph or less, was struck by another vehicle (where the truck’s RWAL could not have 

been a factor in the crash). For example, the results for pickup trucks in Michigan indicate a 42 

percent reduction of nonfatal rollovers29: 

MICHIGAN, 1990-91 Control Ratio of 

PICKUP TRUCKS Rollovers Group Rollover/Control 

Last 2 model years without RWAL 1,095 3,634 .301 

First 2 model years with RWAL 737 4,215 .175 

On the average, the analyses showed about a 30 percent reduction of nonfatal rollovers and a 20 

percent reduction of nonfatal side impacts with fixed objects.30

A similar analysis investigated the effect of RWAL in multivehicle crashes. Involvements as a 

frontally impacting truck in a multivehicle collision, traveling faster than 5 mph, were compared 

to the control group of vehicles struck while standing still or moving 5 mph or less. The ratio of 

striking to control-group involvements was about the same for trucks with and without RWAL.31

Fatality reduction Statistical analyses of 1989 – mid-1992 FARS data did not show an overall 

reduction of fatal rollovers or side impacts with fixed objects, relative to fatal control-group 

involvements.32 The FARS analysis of fatal involvements as a frontally impacting truck in a 

multivehicle collision (traveling faster than 5 mph) showed mixed/negative results: little or no 

effect for RWAL when the data were limited to trucks of the first model year with RWAL vs. the 

last model year before RWAL; an increase in collisions for trucks of the first two years with 

RWAL vs. the last two years before RWAL.33 Pedestrian crashes were the only type that the 

data hinted at a reduction with RWAL, possibly on the order of 10 percent.34

 

28 Kahane (1993 RWAL), pp. 19-44. 29 Ibid., p. 23. 30 Ibid., p. 108. 31 Ibid., pp. 100-109. 32 Ibid., pp. 42-49 and 100-109. 33 Ibid., pp. 78-85. 34 Ibid., pp. 93-99 and 108. 

26
NHTSA performed another statistical analysis of 1989-93 FARS data, using logistic regression 

of the ratio of relevant crashes to control-group crashes. This study, likewise, associated RWAL 

with a statistically significant increase of fatal involvements as the striking vehicle in a 

multivehicle collision. It did not find a reduction for RWAL in fatal rollovers or side impacts 

with fixed objects. Pedestrian crashes were not considered in that study.35

RWAL is apparently effective in preventing yaw in the relatively low-speed situations where 

rear-wheel lockup would have caused the truck to run off the road with nonfatal consequences. 

It may be less effective in high-speed scenarios that precipitate fatal crashes. Also, many of 

these fatal crashes do not involve pre-crash braking – e.g., when the driver is impaired. Since 

RWAL usually does not reduce, and may even increase stopping distances, the absence of 

benefits in multivehicle crashes is not surprising. 

Four-wheel antilock brake systems (ABS) for passenger cars and light trucks

Regulatory history and voluntary installations As described above (regulatory history of 

RWAL), NHTSA considered, but eventually deferred any requirement for ABS on passenger 

vehicles with GVWR less than 10,000 pounds. 

Modern 4-wheel ABS was first offered as standard equipment in 1985 on some lines of BMW, 

Lincoln and Mercedes and in 1986 on Chevrolet Corvette. Availability of ABS increased 

gradually in 1987-90 and dramatically in 1991-92, when it became standard on the majority of 

GM cars. Throughout 1994-2001, about 60-65 percent of new passenger cars were equipped 

with ABS. In general, ABS is usually standard on the larger and more expensive cars, optional 

and not too frequently sold on small economy cars. Four-wheel ABS installations for light 

trucks began in 1989 on some GM Astro/Safari minivans, Jeep Cherokee and Jeep Wagoneer. 

The market share for 4-wheel ABS in new light trucks steadily increased during the 1990’s, as 

RWAL was phased out, and had reached about 80 percent by 2001.36

How ABS works Few drivers are able to modulate pressure on the brake pedal optimally, given 

a sudden emergency situation or unexpectedly slippery surface. If excess pedal pressure locks 

only the front wheels, the vehicle will continue in a straight path, but the driver will be unable to 

steer it and avoid obstacles. If it locks the rear wheels, the vehicle can lose control. ABS senses 

if any of the four wheels have locked, and if so, quickly releases the brakes on that wheel and 

lets it start rolling again. Cycles of releasing, holding and reapplying brakes are repeated many 

times per second. 

ABS activation causes noise and pedal vibration in some vehicles, and steering may not be as 

easy as in normal operation. Nevertheless, a reasonably alert driver familiar with the system will 

maintain pressure on the pedal, stop in a minimum distance and be able to steer the vehicle 

throughout the crash avoidance maneuver. 

 

35 Hertz, E., Hilton, J. and Johnson, D.M., An Analysis of the Crash Experience of Light Trucks Equipped with

Antilock Braking Systems, NHTSA Technical Report No. DOT HS 808 278, Washington, 1995. 36 Kahane, C.J., Preliminary Evaluation of the Effectiveness of Antilock Brake Systems for Passenger Cars, NHTSA

Technical Report No. DOT HS 808 206, Washington, 1994, pp. 9 and 119-128; 2002 Ward’s Automotive 

Yearbooks, Ward’s Communications, Detroit; Kahane (1993 RWAL), pp. 15. 

27
NHTSA conducted stopping tests on straight and curved paths and various surfaces with ABSequipped cars, and also for the same cars with the ABS disabled. Results were impressive. 

Yawing was nearly eliminated and steering control maintained. Furthermore, on most surfaces, 

especially wet pavements, cars stopped in a shorter distance with ABS activated and steady pedal 

pressure than with ABS disabled and the trained test driver attempting to modulate and optimize 

the pedal pressure. The principal exception was a gravel surface, where ABS, although 

maintaining directional stability and control, took 28 percent longer to stop than just slamming 

on the brakes and sliding.37

Expected benefits The experience on the test track suggested that ABS could have safety 

benefits in many crash situations. Maintaining steering control and cutting stopping distances, 

especially on wet roads, could reduce frontal impacts into other vehicles and collisions with 

pedestrians. By preventing yaw and preserving steering control, ABS can help drivers keep their 

vehicle on a straight or curving road, and could prevent run-off-road crashes such as rollovers or 

fixed-object impacts. However, there could be some adverse impact due to longer stopping 

distances on gravel and other loose surfaces away from the road. 

Crash avoidance NHTSA’s preliminary evaluation of 4-wheel ABS for passenger cars was 

published in 1994. It is based on 1990-92 crash data from Florida, Missouri and Pennsylvania. 

Crash involvements as a frontally impacting car in a multivehicle collision, traveling faster than 

5 mph, were compared to the control group of cars struck while standing still or moving 5 mph 

or less (where the car’s ABS could not have been a factor in the crash).38 On wet roads, cars 

with ABS experienced a statistically significant, 28 percent reduction of frontal impacts, relative 

to the control group and relative to cars of the same make-models without ABS39: 

WET ROADS Multivehicle Control Ratio of

FL-MO-PA 1990-92 Frontals Group Frontals/Control 

Last 2 model years without ABS 1,220 922 1.323 

First 2 model years with ABS 841 879 .957 

On dry roads, the reduction was 5 percent, not statistically significant. For all road conditions 

(wet, dry, snowy, icy), the overall reduction in multivehicle frontal impacts with ABS was a 

statistically significant 9 percent. 

Run-off-road crashes, however, increased rather than decreased with ABS. Relative to the 

control group, rollovers and fixed-object impacts increased overall by a statistically significant 

19 percent in the ABS-equipped cars. The rate of increase was about the same on dry, wet and 

 

37 Kahane (1994 ABS), pp. 4-9; Hiltner et al., Op. cit.; Arehart et al., Op. cit. 38 Kahane (1994 ABS), pp. 10-57 and 106, especially 51, 53 and 55. 39 Ibid., p. 53.

28
snowy/icy roads.40 The issue of ABS performance in run-off-road crashes will be discussed in 

the next section. 

Fatality reduction The analysis was based on 1989-93 FARS data. In multivehicle crashes on 

dry roads, the ratio of involvements as a frontally impacting car to involvements as a car that was 

struck in the rear or side, or while standing still, was nearly the same with or without ABS. That 

suggests ABS has, at most, a small effect on multivehicle crashes on dry roads. For the 

remaining analyses, multivehicle crash involvements on dry roads (regardless of impact type) 

serve as the control group.41

Multivehicle crash involvements on wet roads were reduced by a statistically significant 24 

percent with ABS42: 

FARS 1989-93 Wet Dry Ratio of 

MULTIVEHICLE CRASHES Roads Roads Wet/Dry 

Last 2 model years without ABS 246 1,021 .241 

First 2 model years with ABS 158 858 .184 

Multivehicle crashes on snowy/icy roads decreased by 13 percent (not significant). Fatal 

collisions with pedestrians, bicyclists, trains or animals, on all road surfaces, were reduced by a 

statistically significant 27 percent.43

On the other hand, fatal run-off-road crashes (rollovers and impacts with fixed objects) increased 

by a statistically significant 28 percent on all road surfaces, with ABS44: 

Rollover + Dry Road 

FARS 1989-93 Fixed Object Multivehicle Ratio 

Last 2 model years without ABS 431 1,021 .422 

First 2 model years with ABS 463 858 .540 

The increases were about equally large on dry, wet and snowy/icy roads. In particular, side 

impacts with fixed objects, a crash type typically preceded by loss of directional control, 

increased by a statistically significant 57 percent. The increase in run-off-road crashes nearly

 

40 Ibid., p. 84-92. 41 Ibid., p. 57-62. 42 Ibid., p. 65. 43 Ibid., p. 63-68. 44 Ibid., p. 95.

29
offset the reductions in pedestrian and wet-road multivehicle crashes, resulting in a near-zero net 

effect on overall fatal-crash risk.45

NHTSA performed another statistical analysis of ABS in passenger cars, based on 1989-93 

FARS data as well as 1989-92/93 data from four States, using logistic regression of the ratio of 

relevant crashes to control-group crashes. This study confirmed the statistically significant 

increases of rollovers and side impacts with fixed objects in the ABS-equipped cars, in both fatal 

and nonfatal crashes. It also confirmed the benefits of ABS in fatal and nonfatal multivehicle 

crashes on wet roads.46 Furthermore, NHTSA’s initial analysis of 4-wheel ABS in light trucks 

showed similar increases (although not statistically significant) of rollovers and side impacts 

with fixed objects in the light trucks with the 4-wheel ABS.47 A 1996 study by the Insurance 

Institute for Highway Safety likewise observed a 28 percent increase in run-off-road crashes with 

ABS.48 Since all these analyses of United States data are based on more or less the same makemodels (and could conceivably have the same biases), it is noteworthy that a Swedish study, 

based on a quite different vehicle mix, also showed a substantial increase of run-off-road crashes, 

relative to multivehicle crashes on dry roads, with ABS.49

Hypotheses for the observed increases in run-off-road crashes included: 

• Driver inexperience/lack of knowledge about ABS. Drivers might remove their foot from 

the pedal in response to the [unanticipated] noise and vibration of ABS, or try to pump 

the pedal as with conventional brakes. 

• More aggressive driving due to a misperception of how much ABS reduces stopping 

distances or enhances control. 

• Longer stopping distances with ABS on the loose surfaces vehicles encounter after they 

leave the road. 

• The enhanced steering control while braking with ABS could allow unsafe panic steering 

maneuvers. 

• Possible flaws in ABS performance in certain maneuvers or on some roadway surfaces. 

NHTSA undertook a multiyear research program to test out these and other hypotheses.

50 

NHTSA, the manufacturers and suppliers and the insurance industry also developed media to 

educate vehicle owners about how ABS responds when activated, and how to use it properly 

(“Don’t let up [on the brakes]”). The research, in fact, has not identified any significant 

problems with ABS other than owners’ initial lack of knowledge and experience with the 

systems. 

 

45 Ibid., p. 115-117. 46 Hertz, E., Hilton, J. and Johnson, D.M., An Analysis of the Crash Experience of Passenger Cars Equipped with

Antilock Braking Systems, NHTSA Technical Report No. DOT HS 808 279, Washington, 1995. 47 Hertz et al. (1995 Light Truck ABS). 48 Farmer, C.M., Lund, A.K., Trempel, R.E. and Braver, E.R., Fatal Crashes of Passenger Vehicles Before and After 

Adding Antilock Brake Systems, Insurance Institute for Highway Safety, Arlington, VA, 1996. 49 Kullgren, A., Lie A. and Tingvall, C., “The Effectiveness of ABS in Real Life Accidents,” Proceedings of the 

Fourteenth International Technical Conference on the Enhanced Safety of Vehicles, NHTSA, Washington, 1994, 

Paper No. 94-S4-O-07. 50 Kahane (1994 ABS), pp. v-viii.

30
Three reports published in 2000-02 suggests that the increase in run-off-road crashes may have 

been largely or entirely temporary. NHTSA’s follow-up analysis based on 1995-96 FARS and 

State data showed that the increase in fatal run-off-road crashes was of lower magnitude than in 

the earlier years. In fact, ABS did not have a statistically significant effect on any type of fatal 

crash, except for an increase in LTV rollovers, whereas several types of nonfatal crash 

involvements were significantly reduced with ABS.51 The IIHS follow-up, while reconfirming 

the increase in run-off-road crashes of MY 1992 vehicles with ABS during CY 1993-95, found 

that these same MY 1992 vehicles did not experience any increase in run-off-road crashes during 

CY 1996-98, when they were 4-6 years old. However, this study did not find a statistically 

significant overall effect for ABS on fatal crashes in 1996-98; it did not analyze nonfatal 

crashes.52 Harless and Hoffer confirmed the IIHS results and, moreover, demonstrated that the 

increase in run-off-road crashes during the earlier years was virtually confined to drinking 

drivers. It was especially prevalent in young, drinking drivers or in drinking drivers with a 

history of high-risk driving behavior.53

These recent results suggest that the problems with ABS may have been largely due to owners’ 

inexperience and lack of knowledge about the systems. Thanks to the efforts to educate the 

public about ABS, and as owners simply accumulated years of experience with their vehicles, the 

increase in run-off-road crashes may have faded away. Moreover, the Harless paper suggests 

this wasn’t everybody’s problem, but was concentrated among drinking drivers. The 

combination of impairment with a sudden, unexpected noise and vibration may have led to 

inappropriate panic reactions. Furthermore, ABS technology has evolved over the years with 

improvements in the response and feedback to the driver, or with added features such as “brake

assist” that amplifies input from the driver. 

ABS may be due for a fresh look. If the effect on run-off-road crashes continues to be neutral, 

even if there is no significant overall effect on fatal crashes, the reductions of various types of 

nonfatal crashes could mark ABS as a technology with net safety benefits.54 

Electronic stability control (ESC) systems (preliminary evaluation) 

Voluntary installation history Mercedes-Benz first offered electronic stability control systems 

in 1997 as standard equipment on the top-of-the-line S600 and SL600 and as an option on some

other luxury cars. The next year, ESC was standard on Cadillac DeVille Concours, BMW 700-

series and a few additional Mercedes models. By 2000, it was standard on most BMW and 

Mercedes cars, Cadillac Seville and a few other GM luxury models, Lexus LS and GS and Acura 

RL. Among SUVs, ESC was standard on Mercedes in 1999, on Lexus LX in 2000, followed by 

Toyota 4Runner and Landcruiser and Lexus RX in 2001. ESC was installed on 7.4 percent of 

 

51 Hertz, E., Analysis of the Crash Experience of Vehicles Equipped with All Wheel Antilock Braking Systems (ABS)

– A Second Update Including Vehicles with Optional ABS, NHTSA Technical Report No. DOT HS 809 144,

Washington, 2000. 52 Farmer, C.M., “New Evidence Concerning Fatal Crashes of Passenger Vehicles Before and After Adding

Antilock Braking Systems,” Accident Analysis and Prevention, Vol. 33, 2001, pp. 361-369. 53 Harless, D.W. and Hoffer, G.E., “The Antilock Braking System Anomaly: A Drinking Driver Problem?,” 

Accident Analysis and Prevention, Vol. 34, 2002, pp. 333-341. 54 National Highway Traffic Safety Administration Evaluation Program Plan, Calendar Years 2004-2007, NHTSA

Report No. DOT HS 809 699, Washington, 2004, pp. 26-27. 

31
vehicles sold in model year 2003. No FMVSS requires ESC systems. However, NHTSA 

believes ESC is a promising safety technology; since 2001, the agency’s annual Buying a Safer 

Car brochures have been informing the public what make-models are equipped with ESC. 

How ESC works ESC systems detect and automatically assist drivers in situations that lead to 

loss of control (e.g. understeer and oversteer) and occur especially in unfavorable conditions 

(rain, snow, sleet, ice). Sensors monitor the speed of each wheel, the steering wheel angle, and 

the yaw rate and lateral acceleration of the vehicle. The yaw rate is the rate of change of the 

vehicle’s heading. The system compares the measured yaw rate to the intended rate of change of 

heading consistent with the speed and lateral acceleration of the vehicle. For example, a yaw 

rate measurement greater than that consistent with the speed and lateral acceleration of the 

vehicle indicates oversteer. ESC would make a rapid automatic intervention to correct the 

vehicle heading by applying the brakes to individual wheels and possibly reducing engine torque 

to help the driver stay on the road. If the vehicle was experiencing the onset of oversteer in a left 

curve, ESC would momentarily apply the brake to the right front wheel to counteract the 

excessive yaw rate and stabilize the vehicle. Some systems may then slow down the vehicle to a 

speed more appropriate for conditions. All current vehicles with ESC are also equipped with 

ABS and traction control systems; the ESC to a large extent builds on ABS technology and 

shares ABS components.55

Expected benefits ESC would appear to be most effective in preventing single-vehicle run-offroad crashes including rollovers and collisions with fixed objects. That is because many of them

involve a loss of directional stability or control during the pre-crash sequence of events. For 

example, if adverse conditions on the road trigger a skid, ESC could stabilize the vehicle and 

prevent the entire off-road excursion. Even if a careless driver has already drifted off the road 

with two wheels, ESC may help maintain directional control and stability, making it easier for 

the driver to get back on the road and avoid a crash. Presumably, ESC would have much less 

effect on collision involvements on the road with other vehicles, pedestrians or animals, because 

a smaller proportion of these crashes are preceded by a loss of directional stability. A unique 

feature of ESC that could make it especially effective is that it can activate without any action by 

a driver (unlike, for example, ABS, which cannot activate unless the driver applies the brakes). 

Crash avoidance – passenger cars NHTSA’s preliminary evaluation was published in 2004.56 

It is based on calendar year 1997-2002 crash data from Florida, Illinois, Maryland, Missouri and 

Utah for model year 1997-2002 cars of make-models that received ESC as standard equipment at 

some point during those model years. Involvements in single-vehicle crashes (excluding 

collisions with pedestrians/bicyclists, animals or trains) were compared to a control group of 

involvements in multivehicle crashes. Cars with ESC experienced a statistically significant 35 

percent reduction of single-vehicle crashes, relative to the control group and relative to cars of 

the same make-models without ESC57: 

 

55 Dang, J.N., Preliminary Results Analyzing the Effectiveness of Electronic Stability Control (ESC) Systems,

NHTSA Evaluation Note No. DOT HS 809 790, Washington, 2004. 56 Ibid. 57 95% confidence bounds: 29 to 41 percent.

32
FL-IL-MD-MO-UT Single-Vehicle Multivehicle Ratio of

1997-2002 Involvements Involvements Single/Multi 

Cars without ESC 1,483 19,044 .0779 

Cars with ESC (same make-models) 699 14,090 .0496 

Fatality reduction – passenger cars A similar analysis of fatal single- vs. multi-vehicle crash 

involvements in 1997-2003 FARS data showed a statistically significant 30 percent reduction of 

fatal single-vehicle crash involvements with ESC.58

Crash avoidance – light trucks In model years 1997-2002, the only LTV make-models

equipped with ESC were SUVs. The analysis of single- vs. multi-vehicle crash involvements by 

SUVs in five States (a database about 1⁄4 as large as the car sample) showed a statistically 

significant 67 percent reduction of single-vehicle crash involvements with ESC.59

Fatality reduction – light trucks Fatal single-vehicle crash involvements of SUVs were reduced 

by a statistically significant 63 percent with ESC.60

Comments on the findings Logistic regression analyses on the proportion of car crash 

involvements that are single-vehicle, controlling for vehicle age and make-model group, driver 

age and gender, attributed nearly the same crash reduction and fatality reduction to ESC as the 

preceding contingency table analyses. 

Multivehicle crash involvements are not necessarily an ideal control group, as they, too, could be 

influenced up to a point by ESC. Because nonfatal multivehicle crashes are far more common 

than single-vehicle crashes, it is at least conceivable that a small relative increase in multivehicle

crashes could offset the reduction in single vehicle crashes (not that there is any intuitive basis 

for anticipating such an increase). However, linear regression analyses of multivehicle crash 

involvement rates per 100,000 vehicle registration years, controlling for vehicle age, attributed 

significant or borderline-significant reductions in those rates to ESC. In other words, the 

preliminary evaluation did not see a negative side effect for ESC in multivehicle crashes, and 

possibly even a benefit. 

However, a caveat on these preliminary findings is that the database consisted primarily of 

luxury make-models; BMW and Mercedes-Benz constituted 61 percent of the passenger car 

sample. A single manufacturer, Toyota/Lexus, contributed 78 percent of the SUVs in the 

database. NHTSA will feel more confident about the overall effectiveness of ESC when the data 

comprise a more representative cross-section of the fleet including non-luxury vehicles and a 

wider variety of manufacturers. 

 

58 95% confidence bounds: 10 to 50 percent. 59 95% confidence bounds: 60 to 74 percent. 60 95% confidence bounds: 44 to 81 percent.

33
FMVSS 108: Lamps, reflective devices, and associated equipment

This standard regulates three innovative safety technologies that have been evaluated by 

NHTSA: 

• Side marker lamps

• Center High Mounted Stop Lamps (CHMSL)

• Retroreflective tape on heavy trailers

The goal of side marker lamps is to make the sides of vehicles more visible in the dark, and to 

prevent nighttime angle collisions. They have been standard equipment on all cars and light 

trucks since model year 1970. CHMSL are designed to enhance the effect of stop lamps and 

reduce front-to-rear collisions, by day and night. They have been standard on cars since model 

year 1986 and were phased into light trucks during model years 1991-94. Retroreflective tape 

makes heavy trailers more visible from the side and the rear, in the dark, so other vehicles won’t 

hit them. It has been standard on new trailers over 10,000 pounds GVWR since December 1, 

1993 and also has to be on older trailers still on the road as of June 1, 2001. 

The second paragraph of FMVSS 108 states, “The purpose of this standard is to reduce traffic 

accidents ... by providing adequate illumination of the roadway and by enhancing the 

conspicuity of motor vehicles ... so that their presence is perceived and their signals understood, 

both in daylight and in darkness.”1

 FMVSS 108 regulates many lamps, reflectors, bulbs and 

flashers on the vehicle exterior, and the systems for controlling them. Most of those devices 

existed well before NHTSA, were specified in SAE standards subsequently incorporated into 

FMVSS 108, and remained unchanged or at most, underwent gradual or subtle changes during 

1968-99. Side marker lamps, CHMSL and retroreflective tape are three exceptions where a 

fundamentally new safety device was required. NHTSA’s evaluations of these three 

technologies will now be discussed, one-by-one. 

Side marker lamps 

Regulatory history FMVSS 108, one of NHTSA’s initial safety standards, took effect for 

vehicles over 80 inches wide (large trucks and buses) on January 1, 1968. It was extended to 

passenger cars and light trucks, effective January 1, 1969. Side marker lamps and/or reflectors 

were required from the start. Vehicles must have two combination lamp/reflectors on each side, 

an amber one as close as possible to the front and a red one close as possible to the rear. 

(Vehicles more than 30 feet long require an additional amber lamp/reflector at the midpoint.) 

However, to give manufacturers of cars and LTVs some more lead time, the standard allowed 

use of just a lamp, or just a reflector, in lieu of a lamp/reflector, during calendar year 1969. 

Since January 1, 1970, all cars and light trucks must have four lamp/reflectors. The side marker 

lamp requirement primarily incorporates SAE Recommended Practice J592. Although issued by 

the SAE in 1964, it did not immediately put side marker lamps on all domestic cars and light 

trucks, because it was only a Recommended Practice, not a Standard. Instead, the proportion of 

new cars and light trucks with side marker lamps increased gradually from 5 percent in model 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.108. 

34
year 1964 to 13 percent in 1967, then jumped to 88 percent in 1968 and reached 100 percent in 

1970.2

How side marker lamps work Before side marker lamps, a car or light truck was very hard to 

see from the side, in the dark. A vehicle entering a right-angle intersection, or pulling out of a 

driveway onto unlit or weakly illuminated roads was virtually invisible to cross traffic, or at least 

did not provide any visual cues to catch the attention of other drivers. Headlamps, in particular, 

focus their beams straight ahead and may barely be visible from the side (unless the approaching 

vehicle is still a substantial distance to the left or right, and there are no vision obstructions such 

as trees or buildings). 

Side marker lamps make cars visible from the side, in the dark, and enable other drivers to avoid 

collisions. Moreover, the use of amber in the front and red in the back sends a visual cue: “You 

are approaching the side of a vehicle – here’s how big it is, and it’s not necessarily getting out of 

your way.” The two colors distinguish the front of a car (white or amber light) from its rear (red 

light). Side marker lamps are on whenever the parking lights are on, and when they aren’t (e.g., 

on a parked vehicle), the reflectors throw back some of the light from other vehicles’ headlamps. 

Two systems have been used to meet the standard. One makes the existing parking lamps and 

tail lamps visible from the side by designing their lens/reflectors to “wrap around” the sides of 

the vehicle. The other approach is to install dedicated side marker lamps, separate from the 

parking lamps and tail lamps. Both methods are acceptable under FMVSS 108 and are believed 

to be essentially equivalent. FMVSS 108, like SAE Recommended Practice J592, requires at 

least 0.62 candela for amber side marker lamps, and 0.25 candela for red ones, as measured from

9 specified observation points. That makes them considerably less bright than, for example, tail 

lamps, let alone stop lamps. Side marker lamp/reflectors are too dim to make vehicles more 

conspicuous by day, and perhaps even to be seen from a long enough distance, in the dark, to 

avoid high-speed, potentially fatal collisions.3

Expected benefits Side marker lamps ought to reduce the number of angle collisions in reduced 

lighting conditions: dark not lighted, dark lighted, dawn or dusk. The definition of an “angle” 

collision varies but generally include crashes where two vehicles approach one another at an 

angle, typically 90 degrees, or where the front of one vehicle hits the side of the other. The 

lamps should have little or no effect on daytime crashes. When two vehicles approach at an 

angle in the dark, there could be benefits if either one is equipped with the lamps, and doubly so 

if both are equipped: lamps on vehicle 1 can help driver 2 avoid a crash, and lamps on vehicle 2 

can help driver 1 avoid it. When the lamps prevent a crash, they not only save the lampequipped vehicle from damage, but also the other vehicle that would have been in the crash. 

Furthermore, if any occupant of either vehicle would have been injured, these injuries are 

prevented. As stated above, it is doubtful if the lamps would have much effect on fatal crashes. 

 

2

 Kahane, C.J., An Evaluation of Side Marker Lamps for Cars, Trucks and Buses, NHTSA Technical Report No. 

DOT HS 806 430, Washington, 1983, pp. 1-7 and 29-32; Federal Register 32 (February 3, 1967): 2414, 32

(December 16, 1967): 18033; 1983 SAE Handbook, Vol. 2, Society of Automotive Engineers, Warrendale, PA, 

1983. 3

 Kahane (1983 Side Marker Lamps), pp. 1-7 and 29-32; Cole, B.L., Dain, S.J. and Fisher, A.J., Study of Motor

Vehicle Signal Systems, HSL Publication No. DOT HS 022 690, Road Safety Information Service, Melbourne, 1977.

35
Crash avoidance NHTSA’s evaluation was published in 1983. It is based on crash data from

North Carolina (1971-80) and Texas (1972-74).4

 The data allow a tally of vehicle involvements 

in angle collisions under reduced-light conditions. They also allow counting a control group of 

involvements in daytime angle collisions. Tallies are compared, for example, in model year 

1967, when only 13 percent of cars, trucks and buses had side marker lamps, and model year 

1968, when 88 percent of cars, trucks and buses were equipped with the lamps: 

 Angle Collisions

 Ratio of

 Night5

 Day Night/Day 

NORTH CAROLINA 

Model year 1967 (13% with side marker lamps) 5,971 20,755 .288 

Model year 1968 (88% with side marker lamps) 7,075 26,351 .268 

TEXAS 

Model year 1967 (13% with side marker lamps) 7,738 30,324 .255 

Model year 1968 (88% with side marker lamps) 8,715 36,618 .238 

In both states, the ratio of nighttime to daytime crashes is a statistically significant 6.7 percent 

lower in the 1968 vehicles. The arithmetic in the preceding tables works out to 8.8 percent fewer 

nighttime angle collision when one of the two vehicles has the lamps than when neither has the 

lamps.6

 That means 16.8 percent fewer nighttime angle collisions when both vehicles have the 

lamps than when neither have them.

7

 Nearly identical effectiveness estimates were obtained 

when the data were expanded to two, three, or four model years before and after the 1968 shift to 

side marker lamps, or in regression analyses of the ratio of nighttime to daytime angle-collision 

involvements by presence of side marker lamps and other factors such as vehicle age.8

 The 

evaluation concluded that the best estimate of side marker lamp effectiveness, based on one of 

these regressions, is a 16 percent reduction of nighttime angle collisions when both vehicles have

the lamps.9

 Using 1979-80 as the “baseline” years, the evaluation estimated that side marker 

lamps would prevent 106,000 police-reported nighttime angle collisions per year when all cars, 

trucks and buses on the road were equipped with the lamps.10

Injury reduction Estimates of injury reduction were obtained by limiting the preceding analyses

of North Carolina and Texas data to injury-producing crashes – i.e., crashes where at least one 

occupant in any of the involved vehicles (not necessarily the vehicle equipped with side marker 

lamps) was injured. All of these analyses show a somewhat stronger reduction of injuryproducing crashes than property-damage-only crashes. The evaluation’s best estimate of side 

 

4

 Kahane (1983 Side Marker Lamps), pp. 39-48. 5

 Includes dark not lighted, dark lighted, dawn and dusk. 6

 (1 - .067) = [.88(1-.088) + .12] / [.13(1-.088) + .87] 7 .168 = 1 – [(1-.088)(1-.088)] 8 Ibid., pp. 69-85. 9 Ibid., pp. 120-122; 90% confidence bounds: 10 to 22 percent. 10 Ibid., pp. 136-139; 90% confidence bounds: 65,000 to 149,000 crashes prevented. 

36
marker lamp effectiveness is a 21 percent reduction of injury-producing nighttime angle 

collisions when both vehicles have the lamps.

11 The evaluation estimated that side marker lamps 

would prevent 93,000 injuries in nighttime angle collisions per year.12

Fatality reduction When the preceding contingency-table and regression analyses were 

performed with 1975-81 FARS data, they did not show any reduction of fatal angle collisions, in 

the dark, with side marker lamps. A case-by-case review of Multidisciplinary Accident 

Investigations (MDAI) showed that the great majority of fatal nighttime angle collisions (but not 

nearly so many nonfatal collisions) involved at least one of these two factors that would make 

the lamps unlikely to help prevent a crash: (1) a vehicle traveling at least 50 mph, too fast for the 

driver to see the relatively dim lamps in time to take evasive action; (2) two vehicles approaching 

at right angles at relatively similar speeds, where drivers ought to see each others’ headlamps 

more easily than the side marker lamps. In addition, many nighttime fatal crashes involve 

alcohol-impaired drivers who are not likely to be alert to the lamps. The evaluation concluded 

that side marker lamps, although highly effective in reducing nonfatal crashes and their injuries, 

have little effect in fatal crashes.13

Center High Mounted Stop Lamps (CHMSL) 

Regulatory history After much experimental research (1974-79), on-the-road testing (1976-79) 

and regulatory analysis, NHTSA amended FMVSS 108 in October 1983 to require CHMSL on 

new passenger cars, effective September 1, 1985. CHMSL were standard equipment on all 

model year 1986 cars; also on 1985 Cadillacs. In addition, consumers welcomed the lamps, 

purchased about 4,000,000 retrofit kits and installed them on their pre-1986 cars. An April 1991 

amendment extended the CHMSL requirement to pickup trucks, vans and SUVs manufactured 

on or after September 1, 1993. All light trucks had the lamps in model year 1994, some makemodels as early as 1991.14

How CHMSL work Stop lamps are a basic tool for preventing rear-impact collisions, daytime 

and nighttime. When a driver applies the brake pedal, the lamps alert the following driver to 

slow down immediately, maintain a safe distance, and be ready to stop. Conventional stop lamps 

are less than optimal for accomplishing their mission. They are low and off toward the sides of 

the vehicle, not where the following driver is looking most of the time. During quick scanning, 

they might be confused with adjacent taillights and turn signals, and misinterpreted to mean a car 

is proceeding or turning, rather than slowing down. 

NHTSA and the insurance industry tested various configurations of experimental stop lamps, in 

the laboratory and on the road, and concluded that the best system combined the two existing 

stop lamps with a third red lamp, mounted in the center of the vehicle, and if possible higher than 

 

11 Ibid., pp. 48-53, 86-89, and 123; 90% confidence bounds: 12 to 29 percent. 12 Ibid., pp. 141-143; 90% confidence bounds: 51,000 to 132,000 injuries prevented. 13 Ibid., pp. 62-66, 100-112 and 125-130; Cole, Dain, and Fisher, Op. Cit. 14 Kahane, C.J. and Hertz, E., The Long-Term Effectiveness of Center High Mounted Stop Lamps in Passenger Cars 

and Light Trucks, NHTSA Technical Report No. DOT HS 808 696, Washington, 1998, pp. 1-2, 9 and 62-63;

Federal Register 48 (October 18, 1983): 48235, 56 (April 19, 1991): 16015; Final Regulatory Impact Analysis, 

Federal Motor Vehicle Safety Standard 108, Center High-Mounted Stop Lamps, NHTSA Docket No. 81-02-N02-

001, 1983. 

37
the other two. The central and raised location of CHMSL puts them in the area where the 

following driver most often glances. It separates them from tail lamps and turn signals and 

minimizes confusion. The high mounting might make it visible through the windows of a 

following vehicle and enable the driver of the third vehicle in a chain to react to the first 

vehicle’s braking. The three lamps form a triangle that might be an additional cue to get a 

driver’s attention and a warning to keep a safe following distance. As a consequence, CHMSL 

significantly reduced the average time for drivers to apply their brakes in response to the signal 

from the vehicle in front of them.

15

Road tests with fleets of taxicabs and telephone-company cars were very encouraging, showing a 

35 percent reduction of rear-impact collisions in the CHMSL-equipped cars relative to controlgroup cars with conventional stop lamps. They paved the way for the CHMSL regulation by 

suggesting the lamps would be highly beneficial and cost-effective.16

Two questions arose during the CHMSL rulemaking in the early 1980’s. One was if the high 

effectiveness in the fleet tests would persist after the lamps became standard equipment on 

millions of vehicles, or if drivers would gradually become acclimatized to the lamps and less 

conscious of them. This would be examined by repeated evaluations of CHMSL for about 10 

years after they became standard on passenger cars. The other was if CHMSL would be 

effective on pickup trucks, where they would likely be on top of the cab, far away from all other 

lamps, or on full-sized vans, where they might be above the following driver’s usual line of 

vision. As a consequence, CHMSL were only required on passenger cars as of September 1, 

1985, and the requirement was extended to light trucks as of September 1, 1993 only after 

additional research satisfied NHTSA that they would be effective there.17

Expected benefits CHMSL ought to reduce the probability of being struck in the rear by another 

vehicle, daytime or nighttime.18 That will help prevent simple two-vehicle front-to-rear

collisions and chain collisions involving three or more vehicles. When the lamps prevent a 

crash, they not only save the struck, CHMSL-equipped vehicle from damage, but also the 

striking vehicle. Furthermore, if any occupant of either vehicle would have been injured, these 

injuries are prevented. To the extent that fatal rear-impact crashes involve much higher speeds 

and different crash conditions from the nonfatal ones, it is not clear if the lamps would have 

much effect, if any, on fatal crashes. 

 

15 Kahane and Hertz, pp. 1-2; Digges, K.H., Nicholson, R.M. and Rouse, E.J., The Technical Basis for the Center 

High Mounted Stoplamp, Paper No. 851240, Society of Automotive Engineers, Warrendale, PA, 1985. 16 Kahane and Hertz, pp. 2-3; Kohl, J.S. and Baker, C., Field Test Evaluation of Rear Lighting Systems, NHTSA 

Technical Report No. DOT HS 803 467, Washington, 1978; Rausch, A., Wong, Jackson I. and Kirkpatrick, M., A 

Field Test of Two Single Center High-Mounted Brake Light Systems, Submission to NHTSA Docket No. 81-02-

N01-031, Insurance Institute for Highway Safety, Arlington, VA, 1981; Reilly, R.E., Kurke, D.S. and Buckenmaier, 

C.C., Jr., Validation of the Reduction of Rear End Collisions by a High Mounted Auxiliary Stoplamp, NHTSA

Technical Report No. DOT HS 805 360, Washington, 1980. 17 Evaluation Plan for Center High-Mounted Stop Lamps, NHTSA Docket No. 81-02-N02-002, 1983; Final

Regulatory Impact Analysis, Amendment to FMVSS 108 to Require Center High-Mounted Stop Lamps on Light

Trucks and Buses, NHTSA Docket No. 81-02-N10-001, 1991. 18 Unlike side marker lamps in angle collisions, CHMSL are beneficial only on the struck vehicle. When two 

vehicles approach at a 90 degree angle, either driver may see the other vehicle’s side marker lamps, but when two

vehicles travel in the same direction, only the following driver can see the other vehicle’s CHMSL.

38
Crash avoidance – passenger cars NHTSA evaluated CHMSL in 1987, 1989 and 1998; only 

the last evaluation, which superseded the earlier results, will be discussed here.19 It is based on 

1986-95 crash data from eight states: Florida, Indiana, Maryland, Missouri, Pennsylvania, Texas, 

Utah and Virginia. These state files identify each crash-involved car’s model year and impact 

site (rear impact vs. other). The basic contingency tables compare the last model year(s) before 

CHMSL became standard equipment to the first model year(s) they were standard. They tally 

how many cars were struck in the rear, and how many cars were involved in any other kind of 

impact (the control group). The following example is based on Florida data for calendar year 

1987, comparing the crash experience of model year 1985 and 1986 cars: 

 Collision Involvements 

 Ratio of

Florida, CY 1987 crashes Rear Impacts Others Rear/Other 

Model year 1985 ( 10% with CHMSL20) 6,773 22,959 .295 

Model year 1986 (100% with CHMSL) 7,161 25,989 .276 

In this example, the ratio of rear impacts to other-type crash involvements is a statistically 

significant 6.6 percent lower in the model year 1986 cars than in the 1985 cars, indicating a 

benefit for CHMSL. However, this analysis understates the effectiveness of CHMSL because it 

does not adjust for vehicle age. Newer cars in general have relatively more rear impacts (and are 

less often the striking vehicle), inflating the “ratio of rear/other crashes.” The evaluation 

developed a regression analysis that adjusted for vehicle age and yielded unbiased estimates of 

the effectiveness of CHMSL. The effect was positive and statistically significant in each of the 

eight states. When the results from the eight states are combined, the weighted-average 

effectiveness of CHMSL is statistically significant in each separate calendar year. However, the 

effect was highest in 1987, dropped in half by 1989, and then leveled off: 

Calendar Rear Impact Reduction Calendar Rear Impact Reduction 

Year by CHMSL (%) Year by CHMSL (%) 

1986 5.1 1991 5.0 

1987 8.5 1992 5.0 

1988 7.2 1993 3.2 

1989 4.3 1994 3.4 

1990 5.3 1995 3.9 

 

19 Kahane and Hertz, pp. 7-41; Kahane, C.J., The Effectiveness of Center High Mounted Stop Lamps: A Preliminary 

Evaluation, NHTSA Technical Report No. DOT HS 807 076, Washington, 1987; Kahane, C.J., An Evaluation of

Center High Mounted Stop Lamps Based on 1987 Data, NHTSA Technical Report No. DOT HS 807 442,

Washington, 1989. 20 Assumed to be equipped with CHMSL retrofit kits (not explicitly noted in the crash data). 

39
Effectiveness dropped significantly in 1988 and 1989, but there was no statistically significant 

downward trend after 1989. The average effectiveness in 1989-95, 4.3 percent, may be 

considered the long-term effectiveness of CHMSL. The initial and long-term effectiveness 

estimates, and their 90% confidence bounds21, are: 

Rear Impact Reduction 90% Confidence 

Calendar Year Group by CHMSL (%) Bounds 

1986 5.1 2.9 to 7.3 

1987 8.5 6.6 to 10.5 

1988 7.2 5.2 to 9.1 

1989-95 (long-term effect) 4.3 3.1 to 5.5 

The decline in effectiveness to 4.3 percent long-term from 8.5 percent in 1987 (and from 35 

percent in the test fleets of taxicabs and telephone-company cars) is consistent with the 

hypothesis that motorists would become acclimatized to the lamps. CHMSL are no longer 

startling, but their good location continues to make them effective. 

More detailed analyses of data from five states (Florida, Maryland, Missouri, Pennsylvania and 

Utah) show CHMSL effective in the dark but even more so in daytime. They are effective 

regardless whether the following driver is young or old, male or female. In general, the simpler 

the crash scene, and the less a driver is distracted by other lights or traffic features, the more 

effective the CHMSL – e.g., at locations away from traffic signals, in rural areas, in simple twovehicle collisions.22

Injury reduction – passenger cars Detailed analyses from five states show CHMSL are almost 

equally effective in preventing nonfatal-injury and property-damage crashes. In other words, the 

lamps’ long-term effect will be to prevent 4.3 percent of the nonfatal injuries to occupants of any 

of the vehicles involved in front-to-rear collisions, including occupants of the striking, frontallyimpacting vehicles.23

Fatality reduction – passenger cars When the basic crash-avoidance analysis was performed 

with 1986-95 FARS data, it did not show a statistically significant reduction of fatal rear-impact 

collisions with CHMSL in any specific calendar year, or in all of the calendar years combined. 

The lamps had little or no effect on fatal crashes at any time during 1986-95. A closer look at 

the data reveals that, in the majority of fatal rear impacts, the struck vehicle was not slowing or 

braking at all prior to the impact: the CHMSL was not activated and could not have had an 

effect.24

 

21 Kahane and Hertz, pp. 39-40 and 81-83 computes 95% confidence bounds; they have been scaled back to 90% 

confidence bounds here (by taking ± 1.645 rather than ± 1.96 standard deviations), for consistency with most of the 

other NHTSA evaluations. 22 Kahane and Hertz, pp. 43-53. 23 Ibid., pp. 53-54. 24 Ibid., pp. 54-60. 

40
Effectiveness – light trucks Pickup trucks, vans and SUVs received CHMSL in 1991, 1992, 

1993 or 1994, depending on the make-model. NHTSA analyzed 1994-96 crash data from six 

states that record the impact site and the VIN, allowing identification of make-model and model 

year: Florida, Maryland, Missouri, North Carolina, Pennsylvania and Utah. The crash-avoidance 

analysis, similar to the one for passenger cars, estimated that CHMSL in light trucks reduced rear 

impacts by a statistically significant 5.0 percent. The 90% confidence bounds are 1.0 to 8.7 

percent. For practical and statistical purposes, this is more or less the same as the 4.3 percent 

long-term effectiveness estimate for passenger cars. The data did not show any significant 

variations in CHMSL effectiveness between pickup trucks, vans and SUVs.25

Summary of benefits Using 1994 as the “baseline” year, and based on a 4.3 percent long-term

effectiveness in light trucks as well as cars, the evaluation estimated that CHMSL would prevent 

92,000 to 137,000 police-reported rear-impact crashes per year, plus 102,000 unreported crashes, 

when all cars and light trucks on the road are equipped with the lamps. That will save 43,000 to 

55,000 people from injury in the police-reported crashes, and 15,000 in the unreported crashes, 

for a total of 58,000 to 70,000 injuries avoided per year. At 1994 costs and prices, the value of 

the property damage avoided, even without counting anything for the injuries prevented, far 

exceeds the consumer cost of CHMSL, making them a highly cost-effective safety device.26

Retroreflective tape on heavy trailers 

Regulatory history After extensive research, on-the-road testing and analysis, NHTSA amended 

FMVSS 108 in December 1992 to require retroreflective tape or sheeting, or reflex reflectors, on 

the sides and rear of heavy trailers (i.e., at least 80 inches wide and with GVWR over 10,000 

pounds), effective December 1, 1993. Retroreflective tape has been used almost exclusively for 

meeting the standard, and it is the subject of NHTSA’s evaluation. On new trailers 

manufactured on or after December 1, 1993, the tape outlines the bottom of the sides of the 

trailers, and the top corners, bottom and underride guard of the rear of the trailers. It is applied in 

a pattern of alternating red and white segments to the side, rear and underride guard, and in white 

to the upper rear corners. FMVSS 108, like other FMVSS, applies to new vehicles at the time 

they are manufactured or imported.27

In addition, the Federal Motor Carrier Safety Administration (FMCSA; and its predecessor, the 

Bureau of Motor Carrier Safety within the Federal Highway Administration) issued a regulation 

in March 1999 requiring all heavy trailers on the road on or after June 1, 2001, including older 

trailers manufactured before December 1, 1993, to have a conspicuity treatment. The FMCSA 

regulation allows older trailers some flexibility on the location and colors of the tape. Before 

1992-93, quite a few manufacturers voluntarily equipped their trailers with tape, but not always 

according to the pattern subsequently chosen by NHTSA. In other words, FMCSA accepts those 

patterns for now and does not require an immediate retrofit to the NHTSA pattern. However, as 

of June 1, 2009, FMCSA will require all heavy trailers on the road to have the NHTSA pattern: 

many pre-1993 trailers would be retired by then, but if not, they would need a retrofit. 

 

25 Ibid., pp. 61-70. 26 Ibid., pp. 71-75. 27 Morgan, C., The Effectiveness of Retroreflective Tape on Heavy Trailers, NHTSA Technical Report No. DOT HS 

809 222, Washington, 2001, pp. 1-6; Federal Register 57 (December 10, 1992): 58406.

41
Furthermore, the FMCSA regulation applies to trailers-in-use. Conspicuity treatments have to be 

maintained “good-as-new” and may be inspected as long as trailers are on the road. When tape 

deteriorates or peels over time, it must be repaired or replaced.28

Although these regulations do not apply directly to passenger cars and light trucks, they are 

included here because their benefits – lives saved, injuries and damages avoided – will accrue

primarily to the occupants of the passenger vehicles that are at risk of hitting the trailers. 

How retroreflective tape works Heavy trailers are quite difficult for drivers of other vehicles to 

see in the dark, and even harder to recognize for what they are. The surfaces of most trailers are 

not shiny and are barely seen until they suddenly loom up, too close to stop in time. Tail lamps, 

clearance lamps and side marker lamps theoretically outline a trailer, but they are isolated points 

of light on a large surface. Drivers might not see enough of them at the same time to understand, 

“There’s a heavy trailer in front of me.” Collisions of passenger vehicles into heavy trailers are 

intrinsically dangerous, day or night, because of the weight and height mismatch of the vehicles. 

In the dark, those collisions were resulting in over 500 fatalities per year during the 1980’s. 

Human-factors research suggested that continuous or semi-continuous retroreflective tape with 

alternating red and white segments would highlight and identify trailers. The tape reflects a car’s 

headlights strongly and it is highly visible in the dark. The red and white pattern flags its bearer 

as a heavy trailer. Since the pattern extends around the sides and rear, a driver can identify a 

trailer as soon as the headlamps shine on any part of the tape. The standard-length segments in 

alternating colors additionally help drivers gauge their distance from the trailer and their rate of

approach.29

A 1983-85 road test of 1,910 trailers equipped with tape and 1,910 control-group trailers showed 

statistically significant reductions of side and rear impacts with the tape, 21 percent in the dark 

and, interestingly, 16 percent in daylight. NHTSA proceeded with the rulemaking, predicted a 

15-25 percent reduction of side and rear impacts in the dark but, conservatively, did not presume 

a reduction of daylight crashes.30

Expected benefits As stated above, retroreflective tape ought to reduce impacts by other 

vehicles into the side or rear of a heavy trailer, in the dark. The tape should not affect singlevehicle crashes of tractor-trailers, or crashes where a truck frontally runs into a car. Highest 

effectiveness is expected on unlighted roads, where a trailer is least visible without the tape, and 

 

28 Federal Register 64 (March 31, 1999): 15587. 29 Burger, W.J., et al., Improved Commercial Vehicle Conspicuity and Signalling Systems, Task I – Accident

Analysis and Functional Requirements, NHTSA Technical Report No. DOT HS 806 100, Washington, 1981; 

Ziedman, K., et al., Improved Commercial Vehicle Conspicuity and Signalling Systems, Task II – Analyses, 

Experiments and Design Recommendations, NHTSA Technical Report No. DOT HS 806 098, Washington, 1981. 

The research indicated that the tape did not have to be fully continuous on the sides of trailers – as little as 50

percent coverage accomplished safety objectives – and FMVSS 108 accordingly requires at least 50 percent

coverage on the sides and continuous tape on the rear; however, many trailers have fully continuous coverage on the 

sides and rear 30 Burger, W.J., et al., Improved Commercial Vehicle Conspicuity and Signalling Systems, Task III – Field Test

Evaluation of Vehicle Reflectorization Effectiveness, NHTSA Technical Report No. DOT HS 806 923, Washington, 

1985; Preliminary Regulatory Evaluation – Proposed Amendment to FMVSS No. 108 to Require Retroreflective 

Material on the Side and Rears of Heavy Trailers, Submission to NHTSA Docket No. 80-02-N09, NHTSA, 1991. 

42
the reflection from the tape stands out the most strongly relative to the background. Less benefit 

is expected on lighted roads, or in twilight, because trailers are more visible, and the tape does 

not stand out as much. Even less benefit, if any, is expected in daylight, because trailers are 

easily visible without the tape, although the red and white pattern might help as an additional 

warning. 

When the tape prevents a crash, it prevents the injuries to the occupants of any of the vehicles 

that would have been involved in the crash: the vehicle striking the trailer as well as the tractor 

pulling the trailer. Of course, most of those injuries would have been in the striking vehicle, and 

most of the striking vehicles would have been cars or LTVs. Unlike side marker lamps and 

CHMSL, there is every reason to hope that the tape will save lives, since impacts of passenger 

vehicles into trailers can easily be fatal at the speeds and sighting distances where the tape is 

likely to be effective. 

The tape might be more effective in rear impacts than side impacts, if only because in most rearimpacts the passenger vehicle’s headlights would point at the trailer, and the driver of the 

passenger vehicle is culpable for not slowing down or stopping in time – whereas in many side 

impacts the passenger vehicle’s headlights might not point at the trailer (e.g., sideswipes), or they 

might not illuminate the trailer soon enough for the car/LTV driver to take action (e.g., highspeed intersection collisions), or trailer conspicuity is not an issue because the truck driver’s 

action (e.g., sudden lane departure) precipitates the crash. 

Crash avoidance NHTSA’s evaluation was published in 2001. The analysis classifies crash 

involvements of heavy trailers (and the tractors that pull them) according to three binomial 

parameters: (1) tape-equipped vs. unequipped trailer; (2) dark vs. daytime crash; (3) rear- or sideimpact vs. control group crash (where trailer visibility is not an issue – single-vehicle crashes and

frontal impacts by tractor trailers). Since none of NHTSA’s crash data at hand identified 

whether trailers had retroreflective tape, NHTSA worked out 1997-99 agreements with Florida 

and Pennsylvania state police to supplement their reports on crashes involving tractor trailers 

with a special form describing each trailer and its presence/condition of tape.31

The basic analysis32 is a three-dimensional contingency table of the crash involvements of heavy 

trailers by the three binomial parameters. Here are the combined results for Florida and 

Pennsylvania: 

 

31 Morgan (2001 Retroreflective Tape), pp. 7-21. 32 Ibid., pp. 23-37. 

43
 Side & Control Ratio: Excess

Rear Group S & R/ S & R 

Impacts Crashes Control Gp in the Dark 

TRAILERS WITHOUT TAPE 

Crashes in the dark33 499 597 .836 1.199 

Crashes in daylight 930 1,334 .697 

TRAILERS WITH TAPE 

Crashes in the dark 1,038 1,609 .645 0.851 

Crashes in daylight 1,897 2,502 .758 

Among trailers without tape, in the dark, there are almost as many side and rear impacts (499) as 

control group involvements (597 single vehicle crashes and frontal impacts): a ratio of .836. In 

daylight, that ratio is only .697. Side and rear impacts are overrepresented in the dark by a factor 

of 1.199 = .836/.697, presumably, because other road users are unable to see the trailers in time

to avoid a crash. 

Among trailers with the tape, the statistics are reversed. The ratio of side and rear impacts to 

control group crashes is lower in the dark (.645) than by day (.758) – as it ought to be, since 

night is a time of lower traffic density, more single-vehicle crashes, and fewer multivehicle 

crashes resulting in side and rear impacts. Side and rear impacts are now, appropriately, 

underrepresented in the dark by a factor of 0.851. This is a 29 percent reduction of side and rear 

impacts in the dark, relative to trailers without the tape, and it is statistically significant.34 The 

actual effectiveness of the tape has exceeded the predictions in NHTSA’s regulatory analysis (15 

to 25 percent). 

As expected, the tape is by far the most effective on dark-not-lighted roads, reducing side and 

rear impacts by a statistically significant 41 percent. In dark-lighted, dawn and dusk conditions, 

the tape did not significantly reduce crashes. The tape also did not significantly reduce crashes 

in daylight. Also as expected, the tape appears to be somewhat more effective in preventing rear 

impacts than side impacts. The tape is more effective when the driver of the impacting vehicle is 

15-50 years old than when he or she is over 50 years old. A possible explanation of the 

difference is that older drivers are less able to see, recognize and/or react to the tape in time to 

avoid hitting the trailer.35

The evaluation estimates that as of June 1, 2001, now that all heavy trailers on the road must 

have retroreflective tape, it is preventing approximately 7,800 police-reported crashes per year.36 

 

33 Includes dark not lighted, dark lighted, dawn and dusk. 34 1 – (0.851/1.199) = 29 percent; 90% confidence bounds: 19 to 39 percent; statistical significance was tested by 

the CATMOD procedure in SAS®, see SAS/STAT® User’s Guide, Vol. 1, Version 6, 4th Ed., SAS Institute, Cary, 

NC, 1990. 

35 Morgan (2001 Retroreflective Tape), pp. 39-50. 36 Ibid., pp. 51-52. 

44
Injury reduction Estimates of injury reduction were obtained by limiting the basic analysis to 

nonfatal, injury-producing crashes – i.e., crashes where at least one occupant in any of the 

involved vehicles (usually a passenger vehicle that hit the heavy trailer) was injured. The tape is 

especially effective, reducing injury-producing side and rear impacts in the dark by a statistically 

significant 44 percent. The evaluation estimates that retroreflective tape is preventing

approximately 3,100 to 5,000 nonfatal injuries per year.37

Fatality reduction When these Florida and Pennsylvania analyses are limited to the fatal 

crashes, they show a statistically significant reduction of side and rear impacts in the dark, with 

tape. The evaluation estimates that retroreflective tape saves 191 to 350 lives per year.38

 

37 Ibid., pp. 48-49 and 52; 44% estimate includes dark not lighted, dark lighted, dawn and dusk conditions; 3,100 to

5,000 is not an interval estimate, but two point estimates, one based on 29% effectiveness (result for analysis of 

crashes of all severities), the other based on 44%. 38 Ibid., pp. 48-49 and 52-53; 191 and 350 are two point estimates, based on 29% and 44% effectiveness, 

respectively, as in the analysis of nonfatal injuries. 

45
FMVSS 201: Occupant protection in interior impact

This standard is indirectly associated with one vehicle modification whose safety benefits have 

been evaluated by NHTSA and more directly associated with two recent innovations that the 

agency is just beginning to evaluate: 

• Redesign of mid and lower instrument panels with improved occupant protection

• Head injury protection upgrade (not yet evaluated)

• Head air bags (not yet evaluated)

The first paragraph of FMVSS 201 says, quite simply, “This standard specifies requirements to 

afford impact protection for occupants.”1

 Primarily, FMVSS 201 consists of performance 

requirements limiting the amount of force allowed when a headform is impacted into various 

sections of the vehicle interior that are typically contacted by occupants’ heads during crashes. 

FMVSS 201 was one of NHTSA’s initial safety standards, effective for passenger cars on 

January 1, 1968. It was extended to pickup trucks, vans and SUVs up to 10,000 pounds GVWR, 

effective September 1, 1981. More recently, performance requirements for cars and LTVs were 

upgraded by adding a 15 mph free-motion headform (FMH) impact test of the upper interior 

components, with a phase-in from September 1, 1998 to September 1, 2002. 

NHTSA believes that most passenger cars met the original head-impact requirements of FMVSS 

201 quite a few years before their effective date of January 1, 1968. The substantial vehicle 

modifications close to 1968 were in the mid and lower instrument panel, typically areas for 

contact by the occupant’s torso and knees. These areas had been contemplated, but ultimately 

not included for regulation by FMVSS 201. 

Redesign of mid and lower instrument panels with improved occupant protection

Regulatory history Instrument panel tops that were padded in some form were standard or 

optional on most passenger cars by 1963. The Society of Automotive Engineers issued 

Recommended Practice J921, defining a 15 mph headform impact test with the instrument panel, 

in June 1965. NHTSA’s original, December 1966 NPRM for FMVSS 201 incorporated the SAE 

Recommended Practice and extended it to other likely head contact areas such as seatbacks, sun 

visors, armrest and projections in head impact areas. The August 16, 1967 final rule finalized 

specifications for instrument panels, seatbacks, sun visors, and armrests. The final rule set a 

peak deceleration of 80 g’s over 3 milliseconds for impact tests of instrument panels and 

seatbacks and certain design criteria for the sun visor and armrest components. Most cars were 

apparently meeting the various head-impact requirements of FMVSS 201 well before 1968.2

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.201. 2

 Kahane, C.J., An Evaluation of Occupant Protection in Interior Impact for Unrestrained Front Seat Occupants of

Cars and Light Trucks, NHTSA Technical Report No. DOT HS 807 203, Washington, 1988, pp. 2-3; Campbell,

B.J., A Study of Injuries Related to Padding on Instrument Panels, HSL Publication No. 00427812, Report No. VJ1823-R2, Cornell Aeronautical Laboratory, Buffalo, 1963; Federal Register 31 (December 3, 1966): 15212; 1967 

SAE Handbook, Society of Automotive Engineers, New York, 1967, pp. 881-884.

46
On the other hand, this NPRM also contemplated force limits for “knee” and “child” impact 

areas – i.e., the lower and mid instrument panel areas anterior to the right-front passenger – but 

they did not become part of FMVSS 201. In 1970, NHTSA again proposed a knee impact test, 

but did not issue a final rule. Thus, even though FMVSS 201 never actually regulated the mid 

and lower instrument panels, the repeated proposals to do so may have influenced the ultimately 

voluntary improvements to crashworthiness in those areas.3

NHTSA’s 1970 NPRM also proposed to extend the original FMVSS 201 requirements to light 

trucks. That part of the proposal was adopted and took effect on September 1, 1981.4

Vehicle modifications, and their purpose In the 1960’s, most right-front passengers were 

unrestrained. Safety researchers such as Daniel at Ford and Wilson at GM grasped that the 

instrument panel was the principal energy-absorbing “ride-down” mechanism for the 

unrestrained passenger in a frontal impact. The panel should decelerate the occupant as 

completely, but gradually as possible, at no time applying a dangerous level of force to the 

occupant. For the most part, instrument panels of the 1960’s were too rigid and needed to be 

softened – but not so much that the occupant would break through to the even more rigid 

structures in front of the panel. Daniel believed panels with 1,200 pounds maximum force 

deflection for the chest in a 20 mph impact, and 1,400 pounds optimum for the knees in a 12 

mph impact could protect even unrestrained occupants in 30 mph barrier impacts.5

A second objective was to “tune” the relative rigidity of the mid and lower instrument panels so 

that the occupant would remain upright during a frontal impact. For example, an excessively 

rigid lower panel might cause the occupant to pitch forward, head first. A third objective was to 

bring the panel as close to the occupant as possible, and to extend it downwards, consistent with 

the occupant’s comfort. The sooner contact begins, and the more extensive the engagement with 

the occupant’s knees, the more gradual the ride-down. 

Happily, the new insight on the design of the panel coincided with the increasing feasibility and 

economy of plastics or thinner steel rather than heavy steel panels for assembling interior 

components. 

NHTSA measured the geometry and force deflection characteristics of instrument panels in 21 

cars ranging from MY 1965 to 1983. The analysis confirmed that manufacturers, especially in 

the late 1960’s, and continuing in the early 1970’s, significantly changed instrument panel design 

in the directions that their researchers believed to be safety-favorable. Panels became less rigid, 

 

3 Kahane (1988 Interior Impact), pp. 2-3; Williams, A.F., Wong, J. and O’Neill, B., “Occupant Protection in Interior

Impacts – An Analysis of FMVSS No. 201,” Proceedings of the Twenty-Third Conference of the American 

Association for Automotive Medicine, American Association for Automotive Medicine, Morton Grove, IL, 1979;

Federal Register 31 (December 3, 1966): 15212, 35 (September 25, 1970): 14936. 4 Federal Register 44 (November 29, 1979): 68470. 5

 Kahane (1988 Interior Impact), pp. 9-15; Daniel, R.P., “Vehicle Interior Safety Constraint Systems,” 1970

International Automobile Safety Conference Compendium, Paper No. 700423, Society of Automotive Engineers,

New York, 1970; Wilson, R.A., “Evaluating Knee-to-Instrument Panel Impacts,” Thirteenth Stapp Car Crash 

Conference, Paper No. 690801, Society of Automotive Engineers, New York, 1969. 

47
extended downwards, and contoured in a manner that occupants would feel comfortable sitting 

closer to them.6

The implementation dates for these changes in LTVs are unknown. However, other safety 

improvements of that era, such as 3-point safety belts and energy-absorbing steering assemblies, 

typically appeared in LTVs about 5-10 years after cars. That suggests the panels may have been 

modified in LTVs more or less throughout the 1970’s, which also were the decade between the 

NPRM to extend FMVSS 201 to light trucks (1970) and the final effective date (September 1, 

1981). 

Expected benefits Since the instrument panel was by far the most common source of lifethreatening as well as moderate injury for unrestrained right-front passengers in frontal crashes, 

the improvements of the late 1960’s and early 1970’s could be expected to reduce injuries and 

fatalities.7

Injury reduction – passenger cars NHTSA’s study, published in 1988, used data from the 

1977-79 National Crash Severity Study8

 (NCSS). It compared non-minor (AIS ≥ 2) injury rates, 

due to instrument panel contact, per 100 front-seat passengers involved in frontal towaway 

crashes, for four model-year groups of cars: 1960-66, 1967-70, 1971-74 and 1975-78. After 

control for Delta V (an indicator of crash severity), the three later model-year groups each had 

significantly lower injury rates from instrument-panel contacts than the 1960-66 cars. The 

reductions were 23, 36 and 21 percent, respectively. The average reduction for all 1967-78 cars, 

relative to the 1960-66 cars, was a statistically significant 29 percent.9

 The differences among 

the three post-standard groups (1967-70, 1971-74 and 1975-78) are not statistically significant. 

The reduction of injuries due to contact with the instrument panel was not offset by any increase 

of injuries from other sources. Using 1982 as the “baseline” year, the evaluation estimated that 

when the pre-1967 cars are phased out and all cars on the road have the improved instrument 

panels, AIS ≥ 2 injuries to right-front passengers will decrease by an estimated 8,000 per year.10

Computer simulations of frontal crashes were consistent with the NCSS results. MVMA2D was 

a computer program to simulate an occupant’s motion and compute the injury-criterion scores 

for contacts with the vehicle interior in a straight-ahead frontal crash. As stated above, NHTSA 

measured the geometry and force-deflection characteristics of instrument panels (and other 

structures) in 21 cars ranging from MY 1965 to 1983. These data were used to set up 

MVMA2D, which was run six times for each car to simulate the motion of an unbelted rightfront passenger: for 50th percentile male, 5th percentile female and 95th percentile male dummies, 

each at 25 mph and 30 mph frontal barrier impacts. In each of these 126 simulations, MVMA2D 

estimated the Head Injury Criterion (HIC), the chest g’s and deflection, the femur load, and six 

other injury criteria for the head, chest and neck.11

 

6

 Kahane (1988 Interior Impact), pp. 43-109. 7 Ibid., pp. xxvii and 15-20. 8

 Kahane, C.J., Smith, R.A. and Tharp, K.J., “The National Crash Severity Study,” Report on the Sixth International

Technical Conference on Experimental Safety Vehicles, NHTSA Report No. DOT HS 802 501, Washington, 1977, 

pp. 493-515. 9

 90% confidence bounds: 10 to 48 percent. 10 Kahane (1988 Interior Impact), pp. 21-41. 11 Ibid., pp. 43-109 and 205-220. 

48
Injury scores were compared on a nonparametric basis12 – i.e. the analysis shows if one group of 

cars is significantly safer than another, but does not estimate the percentage reduction of injury 

risk. The trends are the same as in the NCSS data. The 1969-71 cars and 1976-83 cars both had 

significantly lower overall injury risk than the 1965-66 cars. The average injury risk in 1976-83 

was slightly, but not significantly lower than in 1969-71. Injury risk to the head/neck, chest and 

femur were all lower in 1969-71 and 1976-83 than in 1965-66. 

Moreover, the MVMA2D simulations generated results that were consistent with researchers’ 

intuition about what sort of panel modifications would benefit safety. Reductions in the rigidity 

of the lower and mid panels, and lengthening the panels by extending them downwards and 

towards the occupant, were all associated with significant injury reductions. 

Injury reduction – light trucks NHTSA analyzed overall AIS ≥ 2 injury rates per 100 

unrestrained right-front passengers in frontal towaway crashes in 1982-85 NASS and 1977-79 

NCSS data. In those days, LTVs accounted for a smaller share of the market, and there weren’t 

enough cases to adjust the rates for Delta V or other factors, or to single out injuries due to 

contact with the instrument panel. The analysis did not show a clear reduction in the injury rates. 

In NASS, the injury rate for model year 1971-74 LTVs was 43 percent lower than in 1966-70 

LTVs. But the reduction relative to 1966-70 subsequently dwindled to 29 percent in 1975-78, 5 

percent in 1979-81, and 16 percent in 1982-85. In NCSS, the 1971-74 LTVs had 33 percent 

lower injury rate than 1961-70 LTVs, but the 1975-78 LTVs had the highest rate, 24 percent 

higher than in 1961-70. While the reductions in 1971-74 are effects in the right direction, the 

subsequent trends toward higher injury rates are inconsistent with the idea that panel 

improvements continued throughout the 1970’s. Small samples and inability to control for Delta 

V or other factors made it difficult to obtain statistically meaningful results.13

Fatality reduction – passenger cars The fatality “risk index” of right-front passengers in frontal 

crashes was computed by model year (1964-84), based on a two-step analysis of 1975-84 FARS 

data. The first step was the computation of an absolute risk index for drivers. The analysis 

compares the ratio of driver fatalities in head-on (front-to-front) collisions between cars of two 

different model years. For example, in head-on collisions between MY 1975 and 1979 cars, 37 

drivers of the MY 1975 cars and 90 drivers of the MY 1979 cars were fatalities. In these 

unadjusted data, relative vehicle weight was the dominant factor: since many of the MY 1979 

cars had been downsized, they had higher risk in the head-on collisions with the 1975’s. Next, a 

logistic regression calibrated the expected fatality risk of each driver in a head-on collision, 

given only the curb weights of the two cars, and the age, gender and belt use of the two drivers. 

In each model year’s cars, the actual number of fatalities in the head-on collisions is compared to 

the number that would have been expected, based on their own, and their collision partners’ curb

weight, driver age, gender and belt use. The fatality risk index is the ratio of actual to expected 

fatalities (normalized to 100). 

The fatality risk index for drivers averaged 117.3 in model years 1964-66, had dropped sharply 

to 103 by 1968-70, and remained close to 100 throughout 1973-84. The drop from 117.3 to 103, 

 

12 Using a weighted average of the normalized rank order scores for the various criteria, for the six simulations on

each car. 13 Ibid., pp. 165-173. 

49
a 12 percent reduction, corresponds closely to the effectiveness estimate for energy-absorbing 

steering assemblies.14 In other words, energy-absorbing steering assemblies significantly 

reduced the fatality risk of unrestrained drivers in frontal crashes in 1967-68, and no other 

vehicle modification in 1964-84 had any large effect.15

The second step was the computation of a risk index for right-front passengers relative to drivers. 

It is based on the ratio of right-front passenger to driver fatalities in frontal impacts (including, 

but not limited to head-on collisions) in cars of a given model year that were occupied by a rightfront passenger as well as a driver, both unrestrained. For example, in frontal impacts of MY 

1975 cars with both seats occupied, 1410 passengers and 1472 drivers were fatalities. Next, a 

logistic regression calibrated the expected fatality risk of each driver and each passenger in these 

impacts, given only the age and gender of the two occupants and the exact impact location (pure 

frontal, left front, right front). In each model year’s cars, the actual ratio of right-front to driver 

fatalities is compared to the ratio that would have been expected, based on the two occupants’ 

age/gender and the impact location. The fatality risk index is the actual ratio divided by the 

expected ratio (normalized to 100). 

The relative risk index was 120-125 in model years 1960-65, dropped sharply in the late 1960’s, 

and continued decreasing slowly, leveling out at close to 100 in 1975-84. In other words, the 

right-front seat was at one time substantially more dangerous than the driver’s seat. But the 

safety gap was closed, despite the introduction of energy-absorbing steering assemblies that 

benefited only drivers. Something(s) that was even more effective than the energy-absorbing 

steering assemblies must have been introduced for passengers.16

The absolute fatality risk index for right-front passengers is the product of the driver and the 

passenger-relative-to-driver indices. This index averaged 135.7 in model years 1964-66, 109.1 

in 1968-70, and 99.7 in 1973-84. The drop from 135.7 to 109.1 is a 20 percent reduction, 

equivalent to 665 lives saved per year. The more gradual change from 109.1 to 99.7 is an 

additional 9 percent reduction, equivalent to 235 lives saved per year.17

The redesign of instrument panels was the most important crashworthiness improvement for 

unrestrained right-front passengers in frontal crashes and must have accounted for many of these 

665 + 235 = 900 lives saved per year, but it is difficult to estimate how many. The trend in the 

fatality risk index closely parallels the trends in the NCSS data and MVMA2D simulations: a 

strong improvement in the late 1960’s, with some additional improvements in the early 1970’s 

and leveling out after that. That is consistent with the hypothesis (but not a proof) that the 

fatality reduction largely reflects the instrument panel improvements. It is estimated from NCSS 

data that before FMVSS 201, 616 right-front passengers per year received fatal injuries from

contact with the instrument panel, while Huelke’s in-depth investigations suggested the number 

could be twice as high. If the fatality reduction for improved panels is the same as the AIS ≥ 2 

injury reduction, 29 percent, that would amount to annually preventing 180-360 fatalities due to 

contact with the instrument panel. However, the MVMA2D simulations suggest that the benefits 

 

14 See the FMVSS 203/204 chapter. 15 Ibid., pp. 111-140. 16 Ibid., pp. 140-153. 17 Ibid., pp. 153-156 and 161. 

50
of improved panels are not limited to preventing injuries directly caused by contact with the 

panel: by providing “ride-down” and keeping the occupant upright, they can reduce the severity 

of contacts with other interior surfaces. Other safety standards that benefited unrestrained 

passengers in frontal impacts, such as FMVSS 205 or 212, are unlikely to have saved more than 

100 passengers per year. Taking all these considerations into account, NHTSA estimated that 

improved panels account for approximately 400 to 700 of the 900 passenger lives saved per year 

in frontal crashes. The point estimate is 550, and it is equivalent to a 16 percent reduction of 

unrestrained right-front passenger fatalities in frontal impacts.18

Fatality reduction – light trucks Using 1975-84 FARS data, NHTSA developed fatality risk 

indices for drivers and right-front passengers of light trucks, analogous to the indices for cars. 

The absolute risk index for right-front passengers dropped from an average of 127 in model 

years 1966-68 to an average of 98 in 1975-80. The drop was sharpest in 1969-75 and gradually 

leveled out afterwards. That is a 23 percent fatality reduction during the decade when instrument 

panels were modified in light trucks. That is similar to the long-term overall reduction in the risk 

index for car passengers, and it suggests that the effectiveness of improved panels may be about 

the same in light trucks and cars: a 16 percent reduction of unrestrained right-front passenger 

fatalities in frontal impacts.19

Head injury protection upgrade 

On August 14, 1995, NHTSA issued a Final Rule extending the head injury protection 

requirements of FMVSS 201. The existing requirements of FMVSS 201 remained for the 

original target areas. However, a new list of target areas in the vehicle’s upper interior includes 

the A-, B- and other pillars, the front and rear roof header, the roof side rails, and the upper roof, 

among others. These structures are sources of life-threatening head injuries in existing vehicles. 

The impact speed for the free-motion headform (FMH) impact test for the new areas is 15 mph, 

as in the original FMVSS 201, but for these targets, the Head Injury Criterion (HIC) may not 

exceed 1000 for any 36-millisecond period. Impacts may be directed from a range of vertical 

and horizontal angles, not just head-on. Manufacturers were offered a choice of several 

alternative phase-in schedules from September 1, 1998 to September 1, 2002. For example, they 

could certify the new requirements on at least 10 percent of cars and LTVs manufactured from

September 1, 1998 through August 31, 1999; at least 25 percent of cars and LTVs manufactured 

from September 1, 1999 through August 31, 2000; at least 40 percent of cars and LTVs 

manufactured from September 1, 2000 through August 31, 2001; at least 70 percent of cars and 

LTVs manufactured from September 1, 2001 through August 31, 2002; and all cars and LTVs 

manufactured on or after September 1, 2002. This will be a high-priority evaluation for 

NHTSA.

20 

 

18 Ibid., pp. 15-18, 38-39, 92-106 and 161-163; Huelke, D.F. and Gikas, P.W., “Causes of Death in Automobile

Accidents,” Police, Vol. 13, November/December 1968, pp. 81-89. 19 Kahane (1988 Interior Impact), pp. 174-197. 20 Federal Register 60 (August 18, 1995): 43031; National Highway Traffic Safety Administration Evaluation

Program Plan, Calendar Years 2004-2007, NHTSA Report No. DOT HS 809 699, Washington, 2004, p. 8. 

51
Head air bags 

During the 1990’s, manufacturers and suppliers developed head air bags to provide additional 

protection, especially during lateral impacts, and possibly to act as a barrier to occupant ejection 

through side windows. NHTSA believes they are a promising safety technology. On July 29, 

1998, NHTSA amended FMVSS 201 to facilitate the introduction of head air bags. Recognizing 

that the 15 mph headform test might be a problem in target areas where the undeployed air bag is 

stored (and, furthermore, an inappropriate test if the bag usually deploys at that speed), NHTSA 

offered an alternative compliance procedure. Manufacturers have the option to reduce the speed 

of the headform test to 12 mph on target areas where the bag is stored, provided they can meet an 

18 mph lateral (90 degree) crash test for the full vehicle into a pole – with HIC < 1000. The pole 

test simulates a head impact with the deployed bag. In model year 1999, BMW and Volvo 

introduced head air bags in some of their cars. By 2001, many of the large manufacturers 

offered them on a variety of cars and/or LTVs. Designs of head air bags include “curtains” or 

“tubes” that drop down from the roof rail into the side-window area, and side air bags that deploy 

from the seat but extend upward far enough to protect the head impact zones around the side 

window. NHTSA’s annual Buying a Safer Car brochures inform the public what make-models 

are equipped with head air bags. This, too, will be a high-priority evaluation for NHTSA.21

 

21 Federal Register 63 (August 4, 1998): 41451; Buying a Safer Car 2000, NHTSA Publication No. DOT HS 809 

046, Washington, 2000; Buying a Safer Car 2001, NHTSA Publication No. DOT HS 809 152, Washington, 2000; 

Buying a Safer Car 2002, NHTSA Publication No. DOT HS 809 409, Washington, 2002; Buying a Safer Car 2003, 

NHTSA Publication No. DOT HS 809 546, Washington, 2003; NHTSA Evaluation Program Plan, CY 2004-2007, 

p. 13. 

52
FMVSS 202: Head restraints

This standard regulates one safety technology: 

• Head restraints for front-outboard seats 

They are the one safety device aimed at mitigating injury risk in rear impacts, cushioning the 

heads of drivers and right-front passengers. They were introduced in passenger cars over model 

years 1964-69 and in light trucks over a longer period, extending until 1992. The first paragraph 

of FMVSS 202 states, “this standard specifies requirements for head restraints to reduce the 

frequency and severity of neck injury in rear-end and other collisions.”1

Regulatory history FMVSS 202, applying at first only to passenger cars, was proposed in 

December 1967, became a Final Rule in February 1968 and had an effective date of January 1, 

1969. It incorporates parts of General Services Administration Standard 515/22, effective 

October 1967 for federally purchased vehicles. The extension of FMVSS 202 to light trucks 

with GVWR up to 10,000 pounds was issued in September 1989 and took effect on September 1, 

1991.2

How head restraints work “Whiplash” is by far the most frequent injury in rear-impact crashes. 

It is common even in low-speed, non-towaway crashes. It results from strains, tears or 

microscopic damage to muscles, tendons, ligaments, vertebra or nerves in or near the neck. The 

most familiar symptoms are pain or stiffness in the neck and upper back. Also common are pain 

or weakness in the arms or shoulders, and symptoms involving the central nervous system, such 

as headache, sight or hearing disturbances. Symptoms may appear immediately or not for 

several days. They may end in a day or two or they may go on, continually or intermittently, for 

a long time, even years.3

The first causal mechanism identified for whiplash was hyperextension of the neck. In a rear 

impact, a low, pre-FMVSS 202 seatback holds the occupant’s back in place but the head jerks 

backward, over the top of the seatback, twisting the neck and injuring it. The remedy was to 

develop a head restraint that effectively makes the seatback higher, keeps the head upright and in 

line with the torso, and prevents twisting of the neck. However, subsequent research suggests 

that hyperextension is by no means the only mechanism of whiplash; other causes may include 

the longitudinal movement of the head relative to the torso, or rapid changes in spinal column

pressure during the impact. 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.202. 2

 Kahane, C.J., An Evaluation of Head Restraints - Federal Motor Vehicle Safety Standard 202, NHTSA Technical 

Report No. DOT HS 806 108, Washington, 1982, pp. 104-106; Walz, M.C., The Effectiveness of Head Restraints in

Light Trucks, Technical Report No. DOT HS 809 247, Washington, 2001, p. 1; Federal Register 31 (March 8, 

1966): 4096, 31 (July 15, 1966): 9637, 32 (December 28, 1967): 20865, 33 (February 14, 1968): 2945, 54 

(September 25, 1989): 39183. 3

 Kahane (1982 Head Restraints), pp. 80-83; Walz (2001), pp. 2-5; Mertz, H.J., Jr., and Patrick, L.M., “Investigation

of the Kinematics and Kinetics of Whiplash,” Proceedings of Eleventh Stapp Car Crash Conference, Society of 

Automotive Engineers, New York, 1967; States, J.D., Korn, M.W. and Massengill, J.B., “The Enigma of Whiplash

Injuries,” Proceedings of the Thirteenth Annual Conference of the American Association of Automotive Medicine, 

Morton Grove, IL, 1969; Accident Analysis and Prevention, Vol. 32, No. 2, March 2000. 

53
Research on rear impacts and development of prototype head restraints began at the University 

of California, Los Angeles in the mid-1950’s. The manufacturers have developed three main 

types of head restraints for production vehicles: 

• Adjustable head restraints that may be lifted or lowered to suit the occupant. The head 

restraint should be lifted until the top of the restraint is at least level with the tops of the

occupant’s ears, or preferably as high as it can go without blocking the driver’s vision. 

Some head restraints can also be adjusted forwards and backwards; if so, they should be 

moved forward as far as possible consistent with the occupant’s comfort. 

• Integral head restraints, such as “captain’s chairs” or other seatbacks that extend 

upwards behind the driver’s head. 

• Fixed head restraints, such as padded tubes, shaped like an inverted “U,” attached to the 

top of the seatback. 

The test for FMVSS 202 requires the top of the head restraint to reach at least 27.5 inches above 

the “seating reference point” (the level of the seat cushion when the seat is occupied). That 

height provides adequate support for the head and neck of occupants up to 5’10” tall. If it is an 

adjustable head restraint, it only needs to achieve this height in the “up” position. The restraint 

must be able to withstand a static force of 200 pounds in the rearward direction, or meet a 

dynamic test.4

In actual pre-standard cars, the median seatback, without a head restraint, was 23 inches tall, well 

below the level that would be set by FMVSS 202. In actual cars of the 1970’s, the median 

integral or fixed head restraint – and the median adjustable head restraint in the “up” position – 

reached 29 inches, exceeding the FMVSS 202 requirement. However, at that time occupants left 

75 percent of adjustable head restraints in the “down” position, at a median height of 26 inches, 

and did not obtain full protection if they were 5’8” or taller. Integral or fixed head restraints 

predominated on small cars with bucket seats, but were becoming infrequent on bench or splitbench seats. In all, 30 percent of cars had integral or fixed head restraints, while 70 percent had 

adjustable head restraints in the 1970’s. Although adjustable head restraints were often 

mispositioned, consumers seemed to prefer them. A 1974 NHTSA proposal to require integral 

or fixed head restraints for drivers, increase height requirements, and establish a minimum height 

for adjustable restraints in the “down” position was not adopted. 5

By the mid-1990’s, the situation had deteriorated in some ways and improved in others. Just 12 

percent of new cars had integral or fixed head restraints. On the other hand, occupants were now 

leaving only 50 percent of the adjustable restraints “down,” and the median height of adjustable 

 

4

 Kahane (1982 Head Restraints), pp. 103-107; Severy, D.M., Brink, H.M. and Baird, J.D., Backrest and Head

Restraint Design for Rear-End Collision Protection, Paper No. 680079, Society of Automotive Engineers, New 

York, 1968; Code of Federal Regulations, Title 49, Part 571.202. 5

 Kahane (1982 Head Restraints), pp. 113-123 and 257-259; Federal Register 39 (March 19, 1974): 10268. 

54
head restraints in the “down” position had improved to 27 inches – close to the FMVSS 202 

requirement for the “up” position. Also, integral head restraints predominated in light trucks.6

Some questions about head restraints have been raised time and again during the past 30 years. 

(1) Are integral/fixed restraints more effective than adjustable head restraints, as used (often 

incorrectly adjusted), and if so, why don’t more cars have integral or fixed restraints? (2) Should 

head restraints be increased in height (both in the “up” and the “down” positions) to protect 

taller-than-average occupants? How much? Would consumers accept them? (3) How important 

is it for the head restraint to be close to the head? Should head restraints be adjustable 

backwards and forwards, and/or should FMVSS 202 specify a maximum longitudinal distance 

from the head restraint to the head? (4) In combination with a head restraint, is a rigid seatback 

or a flexible seatback more desirable for mitigating whiplash? (5) Will head restraints be less 

effective in pickup trucks with conventional cabs than in other vehicles to the extent that the 

back wall of the cab, immediately behind the front seat, provides some degree of protection?7

Some passenger cars were equipped with head restraints as early as 1964, well before the 

January 1, 1969 effective date. However, only 3 percent of model year 1967 cars and 12 percent 

of model year 1968 cars had them. In model year 1969, as FMVSS 202 took effect in mid-year, 

88 percent of cars were equipped with them. The extension of FMVSS 202 to light trucks was 

proposed in 1988 and took effect in September 1991. Most models of domestic pickup trucks 

were first equipped with head restraints between the proposal and the effective date (model years 

1989-92). By contrast, the majority of vans and SUVs were already equipped with head 

restraints or high seatbacks potentially meeting FMVSS 202 as early as model year 1983.8

Expected benefits Drivers and right-front passengers can expect to receive benefits primarily in 

rear-impact crashes, since other impacts are far less likely to propel occupants backwards, 

directly toward the head restraint. “Whiplash” is usually a complaint-of-pain injury, seldom lifethreatening, but it can manifest itself in many body regions. A significant fatality reduction, or a 

significant reduction in lacerations or related injuries is not anticipated. There is likely to be a 

reduction of minor/moderate non-bleeding injuries to the neck, the head and quite possibly the 

arms and back, even in crashes of low severity (non-towaways). 

Injury reduction – passenger cars NHTSA’s analysis, published in 1982, is based on 1972, 

1974 and 1977 Texas data.9

 Texas files have records on every crash-involved driver, injured or 

not, and permit computation of the overall injury rate per 100 drivers in rear-impact crashes. 

Injury rates are compared for model year 1968, when only 6 percent of cars had adjustable and 6 

percent had integral head restraints, and model year 1969, when 81 percent of cars had 

adjustable, and 7 percent had integral head restraints: 

 

6 Head Restraints – Identification of Issues Relevant to Regulation, Design, and Effectiveness, NHTSA Performance 

Standards, Washington, 1996 ( www.nhtsa.dot.gov/cars/rules/crashworthy/headrest/status9/status9.html#28 ), pp.

19-23. 7

 Walz (2001), pp. 2-5. 8

 Kahane (1982 Head Restraints), p. 104; Walz (2001), p. 2. 9

 Kahane (1982 Head Restraints), pp. 181-197.

55
 N of n Percent

 Drivers Injured Injured

Model year 1968 ( 6% with adj. head restraints) 20,214 1,531 7.57 

Model year 1969 (81% with adj. head restraints) 23,051 1,605 6.96 

The injury rate is significantly lower in the 1969 cars. The arithmetic works out to a 10.4 percent 

injury reduction for adjustable head restraints relative to no head restraints. An identical 

estimate was obtained when the reduction in rear-impact injury rates was measured relative to a 

control group of side impacts, over a wider range of “before” and “after” model years.

Next, the analysis compared a group of 1970-77 make-models equipped almost exclusively 

(96%) with integral restraints to another group of make-models equipped with 97 percent 

adjustable head restraints.10 In Texas, the injury rates in rear impacts were: 

 N of n Percent

 Drivers Injured Injured

Models with 97% adjustable head restraints 17,758 1,394 7.85 

Models with 96% integral head restraints 21,205 1,552 7.32 

The injury rate is significantly lower in the make-models with primarily integral head restraints. 

It works out to a 7.3 percent injury reduction for integral relative to adjustable head restraints. 

The injury reduction for integral head restraints relative to no head restraints at all is 16.9 percent 

– i.e., 1 - [(1 - .104)(1 - .073)]. Head restraints have significantly reduced the frequency of 

whiplash in crashes, but they have not nearly eliminated this type of injury. 

Using 1979 as the “baseline” year, the evaluation estimated that an on-the-road fleet with 100 

percent adjustable head restraints would prevent 52,000 injuries per year in passenger cars, but a 

fleet with 100 percent integral or fixed head restraints would prevent 85,000 injuries per year.11

Fatality reduction – passenger cars In-depth investigations of fatal rear-impact crashes showed 

that most of the fatalities involved fire, occupant ejection or catastrophic intrusion: mechanisms

unlikely to be influenced much, one way or the other, by head restraints. NHTSA analyzed 

1975-80 FARS data by various techniques: rear-impact fatalities, before and after FMVSS 202, 

relative to control groups of fatalities in other crash modes; regression analyses; rear-impact 

 

10 Ibid., pp. 212-225. 11 Ibid., pp. 237-245; 90% confidence bounds for effectiveness of adjustable head restraints: 4.0 to 16.8 percent, for

integral head restraints: 9.1 to 24.7 percent; for benefits of adjustable head restraints: 17,000 to 87,000 injuries 

prevented, for integral head restraints: 40,000 to 130,000 injuries prevented per year. 

56
fatality rates per million vehicle years. None of these analyses showed a statistically significant 

effect for head restraints.12

Injury reduction – light trucks NHTSA’s 2001 evaluation of head restraints for light trucks 

used 1993-98 data from eight states: Florida, Indiana, Maryland, Missouri, North Carolina, 

Pennsylvania, Texas and Utah. Statistics were based on seven domestic make-models of pickup 

trucks that shifted during 1990-92 from few or no head restraints in one model year to 100 

percent or near-100 percent equipped with head restraints in the next year. Injury rates were 

compared for the first two model years with head restraints and the last two years before head 

restraints. Vans and SUVs were mostly equipped with head restraints from the start of

production, precluding computation of “before” injury rates, and could not be included in the 

analyses. Injury rates were computed for drivers and right-front passengers in rear-impact 

crashes and for a control group of frontal crash involvements.13 Injury rates for the combined 

eight state date files were: 

 N of n Percent

 Occupants Injured Injured

REAR IMPACTS 

Last 2 MY before head restraints 43,520 11,500 26.42 

First 2 MY with head restraints 50,434 12,307 24.40 

FRONTAL IMPACTS 

Last 2 MY before head restraints 98,541 23,581 23.93 

First 2 MY with head restraints 106,417 24,631 23.15 

Clearly, the injury reduction is greater in the rear impacts (where head restraints are effective) 

than in the frontal impacts (where head restraints ought to have no effect, and any difference 

between the “before” and “after” is due to various biases in the data). When the data are 

weighted by the number of registered pickup trucks in each state, rather than merely aggregated, 

and after corrections for the small percentages of trucks in the “before” group that already had 

head restraints and for those in the “after” group that still didn’t, this works out to a statistically 

significant 6.1 percent injury reduction for head restraints in rear impacts (relative to the control 

group). Using 1999 as the “baseline” year, the evaluation estimated that when all light trucks on 

the road (pickups, vans and SUVs) are equipped with head restraints, they will prevent 14,900 

injuries per year.14

It is unknown why head restraints are more effective in passenger cars (10.4 – 16.9 percent) than 

in light trucks (6.1%). Perhaps the large mass and extensive rear structure of light trucks, 

especially pickup trucks, offers a degree of protection in rear impacts that makes it less 

 

12 Ibid., pp. 91-95 and 161-177. 13 Walz (2001), pp. 9-27 and 41-46. 14 Ibid., pp. 65-68; 90% confidence bounds for effectiveness: 3.5 to 8.7 percent; for benefits: 8,300 to 21,700 injuries 

prevented, per year. 

57
necessary to have head restraints. Also, this evaluation did not show a significant difference in 

the effectiveness of adjustable vs. integral head restraints in pickup trucks.15

Fatality reduction – light trucks NHTSA’s 2001 evaluation does not analyze fatal crashes 

separately. However, it is reasonable to infer that, just as in passenger cars, head restraints have 

little or no effect on fatalities in light trucks. 

Proposed FMVSS 202 upgrade On January 4, 2001, NHTSA published a proposed rulemaking 

to upgrade FMVSS 202. The new rule would require: 

• Front-seat head restraints in cars and light trucks to reach a height of 31.5 inches in the 

“up” position (vs. 27.5 inches in the current FMVSS). 

• Front-seat head restraints must reach at least 29.5 inches in the “down” position (vs. no

requirement in the current FMVSS). 

• The longitudinal distance (“backset”) between the restraint and the head of the 50th

percentile dummy shall not exceed 2 inches. 

• Head restraints for rear-outboard seats, reaching at least 29.5 inches in the “down” 

position, and meeting the 2-inch limit for backset. 

The upgrade would provide whiplash protection for tall occupants, safeguard people of average 

height even if they leave adjustable restraints in the “down” position, and protect rear-seat 

passengers. The proposal resembles, to some extent, an unsuccessful bid NHTSA made in 1974 

to upgrade FMVSS 202.16

 

15 Ibid., pp. 58-63 and 68-69. 16 Federal Register 66 (January 4, 2001): 967; integral or fixed head restraints would have to reach 31.5 inches in

the front seat and 29.5 inches in the back seat; National Highway Traffic Safety Administration Evaluation Program 

Plan, Calendar Years 2004-2007, NHTSA Report No. DOT HS 809 699, Washington, 2004, p. 33. 

58
FMVSS 203: Impact protection for the driver from the steering control system

FMVSS 204: Steering control rearward displacement

These two standards regulate one safety technology: 

• Energy-absorbing and telescoping steering assembly

It is a basic protection for drivers in frontal crashes, designed to cushion their impact into the 

steering assembly. It was introduced in passenger cars in model years 1967-68 and in light 

trucks over a longer period, extending approximately from 1970 to 1982. 

The first paragraph of FMVSS 203 states, “this standard specifies requirements for steering 

control systems that will minimize chest, neck and facial injuries to the driver as a result of

impact.” FMVSS 204 “specifies requirements limiting the rearward displacement of the steering

control into the passenger compartment to reduce the likelihood of chest, neck or head injury.”1

Regulatory history FMVSS 203 and 204, applying at first only to passenger cars, were among 

NHTSA’s initial safety standards, with a Notice of Proposed Rulemaking in December 1966, a 

Final Rule in February 1967 and an effective date of January 1, 1968. They basically incorporate 

General Services Administration Standard 515/4a, effective October 1967, for federally 

purchased vehicles, and draw on SAE Recommended Practices J850 and J944. FMVSS 203 and 

204 were extended to light trucks with GVWR up to 10,000 pounds, effective September 1, 

1981.2

How it works Before FMVSS 203 and 204, the steering assembly was by far the most common 

source of fatal or serious injuries for drivers in frontal crashes. The pre-standard steering column

was essentially a rigid pole attached to the vehicle’s front structure. When drivers’ forward 

momentum propelled them into the column, it did not “give.” Even worse, when the front 

structure deformed rearwards in a frontal impact, it pushed the column upwards and backwards 

toward the driver.3

The safety technology associated with FMVSS 203 and 204 consists of devices that arrest, 

absorb or deflect the rearward motion of the column in crashes and that deform at a safe level of 

force upon impact by the driver. The single, rigid column was replaced by assemblies of 

concentric tubes. The inner tube slides within the outer tube (telescopes) to make the assembly 

shorter in case of impact. Usually there are two telescoping sections, each about eight inches 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Parts 571.203 and

571.204. 2

 Kahane, C.J., An Evaluation of Federal Motor Vehicle Safety Standards for Passenger Car Steering Assemblies, 

NHTSA Technical Report No. DOT HS 805 705, Washington, 1981, pp. 86-87; Federal Register 31 (March 8, 

1966): 4091, 31 (July 15, 1966): 9631, 31 (December 3, 1966): 15212, 32 (February 3, 1967): 2414, 44 (November 

29, 1979): 68470; 1968 SAE Handbook, Society of Automotive Engineers, New York, 1968, pp. 915-916 and 923-

925. 3

 Kahane (1981 Steering Assemblies), pp. 67-80; Huelke, D.F., and Gikas, P.W., “How Do They Die? Medical

Engineering Data from On-Scene Investigation of Fatal Automobile Accidents”, Highway Vehicle Safety, Society of 

Automotive Engineers, New York, 1968; Voight, G. and Wilfert, K., Mechanisms of Injury to Unrestrained Drivers 

in Head-On Collisions, Paper No. 690811, Society of Automotive Engineers, New York, 1969. 

59
long: one in the engine compartment to prevent frontal damage to the vehicle from translating 

into rearward displacement of the steering wheel, and one in the passenger compartment to allow 

the driver to compress the steering assembly forward. The telescoping section in the passenger 

compartment, however, does not slide freely but contains retardant devices such as crushable 

mesh that collapse at a safe, controlled force level, absorbing the energy of the driver’s impact. 

The manufacturers developed about five distinct types of energy-absorbing devices.4

The shear capsule, which brackets the column to the instrument panel, is a one-way gate that 

resists the rearward movement of the column due to vehicle damage but freely allows the 

forward movement of the column upon driver impact. The assembly may contain universal 

joints to give it a flexible Z-shape, further isolating the steering-wheel area from damages within 

the engine compartment. Some vehicles may have a deformable canister in the steering wheel 

instead of/in addition to a telescoping column in the passenger compartment. Steering wheel 

rims and spokes may also be deformable. Manufacturers padded steering-wheel hubs and 

removed hazardous appurtenances such as horn rings. 

In the test for FMVSS 203, a body block simulating an adult torso (the “black tuffy”), moving 

straight ahead, impacts a steering assembly mounted at the manufacturer’s installation angle. 

The steering assembly is intact and has been removed from the vehicle. At an impact speed of 

22 feet per second, the force on the body block may not exceed 2,500 pounds. The design of 

most columns and the test approach have raised several issues over the years. (1) Columns are 

well-designed to compress under axial (straight-ahead) impacts, but there are questions about 

their performance in off-center impacts. (2) The driver might have an easier time compressing 

an intact column (as in the test) than one that has been damaged or displaced during the vehicle 

impact phase. (3) A force level of 2,500 pounds may be acceptable for the healthy adult torso 

but excessive for older adults or when the head or abdomen contacts the steering wheel; a 1970 

proposal for a more stringent requirement was not adopted. (4) It was difficult for some fullsized vans to meet FMVSS 203 since their steering columns were nearly vertical, perpendicular 

to the motion of the body block; the lead-time allowed for extending FMVSS 203 to light trucks 

essentially permitted the phase-out of vans with near-vertical columns.5

FMVSS 204 is tested in the 30 mph, full-vehicle impact with a frontal barrier that simultaneously 

tests FMVSS 208, 219 and 301 as well. The steering assembly is not allowed to intrude more 

than 5 inches rearward, into the passenger compartment on this test. Vertical or sideways motion 

is permitted and has been substantial in a few test vehicles. That has also raised questions about 

the ability of these displaced or damaged columns to compress upon impact by the driver. 

Vehicles with driver air bags – i.e., all new cars and light trucks up to 8,500 pounds GVWR – are 

exempt from the FMVSS 203 test. However, they continue to have energy-absorbing steering 

columns that, in combination with air bags, are still important for providing “crush space” and 

 

4

 Kahane (1981 Steering Assemblies), pp. 87-93; Marquis, D.P., The General Motors Energy Absorbing Column, 

Paper No. 670039, Society of Automotive Engineers, New York, 1967; Huelke, D.F., Accident Investigations of

Performance Characteristics of Energy Absorbing Steering Columns, Paper No. 690184, Society of Automotive 

Engineers, New York, 1969. 5

 Kahane (1981 Steering Assemblies), pp. 93-99; Hill, A., Steering Wheel Oscillations and Vertical Movements in

30 mph Barrier Impacts, NHTSA Technical Report No. DOT HS 803 606, Washington, 1978. 

60
cushioning the driver’s impact. The FMVSS 208 test, which measures the driver’s injury risk in 

a 30 mph crash, implicitly tests the performance of the energy-absorbing steering assembly as 

part of the overall safety system. 

The manufacturers were developing energy-absorbing and telescoping steering assemblies before 

NHTSA existed. All 1967 GM, Chrysler and American Motors cars built in the United States or 

Canada were equipped with them. All model-year 1968 passenger cars had them, even though 

the standards did not take effect until mid-model year (January 1, 1968). Implementation in light 

trucks took place over a longer period and is not as clearly documented: the Volkswagen “bus” 

apparently had them in 1970, all Jeep and GM trucks in 1973, and other trucks in later years, 

some not until the effective date, September 1, 1981.6

Expected benefits Only drivers can expect to receive benefits, since passengers rarely make 

significant contact with the steering assembly. Benefits are primarily in frontal crashes, since 

other impacts rarely propel the driver into the steering assembly directly and with enough force 

to compress the column. The principal benefit would be expected for injuries caused by driver 

contact with the steering assembly; it is theoretically possible, but not likely, that the behavior of 

the steering assembly would affect driver contacts with other parts of the vehicles. The largest 

reductions are expected for chest injuries, although head, neck and abdominal injuries could be 

mitigated as a result of less steering-column intrusion, more deformable steering wheels, and 

removal of hazardous appurtenances. The largest reductions are expected for unbelted drivers, 

since belts absorb much of the driver’s momentum prior to contact with the steering assembly. 

Fatality reduction – passenger cars NHTSA’s analysis, published in 1981, was its first 

comprehensive evaluation of a FMVSS. It is based on 1975-79 FARS data.7

 Since FARS data 

do not indicate the source or body region of fatal injuries, or provide information on nonfatal 

crashes to allow computation of fatality rates, they are best suited for comparing overall fatality 

risk of drivers in frontal crashes, before and after FMVSS 203/204, relative to a control group. 

One possible control group is the passenger fatalities in these same frontal crashes. The 1975-79 

FARS statistics were: 

 Passenger Driver 

 Frontals Frontals 

Model year 1966 (“before”) 1,048 2,119 

Model year 1968 (“after”) 1,463 2,573 

 

6

 Kahane (1981 Steering Assemblies), p. 92; Multidisciplinary Accident Investigation Data File, Editing Manual

and Reference Information, Vol. 2, NHTSA Technical Report No. DOT HS 802 412, Washington, 1977; 1978

Model Year Passenger Car and Truck Accident Investigator’s Manual, Motor Vehicle Manufacturers Association, 

Detroit, 1978; Ludtke, N.F., “1980 and 1979 Ford F-150 Weight and Cost Analysis,” Third Automotive Fuel 

Economy Research Contractors’ Coordination Meeting – Summary Report, NHTSA Technical Report No. DOT HS

805 875, Washington, 1980; Preliminary Evaluation of the Proposed Extension of Standards No. 201, 203 and 204

to Light Trucks, Buses, and Multipurpose Vehicles, NHTSA Plans and Policy, Washington, 1978. 7

 Kahane (1981 Steering Assemblies), pp. 197-203. 

61
This is a statistically significant 13 percent fatality reduction for the drivers, relative to the 

passengers, in model year 1968: 1 – [(2,573/2,119) / (1,463/1,048)] = .13. 

Another control group is driver fatalities in side or rear impacts. The 1975-79 FARS statistics 

were: 

 Driver Driver 

 Side/Rear Frontals 

Model year 1966 (“before”) 1,103 2,119 

Model year 1968 (“after”) 1,508 2,573 

This is a statistically significant 11.1 percent fatality reduction in frontals, relative to side and 

rear impacts, in model year 1968: 1 – [(2,573/2,119) / (1,508/1,103)] = .111. 

The average of these two estimates is a 12.1 percent fatality reduction for drivers in frontal 

crashes. Using 1978 as the “baseline” year, the evaluation estimated that energy-absorbing 

steering assemblies would eventually save 1,300 lives per year in passenger cars, when all cars 

on the road met FMVSS 203 and 204. Only safety belts and air bags save more lives. 8

Injury reduction – passenger cars NHTSA’s 1981 analysis uses data from the National Crash 

Severity Study (NCSS), the predecessor of NASS. These data specify, like NASS, the severity, 

body region and contact source of injuries. The injury rate – the number of fatal or hospitalizing 

injuries due to contact with the steering assembly per 100 drivers involved in frontal towaway 

crashes – was computed for cars with energy-absorbing steering assemblies and compared to the 

rate in cars without the assemblies. These injury rates were controlled for factors such as driver 

age and gender by multidimensional contingency table analysis, a predecessor of the logistic 

regression method widely used today.9

The analysis showed a statistically significant 38.4 percent reduction of fatal or hospitalizing 

injuries due to contact with the steering assembly. Using 1978 as the “baseline” year, the 

evaluation estimated that energy-absorbing steering assemblies would prevent 23,000 nonfatal 

hospitalizations per year when all cars on the road met FMVSS 203 and 204.10

The NCSS data did not show any one of the five types of energy-absorbing columns to be 

significantly more effective, or less effective than the other types, nor did they show a significant 

difference between energy-absorbing columns and energy-absorbing canisters in the steering 

 

8

 90% confidence bounds for effectiveness: 8.5 to 15.5 percent; for benefits: 900 to 1800 lives saved. 9 Ibid., pp. 138-197; Kahane, C.J., Smith, R.A. and Tharp, K.J., “The National Crash Severity Study,” Report on the

Sixth International Technical Conference on Experimental Safety Vehicles, NHTSA Report No. DOT HS 802 501,

Washington, 1977, pp. 493-515. 10 90% confidence bounds for effectiveness: 28 to 48 percent; for benefits: 14,900 to 33,500 hospitalizations 

prevented.

62
wheel. In other words, the United States data did not duplicate the results of a British study 

finding much higher effectiveness for the canisters and much better performance under nonaxial 

loading.11

NHTSA’s evaluation and other analyses showed many frontal crashes in which compression of 

the column was slight or minimal, especially in the presence of nonaxial forces. These results, 

however, tended to be inconclusive because of the difficulty of establishing cause-and-effect 

relationships. It is difficult to determine if columns were “binding” and causing injury to drivers, 

or if the compression of the column was slight because it was not strongly impacted by the 

driver. The effect, if any, of vehicle damage on the column’s ability to compress in response to 

occupant loading is also unclear. In other words, the data did not point to an unequivocal need or 

method for strengthening the FMVSS 203 regulation, and the issue eventually became moot with 

the introduction of air bags and with higher use of safety belts.12

The NCSS data demonstrated the exceptional success of FMVSS 204. Intrusion of the steering 

column in any direction (rearward, upward or sideways) was reduced by 68 percent in frontal 

towaway crashes and rearward intrusion, in particular, was reduced by 81 percent.13

The introduction of energy-absorbing and telescoping steering assemblies, along with 

deformable steering wheels, padded hubs, and removal of hazardous appurtenances, reduced 

injuries to all body regions: chest, abdomen, and head/neck. It did not have any undesirable side 

effects, such as increased driver injuries due to contacts with other parts of the vehicle 

(windshield, instrument panel, etc.).14

Fatality reduction – light trucks NHTSA’s 1988 evaluation of occupant protection in frontal 

interior impact addresses the effect of energy-absorbing steering assemblies in light trucks. 

Since there was uncertainty about exactly when these assemblies were first installed, a direct 

“before-after” comparison, as shown above for cars, seemed unsuitable. Instead, a more 

extended time-series analysis considered head-on collisions between early- and late-model 

vehicles. After controlling for vehicle weight, driver age and gender, who fared better: the driver 

of the late-model truck or the early-model truck? This analysis indicated a 16 percent reduction 

in fatality risk for unrestrained drivers in frontal crashes during the model years that energyabsorbing steering assemblies were primarily installed in light trucks (1973-80). The 

corresponding analysis for passenger cars showed a 12 percent reduction in fatality risk during 

the model years that those assemblies were installed in cars (1967-68). Since the results are 

quite similar (well within sampling-error bounds), NHTSA concludes that energy-absorbing 

 

11 Kahane (1981 Steering Assemblies), pp. 226-236; Gloyns, P.F. and Mackay, G.M., “Impact Performance of Some

Designs of Steering Assembly in Real Accidents and under Test Conditions,” Proceedings of Eighteenth Stapp Car

Crash Conference, Society of Automotive Engineers, Warrendale, PA, 1974. 12 Kahane (1981 Steering Assemblies), pp. 249-269; Garrett, J.W. and Hendricks, D.L., “Factors Influencing the 

Performance of the Energy Absorbing Steering Column in Accidents,” Report on the Fifth International Technical 

Conference on Experimental Safety Vehicles, NHTSA, Washington, 1975; Horsch, J.D., Petersen, K.R. and Viano, 

D.C., Laboratory Study of Factors Influencing the Performance of Energy Absorbing Steering Systems, Paper No. 

820475, Society of Automotive Engineers, Warrendale, PA, 1982. 13 Kahane (1981 Steering Assemblies), pp. 220-226. 14 Ibid., pp. 239-248. 

63
steering assemblies are as effective in light trucks as in passenger cars – i.e., an estimated 12.1 

percent fatality reduction for drivers in frontal crashes.15

Injury reduction – light trucks NHTSA’s crash files, at the time of the 1988 evaluation, did not 

have enough data for a statistically meaningful analysis of the injury-reducing effectiveness of 

energy-absorbing steering assemblies in light trucks.16

 

15 Kahane, C.J., An Evaluation of Occupant Protection in Frontal Interior Impact for Unrestrained Front Seat

Occupants of Cars and Light Trucks, NHTSA Technical Report No. DOT HS 807 203, Washington, 1988, pp. xxxxxxii, xxxiv and 192-194. 16 Ibid., pp. 165-173. 

64
FMVSS 205: Glazing materials

This standard regulates two innovative safety technologies that have been evaluated by NHTSA: 

• High-Penetration Resistant (HPR) windshields

• Glass-plastic windshields

HPR windshields, an essential protection against facial lacerations, have been standard 

equipment in motor vehicles since model year 1966. Glass-plastic windshields, on the other 

hand, although envisioned as even better protection against lacerations, were only installed on a 

few make-models of passenger cars during 1985-87, and then discontinued. 

The first paragraph of FMVSS 205 states, “The purpose of this standard is to reduce injuries 

resulting from impact to glazing surfaces, to ensure a necessary degree of transparency in motor 

vehicle windows for driver visibility, and to minimize the possibility of occupants being thrown 

through the vehicle windows in collisions.”1

 FMVSS 205 regulates all automotive glazing, 

including windshields, side and rear windows, etc. However, only windshields experienced 

dramatic innovations during the 1965-99 time frame that were evaluated by NHTSA. The two 

evaluations will now be discussed, one-by-one. 

High Penetration Resistant (HPR) windshields

Regulatory history FMVSS 205 applies to all motor vehicles. The first version of FMVSS 205 

was one of NHTSA’s initial safety standards, with a Notice of Proposed Rulemaking in 

December 1966, a Final Rule in February 1967 and an effective date of January 1, 1968. It 

primarily incorporates the American National Standards Institute (ANSI) Safety Code Z26.1 

(July 1966) and SAE Standard J938, (October 1965).2

How HPR windshields work Laminated “safety” windshields, with a thin sheet of plastic 

sandwiched between two layers of glass, date back to 1927 in the United States. Nevertheless, 

the pre-HPR windshield caused large numbers of facial lacerations requiring surgical care. The 

glass layers readily broke and tore through the plastic layer in moderately severe frontal crashes 

with head-impact speeds around 13 mph. The HPR windshield incorporated two strategies to 

improve performance. (1) The plastic (polyvinyl butyral) layer was doubled in thickness to 

increase its tear resistance and energy absorption. (2) Even more important, the bond between 

the glass and the plastic layers was loosened by adding moisture to the plastic; as a result, the 

plastic flexed away from the glass pane rather than being torn by the glass. This allowed the 

windshield to bulge at a safe force level, without tearing, upon head-impacts ranging up to 22-29 

mph, a quite severe crash. The test for FMVSS 205 specifies that a 5-pound steel ball must not 

penetrate the windshield at 19 mph – i.e., fast enough that pre-HPR windshields fail but slow 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.205. 2

 Kahane, C.J., An Evaluation of Windshield Glazing and Installation Methods for Passenger Cars, NHTSA

Technical Report No. DOT HS 806 693, Washington, 1985, pp. 1-2; Federal Register 31 (March 8, 1966): 4091, 31

(July 15, 1966): 9631, 31 (December 3, 1966): 15219, 32 (February 3, 1967): 2414; Safety Code for Safety Glazing 

Materials for Glazing Motor Vehicles Operating on Land Highways, Standard Z26.1, American National Standards

Institute, New York, 1966; 1968 SAE Handbook, Society of Automotive Engineers, New York, 1968. 

65
enough that HPR windshields succeed. The glass and auto manufacturers developed HPR 

windshields before NHTSA existed. All 1965 Ford Thunderbirds and all domestic passenger 

cars beginning in model year 1966 have HPR windshields.3

Expected benefits Drivers and front-seat passengers can expect to benefit in frontal crashes that 

propel them into the windshield. The zone of benefits is for head impacts between 13 and 22-29 

mph, where the pre-HPR windshield tears but the HPR windshield remains intact while 

crumpling and bulging. The most common benefit ought to be a reduction of “nonminor” 

(AIS ≥ 2) facial lacerations from torn glass – injuries that cause disfigurement, extend into the 

subcutaneous tissue or require more than first aid or simple closure. There should be a large 

reduction in serious injuries to the eyes, lips or tongue that occur, in pre-HPR windshields, when 

the occupant’s head rebounds through the break in the windshield. There may be a reduction in 

fractures to the nose or facial bones caused by edges of broken windshields. There would likely 

be a smaller reduction of minor lacerations, since they can occur even without tears in the 

windshield. Blunt impact trauma is less likely to be mitigated. Fatal head injuries are hardly 

ever due to windshield contact alone, and unlikely to be affected by the HPR windshield. 

Injury reduction – passenger cars NHTSA’s evaluation was published in 1985. It uses data 

from the National Crash Severity Study (NCSS), the predecessor of NASS. These data specify, 

like NASS, the severity (AIS), body region, lesion and contact source of injuries. The injury rate 

– the number of AIS ≥ 2 lacerations of the face or head due to contact with the windshield, per 

1000 front-seat occupants involved in frontal towaway crashes – was computed for cars of the 

first model years with HPR windshields and compared to the rate in cars of the last model years 

with pre-HPR windshields.4

 For example, a comparison of cars of the first five years with HPR 

windshields and the last five years without them showed a dramatic, statistically significant 74 

percent injury reduction with HPR: 

 AIS ≥ 2 N of Lacerations per 

 Lacerations Occupants 1000 Occupants

Model year 1961-65 (“before”) 38 4,958 7.66 

Model year 1966-70 (“after”) 52 26,110 1.99 

Nearly identical reductions were observed when the data were limited to four, three, two or just 

one model year before and after the shift to HPR. The 74 percent injury reduction is one of the 

 

3

 Kahane (1985 Windshields), pp. 5-11; Patrick, L.M. and Daniel, B.P., “Comparison of Standard and Experimental

Windshields,” Eighth Stapp Car Crash and Field Demonstration Conference, Wayne State University Press, 

Detroit, 1966; Rieser, R.G. and Michaels, G.E., “Factors in the Development and Evaluation of Safer Glazing,”

Ninth Stapp Car Crash Conference, University of Minnesota, Minneapolis, 1966; Widman, J.C., Recent 

Developments in Penetration Resistance of Windshield Glass, Paper No. 650474, Society of Automotive Engineers, 

New York, 1965. 4

 Kahane (1985 Windshields), pp. 77-80; Kahane, C.J., Smith, R.A. and Tharp, K.J., “The National Crash Severity

Study,” Report on the Sixth International Technical Conference on Experimental Safety Vehicles, NHTSA Report 

No. DOT HS 802 501, Washington, 1977, pp. 493-515.

66
highest ever observed for any of the FMVSS. After 1966, there was an almost miraculous 

reduction of disfiguring facial injuries in motor vehicle crashes.5

 Using 1982 as the “baseline” 

year, the evaluation estimated that HPR windshields would prevent 39,000 AIS ≥ 2 lacerations 

per year when all cars on the road were equipped with them.

6

HPR windshields reduce facial fractures involving windshield contact by 56 percent, preventing 

8,000 fractures per year. In all, the windshields prevent 47,000 AIS 2-4 injuries per year7

(39,000 lacerations plus 8,000 fractures). Many of these injuries involved the eyes, nose or 

mouth, and were especially distressing. HPR windshields reduced injuries to the eyes, nose or 

mouth involving contact with windshields by 72 percent, preventing 19,000 such injuries per 

year. 

HPR windshields were also rather effective in preventing minor (AIS 1) facial lacerations due to 

windshield contact, reducing them by a statistically significant 25 percent. However, HPR 

windshields had little or no observed effect on concussions, contusions or complaints of pain.8

NHTSA also analyzed 1974 New York State crash data to corroborate the NCSS results. These 

data indicate the body region and lesion of an occupant’s most severe injury, but not the contact 

source. Severity of nonfatal injuries is indicated by a three-letter scale (A, B, C) but not the AIS. 

Facial injuries with level A (severe) bleeding in frontal crashes [due to any contact source] were 

reduced by approximately 50 percent with HPR windshields; facial fractures by 25-30 percent. 

In other words, the New York results support the NCSS findings.9

Fatality reduction – passenger cars NHTSA’s 1985 analysis is based on 1975-82 FARS data. 

Since FARS does not indicate the source or body region of fatal injuries, or provide information 

on nonfatal crashes to allow computation of fatality rates, it is best suited for comparing overall 

fatality risk of front-seat occupants in frontal crashes, before and after HPR windshields, relative 

to a control group of nonfrontal fatalities. Since energy-absorbing steering columns were 

introduced in model years 1967-68, 1-2 years after the HPR windshield, the analysis must either 

be limited to model year 1966 and earlier, or it must somehow control for the energy-absorbing 

column. NHTSA used a log-linear regression of the frontal/nonfrontal fatality ratio, by calendar 

year and model year, with independent variables: HPR windshield, energy-absorbing column, 

vehicle age, and calendar year. The effect attributed to the HPR windshield was negligible, and 

it was not statistically significant. The evaluation concluded that the HPR windshield, although 

highly effective in reducing nonfatal injuries, has little effect on fatalities.10

Injury and fatality reduction – light trucks NHTSA’s 1985 evaluation only addressed the 

performance of windshields in passenger cars. However, since the mechanisms of injuries 

 

5

 Huelke, D.F., Grabb, W.C., Dingman, R.O. and Oneal, R.M., “The New Automotive Windshield and its 

Effectiveness in Reducing Facial Lacerations,” Plastic and Reconstructive Surgery, Vol. 41, No. 6, June 1968. 6

 90% confidence bounds for effectiveness: 65 to 83 percent; for benefits: 25,000 to 53,000 lacerations prevented. 

See Kahane (1985 Windshields), pp. 127-128 and 225-235. 7

 90% confidence bounds: 31,000 to 62,000 injuries. 8 Ibid., pp. 77-95 and 225-235. 9 Ibid., pp. 101-116. 10 Ibid., pp. 122-127. 

67
involving windshield contact are presumably similar in cars and light trucks, the effectiveness 

estimates for cars are probably appropriate for light trucks as well. 

Glass-plastic windshields 

Since facial lacerations are so often due to contact with shattered, torn or crumpled glass, it 

would seem preferable to line the interior surface of the windshield with shatterproof, energyabsorbing plastic. However, glass is scratch-resistant and its long-term optical qualities are far 

superior to most plastics, making it essential for windshields and other windows that drivers 

must look through. Circa 1980, glass manufacturers developed a polyurethane sheet that was 

transparent and durable enough for use as a windshield’s inner lining. In 1983, NHTSA 

amended FMVSS 205 to permit the use of glass-plastic glazing at the option of the motor vehicle 

manufacturer. The amendment includes numerous tests to assure that the plastic resists 

scratching, clouding and corrosion by chemicals. The inner lining is applied to the HPR 

laminated windshield and makes the glass-plastic windshield a four-ply material.11

It was hoped that glass-plastic windshields, by largely eliminating any exposure of occupants to 

glass surfaces in frontal crashes, would substantially reduce laceration injuries relative to the 

conventional HPR windshield, especially the minor (AIS 1) lacerations where the HPR 

windshield did not have that large an effect. 

Glass-plastic windshields were standard equipment in the 1985-87 Cadillac Seville, 1986-87 

Cadillac Eldorado, 1986-87 Buick Riviera and 1986-87 Oldsmobile Toronado as well as in 

substantial test fleets of several manufacturers, over 200,000 cars in all. However, the 

manufacturers discontinued installing glass-plastic windshields after 1987, largely because of 

durability problems in day-to-day use and high replacement costs. An additional consideration, 

perhaps, was that increased use of safety belts and installation of air bags would soon be 

reducing the frequency of occupant contacts with the windshield, anyway.12

Injury reduction NHTSA’s evaluation was published in 1993. It is based on crash data from

New York (1986-88), Pennsylvania (1985-88) and Indiana (1985-89). These state files 

distinguish between injuries with bleeding (primarily lacerations), injuries without bleeding (e.g., 

contusions or complaints of pain) and uninjured occupants. They identify the vehicle’s makemodel or VIN. However, not all of these files identify the impact location (frontal, side, etc.) or 

details about an injury’s body region, severity or specific lesion. The rate of injuries with 

bleeding per 100 crash-involved front-seat occupants was computed for the four make-models 

that had glass-plastic windshields as standard equipment and compared to the rate in three 

“control-group” make-models that had conventional HPR windshields; 1985-87 Cadillac Deville, 

1986-87 Buick Electra and 1986-87 Oldsmobile 98.13 For example, the injury rates for drivers in 

the combined New York and Pennsylvania data were as follows: 

 

11 Parsons, G.G., An Evaluation of the Effects of Glass-Plastic Windshield Glazing in Passenger Cars, NHTSA 

Technical Report No. DOT HS 808 062, Washington, 1993, Chapter 1; Federal Register 48 (November 16, 1983):

52065; Code of Federal Regulations, Title 49, Part 571.205; Final Regulatory Evaluation, Anti-Lacerative Glazing,

FMVSS 205, NHTSA Plans and Policy, Washington, 1983. 12 Parsons (1993), Chapters 3 and 4. 13 Ibid., Chapter 2.

68
Injuries with N of Injuries with Bleeding 

Bleeding Drivers per 100 Occupants 

Control group 295 7,843 3.76 

Glass-plastic windshields 85 1,942 4.38 

Since the observed injury rate is actually slightly higher in the cars with glass-plastic windshields 

than in the control-group make-models, these data, as well as the other tables in the evaluation 

report, do not suggest that glass-plastic windshields reduced the overall rate of injuries with 

bleeding. (It is unknown whether or not they reduced the average severity of the injuries.) 

More detailed (but less numerous) crash data from the operators of the test fleets are consistent 

with the statistical finding. They suggest that glass-plastic windshields were quite successful in 

keeping occupants away from contact with glass, but occupants nevertheless sustained 

lacerations due to skin tissue “splitting” or “tearing” from blunt impact with the plastic surface, 

or from sliding of the head or face against the plastic inner layer.14

Potential future applications Although the glass-plastic windshields actually installed during 

the 1980’s were not successful in terms of durability or in reducing the overall frequency of 

lacerations, NHTSA is confident that glass-plastic glazing could have great potential benefits in 

other applications. Specifically, side windows of motor vehicles are currently made of tempered 

glass. The entire pane breaks into many small pieces upon impact. Although that has the 

advantage of preventing serious lacerations, it results in wide-open windows that become portals 

for occupant ejection. An inner layer of plastic with appropriate strength, durability and optical 

qualities could become one component in a system that would keep the occupant inside the 

vehicle.15

 

14 Ibid., p. 2-32. 15 Willke, D., Summers, S., Wang, J., Lee, J., Partyka, S. and Duffy, S., Ejection Mitigation Using Advanced

Glazing: Status Report II, NHTSA, Washington, 1999 ( www-nrd.nhtsa.dot.gov/pdf/nrd-11/glazing0999.pdf ) 

69
FMVSS 206: Door locks and door retention components

This standard regulates one safety technology that has been evaluated by NHTSA: 

• Stronger locks, latches and hinges for side doors

The first paragraph of FMVSS 206 states unequivocally that its purpose is to prevent occupant 

ejections: “This standard specifies requirements for door locks and door retention components 

including latches, hinges and other supporting means, to minimize the likelihood of occupants 

being thrown from the vehicle as a result of impact.”1

 FMVSS 206 took effect for doors on the 

side of passenger cars on January 1, 1968, multipurpose passenger vehicles on January 1, 1970, 

and other light trucks on January 1, 1972. Its 1997-98 extension to doors on the back ends of 

vehicles that access seating areas, such as station-wagon tailgates or minivan hatches (but 

excluding trunk lids), has not yet been evaluated by NHTSA.2

Regulatory history Self-regulation of side door locks, latches and hinges by the industry began 

in November 1962, well before NHTSA existed, with SAE Standard J839, “Passenger Car Side 

Door Latch Systems.” In 1965, SAE substantially upgraded J839 to J839b, nearly doubling the 

strength requirements, and introduced another standard, J934, “Vehicle Passenger Door Hinge 

Systems.” J839b and J934 were essentially incorporated into FMVSS 206, one of NHTSA’s 

initial safety standards, with a Notice of Proposed Rulemaking in December 1966, a Final Rule 

in February 1967 and an effective date of January 1, 1968.3

What happened Safety researchers in the 1950’s learned that car doors were forced open in 

many crashes, especially rollovers; that occupants were often ejected via the opened doors; and 

that being “thrown clear” in a crash was not an advantage but a terrible risk, especially in 

rollovers, where an occupant could be wedged between the car and the ground. Safety door 

latches were introduced in the 1955-56 domestic cars to assure that doors would not pop open 

when occupants on the inside, or objects/ground on the outside brushed against door handles 

during crashes. During about 1962-68, the manufacturers began an almost continuous process of 

strengthening latches and hinges in their various make-models. Doors can open in crashes if 

latches or hinges are pulled apart by impact damage, or if latches and hinges are pulled loose 

from their supporting structures. The net effect of these cumulative improvements was a 

dramatic reduction of door-opening, as seen in Automotive Crash Injury Research (ACIR), a 

crash data file of the 1950’s and 60’s:4

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.206. 2 Federal Register 32 (February 3, 1967): 2414, 34 (January 24, 1969): 1150, 60 (September 28, 1995): 50124. 3

 Kahane, C.J., An Evaluation of Door Locks and Roof Crush Resistance of Passenger Cars – Federal Motor

Vehicle Safety Standards 206 and 216, NHTSA Technical Report No. DOT HS 807 489, Washington, 1989, pp. 2-4;

1965 SAE Handbook, Society of Automotive Engineers, New York, 1965, p. 893; 1967 SAE Handbook, Society of 

Automotive Engineers, New York, 1967, pp. 904-906; Federal Register 31 (March 8, 1966): 4091, 31 (July 15, 

1966): 9631, 31 (December 3, 1966): 15219, 32 (February 3, 1967): 2414. 4

 Kahane (1989 Door Locks/Roof Crush Resistance), pp. 27-30; Garrett, J.W., The Safety Performance of 1962-63 

Automobile Door Latches and Comparison with Earlier Latch Designs, Report No. VJ-1823-R7, Cornell 

Aeronautical Laboratory, Buffalo, 1964; Garrett, J.W., Comparison of Door Opening Frequency in 1967-68 Cars 

with Earlier Model U.S. Cars, NHTSA Technical Report No. DOT HS 800 231, Washington, 1969. 

70
Percent of ACIR Crashes 

Model Year Where Door Opened 

 Pre-1956 43 

 1956-61 28 

 1962-63 23 

 1964-66 17 

 1967-68 12 

Expected benefits The fewer doors open in crashes, the fewer ejections via that portal, 

especially in rollovers. Since it is safer to stay inside a vehicle than be ejected, there ought to be 

a significant fatality reduction, especially in rollovers. This should benefit all occupants who are 

at risk of being ejected via a side door, drivers and passengers, front-seat and second-seat. 

Fatality reduction – passenger cars Frankly, it is difficult to compute the benefits of this 

technology. Since improvements entered gradually over several years (and NHTSA does not 

know exactly when on what models), a diffuse time-series approach must replace the customary 

“just before-just after” comparison. Moreover, door locks were just one influence on rollover 

fatalities in the 1960’s: above all, car size changed from year to year, and when cars grow, 

rollover fatalities decrease. Nevertheless, there is no doubt that improved door locks have saved 

lives. The side door was the leading ejection portal in cars of the 1950’s and early 1960’s, but 

door ejections have decreased to the point that the side window became the leading portal in the 

1970’s. The problem is quantifying the benefit. 

NHTSA’s evaluation, published in 1989, computed several rollover-fatality risk indices that 

control for car size, using logistic regression.5

 For example, one analysis used 1975-86 FARS 

data to calibrate the ratio of rollover fatalities to frontal-fixed-object fatalities, as a function of 

model year, track width and curb weight. This ratio was graphed, by model year, for cars with 

55 inch track width and 3000 pound curb weight (median values for cars on the road in 1975-86), 

and then indexed relative to the average value for model years 1975-80. The averages of the two 

indices defined in the evaluation6

 were: 

Model Year Rollover Fatality Risk Index 

 1963-64 123 

 1968-70 107 

 1975-80 100 

The risk indices dropped substantially between 1963-64 and 1968-70, when door locks steadily 

improved. However, door locks were not the only factor that influenced rollover fatalities in 

those model years. The evaluation specifically estimated that the 1962-68 improvements to door 

 

5

 Kahane (1989 Door Locks/Roof Crush Resistance), pp. 127-204. 6 Ibid., p. 202, average of the indices NEWROLL2 and NEWROLL3. 

71
locks reduced fatalities involving occupant ejection in rollovers by 15 percent. Using 1982 as 

the “baseline” year, the evaluation estimated these improvements were saving approximately 400 

lives per year.7

Injury reduction – passenger cars NHTSA’s evaluation does not include any analysis or 

estimate of the effect of door locks on nonfatal injuries. However, other studies such as 

NHTSA’s 1985 evaluation of windshields suggest that occupant ejections cause similar numbers 

of serious nonfatal injuries (AIS 3-5) and fatalities.8

 It is likely that the improvements to door 

locks, latches and hinges are about as effective in reducing serious injuries as fatalities, and that 

they are preventing comparable numbers of AIS 3-5 injuries and fatalities. 

Fatality and injury reduction – light trucks NHTSA’s 1989 evaluation only addressed the 

performance of door locks in passenger cars. Since FMVSS 206 was extended to light trucks a 

few years after it took effect for cars, and since the door components of trucks and cars are 

similar, it seems plausible that the gradual improvement of door locks in cars was matched by a 

comparable effort in light trucks, with a similar effectiveness in reducing fatalities associated 

with door ejections. However, National Crash Severity Study (NCSS) data show that, 

proportionately, the door is the ejection route in only 2/3 as often in LTV rollovers as in car 

rollovers. Thus, the overall reduction of ejection fatalities in rollovers, estimated to be 15 

percent in cars, would be 10 percent in LTVs.9

Potential FMVSS 206 upgrade Whereas improvements to door locks of the 1960’s greatly 

reduced the incidence of doors opening in crashes and occupant ejection via the open door, they 

did not eliminate these safety problems. NHTSA has been studying door latch integrity for some

years, assessing the potential for benefits from strengthening the existing test procedures and/or 

adding new procedures to FMVSS 206.10

 

7 Ibid., pp. xxix and 222-225. 8 Kahane (1985 Windshields), pp. 161-163. 9

 An analyis of MY 1990-2003 cars and LTVs in 1995-2003 NASS data confirms the dramatic, long-term reduction

in ejections via the open door. In NCSS, the open door accounted for 32 percent of ejections in car rollovers, 20

percent in LTVs. In NASS, the open door accounted for just 8 percent of ejections in car rollovers, 7 percent in 

LTVs. Thus, our conclusions that FMVSS 206-related technology reduced overall rollover fatality risk by 15

percent in cars and 10 percent in LTVs may even be a little bit conservative if the long-term, continuing

improvement of doors is taken into account. 10 B.01.04 Door Latch Integrity. NHTSA Research & Development, www-nrd.nhtsa.dot.gov/departments/nrd01/summaries/b0104.html , June 2000; Federal Register 60 (July 12, 1995): 35889. 

72
FMVSS 207: Seating systems

“This standard establishes [a variety of strength] requirements for seats, their attachment 

assemblies, and their installation to minimize the possibility of their failure by forces acting on 

them as a result of vehicle impact.”1

 It is, however, linked with just one tangible safety 

modification that has been evaluated by NHTSA: 

• Seatback locks for 2-door cars with folding front seatbacks 

The locks are designed to mitigate injury risk in frontal impacts by keeping seatbacks upright 

and in place. They are supposed to prevent seatbacks from folding over and pushing on frontseat occupants and to keep unrestrained back-seat occupants in the back-seat area. They were 

introduced in 2-door passenger cars primarily in model years 1967-68. 

Regulatory history FMVSS 207, one of NHTSA’s initial safety standards, took effect for 

passenger cars on January 1, 1968 and was extended to trucks, buses and multipurpose vehicles, 

effective on January 1, 1972. Except for the seatback lock requirement, FMVSS 207 largely 

incorporated SAE Recommended Practice J879, which had been in place since November 1963. 

Thus, the locks were the only substantial modification in domestic cars during the time frame of 

the FMVSS 207 rulemaking.2

How seatback locks are supposed to work Two-door cars generally need front seatbacks that 

fold down and out of the way to give passengers room to get in and out of the back seat. Without 

the locks, these seatbacks are likely to fold over in frontal crashes, even at low severities. That 

could potentially increase injury risk for front-seat occupants by adding some or all of the 

momentum of the 25-35 pound seatbacks to the momentum of the occupants as they slam into 

structures at the front of the passenger compartment. The locks could be even more beneficial 

when there are unrestrained back-seat occupants. In a car without the locks, the back-seat 

passenger could move forward with the seatback and this combined load could weigh upon the 

front-seat occupant. As the seatback folds over, it can act as a ramp for the back-seat passenger, 

who will vault head-first into the front compartment, contact the windshield or header, or make 

head-to-head contact with front-seat occupants. With the locks, a seatback could remain upright 

and be a relatively benign surface for the rear-seat passenger to impact.3

However, for seatback locks to be effective, they must endure the impact forces to which they 

are exposed. FMVSS 207 (which makes no explicit claim of effectiveness when back-seat 

passengers are present) only requires the locks to withstand a dynamic load of 20 times the 

weight of the seatback. When the 150-pound weight of an adult back-seat passenger is added to 

the 25-35 pound weight of the seatback, even a low-severity crash with acceleration levels well 

below 10 g’s can produce loads exceeding the FMVSS 207 level. 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.207. 2

 Kahane, C.J., A Preliminary Evaluation of Seat Back Locks, NHTSA Technical Report No. DOT HS 807 067, 

Washington, 1987, pp. 2-3; Federal Register 31 (December 3, 1966): 15219, 32 (February 3, 1967): 2414, 36 

(December 2, 1971): 22902, 1968 SAE Handbook, Society of Automotive Engineers, New York, 1968, pp. 954-955. 3

 Kahane (1987 Seatback Locks), pp. 10-12; Severy, D.M., Brink, H.M., Baird, J.D. and Blaisdell, D.M., “Safer Seat 

Designs,” Thirteenth Stapp Car Crash Conference, Society of Automotive Engineers, New York, 1969, pp. 323-

325. 

73
The manufacturers have developed two types of seatback locks for production vehicles: 

• Manual seatback locks: occupants disengage the lock by operating a lever or pressing a 

button (not necessarily in a convenient location) every time they get in or out of the car. 

• Automatic inertial seatback locks that allow free movement of the seatback during 

normal vehicle operation and only lock up during impacts, road bumps, or emergency 

braking. The technology is similar to, and probably inspired by inertial locking 

retractors for safety belts. 

Volkswagen and Opel installed manual seatback locks in their model year 1966 cars; GM, Fiat, 

Renault and Datsun in 1967; and Ford and Chrysler in the full model year 1968 – all before the 

January 1, 1968 effective date. Automatic seatback locks are obviously more convenient for 

passengers, and they have completely superseded the manual type in domestic cars since about 

1980. In addition to being more convenient, automatic locks preclude an imaginable (but 

unsubstantiated) safety problem: during a fire, immersion or other emergency egress situation, 

back-seat passengers could be delayed while they locate and operate manual locks, but can exit 

immediately from cars with automatic locks that allow free movement of the seatback.4

Potential benefits Drivers and right-front passengers might experience a reduction of fatalities 

and injuries in frontal crashes, when the back seat is unoccupied, provided that a locked seatback 

puts less load on them than a freely moving, pre-FMVSS 207 seatback. When the back seat is 

occupied, both front-outboard and rear-outboard occupants might experience a more substantial 

reduction of fatalities and injuries in frontal crashes, provided that the locks are able to withstand 

the impact force of the back-seat occupant. In addition, upright seatbacks might help contain 

back-seat occupants within their seating area and reduce their risk of ejection from the car. 

Evaluation findings NHTSA’s study, published in 1987, includes statistical analyses of crash 

data comparing injury and fatality rates in 2-door cars just before and after the introduction of 

seatback locks; sled tests simulating frontal crashes of seat systems with and without the locks, to 

study the effect of the locks on occupant force levels and kinematics; and a review of in-depth 

crash investigations to determine the ability of seatback locks to endure impact forces, as a 

function of Delta V. 

Crash data analyses Injury rates per 100 crash-involved occupants are computed for domestic 2-

door cars of the model year(s) just before and just after the introduction of manual seatback locks 

(GM in 1967, Ford and Chrysler in 1968). Corresponding rates are computed for a control group 

of 4-door cars of these same model years (i.e., just before and after seatback locks were 

introduced in the 2-door cars made by that manufacturer). Four-door cars are a useful control 

group because they received all of the safety improvements that 2-door cars got during that time 

frame – except seatback locks. In other words, did the injury reduction in 2-door cars (after vs. 

before seatback locks) surpass the corresponding reduction in 4-door cars? Injury rates were 

computed from 1973-77 Washington State data, 1972-74 Texas data and 1974 New York State 

 

4 Kahane (1987 Seatback Locks), pp. 4-5 and 11-12.

74
data.5

 Similarly, fatality rates per million vehicle registration years are computed from 1975-85 

FARS data and R.L. Polk registration data (their “National Vehicle Population Profile”).6

None of these analyses showed a statistically significant reduction of injury or fatality rates in 2-

door cars above and beyond the corresponding reduction in 4-door cars. There was no observed 

benefit for front-seat occupants, regardless of whether the seat behind them was unoccupied, 

occupied by an adult, or occupied by a child. There was no reduction of injury or fatality rates, 

or of ejection, for back-seat occupants, adults or children. 

Sled tests NHTSA sponsored 28 sled tests, involving 84 unrestrained 50th percentile Part 572 

dummies.7

 Fourteen of these tests used a sled buck that simulated the passenger compartment of

a 1981 domestic sedan with operational seatback locks: speeds ranged from 15 to 30 mph, 

impacts were full-frontal or oblique-frontal, dummies occupied the front-outboard seats in all 

tests and the rear-outboard seats in eight tests. The other 14 tests exactly replicated the above 

series, except that the seatback locks were removed to allow the seatbacks to pivot freely in the 

crash, simulating a pre-FMVSS 207 car. That provided 42 matched pairs of dummies tested 

under identical conditions, except one of them had the seatback lock and the other did not. The 

Head Injury Criterion (HIC), chest g’s, femur loads, mean strain criterion, total laceration index 

and other measures were computed for each dummy. 

The statistical analysis of the 42 matched pairs considers the average difference of the injury 

criterion in the test with seatback locks and in the corresponding test without seatback locks. 

These average differences were not significantly different from zero for any of the injury criteria. 

In other words, the dummies had the same average injury severity with and without the seatback 

locks. When the matched pairs were divided into three principal subgroups – front-seat 

occupants with nobody sitting behind them, front-seat occupants with somebody sitting behind 

them, and back-seat occupants – there was no significant benefit for seatback locks in any 

subgroup. 

The films from the sled tests explain why seatback locks did not significantly reduce injury risk: 

• Seatbacks (with or without the locks) only “follow” front-seat occupants gradually in a 

frontal crash, barely touch occupants at the crucial moment when they first slam into the 

steering assembly or instrument panel, and subsequently only apply force over an 

extended time period that hardly spikes up the injury criteria.

• At 26.5 mph the impact of a back-seat dummy sheared the seatback lock or tore the entire 

front seat out of its track every time. 

• At 22.5 mph, although seatback locks remained intact, rear-seat dummies deflect the 

front seatback forward quite a bit and are not well contained in the back-seat area. 

In-depth crash investigations NHTSA’s Multidisciplinary Accident Investigation (MDAI) File 

provides detailed information on the performance of the seat and seatback lock in 1968-78 

crashes, plus a description of the vehicle damage that allows a rough estimate of Delta V in 

 

5 Ibid., pp. 55-96. 6 Ibid., pp. 97-135. 7 Ibid., pp. 21-54. 

75
frontal crashes.8

 “Seat separation” is defined to include breakage of seatback locks and/or (much 

less frequently) seats tearing loose from tracks, seat tracks tearing loose from floors, seatbacks 

tearing loose from seat cushions. The MDAI data suggest front-seat separation occurred quite 

frequently in frontal impacts of 2-door cars equipped with seatback locks, when there was a 

back-seat occupant weighing 100 pounds or more: 

Delta V (mph) Percent of Front Seats Separated 

10 – 14.9 30 

15 – 19.9 37 

20 – 29.9 51 

 30 + 85 

This performance obviously limited any potential benefits for seatback locks when there were 

back-seat occupants. 

Given the absence of statistically significant positive findings in the crash-data analyses, the 

negligible effect of seatback locks on dummy kinematics in sled tests, and the high rates of frontseat separation when there are back-seat occupants, NHTSA’s evaluation concluded that 

seatback locks do not have a measurable overall effect on fatalities and injuries. It is conceivable 

that the locks are effective in certain narrowly defined crash types, but not to the extent of 

producing a statistically discernable overall effect. 

 

8 Ibid., pp. 146-152. 

76
FMVSS 208: Occupant crash protection

FMVSS 209: Seat belt assemblies

FMVSS 210: Seat belt assembly anchorages

These three standards regulate safety belts. FMVSS 208 also regulates frontal air bags. Safety 

belts and air bags are probably the two best-known systems to protect occupants from death and 

injury in crashes. However, they include ten somewhat distinct safety technologies that have 

been evaluated, or will be evaluated by NHTSA: 

SAFETY BELTS 

• Lap belts for front-seat occupants

• Lap belts for back-seat occupants

• Manual 3-point lap-shoulder belts for front-seat occupants

• 3-point lap-shoulder belts for back-seat occupants

• Automatic safety belts

• Pretensioners and load limiters for safety belts (not yet evaluated)

AIR BAGS 

• Frontal air bags

• On-off switches for passenger air bags in pickup trucks

• 1998-99 redesign of air bags (not yet evaluated)

• Advanced air bags (not yet evaluated)

Safety belts are the basic protection system for all occupants in most types of crashes, designed 

to keep occupants within the vehicle and close to their original seating position, provide “ridedown” by gradually decelerating the occupant as the vehicle deforms and absorbs energy, and, if 

possible, prevent occupants from contacting harmful interior surfaces or one another. Lap belts 

for front outboard occupants were first offered as options in 1956 and have been standard on 

passenger cars since 1964. Shoulder harnesses were added in 1968-69 in passenger cars; modern 

3-point lap-shoulder belts became standard in 1974. Automatic belts that require no action by 

the occupant were furnished on many cars starting in 1987, but had been phased out by 1997. 

Air bags are an effective supplemental protection system for front-outboard occupants in frontal 

and partially frontal crashes. They significantly added to the energy absorption and ride-down 

offered by previously existing structures (safety belts, energy-absorbing steering columns and 

deformable instrument panels). They also help prevent head contacts with the windshield or

windshield header. 

FMVSS 208 “specifies performance requirements for the protection of vehicle occupants in 

crashes.” FMVSS 209 “specifies requirements for seat belt assemblies.” FMVSS 210 

“establishes requirements for seat belt assembly anchorages to insure their proper location and to 

reduce the likelihood of their failure.” The three standards work together as a single unit to 

protect occupants in crashes.1

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Parts 571.208, 571.209

and 571.210. 

77
Overview of regulatory history Here are the highlights of the long regulatory history of FMVSS 

208-209-210 – the amendments most associated with tangible changes in occupant protection 

technology. In many cases, manufacturers implemented the new technologies a few years, or 

even many years before the effective dates. Not included are a large number of primarily 

technical or interpretative amendments, or proposals and rules that were cancelled or changed 

before they took effect. 

FMVSS 208, 209 and 210 were among NHTSA’s initial safety standards, with a Notice of 

Proposed Rulemaking in December 1966, a Final Rule in February 1967, and an effective date of

January 1, 1968. FMVSS 208 originally required lap belts at each designated seating position in 

passenger cars only, plus shoulder belts at the front-outboard seats if lap belts alone could not 

prevent dummies from contacting the windshield header in static tests. Most new passenger cars 

received shoulder belts at that time. FMVSS 209 specified performance requirements for the 

belts themselves, while FMVSS 210 specified requirements for the anchorages that secure the 

belt systems to the vehicle.2

NHTSA extended the original FMVSS 208 requirements to LTVs up to 10,000 pounds GVWR, 

effective July 1, 1971. The extension did not result in much immediate change, because most 

LTV make-models had been equipped with lap belts by 1968 or earlier and continued to have 

only lap belts up to the mid 1970’s.3

 

Responding to (1) the inadequate restraint provided by lap belts alone for the head and torso, 

(2) the inadequate restraint provided by loosely worn belts and (3) low belt use, NHTSA 

amended FMVSS 208, effective January 1, 19724

: 

• To require shoulder belts at the front outboard seats of all passenger cars (dropping the 

test of contact with the windshield header). Shoulder belts at that time could still be 

separate or integral with the lap belt.

• To require emergency-locking or automatic-locking retractors. 

• To require a warning to sound when the front-outboard lap belts were not buckled. 

• To permit an automatic restraint system, such as air bags or automatic belts, as an 

alternative to the manual shoulder belt and the buzzer. 

• To include, for the first time, a 30 mph frontal barrier test (on which manual belts must 

remain intact, and optional automatic systems must meet injury criteria on the dummies). 

Responding to (1) very low use of the separate shoulder belt and (2) continued low use of lap 

belts, NHTSA amended FMVSS 208, effective September 1, 1973 to require5

: 

• Integral, 3-point lap-shoulder belts at the front outboard seats of passenger cars (or, 

alternatively, automatic protection). 

• Ignition interlocks whereby front-outboard belts must be buckled before a car can be 

started. 

 

2 Federal Register 31 (December 3, 1966): 15219, 32 (February 3, 1967): 2414. 3 Federal Register 35 (September 30, 1970): 15222. 4 Federal Register 36 (March 10, 1971): 4600; Code of Federal Regulations, Title 49, Part 571.208 S4.1.1. 5 Federal Register 38 (June 20, 1973): 16072; Code of Federal Regulations, Title 49, Part 571.208 S4.1.2. 

78
The ignition interlock was not a successful measure. NHTSA amended FMVSS 208, effective 

October 29, 1974, to delete this requirement. A 4-8 second visible and audible warning took its 

place.6

As part of its effort to bring safety requirements for LTVs up to the same level as cars, NHTSA 

amended FMVSS 208 to require integral, 3-point lap-shoulder belts (or, alternatively, automatic 

protection) at the front-outboard seats of most LTVs effective January 1, 1976 and all LTVs with 

GVWR up to 10,000 pounds effective September 1, 1981.7

Low use of manual belts continued into the early 1980’s. On July 17, 1984, NHTSA amended 

FMVSS 208 to phase automatic protection, such as air bags or automatic belts, into the frontoutboard seats of passenger cars between September 1, 1986 and September 1, 1989. To 

encourage the development of air bags, NHTSA exempted the right-front seat from the automatic 

protection requirement until August 31, 1993 in cars with driver air bags. NHTSA, the 

manufacturers and the safety community dedicated themselves to a successful effort to 

encourage buckle-up laws in the States. Comfort and convenience standards for belts were also 

added to FMVSS 208, effective September 1, 1986. During the implementation of automatic 

protection, automatic belts initially predominated, then driver air bags with manual 3-point belts, 

and, after September 1, 1993, dual air bags with manual 3-point belts.8

The superior protection of lap-shoulder belts, as compared to lap belts alone, was extended to the 

rear-outboard seats. Cars had to have 3-point belts, effective December 11, 1989, and LTVs, 

starting September 1, 1991.9

Automatic protection was to be phased into the front-outboard seats of LTVs with GVWR 8,500 

pounds or less from September 1, 1994 to September 1, 1997. Manufacturers used air bags with 

manual belts.10

On-the-road experience and consumer reaction soon demonstrated that the combination of 

manual 3-point belts with air bags was the most effective and desirable system. All cars 

manufactured after September 1, 1997, and all LTVs after September 1, 1998 were required to 

have manual 3-point belts and air bags for the driver and the right-front passenger. Automatic 

belts were phased out.11

Air bags of the early 1990’s presented risks to infants, children under the age of 12, and certain 

other individuals. NHTSA urged that high-risk individuals travel in the back seat when possible. 

 

6 Federal Register 39 (October 31, 1974): 38380, 39 (December 6, 1974): 42692. 7 Federal Register 40 (July 9, 1975): 28805; Code of Federal Regulations, Title 49, Part 571.208 S4.2.1. 8 Federal Register 46 (January 8, 1981): 2064, 49 (July 17, 1984): 28962, 50 (August 23, 1985): 34152; Code of

Federal Regulations, Title 49, Parts 571.208 S4.1.3, 4.1.4 and S7.4 9

 From December 11, 1989 to August 31, 1990, cars were allowed separate lap and shoulder belts as an alternative to 

3-point belts, but nobody exercised that option; Federal Register 54 (June 14, 1989): 25275, 54 (November 2, 

1989): 46257; Code of Federal Regulations, Title 49, Parts 571.208 S4.1.4.2 and S4.2.4. The requirement does not 

apply to some types of seats/vehicles. 10 Federal Register 56 (March 26, 1991): 12472; Code of Federal Regulations, Title 49, Part 571.208 S4.2.5. 11 Federal Register 58 (September 2, 1993): 46551; Code of Federal Regulations, Title 49, Part 571.208 S4.1.5.3

and S4.2.6.2.

79
The agency also amended FMVSS 208 with measures to reduce risk when these people must 

travel in the front seat: 

• Effective June 22, 1995, NHTSA permitted on-off switches for the passenger air bag in 

pickup trucks without back seats or other vehicles that cannot accommodate child safety 

seats in the back seat. This facilitated the implementation of passenger air bags in pickup 

trucks. Effective January 19, 1998, NHTSA also enabled people who must transport 

high-risk individuals in the front seats of any vehicle to obtain aftermarket on-off 

switches at their own expense.12

• Effective September 1, 1997, the agency relaxed some aspects of the frontal impact test 

in order to facilitate the introduction of “redesigned” air bags that deploy less 

forcefully.13

• From September 1, 2003 to September 1, 2005, “advanced” air bags will be phased in 

that do not deploy at all (“suppression”) or deploy only at a low level of force (“low-risk 

deployment”) if a small child is present, or if an older child/small adult is out-of-position, 

close to the air bag.14 

Lap belts for front-seat occupants

History Ford and Chrysler began to offer front-outboard lap belts as an option on some of their 

1956 models. Even before then, consumers were outfitting their vehicles with aftermarket lap 

belts; the American Medical Association and the National Safety Council, among others 

recommended belts in cars. In 1961, Wisconsin required front-outboard lap belts in all new cars 

sold there; New York State required anchorages to allow installation of aftermarket belts. By 

1964, about half of the States had such laws. During that time, SAE issued Recommended 

Practices J4 for belts and J787 for anchorages; they were the starting points for FMVSS 209 and 

210. The domestic manufacturers phased in lap belts at the front-outboard positions of all new 

cars by 1964-65, extending to the front-center seat by 1968. FMVSS 208 took effect in 

passenger cars on January 1, 1968 and in LTVs on July 1, 1971, requiring a shoulder belt on a 

front-outboard seat if a dummy restrained by just a lap belt could reach the windshield header. 

Lap-shoulder belts superseded lap belts at the front-outboard seats, immediately in passenger 

cars during MY 1968, more gradually in LTVs during 1969-81. However, front-center seats 

continue to be equipped with just lap belts.15

How lap belts work The principal benefit of a lap belt is to reduce greatly the likelihood of total 

ejection of an occupant from the vehicle during a crash. Ejection increases fatality risk in a crash 

by a factor of nearly four, all else being equal, because the ground is a less forgiving surface than 

the vehicle interior, and because the occupant may be caught between his or her own vehicle, the 

ground, and/or other vehicles. During 1977-99, 28 percent of unrestrained fatalities in cars, and 

 

12 Federal Register 60 (May 23, 1995): 27233, 62 (November 21, 1997): 62406 Code of Federal Regulations, Title 

49, Part 571.208 S4.5.4 and Part 595. 13 Federal Register 62 (March 19, 1997): 12960; Code of Federal Regulations, Title 49, Part 571.208 S13. 14 Federal Register 65 (May 12, 2000): 30679; Code of Federal Regulations, Title 49, Part 571.208 S14. 15 Performance of Lap Belts in 26 Frontal Crashes, National Transportation Safety Board Report No. NTSB/SS86/03, Publication No. PB86-917006, Washington, 1986, pp. 225-230; 1965 SAE Handbook, Society of Automotive 

Engineers, New York, 1965, pp. 868-872; Federal Register 32 (February 3, 1967): 2414, 35 (September 30, 1970): 

15222. 

80
48 percent in LTVs were ejectees; the percentages may have been higher before improved door 

locks (FMVSS 206).16

There was also hope, initially, that lap belts would be valuable for preventing, or reducing the 

severity of contacts with the vehicle interior, or with other occupants. These hopes were only 

partially realized – e.g., in farside or oblique frontal impacts, where the interior is furthest from

the occupant. However, in direct frontal crashes, lap belts do not necessarily prevent head 

contacts with the interior. Furthermore, restraining the lower torso but not the thorax can have 

two effects that potentially increase rather than mitigate injury. Concentration of the occupant’s 

force on the lap belt can result in abdominal injury, especially if the belt rides up from the pelvis 

to the waist (“submarining”). The head and chest can jackknife forwards and downwards at a 

high velocity.17

Expected benefits Substantial fatality reduction should be expected in rollovers, where the 

majority of unrestrained fatalities are ejectees. Fatality and injury reduction may be expected in 

farside and oblique frontal crashes, and in crashes with multiple harmful events, where occupants

are ejected or tossed around within the vehicle. Possible adverse effects, especially in frontal 

crashes, could detract from overall effectiveness. Lap belts should be more effective in LTVs 

than in cars, since there are more rollovers, more ejections, and more space within the vehicle. 

Early effectiveness studies Early analyses were usually based on fatalities or injuries per 100 

crash-involved occupants. For example, if 10 percent of unrestrained occupants were injured, 

and 5 percent of lap-belted occupants, the effectiveness estimate was 50 percent. These studies 

estimated reductions of fatalities and/or serious injuries ranging from 35 percent upwards to 78 

percent. Researchers grasped that several factors were definitely or possibly inflating the 

effectiveness attributed to belts:

18

• People who buckle up also tend to drive more carefully than those who do not. They 

have less severe crashes, thus, lower injury rates per 100 crash involvements. 

• Additional bias in favor of belts may occur if uninjured, unrestrained people report 

themselves, or are reported as belt users. That would lower the injury rate in the “belted” 

population, and raise it for the “unrestrained.” 

• Statistically meaningful results on fatality reduction are difficult to achieve because there 

are relatively few fatality cases on individual State crash files. 

 

16 Kahane, C.J., Fatality Reduction by Safety Belts for Front-Seat Occupants of Cars and Light Trucks, NHTSA

Technical Report No. DOT HS 809 199, Washington, 2000, pp. 31-33; Evans, L., Traffic Safety and the Driver, Van

Nostrand Reinhold, New York, 1991, pp. 52-54; Sikora, J.J., Relative Risk of Death for Ejected Occupants in Fatal

Traffic Accidents, NHTSA Report No. DOT HS 807 096, Washington, 1986. 17 Performance of Lap Belts in 26 Frontal Crashes; whereas that report focuses on back-seat occupants, the 

conclusions are also pertinent to front-seat occupants. 18 Safety Belt Usage – A Review of Effectiveness Studies – Suggestions for State Programs, NHTSA Report No.

DOT HS 801 988, Washington, 1976; Tourin, B. and Garrett, J.W., Safety Belt Effectiveness in Rural California

Automobile Accidents, Cornell Aeronautical Laboratory, Buffalo, 1960; Levine, D.N. and Campbell, B.J., 

Effectiveness of Lap Seat Belts and the Energy Absorbing Steering Column in the Reduction of Injuries, HSL 

Publication No. 00221617, Highway Safety Research Center, University of North Carolina, Chapel Hill, 1971; 

Kahane, C.J., Usage and Effectiveness of Seat and Shoulder Belts in Rural Pennsylvania Accidents, NHTSA

Technical Note No. DOT HS 801 398, Washington, 1974. 

81
NHTSA’s Restraint Systems Evaluation Project (RSEP) of 1974-75 addressed the first two 

problems. Multidisciplinary teams investigated a probability sample of towaway crashes 

involving 21,000 front-outboard occupants. Detailed information about vehicle damage made it 

possible to adjust the injury rates for differences in crash severity, using multidimensional 

contingency table analysis. Investigators were trained to report belt use as accurately as possible, 

based on an extensive checklist of evidence from the vehicle, driver interviews, the police report, 

and medical information. RSEP estimated that lap belts reduce moderate (AIS ≥ 2) injuries by 

31 percent and severe (AIS ≥ 3) injuries by 46 percent.19

In 1984, in support of the rulemaking on automatic protection, NHTSA supplemented the RSEP 

data with NCSS plus all available NASS data. The additional data permitted a more extensive 

and realistic adjustment for crash severity, producing somewhat lower, but statistically 

significant injury reductions. They remain NHTSA’s most reliable statistical results, and they 

will be discussed below. Based on these analyses and other studies available at that time, 

NHTSA’s best estimates were that lap belts reduce fatalities by 30-40 percent, AIS 2-5 

(moderate to critical) injuries by 25-35 percent, and AIS 1 (minor) injuries by 10 percent, for 

front-seat occupants of passenger cars.20

Fatality reduction – passenger cars Double-pair comparison, as originally applied by Evans to 

study lap-shoulder belts, greatly facilitated the estimation of fatality reduction.21 Double-pair 

comparison allows the direct use of FARS data that have a much higher N of fatalities than 

NASS or State files. It implicitly adjusts or controls for the differences in the severity of crashes 

involving belted and unrestrained occupants. Until 1985, before buckle-up laws, FARS data 

were accurate or at least unbiased in the reporting of belt use. 

A new double-pair analysis of lap-belt effectiveness was performed for this report, using the 

technique developed in NHTSA’s evaluation of 3-point belts (and similar to Evans’).22 The 

analysis is based on MY 1956-73 cars (before 3-point belts) in CY 1975-85 FARS data. It is 

limited to cars with a driver and a right front (RF) passenger (and perhaps other passengers). 

The driver, or the RF passenger, or both were fatally injured. Only lap-belted and unrestrained 

drivers and RF passengers, age 14-97, are included. The 34,889 vehicle cases tabulate as 

follows: 

 

19 Reinfurt, D.W., Silva, C.Z. and Seila, A.F., A Statistical Analysis of Seat Belt Effectiveness in 1973-75 Model 

Cars Involved in Towaway Crashes, Volume 1, NHTSA Report No. DOT HS 802 035, Washington, 1976, pp. viiviii. 

20 Kahane, C.J., Addendum to "Seat Belt Effectiveness Estimates Using Data Adjusted for Damage Type”, NHTSA 

Docket No. 74-14-N35-229-05, 1984; Final Regulatory Impact Analysis, Amendment to Federal Motor Vehicle 

Safety Standard 208, Passenger Car Front Seat Occupant Protection, NHTSA Report No. DOT HS 806 572, 

Washington, 1984, p. IV-2. 21 Evans, L., “Double Pair Comparison - A New Method to Determine How Occupant Characteristics Affect Fatality 

Risk in Traffic Crashes,” Accident Analysis and Prevention, Vol. 18, June 1986, pp. 217-227; Evans, L., “The

Effectiveness of Safety Belts in Preventing Fatalities,” Accident Analysis and Prevention, Vol. 18, June 1986, pp. 

229-241. 22 Kahane (2000), pp. 5-10. 

82
Vehicles Driver Died Driver Survived Both 

RF Survived RF Died Died 

Both unrestrained 13,064 14,781 5,926 

Driver unrestrained, RF lap-belted 111 93 32 

Driver lap-belted, RF unrestrained 104 201 73 

Both lap-belted 178 261 65 

This can be tabulated as fatality rather than vehicle cases, by adding the “both died” column to 

each of the preceding columns: 

Fatalities Driver RF Driver/RF

 Fatalities Fatalities Risk Ratio

Both unrestrained 18,990 20,707 0.917 

Driver unrestrained, RF lap-belted 143 125 1.144 

Driver lap-belted, RF unrestrained 177 274 0.646 

Both lap-belted 243 326 0.745 

It is clear that (1) the overwhelming majority of people killed in CY 1975-85 crashes were 

unrestrained; (2) in these older cars, unrestrained drivers are at slightly lower risk than their RF 

passengers; and (3) whoever buckled up with lap belts reduced their risk. The four rows of data 

allow a total of four double-pair comparisons, two for computing the effectiveness of belts for 

drivers, and two for RF passengers. The first comparison for the driver is based on the first and 

third rows of data: 

 Driver RF Driver/RF

 Fatalities Fatalities Risk Ratio

Driver unrestrained RF unrestrained 18,990 20,707 0.917 

Driver lap-belted RF unrestrained 177 274 0.646 

In both pairs, the driver’s fatality risk is compared to the same control group: the unrestrained RF 

passenger. The unrestrained driver has slightly lower fatality risk than the unrestrained RF in the 

same crash, the lap-belted driver, substantially lower. The fatality reduction for lap belts is: 

1 - (0.646/0.917) = 30 percent. 

The other comparison for the driver is based on the second and fourth rows of data: 

83
 Driver RF Driver/RF

 Fatalities Fatalities Risk Ratio

Driver unrestrained RF lap-belted 143 125 1.144 

Driver lap-belted RF lap-belted 243 326 0.745 

Here, the control group is the lap-belted RF passenger. The unrestrained driver has higher 

fatality risk than the lap-belted RF in the same crash, the lap-belted driver, lower. The fatality 

reduction is: 1 - (0.745/1.144) = 35 percent. The effectiveness estimates for drivers are similar 

with the two control groups. 

The first double-pair comparison to estimate belt effectiveness for the RF passenger is obtained 

by using the first two rows of data, reversing the order of the columns and computing the 

RF/Driver rather than the Driver/RF risk ratio: 

 RF Driver RF/Driver

 Fatalities Fatalities Risk Ratio

RF unrestrained Driver unrestrained 20,707 18,990 1.090 

RF lap-belted Driver unrestrained 125 143 0.874 

The control group is the unrestrained driver. The fatality reduction for the lap-belted RF 

passenger is: 1 - (0.874/1.090) = 20 percent. The second estimate uses the last two rows of data: 

 RF Driver RF/Driver

 Fatalities Fatalities Risk Ratio

RF unrestrained Driver lap-belted 274 177 1.548 

RF lap-belted Driver lap-belted 326 243 1.342 

The control group is the lap-belted driver. The fatality reduction for the lap-belted RF passenger 

is: 1 - (1.342/1.548) = 13 percent. Again, the two control groups produce similar estimates. 

Also, lap-belt effectiveness is lower for the RF passenger than for the driver. 

NHTSA’s 2000 evaluation of 3-point belts develops a weighting procedure that combines the 

two driver estimates and the two RF estimates into a single number, the overall, average fatality 

reduction for front-seat lap belts in passenger cars: 27 percent. 

By crash mode, the estimated fatality reduction for lap belts is: 43 percent in rollovers, 22 

percent in frontals, and 21 percent in side impacts, rear impacts and other crashes. 

84
Fatality reduction – light trucks A new double-pair comparison analysis was similarly 

performed for light trucks. The fatality reduction by lap belts for front-seat occupants averaged 

48 percent. There were not enough FARS cases for statistically meaningful separate analyses by 

crash mode. That is very close to a previous NHTSA estimate of 50 percent fatality reduction by 

lap belts in the front-center seat of LTVs, not obtained directly from crash data, but inferred by 

examining the relationships between other estimates: lap-belt vs. 3-point-belt effectiveness in 

cars and 3-point belt effectiveness in LTVs vs. cars.23 

Injury reduction – passenger cars As stated above, NHTSA analyzed a database in 1984 that 

combined the RSEP, the National Crash Severity Study (NCSS) plus all available NASS cases. 

(NCSS was the predecessor of NASS.) Injury rates were computed per 100 towaway-involved 

occupants: unrestrained, lap-belted, and lap-shoulder belted. The rates were adjusted for 

differences in impact location (front, side, rollover) and damage severity (CDC extent zone), 

using a Mantel-Haenszel model, a simpler approach than the logistic regression method widely 

used today. Lap belts reduced the adjusted overall (AIS ≥ 1) injury rate by 8 percent, moderate 

(AIS ≥ 2) injuries by 22 percent and severe (AIS ≥ 3) injuries by 33 percent.24

Injury reduction – light trucks NHTSA has not analyzed the injury reduction for lap belts for 

front-outboard occupants of LTVs. However, the agency estimated that lap belts in front-center 

seat of LTVs reduce AIS 2-5 injuries by 55 percent and AIS 1 injuries by 10 percent. The 

estimate was not obtained directly from crash data, but inferred by examining the relationships 

between other estimates: lap-belt vs. 3-point-belt effectiveness in cars, 3-point belt effectiveness 

in LTVs vs. cars, and fatality reduction vs. injury reduction.25

Lap belts for back-seat occupants

History The domestic manufacturers were providing lap belts at the rear-outboard positions by 

MY 1967. FMVSS 208 required safety belts at all rear seats, including the rear-center and the 

third row of seats in a station wagon, effective January 1, 1968 in passenger cars and July 1, 

1971 in LTVs. As late as MY 1987, over 90 percent of new cars and LTVs had lap belts, not 3-

point belts at the rear-outboard seats. In cars, over 90 percent of rear-center seats had lap belts 

(not 3-point belts) as late as 1998.26

How lap belts work Here, too, the principal benefit of a lap belt is to reduce greatly the 

likelihood of total ejection. Lap belts may prevent, or reduce the severity of some interior 

contacts – e.g., in farside or oblique frontal impacts. There was, perhaps, some optimism that, in 

direct frontal crashes, lap belts would have fewer shortcomings in the back seat than in the front 

seat. Back-seat occupants would hit the front seatback with their heads and chests. It is a wellpadded surface, more benign than anything front-seat occupants might contact. However, the 

National Transportation Safety Board’s 1986 study indicated that lap-belted back-seat occupants 

 

23 Final Regulatory Impact Analysis, Extension of the Automatic Restraint Requirements of FMVSS 208 to Trucks, 

Buses and Multi-Purpose Passenger Vehicles, NHTSA Docket No. 74-14-N70-001, 1990, p. 23. 24 Kahane (1984 Seat Belts); 90% confidence bounds for effectiveness: AIS ≥ 1 injuries, 6 to 13 percent; AIS ≥ 2 

injuries, 13 to 42 percent; AIS ≥ 3 injuries, 20 to 76 percent. 25 Final Regulatory Impact Analysis, Extension of the Automatic Restraint Requirements of FMVSS 208 to Trucks, 

Buses and Multi-Purpose Passenger Vehicles, p. 23. 26 Performance of Lap Belts in 26 Frontal Crashes, pp. 225-230. 

85
had a high risk of abdominal injuries and head injuries in frontal crashes. These occupants 

experienced a concentrated force of the lap belt on their abdomens and their upper bodies 

jackknifed over the belt at a high velocity.27

Fatality reduction – passenger cars NHTSA’s evaluation, published in 1999, is based on 

double-pair comparison analysis of 1988-97 FARS data.28 Front-seat occupants (drivers and RF 

passengers) were the control groups used to compare the relative fatality risk of lap-belted vs. 

unrestrained rear-outboard occupants, as, for example, in the following table: 

 Back-Seat Front-Seat Back-Seat Front-Seat Back/Front 

Belt Use Belt Use Fatalities Fatalities Risk Ratio 

Unrestrained 3-point belts 3,028 2,098 1.443 

Lap belts 3-point belts 1,135 1,079 1.052 

In this example, unrestrained back-seat occupants had considerably higher fatality risk than 

front-seat occupants protected by 3-point belts. However, lap-belted back-seat occupants had 

only slightly higher risk than 3-point-belted front-seat occupants of the same cars: the greater 

safety of the back seat nearly offsets the superior restraint system in the front seat. 

The overall, average fatality reduction for lap belts at the rear-outboard seats of passenger cars 

was 32 percent.29 However, the effectiveness of lap belts varies greatly by crash mode. The 

estimated fatality reduction is 76 percent in rollovers and 39 percent in side impacts, but it is zero 

in frontals, rear impacts and other crashes. 

A supplement to FARS called the Multiple Cause of Death (MCOD) file gleans injury 

information from death certificates. These data show why lap belts have no net benefit in frontal 

crashes. The rate of life-threatening abdominal injuries is three times as high for a lap-belted 

occupant as for an unrestrained occupant. That offsets any benefits of lap belts in frontals, such 

as a reduction of ejections or head injuries. In frontal crashes, occupants age 55 or older actually 

have higher fatality risk with lap belts than unrestrained; they have exceptionally high risk of 

abdominal injury with lap belts.30

Fatality reduction – light trucks NHTSA’s 1999 evaluation similarly analyzes vans and SUVs. 

The fatality reduction by lap belts for back-seat occupants averaged 63 percent.31 By crash 

mode, the estimated fatality reduction for lap belts is: 80 percent in rollovers, 44 percent in 

frontals, and 64 percent in side impacts, rear impacts and other crashes. A high percentage of 

rear-seat fatalities in LTVs are ejectees, even in frontals. 

 

27 Ibid., pp. 1-11. 28 Morgan, C., Effectiveness of Lap/Shoulder Belts in the Back Outboard Seating Positions, NHTSA Technical 

Report No. DOT HS 808 945, Washington, 1999. 29 Ibid., pp. x and 13-30; 90% confidence bounds, 23 to 40 percent. 30 Ibid., pp. xi-xiii, 47-52 and 99-111. 31 Ibid., pp. xii and 83-97; 90% confidence bounds, 52 to 71 percent. 

86
Injury reduction – passenger cars A 1987 NHTSA report estimated the effectiveness of lap 

belts in reducing nonfatal injuries, based on double-pair comparison analyses of 1982-85 

Pennsylvania crash data. Compared to unrestrained back-seat occupants, lap belts reduced fataland-serious (K + A) injury risk by 37 percent, moderate-to-fatal (K + A + B) injury risk by 33 

percent, and overall (K + A + B + C) injury risk by 11 percent.32

Injury reduction – light trucks The agency has not analyzed crash data to estimate the injury 

reduction for lap belts in LTVs. However, a NHTSA Regulatory Impact Analysis in 1990 

projected that lap belts in back seats of LTVs could reduce AIS 2-5 injuries by 35.5 percent and 

AIS 1 injuries by 5.5 percent. Here, the agency assumed the same effectiveness in cars and 

LTVs; in retrospect, the AIS 2-5 number would appear to be an underestimate for the LTVs.33

Manual 3-point lap-shoulder belts for front-seat occupants 

History Volvo introduced 3-point lap-shoulder belts as standard equipment in Sweden in 1959 

and in the United States in 1963. In 1968, Volkswagen and, apparently, Audi, BMW and 

Mercedes made 3-point belts standard. At that time, the domestic and, apparently, the Japanese 

manufacturers installed separate lap and shoulder belts in all new cars. Retractor systems were 

required effective January 1, 1972, and had been phased in by MY 1972. Effective January 1, 

1968, FMVSS 208 originally required shoulder belts only if lap belts alone could not prevent 

contact with the windshield header. Effective January 1, 1972, FMVSS 208 required shoulder 

belts on all passenger cars, and effective September 1, 1973, shoulder belts had to be integral 

with the lap belt. Thus, from model year 1974 onwards, all passenger cars, except those with 

automatic belts, have had the modern system of integral 3-point belts with automatic locking 

retractors.34

LTVs were equipped with 3-point belts later than cars, but they went directly from lap belts to 3-

point belts, skipping separate lap and shoulder belts. FMVSS 208 required 3-point belts 

effective January 1, 1976 for all LTVs with GVWR up to 10,000 pounds except forward-control 

vehicles and some other types, and effective September 1, 1981 on the forward-control vehicles. 

However, Volkswagen had introduced 3-point belts by 1969. NCSS and NASS data indicate that 

other manufacturers began to phase them in during 1972, 1973 or 1974. The phase-in was 

completed in pickup trucks and SUVs by January 1, 1976, and in vans by MY 1980.35 

How 3-point belts work The combination of a lap and shoulder belt furnishes at least as much 

protection against ejection as a lap belt alone, and possibly more, because the shoulder strap 

 

32 Kahane, C.J., “Fatality and Injury Reducing Effectiveness of Lap Belts for Back Seat Occupants,” Restraint 

Technologies: Rear Seat Occupant Protection, Paper No. 870486, Society of Automotive Engineers Publication No. 

SP-691, Warrendale, PA, 1987, pp. 45-52; 90% confidence bounds for effectiveness: K + A injuries, 23 to 51

percent; K + A + B injuries, 26 to 40 percent; all injuries, 7 to 15 percent. 33 Final Regulatory Impact Analysis, Extension of the Automatic Restraint Requirements of FMVSS 208 to Trucks, 

Buses and Multi-Purpose Passenger Vehicles, p. 23; Final Regulatory Evaluation, Rear Seat Lap Shoulder Belts in

Passenger Cars, NHTSA Docket No. 87-08-N03-001, 1989, p. IV-1. 34 Performance of Lap Belts in 26 Frontal Crashes, pp. 225-230; Federal Register 32 (February 3, 1967): 2414, 36

(March 10, 1971): 4600, 38 (June 20, 1973): 16072; Code of Federal Regulations, Title 49, Part 571.208 S4.1.1 and

S4.1.2. 35 Federal Register 40 (July 9, 1975): 28805; Code of Federal Regulations, Title 49, Part 571.208 S4.2.1. 

87
might sometimes prevent partial ejection through the side window. But lap-shoulder belts also 

significantly reduce the injury severity of occupants who remain within the vehicle, and they 

avoid most of the additional injury risks associated with lap belts. The lap-shoulder belt is the 

basic protection system for all occupants in most types of crashes. Ideally, belts provide “ridedown” by linking the occupant to the vehicle structure. They gradually decelerate the occupant 

as the vehicle deforms and absorbs energy and as the belts themselves “give” a little – but not so 

much as to allow forceful contacts with interior surfaces. They keep the occupant in an upright, 

seated position and reduce the risk of flexion/tension injuries. In general, lap-shoulder belts 

accomplish these missions, although they cannot always prevent head contacts with interior 

surfaces, may sometimes place excessive force on the occupant in severe crashes, and are less 

effective if the passenger compartment is damaged, as in a nearside impact. 

Separate shoulder belts were uncomfortable and inconvenient, and were only used by about 15-

25 percent of the people who buckled the lap belt. The most important feature of the integral 3-

point belt is that everybody who buckled up received the protection of both the shoulder and the 

lap restraint, except for a small percentage of occupants who misused the shoulder belt by 

running it behind their backs or under their arms. Furthermore, the public did not consider the 

double belt excessively burdensome, because use of 3-point belts was as high or higher than use 

of the lap belt alone.36 Technological advances made the 3-point belt acceptable to the public. 

Most important was the locking retractor. Whereas “airline style” lap belts are merely

inconvenient, a shoulder belt that is not self-adjusting would be unacceptable because drivers 

must lean forward or sideways in the course of normal driving (and passengers also desire some

flexibility). The locking retractor is a system that spools out more webbing when occupants wish 

to move around during normal driving, locks the spool when it senses a crash or other sudden 

decelerations (e.g., driving over potholes), and picks up excessive slack in the belt. Slack is 

comfortable, up to a point, in normal driving operations but most undesirable in a crash because 

it defeats the early engagement of the occupant with the belts. The system had to be fine-tuned. 

Belts should never feel too tight or too loose, lock too seldom or too often, or allow excessive 

slack. NHTSA’s comfort and convenience standards for belts addressed these issues.37

Two problems with 3-point belts were excessive slack in some crashes, and excessive force on 

some occupants in other crashes. Pretensioners and load-limiters, discussed later, address those 

shortcomings. 

Belt use trends Safety belt use in the United States has increased from about 11 percent in 1979-

82 to 80 percent in 2004. This has saved more lives than any other vehicle safety program. 

Finally, the vast majority of people are using the basic occupant protection that has been in their 

vehicles since the 1970’s. 

The National Occupant Protection Use Surveys (NOPUS) of 1994, 1996, and every year since 

1998, give unbiased estimates of belt use by front-outboard occupants of cars and LTVs on the 

nation’s streets, roads and highways during daylight hours, based on direct observation of a 

 

36 Reinfurt, D.W., Silva, C.Z. and Seila, A.F, p. 18; Phillips, B.M., Safety Belt Usage Among Drivers, NHTSA 

Report No. DOT HS 805 398, Washington, 1980, pp. 4-5. 37 Federal Register 46 (January 8, 1981): 2064, 50 (August 23, 1985): 34152; Code of Federal Regulations, Title 49, 

Part 571.208 S7.4

88
probability sample of vehicles and roadways. While unbiased, NOPUS results can have 

sampling error; 95% confidence bounds were initially + 4 percent but in recent years have 

shrunk to + 2 percent or less.38

From 1976 to 1991, NHTSA estimated national safety belt use by drivers in the “19 City 

Survey.” It was not a probability sample of the nation’s roadways. Contractors observed belt 

use at randomly selected controlled intersections in 19 metropolitan regions purposively chosen 

as a cross-section of the nation’s urban areas. Surveyors returned to the same intersections and 

cities year after year.39 The point estimates generated by the 19 City Survey are not directly 

comparable to NOPUS and do not have estimates of sampling error.40

The 19 City estimates of belt use in the United States from 1976 to 1991 and the NOPUS 

estimates from 1994 to 2004 are the following: 

 

38 Observed Safety Belt Use in 1996, NHTSA Research Note, Washington, 1997; Observed Safety Belt Use, Fall 

2000 National Occupant Protection Use Survey, NHTSA Research Note, Washington, 2001; Glassbrenner, D.,

Safety Belt and Helmet Use in 2002 – Overall Results, NHTSA Technical Report No. DOT HS 809 500,

Washington, 2002; Glassbrenner, D., Safety Belt Use in 2003, NHTSA Technical Report No. DOT HS 809 646, 

Washington, 2003; Glassbrenner, D., Safety Belt Use in 2004 – Overall Results, NHTSA Research Note No. DOT 

HS 809 783, Washington, 2004. 39 Stowell, C. and Bryant, J., Safety Belt Usage: Survey of the Traffic Population, NHTSA Report No. DOT HS 803

354, Washington, 1978 (this initial survey encompassed only 15 of the 19 cities); Phillips, B.M., Safety Belt Usage 

Among Drivers, NHTSA Report No. DOT HS 805 398, Washington, 1980; Phillips, B.M., Restraint System Usage 

in the Traffic Population, NHTSA Report No. DOT HS 806 424, Washington, 1983; Perkins, D.D., Cynecki, M.J. 

and Goryl, M.E., Restraint System Usage in the Traffic Population, NHTSA Report No. DOT HS 806 582,

Washington, 1984; Goryl, M.E. and Cynecki, M.J., Restraint System Usage in the Traffic Population, NHTSA

Report No. DOT HS 806 714, Washington, 1985; Goryl, M.E., Restraint System Usage in the Traffic Population, 

NHTSA Report No. DOT HS 806 987, Washington, 1986; Goryl, M.E. and Bowman, B.L., Restraint System Usage 

in the Traffic Population, NHTSA Report No. DOT HS 807 080, Washington, 1987; Bowman, B.L. and Rounds, 

D.A., Restraint System Usage in the Traffic Population 1987 Annual Report, NHTSA Report No. DOT HS 807 342,

Washington, 1988; Bowman, B.L. and Rounds, D.A., Restraint System Usage in the Traffic Population 1988 Annual

Report, NHTSA Report No. DOT HS 807 447, Washington, 1989; Datta, T.K. and Guzek, P., Restraint System Use 

in 19 U.S. Cities 1989 Annual Report, NHTSA Report No. DOT HS 807 595, Washington, 1990; Datta, T.K. and 

Guzek, P., Restraint System Use in 19 U.S. Cities 1990 Annual Report, NHTSA Report No. DOT HS 808 147, 

Washington, 1991; Datta, T.K. and Guzek, P., Restraint System Use in 19 U.S. Cities 1991 Annual Report, NHTSA 

Report No. DOT HS 808 148, Washington, 1992. 40 NOPUS and the 19 City Survey never overlapped. However, both studies overlapped with a NHTSA computation

of national averages based on individual State surveys during the 1990’s. These averages cannot be considered

unbiased estimates of the nation’s belt use for various reasons – e.g., the exclusion of pickup trucks (that have lower

belt use) in up to half the State surveys before 1997. In 1991, belt use was 51 percent in the 19 City Survey and

averaged 58 percent in the State surveys; in 1994, belt use was 58 percent in NOPUS and averaged 66 percent in the 

State surveys. Thus, the State survey averages exceed the 19 City and NOPUS estimates by approximately the same

amounts (7 or 8 percentage points) in 1991 and 1994, respectively. See also Kahane (2000), pp. 63 and 75-76. 

89
SAFETY BELT USE IN THE UNITED STATES, 1976-2004 

(19 City Survey, 1976-1991; NOPUS, 1994-2004) 

1976 19 % 

1977 

1978 13 

1979 11 

1980 

1981 11 

1982 11 

1983 14 

1984 14 

1985 21 

1986 37 

1987 42 

1988 46 

1989 46 

1990 49 

1991 51 

1992 

1993 

1994 58 

1995 

1996 61 

1997 

1998 69 

1999 

2000 71 

2001 73 

2002 75 

2003 79 

2004 80 

90
Safety belt use actually deteriorated from 19 percent in 1976 to 11 percent in 1979-82, in the 

wake of the unsuccessful ignition interlock and prior to national buckle-up campaigns. NHTSA 

responded in the early 1980’s with “Get It Together,” its first national campaign for State, 

community and private organizations to promote safety belts. Belt use has improved ever since 

1982.41

The greatest jump in belt use, however, took place in 1985-1986-1987 as buckle-up laws took 

effect in 29 States, including all ten most populous States. New York’s law was the first, 

effective December 1, 1984, followed by New Jersey, Illinois and Michigan. Simultaneous with 

the July 1984 decision on automatic crash protection, NHTSA, the manufacturers – through their 

Automotive Coalition for Traffic Safety (ACTS) – and the safety community dedicated 

themselves to a successful effort to encourage buckle-up laws in the States. By 1995, 49 States, 

the District of Columbia and Puerto Rico had buckle-up laws.42

Even though most of the States had buckle-up laws by 1990, belt use hardly leveled off, but 

rather continued to increase steadily, from 49 percent in 1990 to 80 percent in 2004. Sustained 

national campaigns, spearheaded by DOT/NHTSA and supported by States, communities and the 

private sector, have played an important role. They combine public information and education 

about the life-saving benefits of belts, law enforcement by States and communities, and 

additional information to make the public aware of the enforcement programs. Campaigns 

include “70% By 92” and “Avoid The Summertime Blues” in the early 1990’s, “Buckle-Up 

America” starting in the late 1990’s, and, in this decade, “Click It Or Ticket.” There has also 

been a push for “primary” buckle-up laws that allow police to make a traffic stop solely upon 

observation of a belt law violation; there are 22 primary laws in 2004, up from 9 in 1993. 

Finally, after 20 years of cumulative and sustained education about safety belts, a generation of 

Americans has been buckling up since childhood, and views safety belts as a basic part of riding 

in a vehicle.43

 

 

41 Get It Together, NHTSA Publication No. DOT HS 806 254, Washington, 1982; Stowell and Bryant; Phillips 

(1980); Phillips (1983). 42 Third Report to Congress – Effectiveness of Occupant Protection Systems and Their Use, NHTSA Report No. 

DOT HS 808 537, Washington, 1996; ACTS, Automotive Coalition for Traffic Safety, Inc., State Laws Database 

www.actsinc.org . 43 Buckle Up: Avoid the Summertime Blues, HSL Publication No. DOT HS 041 653, NHTSA, Washington, 1991; 

“70 by 92: Increased Safety-Belt Use,” Journal of the American Medical Association, Vol. 268, July 15, 1992, p.

318; Buckle Up America, NHTSA Publication No. DOT HS 808 628, Washington, 1997; “’Click It Or Ticket’

Expands beyond North Carolina,” Status Report, Vol. 36, November 15, 2001, p. 4, Insurance Institute for Highway 

Safety, Arlington, VA; Eby, D.W., Vivoda, J.M. and Fordyce, T.A., Direct Observation of Safety Belt Use in

Michigan: Fall 1999, Report No. UMTRI-99-33, University of Michigan Transportation Research Institute, Ann

Arbor, 1999; Safety Belt Use Laws, Insurance Institute for Highway Safety, Arlington, VA, 2004

(http://www.hwysafety.org/safety%5Ffacts/state%5Flaws/restrain3.htm). 

91
SAFETY BELT USE (%) IN THE UNITED STATES, BY CALENDAR YEAR 

 100 ˆ 

 ‚ 

 95 ˆ 

 ‚ 

 90 ˆ 

 ‚ 

 85 ˆ 

 ‚ 

 80 ˆ 22 primary laws Q

 ‚ Q

 75 ˆ Q

 ‚ ‘Click It Or Ticket’ Q

 70 ˆ Q 

 ‚ Q

 65 ˆ ‘Buckle-Up America’ 51 laws, 9 primary 

 ‚ Q 

 60 ˆ 

 ‚ Q 41 buckle-up laws 

 55 ˆ 

 ‚ ‘70% By 92’ Q 

 50 ˆ ‘Summertime Blues’ Q 36 buckle-up laws 

 ‚ Q Q

 45 ˆ 

 ‚ Q 

 40 ˆ 29 buckle-up laws 

 ‚ Q

 35 ˆ 

 ‚ 

 30 ˆ 22 State buckle-up laws 

 ‚ 

 25 ˆ 

 ‚ Q

 20 ˆ 

 ‚ Q

 15 ˆ Q Q NY: first buckle-up law 

 ‚ Q

 10 ˆ Q Q Q

 ‚ ‘Get It Together’ campaign 

 5 ˆ 

 ‚ 

 0 ˆ 

 ________________________________________________________________________________________

 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 

CALENDAR YEAR 

92
Furthermore, belt use “where it counts” – i.e., by typical drivers and passengers in potentially 

fatal crashes – is quite close to the belt use observed on the road by surveys such as NOPUS. 

Drivers who drink or engage in other antisocial behaviors44 have lower belt use. But among 

other drivers, even those held culpable for the crash, the proportion of fatalities that wore safety 

belts is consistent with the belt use in NOPUS and the fatality-reducing effectiveness of belts.45 

Early effectiveness studies NHTSA’s Restraint Systems Evaluation Project (RSEP) of 1974-75 

was the first statistical analysis in the United States with a large sample of crash-involved 

occupants who wore lap-shoulder belts. After controlling for damage location and severity, 

occupant age and vehicle weight, RSEP estimated that lap-shoulder belts reduce moderate 

(AIS ≥ 2) and severe (AIS ≥ 3) injuries by 57 percent. RSEP hinted that fatality reduction might 

be close to 60 percent.46

By 1984, during the rulemaking on automatic protection, NHTSA realized that fatality reduction 

had to be somewhat lower than 60 percent. Buckle-up laws outside the United States were 

saving lives, but not as many as would be predicted based on 60 percent effectiveness. A review 

of 781 unrestrained fatalities in NCSS suggested that belts would have had little effect in nearly 

half of the cases. The agency performed two new analyses of belt effectiveness. RSEP data 

were supplemented with NCSS data plus all available NASS cases. The additional data 

permitted a more extensive adjustment for crash severity, and showed a statistically significant 

49 percent reduction of fatalities and 45 percent reduction of severe (AIS ≥ 3) injuries. NHTSA 

compared the increase in belt use with the fatality reduction in 11 nations or Canadian Provinces 

that enacted buckle-up laws. The fatality reduction, on the average, suggested belts were 47 

percent effective when used. In 1984, based on these analyses, NHTSA lowered its “best 

estimates” to 40-50 percent fatality reduction, 45-55 percent AIS 2-5 reduction, and 10 percent 

AIS 1 reduction.47

 

44 Drugs, speeding, reckless driving, escaping police, racing, driving without a license. 45 Partyka, S.C., Belt Use in Serious Impacts Estimated from Fatality Data, NHTSA Technical Report No. 807 519, 

1989; Kahane (2000), pp. 43-51 and 64-70. 46 Reinfurt, D.W., Silva, C.Z. and Seila, A.F., pp. iv-viii; Safety Belt Usage – A Review of Effectiveness Studies – 

Suggestions for State Programs. 47 Final Regulatory Impact Analysis, Amendment to Federal Motor Vehicle Safety Standard 208, Passenger Car 

Front Seat Occupant Protection, pp. IV-2 – IV-16; Kahane, C.J., Estimates of Fatality Reduction for Air Bags and 

Lap/Shoulder Belts Based on Case by Case Analysis of Unrestrained Fatalities, NHTSA Docket No. 74-14-N35-

012, 1984; Kahane (1984 Seat Belts), 90% confidence bounds for effectiveness: fatalities, 37 to 68 percent; AIS ≥ 3 

injuries, 38 to 55 percent. 

93
Expected benefits Large fatality reductions should be expected in rollovers, where the majority 

of unrestrained fatalities are ejectees. Substantial fatality and injury reduction may be expected 

in direct-frontal, oblique-frontal and farside crashes, except in impacts too severe for belts to 

effectively protect against contacts with interior surfaces. Effectiveness will be lowest in 

nearside impacts or other catastrophic crashes that reduce the space available to the occupant 

within the vehicle. Lap-shoulder belts should be more effective in LTVs than in cars, overall and 

specifically in side impacts, since there are more rollovers, more ejections, and fewer 

catastrophic damages. 

Fatality reduction – passenger cars Evans’ double-pair comparison analyses of 1985-86 were 

an important advance in the estimation of fatality reduction. They confirmed NHTSA’s estimate 

that effectiveness was in the 40’s.48 Double-pair comparison allows the direct use of FARS data. 

It implicitly controls for crash severity. Until 1985, before buckle-up laws, FARS data were 

accurate or at least unbiased in the reporting of belt use. NHTSA’s current estimate of overall 

belt effectiveness, in its 2000 evaluation, is based on a double-pair analysis of MY 1975-86 cars 

in CY 1977-85 FARS data. It is limited to cars with a driver and an RF passenger (and perhaps 

other passengers). The driver, or the RF passenger, or both were fatally injured. Only 3-pointbelted and unrestrained drivers and RF passengers, age 14-97, are included. This basic table 

demonstrates the life-saving benefit of 3-point belts.49

 Driver RF Driver/RF

 Fatalities Fatalities Risk Ratio

Both unrestrained 16,503 16,786 0.983 

Driver unrestrained, RF belted 374 226 1.655 

Driver belted, RF unrestrained 288 589 0.489 

Both belted 739 895 0.826 

When the driver and RF passenger were both unrestrained, they had nearly equal risk. 

Unrestrained drivers had nearly double the risk of the belted RF passengers riding with them. 

Belted drivers had less than half the risk of unrestrained RF passengers. The evaluation report 

developed a procedure that combined these statistics into a single estimate of the overall fatality 

reduction for 3-point belts in passenger cars, 47.8 percent. This is very close to 45 percent, the 

midpoint of the agency’s 1984 “best estimate” range of 40-50 percent and it essentially confirms

that earlier estimate. 

Immediately after 1985, double-pair comparison began producing inflated results. Whereas 

FARS apparently continued to report accurately the belt use of fatally injured front-outboard 

occupants, buckle-up laws gave survivors a motive to declare they had been belted in some of 

the cases where they were actually unrestrained. In CY 1986, belt “effectiveness” jumped up 

over 60 percent, and it stayed there. However, numerous FARS analyses revealed that the 

degree of exaggeration in the effectiveness estimate varied little from year to year, State to State, 

by crash type, vehicle type or occupant characteristics. NHTSA developed an empirical tool 

 

48 Evans (1986 Double Pair Comparison); Evans (1986 Belt Effectiveness). 49 Kahane (2000), pp. 5-10. 

94
called the “Universal Exaggeration Factor” to adjust the biases out of double-pair comparison 

estimates based on 1986-99 FARS data. That opened up the 1986-99 FARS database, with its 

incomparably greater number of belted cases than the earlier FARS, permitting point-estimation 

of belt effectiveness by crash type, occupant age and gender, vehicle type, etc:50

FATALITY REDUCTION (%) BY MANUAL 3-POINT BELTS IN PASSENGER CARS 

For Drivers and Right-Front Passengers 

Fatality Reduction (%) Sampling Error Range51

IN ALL CRASHES 45 x 

BY Frontal impacts 50 x 

IMPACT Side impacts 21 xx 

TYPE: Nearside 10 xx 

 Farside 39 x 

 Rollovers (primary) 74 x 

Rear impacts & other crashes 56 x 

 

BY Single vehicle 58 x 

CRASH Multivehicle 32 x 

TYPE: With a car 41 x 

With a light truck 31 x 

With a heavy truck 25 xx 

BY SEAT Driver 48 x 

POSITION: Right-front passenger 37 x 

BY 5- 9 (RF passengers) 34 xxx 

OCCUPANT 10-14 (RF passengers) 35 xx 

AGE: 15-29 50 x 

 30-54 49 x 

 55-69 43 x 

 70-79 38 x 

80 and older 27 xx 

BY Male 45 x 

GENDER: Female 45 x 

 

50 Ibid., pp. 10-43. 51 Minimum sampling error range: “x” denotes 2-sigma sampling error at least in the + 4-10 percentage point range 

(plus possible, additional, unknown non-sampling error); “xx” = at least + 10-20 percentage points; “xxx” = at least 

+ 20-50 percentage points. 

95
Fatality Reduction (%) Sampling Error Range52

BY No air bags. 45 x 

AIR BAG MY 1975-79 47 x 

TYPE: MY 1980-85 46 x 

Dual air bags. 48 x 

BY 2499 pounds or lighter 48 x 

CURB 2500-3149 pounds 44 x 

WEIGHT: 3150 pounds or heavier 41 x 

Three-point belts are most effective in rollovers (74 percent), but they are also highly effective in 

frontals (50 percent), farside impacts (39 percent) and all crash types except nearside impacts (10 

percent). They are effective in single- and multivehicle crashes (but especially the single-vehicle

crashes, where most of the rollovers are); slightly more effective for drivers (48 percent) than RF 

passengers (37 percent); beneficial for all age groups, but especially at age 15-54; equally 

effective for males and females; consistently beneficial from MY 1975 onwards, including in 

cars without air bags and with air bags; and effective in cars of all sizes. 

Fatality reduction – light trucks In 1989 the agency concluded, based on double-pair 

comparison analyses by Partyka, that the overall fatality-reducing effectiveness of 3-point belts 

in LTVs was greater than in cars, and that it was close to 60 percent.53 NHTSA’s 2000 

evaluation reconfirms that estimate and provides more detailed estimates of belt effectiveness in 

LTVs by crash type, occupant age and gender, vehicle type, etc:54 

 

52 Minimum sampling error range: “x” denotes 2-sigma sampling error at least in the + 4-10 percentage point range 

(plus possible, additional, unknown non-sampling error); “xx” = at least + 10-20 percentage points; “xxx” = at least 

+ 20-50 percentage points. 53 Final Regulatory Impact Analysis, Extension of the Automatic Restraint Requirements of FMVSS 208 to Trucks, 

Buses and Multi-Purpose Passenger Vehicles, p. 23; Partyka, S.C., “Belt Effectiveness in Pickup Trucks and 

Passenger Cars by Crash Direction and Accident Year (May 1988),” Papers on Adult Seat Belts - Effectiveness and 

Use, NHTSA Technical Report No. DOT HS 807 285, Washington, 1988, pp. 99-102. 54 Ibid., pp. 10-43. 

96
FATALITY REDUCTION (%) BY MANUAL 3-POINT BELTS IN LTVs 

For Drivers and Right-Front Passengers 

Fatality Reduction (%) Sampling Error Range55

IN ALL CRASHES 60 x 

BY Frontal impacts 53 x 

IMPACT Side impacts 48 x 

TYPE: Nearside 41 xx 

 Farside 58 x 

 Rollovers (primary) 80 x 

Rear impacts & other crashes 81 x 

BY Single vehicle 70 x 

CRASH Multivehicle 43 x 

TYPE: With a car 57 x 

With a light truck 45 xx 

With a heavy truck 28 xx 

BY SEAT Driver 61 x 

POSITION: Right-front passenger 58 x 

BY 5- 9 (RF passengers) 59 xxx 

OCCUPANT 10-14 (RF passengers) 63 xx 

AGE: 15-29 63 x 

 30-54 64 x 

 55-69 53 xx 

 70-79 42 xx 

80 and older 30 xxx 

BY Male 60 x 

GENDER: Female 62 x 

BY No air bags. 60 x 

AIR BAG MY 1975-79 49 xx 

TYPE: MY 1980-85 63 x 

Dual air bags. 63 xx 

BY TRUCK Pickup truck 58 x 

TYPE: Van or SUV 63 x 

 

55 Minimum sampling error range: “x” denotes 2-sigma sampling error at least in the + 4-10 percentage point range 

(plus possible, additional, unknown non-sampling error); “xx” = at least + 10-20 percentage points; “xxx” = at least 

+ 20-50 percentage points. 

97
Belts are exceedingly effective in rollovers (80 percent), but they are also very effective in all 

other types of crashes, including even nearside impacts (41 percent), because LTVs are better 

able than cars to resist catastrophic damage in side impacts. They are effective in single-vehicle 

crashes and multivehicle crashes (but least so in impacts with heavy trucks); beneficial for all 

age groups; consistently effective from MY 1980 onwards, including in LTVs without air bags 

and with air bags; and beneficial in pickup trucks, vans and SUVs. 

Injury reduction – passenger cars As stated above, NHTSA analyzed a database in 1984 that 

combined the RSEP, NCSS, plus all available NASS cases. Injury rates were computed per 100 

towaway-involved occupants: unrestrained, lap-belted, and lap-shoulder belted. The rates were 

adjusted for differences in impact location (front, side, rollover) and damage severity (CDC 

extent zone), using a Mantel-Haenszel model, a simpler approach than the logistic regression 

method widely used today. Lap-shoulder belts reduced the adjusted overall (AIS ≥ 1) injury rate 

by 13 percent, moderate (AIS ≥ 2) injuries by 46 percent and severe (AIS ≥ 3) injuries by 45 

percent.56 

Injury reduction – light trucks NHTSA has not statistically analyzed the injury reduction by 3-

point belts for front-outboard occupants of LTVs. However, the agency estimated that they 

reduce AIS 2-5 injuries by 65 percent and AIS 1 injuries by 10 percent. The estimate was 

inferred by examining the relationships between other estimates: 3-point belt fatality reduction in 

LTVs vs. cars, and fatality reduction vs. injury reduction in cars.57 

Three-point lap-shoulder belts for back-seat occupants

History Volvo made 3-point belts standard at the rear-outboard positions in MY 1971, and 

Mercedes in MY 1974. The 1982 Honda Accord was the first high-sales make-model equipped 

with 3-point belts. The majority of new cars had them at least one or two years before the 

December 11, 1989 effective date specified in FMVSS 208. The first LTVs with 3-point belts 

were some Isuzu Troopers in 1987, all Troopers and all full-sized GM vans in 1988. FMVSS 

208 required them in all LTVs starting September 1, 1991. Retrofit kits could be purchased for 

many earlier vehicles equipped only with lap belts at the rear-outboard positions.

58

“Anton’s Law,” signed on December 4, 2002, directs NHTSA to issue by December 2004, a 

regulation requiring lap/shoulder belts for each rear seating position – i.e., including rear-center 

seats – in passenger vehicles with GVWR ≤ 10,000. Phase-in is scheduled from September 1, 

2005 to September 1, 2007. In fact, manufacturers have already been installing 3-point belts at 

rear-center seats of many vehicles, especially from 1999 onward, well in advance of the new 

 

56 Kahane (1984 Seat Belts); 90% confidence bounds for effectiveness: AIS ≥ 1 injuries, 9 to 17 percent; AIS ≥ 2 

injuries, 40 to 54 percent; AIS ≥ 3 injuries, 38 to 55 percent. 57 Final Regulatory Impact Analysis, Extension of the Automatic Restraint Requirements of FMVSS 208 to Trucks, 

Buses and Multi-Purpose Passenger Vehicles, p. 23. 58 Federal Register 54 (June 14, 1989): 25275, 54 (November 2, 1989): 46257; Code of Federal Regulations, Title 

49, Parts 571.208 S4.1.4.2 and S4.2.4; from December 11, 1989 to August 31, 1990, cars were allowed separate lap 

and shoulder belts as an alternative to 3-point belts, but nobody exercised that option; Document Nos. 001, 002, 003,

005, 016, 018-H and 035 in Docket No. 89-01-N01 and Nos. 006, 007, 008, 009, 011, 012, 014, and 015 in NHTSA

Docket No. 89-01-N03, 1992 (Lap-Shoulder Belts in the Back Seat); Lap/Shoulder Belt Kits for Rear Seats, NHTSA 

Publication No. DOT HS 807 881, Washington, 1992. 

98
requirement. By MY 2001, the majority of new passenger cars had 3-point belts at the rearcenter seats.59 

How 3-point belts work – expected benefits As in the front seat, a lap and shoulder belt ought to 

provide excellent protection against ejection, provide “ride-down,” keep occupants in an upright, 

seated position and reduce the severity of interior contacts. They should be effective in most 

crash modes, including frontals (but less so in severe nearside impacts or other catastrophic 

crashes). They should greatly alleviate the problem of abdominal injuries experienced with lap 

belts alone. 

Fatality reduction – passenger cars NHTSA’s 1999 evaluation is based on double-pair 

comparison analysis of 1988-97 FARS data. Front-seat occupants (drivers and RF passengers) 

were the control groups used to compare the relative fatality risk of belted vs. unrestrained rearoutboard occupants, in the following table:60

 Back-Seat Front-Seat Back-Seat Front-Seat Back/Front 

Belt Use Belt Use Fatalities Fatalities Risk Ratio 

Unrestrained Unrestrained 4,953 7,248 0.683 

3-point belts Unrestrained 119 344 0.346 

Unrestrained Air bag alone 650 820 0.793 

3-point belts Air bag alone 49 148 0.331 

Unrestrained 3-point belts 3,028 2,098 1.443 

3-point belts 3-point belts 807 880 0.917 

Unrestrained 3-pt. + air bag 670 371 1.806 

3-point belts 3-pt. + air bag 431 490 0.880 

In each of these four comparisons with a control group, the back-seat occupants protected with 3-

point belts had substantially lower risk than the unrestrained back-seat occupants. For example, 

relative to unrestrained front-seat occupants, unrestrained back-seat occupants had a risk ratio of 

0.683, belted back-seat occupants just 0.346. The overall, average fatality reduction for 3-point 

belts at the rear-outboard seats of passenger cars was 44 percent.61

The preceding table also shows that the back seat is a safer place to ride than the front seat. 

Unrestrained back-seat occupants had 32 percent lower fatality risk than unrestrained front-seat 

occupants of the same car, and they had lower fatality risk than unbelted front-seat occupants in 

cars with air bags. Back-seat occupants using 3-point belts had lower fatality risk than front-seat 

 

59 Anton’s Law, Public Law 107-318, December 4, 2002. 60 Morgan (1999), p. 19. 61 Ibid., pp. x and 13-30; 90% confidence bounds, 38 to 50 percent.

99
occupants using 3-point belts, even if the car was also equipped with an air bag in the front seat. 

(For additional discussion, see the FMVSS 213 chapter.) 

Three-point belts are effective in all crash modes, including frontals. The estimated fatality 

reduction is: 77 percent in rollovers, 42 percent in side impacts, 29 percent in frontals, and 31 

percent in rear impacts and other crashes. 

Analyses of the FARS Multiple Cause of Death (MCOD) file showed that 3-point belts reduce 

the risk of life-threatening abdominal injuries by 52 percent and head injuries by 47 percent 

relative to lap belts only, in frontal crashes. (Occupants wearing 3-point belts, however, still 

have higher risk of abdominal injury than unrestrained people, but their risk of head injury is 63 

percent lower.) Three-point belts are beneficial for occupants of all age groups, including those 

age 55 or older.62

Fatality reduction – light trucks NHTSA’s 1999 evaluation analyzes vans and SUVs. Threepoint belts are highly effective: the fatality reduction for back-seat occupants averaged 73 

percent.63 By crash mode, the estimated fatality reduction is: 84 percent in rollovers, 50 percent 

in frontals, and 70 percent in side impacts, rear impacts and other crashes. 

Injury reduction – passenger cars NHTSA’s 1999 study did not attempt to obtain point 

estimates of the effectiveness of 3-point belts in reducing nonfatal injuries, because belt use 

appeared to be substantially overreported in available State crash files. However, an “as-used” 

analysis of 1990-96 Pennsylvania data showed rear-outboard occupants of cars equipped with 3-

point belts (regardless of whether or not these occupants wore the belts) had a statistically 

significant 12 percent fewer moderate-to-fatal (K + A + B) injury rate in frontal crashes than 

occupants of cars equipped with lap belts only. In 1990-96 Florida data, the reduction was 6 

percent, also statistically significant.64 In 1989, the agency had projected that 3-point belts in 

back seats of cars could reduce AIS 2-5 injuries by 45-55 percent and AIS 1 injuries by 10 

percent. The estimate was not obtained directly from crash data, but inferred by examining the 

relationships between other estimates: lap-belt vs. 3-point-belt effectiveness in the front seat of 

cars, lap belt effectiveness in the rear seat vs. the front, and fatality reduction vs. injury 

reduction.65

Injury reduction – light trucks The agency has not analyzed crash data to estimate the injury 

reduction for 3-point belts in LTVs. NHTSA’s Regulatory Impact Analysis in 1990 projected 

that 3-point belts in back seats of LTVs could reduce AIS 2-5 injuries by 50 percent and AIS 1 

injuries by 5.5 percent. Here, the agency assumed the same effectiveness in cars and LTVs; in 

retrospect, the AIS 2-5 number would appear to be an underestimate for the LTVs.66

 

62 Ibid., pp. xi-xiii, 47-52 and 99-111. 63 Ibid., pp. xii and 83-97; 90% confidence bounds, 64 to 79 percent. 64 Ibid., pp. 75-82. 65 Final Regulatory Evaluation, Rear Seat Lap Shoulder Belts in Passenger Cars, pp. IV-1 – IV-26. 66 Final Regulatory Impact Analysis, Extension of the Automatic Restraint Requirements of FMVSS 208 to Trucks, 

Buses and Multi-Purpose Passenger Vehicles, p. 23; Final Regulatory Evaluation, Rear Seat Lap Shoulder Belts in

Passenger Cars, p. IV-1. 

100
Automatic safety belts 

Types of automatic belts – how they worked There have been two fundamentally different types 

of automatic safety belts for front-outboard occupants of passenger cars: 2-point and 3-point. A 

2-point automatic belt was a diagonal torso belt, running from the roof rail or the top of the door 

down to a floor anchor near the center of the car. An entirely separate manual lap belt and/or 

knee bolster had to be added for lower-torso restraint. Motorized 2-point belts were anchored to 

a track on the roof rail. A motor automatically rolled the anchor backward, moving the torso belt 

into place, when the ignition was turned on, and rolled it forward, away from the occupant, when 

he or she prepared to leave the car. All motorized belt systems came with a manual lap belt. 

Non-motorized 2-point belts were anchored to the door. They were designed to move into place 

when the door shut and away when it opened. Before 1990, some of them did not come with a 

lap belt. All 2-point belts could be loosened for emergency egress, by a device that spooled the 

belt out temporarily and/or by a buckle that could be permanently disconnected or reconnected as 

the occupant wished. 

Automatic 3-point belts, when in use, closely resemble manual 3-point belts, but they are 

anchored to the door rather than the roof rail/B-pillar and fashioned so as to move into place 

around the occupant when the door shuts and move away when the door opens. They have a 

buckle close to the anchor point at the center of the car. If the occupant so chooses, he or she 

may unbuckle it and let the belts retract toward the door; thereafter, the belts may be manually 

buckled and unbuckled just like conventional, manual 3-point belts, each time he or she rides in 

the car. 

To qualify as automatic crash protection under FMVSS 208, cars with automatic belts had to 

meet that standard’s 30 mph frontal test requirement. Manual lap belts were not compulsory 

since the automatic belt, by itself, satisfied the FMVSS 208 requirement for a belt system.

67

History Twelve model years before FMVSS 208 required automatic protection on any vehicle, 

Volkswagen introduced non-motorized 2-point belts, with knee bolsters but no lap belt, as part of 

a popular option package on their MY 1975 Rabbit. From 1975 to 1984, approximately 30 

percent of Rabbits were sold with automatic belts, comprising nearly 400,000 cars. Toyota made 

the motorized 2-point belt standard on all Cressidas, starting in 1981, accounting for over 

200,000 cars in 1981-86.68

The phase-in of automatic protection began on September 1, 1986. During model year 1987, the 

first year of the phase-in, 91 percent of the cars with automatic protection had automatic belts 

(only 9 percent had air bags), and in MY 1988, 93 percent. Starting in 1989, sales of cars with 

air bags steadily gained relative to automatic belts. Nevertheless, in MY 1990, the first year after 

FMVSS 208 was fully phased in, over 70 percent of the cars had automatic belts, comprising 

over 6 million cars. Sales of cars with automatic belts decreased each year after 1990. By 1997, 

one year before FMVSS 208 required it, all new cars had dual air bags and manual 3-point belts 

– but not before 31 million cars with automatic belts were sold. Close to 20 million of them

 

67 Code of Federal Regulations, Title 49, Parts 571.208 S4.1.2.1 and S4.5.3. 68 Final Regulatory Impact Analysis, Amendment to Federal Motor Vehicle Safety Standard 208, Passenger Car 

Front Seat Occupant Protection, pp. II-3 and IV-23. 

101
were still on the road as of 2003. Over the years, sales of automatic 2-point belts (17 million 

cars) slightly outnumbered automatic 3-point belts (14 million cars). LTVs were not equipped 

with automatic belts. 

Automatic belt use In 1983-84, when NHTSA developed the automatic protection requirement 

of FMVSS 208, automatic belts were a promising alternative. Manual belt use was 14 percent, 

whereas automatic belt use was observed to be 96 percent in the Toyota Cressida (motorized) 

and 75 percent in the Volkswagen Rabbit (non-motorized 2-point) in the 19-City Study.69 State 

buckle-up laws quickly narrowed the gap between manual and automatic belt use. In the 19-city 

survey of 1991, manual belt use in MY 1987-90 cars had risen to 56 percent, while automatic 

belt use was 91-97 percent in cars with motorized 2-point belts, 74 percent with non-motorized 

2-point belts, and 64 percent with 3-point belts.70 In the 1994 NOPUS, use of manual belts in 

late-model (MY 1989-94) cars was up to 69 percent, exactly the same as 3-point automatic belts; 

use of 2-point automatic belts was not much higher: 78 percent for motorized, 75 percent for 

non-motorized.71 NHTSA believes that, during most of the 1990’s, use rates of manual and 

automatic 3-point belts were almost equal, increasing from year to year, while use of 2-point 

belts was close to 84 percent, changing little from year to year.72

In 1987, the Insurance Institute for Highway Safety observed 253 parked, unoccupied cars with 

3-point automatic belts. Already at this early date, over 99 percent of them had been unbuckled 

and allowed to retract toward the door; functionally rendering them a manual belt system. It is 

little wonder, then, that automatic 3-point belts had the same use rates as manual within a few 

years after their introduction. By contrast, over 95 percent of the 753 2-point belts in their 

survey were still connected in the “automatic” mode (although that percentage must have 

decreased in later years).73

All of the preceding statistics for 2-point belts are use rates for the automatic shoulder belt. 

However, most of those cars also had a manual lap belt. Lap belt use has been lower than 

shoulder belt use, but it is unclear by how much. (Lap belt use is, among other things, more 

difficult to observe than shoulder belts.) Lap belt use was only 29 percent in a 1989-90 North 

Carolina observational survey, 43 percent in a 1987 IIHS study, but 69 percent in 1992 Michigan 

observations. Shoulder belt use was over 90 percent in all three of these surveys.74

 

69 Perkins, Cynecki and Goryl, p. 16. 70 Evaluation of the Effectiveness of Occupant Protection, Interim Report, NHTSA Report No. DOT HS 807 843, 

1992, pp. 11-17. 71 The 1994 NOPUS controlled-intersection survey was the only one to record license plates and obtain VINs from

DMVs; NHTSA decoded the VINs to identify the model year and type of occupant protection. 72 Kahane (2000), pp. 41 and 52-55. 73 Williams, A.F., Wells, J.K., Lund, A.K. and Teed, N., “Observed Use of Automatic Seat Belts in 1987 Cars,” 

Accident Analysis and Prevention, Vol. 21, October 1989, pp. 427-433. 74 Ibid.; Hunter, W.W. et al., Analysis of Occupant Restraint Issues from State Accident Data, HSL Publication No. 

00578847, Report No. HSRC-TR75, Highway Safety Research Center, University of North Carolina, Chapel Hill, 

1990, Chapter 6; Streff, F.M., Molnar, L.J. and Christoff, C., “Automatic Safety Belt Use in Michigan: A Two-Year 

Follow-Up,” Journal of Safety Research, Vol. 25, Winter 1994, pp. 215-219; Schmidt, R.A., Young, D.E. and 

Ayres, T.J., “Automobile Seat Belts: Usage Patterns in Automatic Belt Systems,” Human Factors, Vol. 40, March 

1998, pp. 126-135.

102
Expected benefits Automatic 3-point belts closely resemble manual 3-point belts and may 

provide equally good protection. One caveat is that, being door-mounted, they might release in a 

crash that damages and opens the door, and allow more ejections than manual 3-point belts. 

Similarly, an automatic 2-point belt in combination with the manual lap belt may be functionally 

equivalent to a manual 3-point belt and equally effective. Without the lap belt, it stands to 

reason that 2-point belts would be less effective overall, but it is not clear where benefits would 

be reduced. Since the vehicle must meet the FMVSS 208 frontal barrier test without the lap belt, 

effectiveness could still be high in frontal crashes. However, without the lap belt, occupants 

might be more prone to slide beneath the shoulder belt (submarining) and they might not be as 

well protected from ejection. 

Fatality reduction, automatic 3-point belts NHTSA’s 2000 evaluation estimated the fatality 

reduction for automatic 3-point belts, based on the same double-pair comparison analysis of 

1986-99 FARS data used for manual belts. Automatic and manual belts are equally effective: 

they reduce fatalities by 45 percent.75 Furthermore, an analysis of 1986-91 FARS data did not 

show any significant increases in occupant ejections as make-models shifted from manual belts 

to automatic 3-point belts during 1987-89.76 Automatic and manual 3-point belts appear to have 

essentially the same effectiveness and use rates. 

Fatality reduction, automatic 2-point belts The 2000 study estimated a 32 percent overall 

fatality reduction for automatic 2-point belts. That is significantly less than the 45 percent 

effectiveness of manual 3-point belts. However, this 32 percent effect is an average, comprising 

people who did not buckle the manual lap belt as well as those who did. (FARS data cannot be 

relied on to identify use of the lap belt.) If lap belt use has been as low as suggested by the North 

Carolina survey – less than one-third of shoulder belt use – it is easy to see how net effectiveness 

could drop to 32 percent. But if lap belt use were as high as the Michigan survey – over twothirds of shoulder belt use – it would imply these systems are not very effective without the lap 

belt.77 In any case, given recent use rates for manual belts, such as 80 percent in 2004, the 

combination of manual belts with air bags is clearly more beneficial than any automatic belt 

system. 

Pretensioners and load limiters for safety belts 

Safety belt pretensioners retract the safety belt almost instantly in a crash to remove excess slack. 

They are mechanical or pyrotechnic devices located within the belt’s retractor assembly. By 

pulling in slack, they reduce occupants’ impacts with interior surfaces and help the belt engage 

with the occupant to expedite “ride-down.” Load limiters and other energy management systems 

allow safety belts to yield in a crash, preventing the shoulder belt from exerting too much force 

on the chest of an occupant. In NHTSA’s frontal New Car Assessment Program (NCAP) test, a 

35 mph impact into a rigid barrier with belted dummies, the combination of pretensioners and 

 

75 Kahane (2000), pp. 40-41; the point estimate for the 3-point automatic belts was actually 48 percent; since it was 

not significantly different from the 45 percent estimate for manual belts, the two systems may be considered equally

effective, since they essentially work the same way. 76 Evaluation of the Effectiveness of Occupant Protection, Interim Report, pp. 43-46. 77 Kahane (2000), pp. 40-41; the point estimate for the 3-point automatic belts was actually 48 percent; since it was 

not significantly different from the 45 percent estimate for manual belts, the two systems may be considered equally

effective, since they essentially work the same way. 

103
load limiters reduced (i.e., improved) Head Injury Criterion (HIC) by 232, chest acceleration by 

an average of 6.6 g's, and chest deflection by 10.6 mm, for drivers and right front passengers. 

Each of these reductions was statistically significant. This is a promising indication that 

pretensioners and load limiters make belts more effective in at least one type of crash. 

Approximately 63 percent of MY 2002 cars and LTVs were equipped with pretensioners, and 84 

percent with load limiters or other energy management systems. When these vehicles have been 

on the road long enough to accumulate sufficient crash experience, NHTSA will analyze FARS 

data, based on double-pair comparison, to see if pretensioners and load-limiters enhance the 

overall fatality-reducing effectiveness of safety belts.78 

Frontal air bags 

How air bags work A dual air bag system includes sensors at various locations in the vehicle 

that send an electrical signal if they experience a substantial deceleration and velocity change 

from a frontal direction. A control module commands the air bags to deploy if these signals 

imply that the vehicle has been in a relatively severe frontal impact. Two air bag assemblies 

include a charge of Sodium Azide propellant that will generate Nitrogen gas upon firing and/or a 

cylinder of compressed Argon gas and an inflatable bag made of fabric. All bags have vents to 

release the gas gradually after a deployment. Many have tethers (internal straps) that limit how 

far the bag can deploy toward the occupant, and make it spread outward, over a larger area. 

These assemblies are located in the steering wheel hub for the driver, in the instrument panel for 

the passenger. A driver-only air bag system has all of these except the passenger bag assembly. 

In a severe frontal crash such as a 30 mph barrier impact, even while the front bumper comes to 

an immediate stop against the barrier and the sheet metal deforms, the occupants remain in their 

seats for about the first 50 milliseconds or more, and the compartment interior continues forward 

at close to 30 mph as if nothing had happened yet. In the next 50-75 milliseconds, the 

compartment is slowed to a stop while unrestrained occupants continue to move forward at close 

to 30 mph, fly out of their seats, and strike the steering assembly, instrument panel and other 

structures at a high relative speed. 

The technological marvel of the air bag is that it fully deploys in less than 50 milliseconds, 

before a correctly positioned occupant has even begun to move out of the seat. In that time, the 

sensors detect the crash, the control module sends signals to fire the propellant or open the 

cylinders, and gas is generated or released at high enough pressure for the bags to burst through 

“doors” in the steering wheel hub and instrument panel, and to fill up entirely. As the occupant 

begins to move forward, he or she will almost immediately contact an energy-absorbing surface 

that is ideally “tuned”: soft enough to cushion the head and neck without serious injury, yet rigid 

enough to absorb much of the torso’s kinetic energy. This energy is absorbed as the occupant 

compresses the bag and pushes the gas out through the vents. 

The air bag is one key component in a chain of deformable devices that allow the occupant to 

“ride down” from 30 mph to 0 mph as gradually as possible, remaining in an upright position. 

 

78 Walz, M.C., NCAP Test Improvements with Pretensioners and Load Limiters, NHTSA Technical Report No. 

DOT HS 809 562, Washington, 2003; National Highway Traffic Safety Administration Evaluation Program Plan, 

Calendar Years 2004-2007, NHTSA Report No. DOT HS 809 699, Washington, 2004, p. 4. 

104
The other components are: the continuing crumple of the sheet metal in the front of the vehicle 

even after the occupant moves out of the seat; the compression of the energy-absorbing steering 

assembly (FMVSS 203/204), facilitated by transmission of force through the air bag; 

deformation of the instrument panel by the knees (FMVSS 201); and the “give” in the seat belt 

system (especially with load limiters) and the seat structure. 

An air bag must deploy rapidly and with great force if it is to get its job done in less than 50 

milliseconds. For adequate gas pressure (energy-absorbing capability) in the fully deployed bag, 

there must be much higher gas pressure and temperature as the bag begins to deploy. Initial bag 

velocities of 200 mph or more were not unusual in the 1985-97 generation of air bags. Whereas 

air bags are of great value to the correctly positioned occupant, they can increase risk for an outof-position occupant who is touching a deployment “door,” or is within about 4 inches of it, at 

the moment of deployment. 

How do people get close to the air bag? Infants in rear-facing child safety seats would be 

adjacent to the deployment door at all times, and must never be placed in the front seat of a 

vehicle with a working passenger air bag. Other people may be jostled forward from their seats 

during hard braking, bumps on or off the road, and/or minor impacts before the one that deploys 

the bag. A correctly worn safety belt or forward-facing safety seat and/or the inertial weight of 

an adult reduce the tendency to slide forwards. Thus, unrestrained children 1-12 years old are 

especially vulnerable. Drivers of short stature (usually less than 5 feet tall) who must sit within 

10 inches of the steering wheel in order to operate the pedals are also more prone than others to 

be thrown within 4 inches of the deployment door. Temporary proximity to the air bag can result 

from leaning forward to adjust the radio or other controls. People who lean their arms across the 

steering wheel can sustain arm injuries from the air bag that, of course, are rarely lifethreatening. 

The only two guaranteed methods to stay away from an air bag are to ride in the back seat or to 

turn the on-off switch “off,” if one is available. NHTSA recommends that children up to age 12 

ride in the back seat if possible; it is the safest place in the vehicle. Risk can be greatly reduced, 

although not totally eliminated, by using safety belts/forward-facing safety seats, moving the 

passenger seat backward, moving adjustable pedals backward if this feature is available, and not 

leaning one’s arms across the steering wheel. For the overwhelming majority of occupants age 

13 or older who wear safety belts, the risk of serious injury from air bags is so negligible relative 

to their potential benefits that they should not even consider obtaining an aftermarket on-off 

switch. 

Safety belts remain the primary occupant protection system and need to be worn in vehicles with 

air bags. In side impacts, rear impacts and primary rollovers, air bags generally do not deploy, 

and even if they do, they have limited benefits. Air bag deployments are, of course, beneficial in 

relatively severe frontal and oblique-frontal crashes, but there is no guarantee an air bag will 

deploy in a particular crash. While brochures indicate that air bags begin to deploy in frontals 

equivalent to 8-14 mph barrier crashes, this is at best a rule of thumb. Deployments occasionally 

happen at lower speeds and sometimes do not take place at substantially higher Delta V. This is 

not an evidence of malfunction; rather, the sensors take into account various aspects of the crash 

pulse and don’t just measure Delta V. Frontal air bags do not prevent ejection and they may 

105
have limited benefits if a frontal impact is followed by a rollover, side impact, fire or immersion. 

They deflate rapidly after deploying and may not be as helpful in multiple impacts. 

Notwithstanding these caveats, air bag systems usually deploy when they are needed, don’t 

deploy when they aren’t needed, and seldom malfunction. The manufacturers and NHTSA 

constantly review the performance of the systems and promptly correct problems that may 

develop over time.79

History Air bags to cushion occupants in frontal crashes were conceptualized in the 1950’s. 

Prototypes were built and tested in the early 1960’s. NHTSA announced in 1969 it was 

considering air bags or other automatic protection, especially in view of low belt use, and issued 

its first NPRM for automatic protection in 1970. The original January 1, 1972 effective date was 

postponed or cancelled several times for reasons such as revision of the test requirements, 

alternative proposals for occupant protection, risk to children/out-of-position occupants and lack 

of industry/public support. However, NHTSA’s July 17, 1984 rule to phase automatic protection 

into the front-outboard seats passenger cars was successfully implemented during 1986-89.80

On-the-road experience began in 1972-73: 831 MY 1972 Mercury Montereys with passenger air 

bags and 1000 MY 1973 Chevrolet Impalas with dual air bags. These cars were driven by 

corporate personnel or leased to corporate fleets. In MY 1974-75, the general public bought 

10,281 full-size Buicks, Cadillacs and Oldsmobiles with optional dual air bags. No air bags were 

offered on new MY 1976-83 cars. During MY 1985 (or possibly in late MY 1984), driver air 

bags of the next design generation (1984-97) began to appear in some Mercedes models for sale 

to the public and in 5,000 Ford Tempos purchased by the Federal government. Driver air bags 

were standard on all 1986 Mercedes.81

The FMVSS 208 phase-in of automatic protection began on September 1, 1986. To help get air 

bags into cars, recognizing that the development of passenger air bags was taking longer than 

driver air bags, NHTSA exempted the right-front seat from the automatic protection requirement 

until August 31, 1993 in cars with driver air bags. During MY 1987-88, fewer than 10 percent of 

cars with automatic protection had air bags, while over 90 percent had automatic belts. The 

public, however, soon expressed a preference for air bags. In mid-1988, Chrysler committed 

itself to shift from automatic belts to air bags within the next few years. By 1990-91 all domestic 

manufacturers made driver air bags standard on some models with high sales; in 1992-93 driver 

 

79 Air Bags & On-Off Switches, NHTSA Publication No. DOT HS 808 629, Washington, 1997; Fifth/Sixth Report to

Congress – Effectiveness of Occupant Protection Systems and Their Use, NHTSA Report No. DOT HS 809 442,

Washington, 2001, pp. 2-3. 80 Clark, C., Blechschmidt, C. and Gordon, F., “Impact Protection with the ‘Airstop’ Restraint System,” Eighth 

Stapp Car Crash and Field Demonstration Conference, Wayne State University Press, Detroit, 1966; Federal 

Register 34 (July 2, 1969): 11148, 35 (May 7, 1970): 7187, 42 (July 5, 1977): 34289, 46 (October 29, 1981): 53419, 

49 (July 17, 1984): 28962; “Air Bag Chronology,” USA Today, July 13, 1999. 81 Final Regulatory Impact Analysis, Amendment to Federal Motor Vehicle Safety Standard 208, Passenger Car 

Front Seat Occupant Protection, p. IV-40; Smith, R.A. and Kahane, C.J., 1974 Accident Experience with Air 

Cushion Restraint Systems, NHTSA Technical Note No. DOT HS 801 565, Paper No. 750190, Society of

Automotive Engineers, Warrendale, PA, 1975; Bloch, B., “Advanced Designs for Side Impact and Rollover 

Protection,” Sixteenth International Technical Conference on the Enhanced Safety of Vehicles, NHTSA Report No.

DOT HS 808 759, Washington, 1998, p. 1780; Recent Air Bag Field Performance, Research Note, NHTSA National 

Center for Statistics and Analysis, 1986; Kahane, C.J., Fatality Reduction by Air Bags, NHTSA Technical Report

No. DOT HS 808 470, Washington, 1996, p. 89. 

106
air bags peaked at 49 percent of new car sales. Starting September 1, 1993, cars could not have 

just a driver air bag and manual belts, but they could have a driver air bag and an automatic belt 

for the RF passenger; in fact 25 percent of MY 1994 cars had that configuration.82

Dual air bags were available on Porsche in 1987-89 and standard in 1990. They became

available on a few other models in 1990-91, were in 5 percent of MY 1992 cars and 14 percent 

of MY 1993, including, for example, all the Chrysler LH cars. By MY 1994, the manufacturers 

could place dual air bags in 58 percent of their cars, and in 1995, 90 percent. All new cars had 

dual air bags with manual 3-point belts from MY 1997 onward, one year in advance of the 

FMVSS 208 requirement.83

Chrysler equipped some MY 1991 minivans and all 1992’s with driver air bags. Chrysler and 

Toyota minivans were the first with dual air bags, in MY 1994. The FMVSS 208 phase-in of 

automatic protection into light trucks started on September 1, 1994. By then, the majority of 

LTVs at least had driver air bags and 16 percent had dual air bags. Most SUVs and vans had 

dual air bags by MY 1996-97, two to three years in advance of the FMVSS 208 requirement. In 

pickup trucks without back seats, and in other vehicles that could not accommodate a child 

restraint in the back seat, however, passenger air bags would have posed a risk to children 

obligated to ride in the front seat. After NHTSA permitted on-off switches for the passenger air 

bag in such vehicles, effective June 22, 1995, dual air bags with the switches began to appear in 

1996 Ford Rangers, and were standard in all pickup trucks with GVWR < 8,500, excluding crewcab models, by MY 1998. LTVs with GVWR over 8,500 pounds are exempt from the automatic 

protection requirement and often do not have air bags.84

Expected benefits Air bags ought to be quite effective in frontal crashes, the closer to directly 

frontal, the more effective. They should very substantially reduce life-threatening head and chest 

injuries in these crashes. They should be effective, but to a lesser extent, in oblique frontal 

crashes, because occupants are often injured by components off to the side, not in a trajectory to 

the air bag. Air bags ought to save lives of belted as well as unrestrained occupants, because 

safety belts alone cannot prevent all contacts with the compartment interior in frontal crashes. 

Air bags will have no effect in crashes where they do not deploy, including most 90-degree side 

impacts, rear impacts and rollovers. Frontal air bags generally will not block occupant ejection 

from the vehicle, except possibly through the windshield portal. When frontal crashes are 

followed by other harmful events such as secondary impacts, rollovers or fires, the air bags 

might not prevent injuries associated with the subsequent events. Intuitively, air bags would be 

less effective in catastrophic crashes where the integrity of the occupant compartment is lost. 

Passenger air bags would clearly be dangerous to infants in rear-facing safety seats in the front 

seat of a vehicle, and they could also increase the net fatality risk for some other types of child 

 

82 Federal Register 49 (July 17, 1984): 28962, 55 (January 17, 1990): 1586; Code of Federal Regulations, Title 49, 

Parts 571.208 S4.1.4; Kahane (1996), pp. 77-95. 83 Federal Register 58 (September 2, 1993): 46551; Code of Federal Regulations, Title 49, Part 571.208 S4.1.5.3; 

Kahane (1996), pp. 77-95. 84 Federal Register 56 (March 26, 1991): 12472, 58 (September 2, 1993): 46551, 60 (May 23, 1995): 27233; Code

of Federal Regulations, Title 49, Part 571.208 S4.2.5, 4.2.6.2 and S4.5.4; Kahane (1996), pp. 97-101. 

107
passengers. As of October 1, 2004, NHTSA reported 23 confirmed cases of infants in rearfacing safety seats and 132 other children who received fatal injuries from air bag deployments 

in relatively low-speed crashes.85 However, the latter is not necessarily the “net” increase, since 

air bags may have saved some children in other crashes. 

Early predictions of fatality reduction In 1974, NHTSA predicted that air bags would reduce 

overall fatality risk by 32 percent relative to an unrestrained occupant, and that air bags would 

save 9,000 lives per year. In 1977, after the energy crisis, 55 mph speed limit and other factors 

had dramatically reduced overall traffic fatalities, NHTSA upped the effectiveness estimate for 

air bags to 40 percent and still predicted they would save 9,000 lives per year. Because air bags 

protected dummies in 35 mph frontal barrier crashes, the analyses assumed that air bags would 

essentially eliminate fatalities in frontal crashes on the highway with Delta V ≤ 35 mph (57 to 65 

percent of all unrestrained frontal fatalities) – regardless of what contact points or injury 

mechanisms were actually causing the fatalities. The analyses also assumed air bags would have 

some benefits in side impacts, rear impacts and rollovers if these crashes included a secondary 

frontal impact or a frontal-force component in the main impact.86

During the 1984 rulemaking on automatic protection, NHTSA took a hard second look at air bag 

effectiveness, based on the agency’s data systems created during 1977-84. Two NHTSA 

analysts independently reviewed approximately 800 unrestrained front-outboard fatality cases on 

the NCSS file. Both studies concluded that 72-77 percent of crash fatalities were unlikely to be 

mitigated by air bags because they were attributed to contacts with the vehicle’s side interior or 

other non-frontal areas, ejection through side doors or windows, catastrophic damage to the 

vehicle interior, fire or immersion. Thus, the overall fatality reduction for air bags could not 

exceed 23-28 percent and presumably would be some fraction of that. NHTSA at that time 

essentially halved its predictions, ranging them down to 20 percent fatality reduction and 4,570 

lives saved per year.87

Fatality reduction – passenger cars – drivers The four NHTSA analyses of the actual crash 

experience of cars equipped with air bags, in 1992, 1996, 1999 and 2001, have had remarkably 

consistent results. Air bags reduced overall fatality risk by 12 percent, 11 percent, 11 percent 

and 12 percent, respectively. The last study is based on the most data and it is NHTSA’s best 

estimate.88

 

85 NCSA Special Crash Investigations, Downloadable Files. NHTSA, Washington (www-nrd.nhtsa.dot.gov/

departments/nrd-30/SCI.html). 86 Final Regulatory Impact Analysis, Amendment to Federal Motor Vehicle Safety Standard 208, Passenger Car 

Front Seat Occupant Protection, pp. IV-37 – IV-39; Analysis of Effects of Proposed Changes to Passenger Car 

Requirements of FMVSS 208, NHTSA Docket No. 74-14-N01-104, Washington, 1974; Standard No. 208 – Passive 

Restraint Amendment, Explanation of Rulemaking Action, NHTSA Docket No. 74-14-N10-011, NHTSA Report No.

DOT HS 802 523, Washington, 1977. 87 Partyka, S.C., “Assessment of the Potential of Air Bags to Prevent Car Occupant Fatalities Using NCSS Data,” 

Final Regulatory Impact Analysis, Amendment to Federal Motor Vehicle Safety Standard 208, Passenger Car Front

Seat Occupant Protection, pp. 3 and IV-47 – IV-67; Kahane (1984 Air Bags). 88 Evaluation of the Effectiveness of Occupant Protection, Interim Report, pp. 21-25; Kahane (1996), pp. 7-12; 

Fourth Report to Congress – Effectiveness of Occupant Protection Systems and Their Use, NHTSA Report No. 

DOT HS 808 919, Washington, 1999, pp. 8-11; Fifth/Sixth Report to Congress, pp. 6-11.

108
Each of these studies estimated fatality reduction based on two double-pair comparison analyses, 

and averaged the two results. The first analysis is feasible because a large number of makemodels were initially equipped with only a driver air bag at some point before 1994. The 

driver’s seats changed from no air bags to air bag-equipped, while the RF passenger seat stayed 

the same: no air bag. That allows double-pair comparison, with the RF passenger as the control 

group. NHTSA’s 2001 study was based on CY 1986-2000 FARS data involving MY 1985-2000 

cars equipped with 3-point belts and no air bags, or with 3-point belts and a driver-only air bag. 

It is limited to cases where the driver’s and right-front seats were both occupied; the RF 

passenger was at least 5 years old; and the driver, or the RF passenger, or possibly both died: 

Driver’s RF Passenger Driver RF Passenger Driver/RF 

 Seat Seat Fatalities Fatalities Risk Ratio 

No air bag No air bag 22,535 24,168 0.932 

Air-bag equipped No air bag 3,654 4,420 0.827 

In cars with no air bags, drivers are nearly as much at risk as RF passengers. In cars with driver 

air bags, there are substantially fewer driver fatalities than passenger fatalities. Drivers 

experienced a statistically significant 11 percent fatality reduction with air bags: 

1 – [(3,654/4,420) / (22,535/24,168)] = .113 

This is called an “as used” analysis, because it includes all types of crashes, and it is not limited 

to crashes in which the air bag deployed. It estimates the overall effectiveness of air bags as a 

system. 

The second analysis is based on another distinctive characteristic 

of air bags: they are primarily designed for action in frontal 

crashes. With an inclusive definition of “frontal and partially 

frontal” crashes (initial or principal impact location between 10:00 

and 2:00), it can be assumed that air bags have little effect in the 

remaining “non-frontal” crashes. These non-frontal fatalities are a 

control group. NHTSA’s 2001 study was based on CY 1986-2000 

FARS data and limited to selected MY 1985-2000 make-models 

equipped with 3-point belts that shifted from no air bags to driver 

(or dual) air bags. Driver fatalities in cars of the last 3 model years 

before air bags were compared to fatalities in cars of the first 3 model years with driver (or dual) 

air bags. (In this analysis, it does not matter if the RF seat is occupied or unoccupied, or what 

sort of occupant protection it has.): 

109
 Frontal (10-2:00) Non-Frontal Frontal/Non-Frontal 

 Fatalities Fatalities Risk Ratio

Driver seat without air bag 5,434 2,860 1.900 

Driver seat equipped with air bag 3,360 2,223 1.511 

Drivers of cars equipped with air bags experienced a statistically significant 20 percent reduction 

of frontal fatalities: 

1 – [(3,360/2,223) / (5,434/2,860)] = .204 

Because 65 percent of fatalities were frontal (by this rather inclusive definition of “frontal”), that

amounts to a 13 percent overall reduction of fatalities: 

.204 [5,434 / (5,434 + 2,860)] = .134 

The two statistically significant estimates of overall fatality reduction (11 and 13 percent) 

average out to 12 percent. 

Air bags are most effective in “purely frontal” crashes where the principal impact is at a 12:00 

location and it is also the most harmful event – i.e., the most harmful event is not a subsequent 

rollover, fire, or immersion. The first analysis method demonstrates the high effectiveness of air 

bags: 

Purely Frontal Crashes 

Driver’s RF Passenger Driver RF Passenger Driver/RF 

 Seat Seat Fatalities Fatalities Risk Ratio 

No air bag No air bag 7,597 8,241 0.922 

Air-bag equipped No air bag 950 1,438 0.661 

The average for the two analysis methods is a 29 percent fatality reduction in purely frontal 

crashes. Effectiveness drops off steeply as the impact moves away from purely frontal. When 

the principal impact is at an 11:00 or 1:00 location and is also the most harmful event, air bags 

reduce fatality risk by 15 percent; when the principal impact/most harmful event is at a 10:00 or 

2:00 location, fatality reduction for air bags is 6 percent. When the principal impact is 3-9:00 or 

to the top of the car, or when the most harmful event is a rollover, fire, immersion or other noncollision, effectiveness is zero. 

Enough data were available to obtain statistically significant estimates of fatality reduction for 

subpopulations of drivers: 

110
FATALITY REDUCTION (%) BY AIR BAGS IN PURELY FRONTAL CRASHES 

Drivers of Passenger Cars 

 Fatality Reduction (%) 

IN ALL PURELY FRONTAL CRASHES 29 

BY 14-29 29 

OCCUPANT 30-55 30 

AGE: 56-69 30 

70 and older 20 

BY Male 29 

GENDER: Female 29 

BY Belted 21 

BELT USE: Unbelted 34 

BY 2778 pounds or lighter 30 

CURB 2779-3119 pounds 28 

WEIGHT: 3120 pounds or heavier 26 

Air bags are about equally effective for young and middle-aged drivers (29-30 percent), and 

perhaps slightly less effective for drivers age 70 or older (20 percent). As of October 1, 2004, 

NHTSA reported 84 confirmed cases of adult drivers, including 28 age 70 or older, who had 

received fatal injuries from air bag deployments in relatively low-speed crashes – but, clearly, 

the lives saved by air bags in more severe crashes far exceed these losses, in all age groups.1

 Air 

bags are equally effective for male and female drivers, and about equally effective in cars of 

various sizes. They are quite effective for unrestrained drivers (34 percent), but also provide 

significant supplemental protection for belted drivers (21 percent). Since 3-point belts, by 

themselves, reduce fatality risk by 50 percent in frontal crashes (see above), the combination of 

3-point belts with air bags reduces fatality risk by an estimated 61 percent in purely frontal 

crashes: 

1 – [(1 – .50) / (1 – .21)] = .605 

NHTSA was also able to estimate the fatality reduction in all crashes (not just purely frontal) 

separately for belted and unbelted drivers. Air bags reduced overall fatality risk by 11 percent 

for belted drivers and 14 percent for unbelted drivers. Since 3-point belts, by themselves, reduce 

fatality risk by 45 percent, the combination of 3-point belts with air bags reduces fatality risk by 

an estimated 51 percent: 

1 – [(1 – .45) / (1 – .11)] = .5105 

 

1

 NCSA Special Crash Investigations, Downloadable Files, NHTSA, Washington (www-nrd.nhtsa.dot.gov

/departments/nrd-30/SCI.html). 

111
Fatality reduction – passenger cars – right-front passengers age 13 and older Essentially the 

same two double-pair comparison analyses can be used to compute fatality reduction for RF 

passengers. Separate estimates are obtained for passengers age 13 or older, who ought to benefit 

significantly from air bags, and children age 12 or younger, who might experience increased 

fatality risk.

The first analysis method works because quite a few make-models had only driver air bags up to 

MY 1993 and were equipped with dual air bags starting in MY 1994. The RF seats changed 

from no air bags to air bag-equipped, while the driver’s seat stayed the same: air bag-equipped. 

That allows double-pair comparison, with the driver as the control group. The following 

example from NHTSA’s 2001 study was based on purely frontal crashes where the driver’s and 

right-front seats were both occupied; the RF passenger was at least 13 years old; and the driver, 

or the RF passenger, or possibly both died:2

 

Purely Frontal Crashes 

RF Passenger Driver’s RF Passenger Driver RF/Driver 

 Seat Seat Fatalities Fatalities Risk Ratio 

No air bag Air-bag equipped 1,427 914 1.561 

Air-bag equipped Air-bag equipped 1,282 1,179 1.087 

In these purely frontal crashes, when the driver had an air bag and the passenger did not, the 

fatality risk was substantially higher for the passenger. But with dual air bags, the fatality risk 

was about the same for drivers and passengers. The average for this analysis method and the 

other method (based on purely frontal vs. non-frontal fatalities) is a statistically significant 32 

percent fatality reduction in purely frontal crashes. In other words, air bags are just as effective, 

and perhaps a bit more effective for RF passengers age 13 and older than they are for drivers (29 

percent fatality reduction). 

Effectiveness drops off to 24 percent in 11:00 or 1:00 principal impact/most harmful events, 4 

percent in 10:00 or 2:00 impacts, and near zero in non-frontal crashes or when most harmful 

event is a rollover, fire, immersion or other non-collision. In all types of crashes, air bags reduce 

the fatality risk of RF passengers age 13 and older by an average of 14 percent. 

Air bags are about equally effective for passengers age 13-29, 30-55, 56-69 and 70+, and in cars 

of various sizes. 

Fatality reduction – light trucks – drivers NHTSA’s 2001 study had enough FARS data for 

statistically significant estimates of the effect of air bags in pickup trucks, SUVs and vans, based 

on the same analysis methods as for cars. Driver air bags reduced fatality risk in purely frontal 

crashes by 29 percent, and in all crashes by 12 percent. These estimates are exactly the same as 

 

2 Fifth/Sixth Report to Congress, pp. 10-11. 

112
the corresponding results for passenger cars, and they suggest that air bags are about equally 

effective for LTV and car drivers.3

Fatality reduction – light trucks – right-front passengers age 13 and older NHTSA’s 2001 

report had fewer data on LTV passengers than on drivers or car passengers, because most LTVs 

were not equipped with dual air bags until 1996-98. Nevertheless, there are enough data for a 

statistically significant estimate that passenger air bags reduced fatality risk in purely frontal 

crashes by 32 percent. It is exactly the same as the corresponding result for car passengers, and 

it suggests that air bags are about equally effective for LTV and car passengers age 13 and 

older.4

Effect on fatalities of right-front passengers age 12 and younger NHTSA has repeatedly 

advised the public about the hazards of air bags to infants and children, and it periodically 

updates a list of Special Crash Investigations (SCI) of children who received fatal injuries from

air bags in relatively low-speed crashes. NHTSA’s 1996 evaluation recommends a double-pair 

comparison method for estimating the effect of air bags on child passenger fatalities. When that 

analysis is updated with the FARS database of the 2001 report, it shows that, in all crashes, child 

passengers age 0-12 in the RF seat have 22 percent higher fatality risk with air bags than without 

them. In crashes where the principal and/or initial impact is at 12:00, risk is 42 percent higher 

with air bags. Both increases are statistically significant. However, the added risk is not at all 

uniform, but depends a lot on the age of the child and restraint use. For infants in rear-facing 

safety seats, air bags increase fatality risk in 12:00 impacts by an estimated factor of 51⁄2. For 

unrestrained infants and children up to age 5, air bags approximately double fatality risk in 12:00 

impacts; for children age 1-5 in safety seats or belts (not necessarily used correctly) and 

unrestrained children age 6-10, air bags increase risk by 70 percent. Each of these three 

increases is statistically significant. Air bags have smaller effects for these groups in obliquefrontal crashes (10-11:00 or 1-2:00). They do not significantly increase or decrease the net 

fatality risk of belted children age 6-10, or of any children age 11-12, and, of course, they have 

little or no effect in non-frontal crashes.5

Based on these statistically derived effectiveness estimates, NHTSA calculates that air bags may 

have resulted in a net increase of 136 child passenger fatalities in FARS-reportable traffic 

crashes on public roads during 1993-2002.6

 That number is somewhat lower than the 159 SCI 

cases (152 “confirmed” and 7 “unconfirmed”) of infants and children with fatal injuries from air 

bags in 1993-2002 crashes, reported as of October 1, 2004. In fact, the two numbers are quite 

compatible: SCI only counts cases where air bags were harmful, not the net increase after 

deducting whatever lives were saved by air bags; furthermore, SCI includes a fair number of 

incidents in private parking lots and other situations that are not reportable to FARS. 

 

3 Ibid., p. 11. 4 Ibid., p. 11. 5

 NCSA Special Crash Investigations, Downloadable Files, NHTSA, Washington (www-nrd.nhtsa.dot.gov

/departments/nrd-30/SCI.html); Kahane (1996), pp. 48-49; these estimates are based on all FARS up to MY and CY

2000 – i.e., a mix of vehicles consisting of many 1st generation air bags and relatively few redesigned (1998-2000)

air bags; in the future, when FARS includes more cases of redesigned air bags, it will be possible to obtain separate 

estimates of the effects of 1st generation and redesigned air bags. 6

 136 is the sum of 130 in Table 2-39 of this report (estimated net fatality increase in vehicles without on-off 

switches) and 6 in Table 2-40 (estimated net increase in pickup trucks with switches that were left on). 

113
Injury reduction NHTSA’s reports to the Congress estimated injury reduction based on injuries 

per 100-crash involved occupants in NASS data, with logistic regression to control for Delta V 

and other variables. The estimates are biased upwards because: 

• Belt use of uninjured occupants appears to be overreported. 

• Vehicles equipped with air bags are substantially newer than vehicles without air bags. 

Neither bias is fully addressed by the logistic regression method. The effectiveness estimates 

increased with each successive report. Furthermore, the use of weighted NASS data increased 

sampling error. For example, the last report to Congress estimated that air bags plus safety belts 

reduced AIS ≥ 3 injury risk by 67 percent relative to an unrestrained occupant, while safety belts 

alone reduced it by 69 percent. Both estimates are implausibly high, and the latter ought not 

have been higher than the former, since it implies that air bags increased the injury risk of a 

belted occupant.7

Less biased and more precise estimates can be obtained from unweighted 1989-2003 NASS 

casualty cases by using double-pair comparison analysis of frontal vs. non-frontal casualties, 

almost exactly as with FARS. To maximize sample size, the analysis comprises fatality cases of

drivers and RF passengers of cars as well as LTVs, belted as well as unrestrained. First, as a 

“calibration run,” fatality reduction is estimated from NASS data; the overall fatality reduction is 

12 percent, statistically significant and exactly the same as the fatality reduction in FARS. The 

same analysis estimates that air bags reduce AIS ≥ 3 injury risk by 15 percent and AIS ≥ 2 injury 

risk by 11 percent, in all crashes. Both reductions are statistically significant.8

Effectiveness can be estimated separately for unrestrained and belted occupants.9

 For 

unrestrained occupants, air bags reduce both AIS ≥ 3 and AIS ≥ 2 injury risk by 21 percent, in all 

crashes. For occupants who buckle up, air bags reduce AIS ≥ 3 injuries by 12 percent and AIS ≥

2 injuries by 4 percent. Since 3-point belts, by themselves, reduce AIS ≥ 3 injuries by 45 percent 

and AIS ≥ 2 by 46 percent in passenger cars (RSEP-NCSS-NASS estimates, see above), the 

injury reduction for the combination of 3-point belts with air bags can be estimated: 

PASSENGER CARS Fatality AIS ≥ 3 AIS ≥ 2 

ALL CRASHES Reduction (%) Reduction (%) Reduction (%) 

3-point belt plus air bag 51 52 48 

Air bag alone 14 21 21 

3-point belt alone 45 45 46 

 

7 Third Report to Congress, p. 20; Fourth Report to Congress, p. 17; Fifth/Sixth Report to Congress, p. 13. 8

 Analysis of unweighted NASS data is unacceptable for estimating national totals or rates (the customary use of

NASS), but may be empirically defensible for effectiveness analyses employing double-pair comparison, based 

entirely on fatal or non-minor injury cases. In this analysis, “frontal” crashes are those with GAD1 = F and/or 

DOF1 = 11, 12 or 1. 9

 Belt use is overreported by uninjured occupants in NASS, but can be assumed accurately reported for people with 

AIS ≥ 2 injuries; the double-pair comparison analysis is based entirely on the injury cases. 

114
In purely frontal crashes,10 air bags reduced AIS ≥ 3 injuries by 32 percent and AIS ≥ 2 injuries 

by 23 percent. For unbelted occupants alone, these reductions are 39 percent and 38 percent, 

respectively. For occupants who buckle up, they are 27 percent and 10 percent, respectively. In 

other words, the AIS ≥ 3 and AIS ≥ 2 injury reductions for air bags are generally similar (and 

sometimes even a little higher) than the fatality reductions, with the one exception that air bags 

apparently do not have that large an effect on the AIS ≥ 2 injuries of belted occupants. 

On-off switches for passenger air bags in pickup trucks

History NHTSA recognized that passenger air bags of the early 1990’s were absolutely 

incompatible with rear-facing child safety seats and also presented risks to child passengers and 

certain other individuals. NHTSA urged that children and other high-risk passengers travel in 

the back seat when possible. The agency also amended FMVSS 208 with measures to reduce 

risk when these people must travel in the front seat. Effective June 22, 1995, more than three 

years before the September 1, 1998 effective date for dual air bags in all LTVs, NHTSA 

permitted (but did not require) on-off switches for the passenger air bag in pickup trucks without 

back seats or other vehicles that could not accommodate rear-facing child safety seats in the back 

seat. This facilitated the implementation of passenger air bags in pickup trucks, beginning with 

some Ford Rangers in MY 1996 and extending to all models with passenger air bags by 1998. 

Effective January 19, 1998, NHTSA also enabled people who must transport high-risk 

individuals in the front seats of any vehicle to obtain aftermarket on-off switches at their own 

expense.11

As of July 1, 2001, there were 11,700,000 pickup trucks factory-equipped with the switches, and 

171,000 other vehicles without back seats, such as some cargo vans and sporty cars. In August 

2002, only 12,513 vehicles were known to have aftermarket switches. Thus, over 97 percent of 

the switches were in pickup trucks. Since MY 2000, an increasing number of pickup trucks have 

full crew cabs whose back seats can accommodate rear-facing infant seats; they do not have the 

switches. Needless to say, pickup trucks over 8,500 pounds GVWR that do not have air bags do 

not have the switches, either. All other pickup trucks in MY 1998-2003 had the switches: 

regular cabs with no back seat at all, but also extended cabs with back seats not designed to 

accommodate a rear-facing infant seat. Although NHTSA’s regulation permits (but does not 

require) switches in new pickup trucks until MY 2012, they may be phased out earlier – e.g., 

during or after the MY 2004-2006 phase-in of advanced systems that automatically suppress the 

deployment of air bags when there is a child passenger.12

How it works An on-off switch is usually located on the driver’s part of the instrument panel, 

but well over to the right where both the driver and the passenger can see it. The ignition key 

operates it. The switch has two settings, “air bag on” and “air bag off.” It remains at its current

setting until somebody uses the key to change it. When the switch is “off,” a light on the 

dashboard advises “air bag off,” and that light stays on as long as the ignition is on. 

 

10 GAD1 = F, DOF1 = 12, and this event is a collision with another vehicle or a fixed object. 11 Federal Register 60 (May 23, 1995): 27233, 62 (November 21, 1997): 62406 Code of Federal Regulations, Title 

49, Part 571.208 S4.5.4 and Part 595. 12 Morgan, C., Results of the Survey on the Use of Passenger Air Bag On-Off Switches, NHTSA Technical Report 

No. DOT HS 809 689, Washington, 2003, pp v and 4-5.

115
Public use and understanding of the switches During July-November 2000, NHTSA sponsored 

a survey of 3,182 pickup trucks (including 617 with child passengers) at 79 sites in 4 States. 

“Since the recommended switch setting depends on who is in the front seat at the moment, the 

survey was performed while the vehicles were occupied.” Investigators observed the actual 

setting of the switch and recorded the passenger’s age. Then they interviewed the driver to find 

out his or her awareness of the switch and its current setting, and the driver’s own criteria for 

turning the switch on or off.13

NHTSA recommends turning the switch “off” if there is a child passenger age 12 or younger in 

the front seat. With very rare exceptions, it should be “on” if the passenger(s) are age 13 or 

older. The principal finding of the survey was that many switches were “on” for child 

passengers in the RF seat, especially age 7-12, while quite a few were “off” for passengers age 

13 or older (the percentage of switches at the recommended setting is shown in bold type)14: 

Age of the RF Passenger Switch “On” (%) Switch “Off” (%) 

Less than 1 year15 14 86

1-6 years 26 74

7-8 41 59

9-10 53 47

11-12 70 30

13-15 78 22 

16-19 83 17 

20-59 85 15 

60-79 81 19 

70 years and older 44 56 

While 86 percent of switches are turned “off” for infants in the RF seat, that percentage

decreases to 74 at age 1-6 and to 30 by age 12. The percentage of switches turned “on” for 

adults does not exceed 85 in any age group, and it drops to 44 at age 70 or older. 

Interviews showed that these drivers were well informed in 2000 about some aspects of the 

switch: 98 percent knew their truck had a switch that could turn the air bag on or off, and 97 

percent correctly identified its setting; 65 percent who had used the switch and even 35 percent 

of those who had never used it volunteered (i.e., without being given a list of choices) that the 

primary purpose of the switch was to prevent “children” from being exposed to a deployment. 

But they were not as well informed about what age children should not be exposed. Some

thought that air bags were safe for 3- or 4-year-olds, while others worried they were unsafe for 

 

13 Ibid., pp. 4-8. 14 Ibid., pp. 13-15 and 22; the report’s statistics for infants in rear-facing seats, forward-facing seats and unrestrained

are combined here, but cases of infants in the center-front seat are not included in the table. 15 29 RF passengers less than 1 year old and/or seated in a rear-facing child safety seat, 4 switches “on.” In these 

four cases, the driver was not the owner of the truck, or mistakenly believed the switch was “off.” Not a single 

driver intentionally left the switch “on” in his or her own truck. 

116
their 6’1” teen-aged children. Thus, the proportion of switches turned off declines gradually as 

the passengers get older, rather than dropping abruptly at age 13.16 

Other factors that can result in switches being “off” for adults or “on” for children:17

• People who sometimes transport children may prefer to leave the switch “off” all the 

time, rather than try to change the setting each time an adult or child rides in the truck. 

They do not want to risk forgetting to turn it off for the child.

• Quite a few people turn the air bag off for older passengers. In fact, older passengers 

derive a significant net benefit from air bags (see above). The older occupant/air bag 

problem is short drivers who must sit close to the steering wheel, not passengers. 

• Some adult passengers who “don’t like air bags” turn off the factory-equipped switches 

in pickup trucks, even though they would not incur the effort and expense to obtain 

aftermarket switches in other vehicles. 

• With an adult in the RF seat and a child in the center-front seat, or vice-versa, the driver 

cannot optimally protect both. 

• People who borrow somebody else’s truck may be unfamiliar with the switch or reluctant 

to change its setting. 

Effect on fatalities On-off switches have been a necessary and fairly successful interim measure 

that made it possible to offer life-saving passenger air bags in pickup trucks as early as 1996-98, 

while allowing the opportunity to protect infants and children from those air bags. Without the 

switches, passenger air bags might not have been feasible until the development of automatic 

suppression technology (scheduled for 2004-2006 phase-in). Table 2-40 of this report estimates 

that the combination of passenger air bags and on-off switches in MY 1996-2002 pickup trucks 

had already saved 117 adults by the end of CY 2002. NHTSA’s earlier evaluation report had 

estimated that they would eventually save 329 adults over the service life of MY 1996-2001 

trucks.18

On the other hand, the combination of air bags and switches has not fully achieved the potential 

benefits it could accrue if they were always at the recommended setting. Table 2-40 estimates 

that 30 adults had died as of December 2002 because the switches were turned off in MY 1996-

2002 pickup trucks. There could be 68 additional fatalities over the service life of MY 1996-

2001 trucks if switches continue to be turned off for 17 percent of adult passengers.19

Of course, the purpose of the switches is to protect infants and children from air bag 

deployments. On October 1, 2004, SCI had 5 actual, “confirmed” cases of infants and children 

with fatal injuries from air bags in pickup trucks where the switch was left “on.” Their ages 

ranged from 2 months to 8 years. The statistical analysis of FARS data in Table 2-40, based on 

the estimated effects of air bags and the percentages of switches left “on,” produces a similar 

estimate: it concludes that the combination of air bags and on-off switches may have resulted in a 

net increase of 6 child passenger fatalities in 1996-2002. Without the switches, air bags in these 

 

16 Ibid., pp. vii, 10-13, 15-16 and 22-23. 17 Ibid., pp. vi-vii, 10-13, and 20-21. 18 Ibid., pp. vi, ix and 31-36. 19 Ibid., pp. vi, ix and 31-36. 

117
pickup trucks would have increased child passenger fatalities by a net 24; the public saved 18 of 

these potential fatalities by turning the switches “off.”

20

Thus, in 1996-2002, the combination of air bags and switches saved an estimated 117 adults in 

pickup trucks, with a net increase of 6 child passenger fatalities. That record can be improved in 

the future with information and education campaigns urging owners of pickup trucks to turn 

switches “off” for child passengers and leave them “on” for adults. 

1998-99 redesign of air bags 

The design of air bags involves a trade-off between supplying enough gas to absorb a substantial 

portion of the kinetic energy of a large, unrestrained person, and minimizing risk to out-ofposition occupants by reducing the force of deployments. In the early 1980’s, when belt use was 

less than 20 percent, the unrestrained occupant was a priority. Air bags had to pass a 30 mph 

crash test with unrestrained dummies. By the mid 1990’s, the majority of occupants buckled up, 

whereas injuries to out-of-position occupants had become an issue. Effective September 1, 1997, 

the agency relaxed some aspects of the frontal impact test with unrestrained dummies in order to 

facilitate the introduction of “redesigned” air bags that deploy less forcefully: instead of a crash 

test with an actual vehicle, manufacturers could use a sled test with a deceleration pulse 

characteristic of a large passenger car – i.e., relatively gradual. In some cases, suppliers achieved 

less forceful deployments by literally “depowering” air bags: removing some of the gasgenerating propellant. Others replaced or supplemented the propellant with a cylinder of stored 

argon gas. The gas can be vented at different rates, depending on the occupant’s belt use and the 

crash severity. Changing the volume of the air bag or its arrangement of tethers were other 

options. This redesign took place in time for the 1998, or at the latest, the 1999 model year. 

However, some air bags had little change from 1997 to 1999. NHTSA will analyze FARS, 

NASS and SCI data to investigate the effects of redesigned air bags for child passengers, older 

adults, out-of-position occupants, and unrestrained occupants.21

Advanced air bags 

In 2000, NHTSA amended FMVSS 208 to make future air bags substantially less hazardous to 

out-of-position occupants, but also more effective for correctly positioned occupants. These 

“advanced” air bags will be implemented step-by-step. From September 1, 2003 to September 1, 

2005, “advanced” air bags will be phased in that do not deploy at all (“suppression”) or deploy 

only at a low level of force (“low-risk deployment”) if a small child is present, or if an older 

child/small adult is out-of-position, close to the air bag. The technology for suppression and 

low-risk deployment includes sensors that detect the weight and/or position of an occupant. 

Furthermore, these air bags will need to pass a barrier and offset test with 5th percentile female 

dummies in addition to the current barrier test with a 50th percentile male dummy. MY 2008-

2010 will phase in a 35 mph barrier test with the belted 50th percentile male dummy, an increase 

 

20 NCSA Special Crash Investigations, Downloadable Files, NHTSA, Washington (www-nrd.nhtsa.dot.gov

/departments/nrd-30/SCI.html). 21 Federal Register 62 (March 19, 1997): 12960; Code of Federal Regulations, Title 49, Part 571.208 S13; NHTSA 

Evaluation Program Plan, CY 2004-2007, pp. 8-9. 

118
from the current 30 mph. The evaluation of advanced air bags will be a high priority for 

NHTSA.

22 

 

22 Federal Register 65 (May 12, 2000): 30679; Code of Federal Regulations, Title 49, Part 571.208 S14; NHTSA 

Evaluation Program Plan, CY 2004-2007, pp. 21-22 and 23-24.

119
FMVSS 212: Windshield mounting

This standard is associated in the public mind with a specific safety technology that has been 

evaluated by NHTSA: 

• Adhesive windshield bonding

In fact, FMVSS 212 is simply a performance standard requiring vehicles to retain not less than 

75 percent of the windshield periphery (50 percent in vehicles with automatic occupant 

protection) after the 30 mph frontal barrier test that NHTSA uses for FMVSS 204, 208, 212, 219 

and 301.1

 The purpose of windshield retention (and tighter bonding) is to prevent occupant 

ejection. FMVSS 212 took effect for passenger cars on January 1, 1970, two years after 

NHTSA’s initial group of safety standards, and it was extended to most light trucks, vans and 

multipurpose vehicles up to 10,000 pounds GVWR, effective September 1, 1978.2

Bonding of the windshield directly to its frame with adhesives gradually (1963-83) superseded 

the earlier method of first enclosing the windshield in a rubber gasket and then attaching the 

gasket to the frame. Thus, the shift to adhesive bonding began in some vehicles well before 

anybody anticipated FMVSS 212, but rubber gaskets persisted in other make-models for quite a 

few years after the standard. Although rubber gaskets are generally a looser installation than 

adhesive bonding, they can readily be designed to meet FMVSS 212. Each installation method 

has advantages, and the gradual shift from one to the other was motivated by various factors, 

sometimes including FMVSS 212. However, NHTSA’s evaluation estimates the effects and 

benefits of adhesive bonding in all make-models of passenger cars, regardless of FMVSS 212’s 

role in motivating its installation. 

How adhesive bonding works Before 1963, windshields were sealed inside a rubber gasket or 

molding that, in turn, was attached and sealed to the frame. It was a relatively loose attachment. 

In low-speed impacts, the rubber gasket had some energy-absorbing “give.” At higher speeds, 

the gasket could partly or completely tear away from the frame, beginning during the initial 

vehicle collision and deformation, and continuing as occupants impact the windshield. The 

advantages of gaskets are their durability, water- and sound-proofing, and perhaps, with pre-HPR 

windshields3

 (pre-1966), hope that windshields that “give” or “pop out” would be less prone to 

lacerate occupants. The important disadvantage of too loose an installation is that occupants are 

more likely to be ejected via the windshield portal. Such ejections almost always follow partial 

or complete separation of the windshield bond. Hardly ever are occupants ejected through the 

glazing while the bond remains intact.4

In the early 1960’s, General Motors found that butyl rubber tape could be used to attach 

windshields directly to the frame, making a firmer bond than rubber gaskets, apparently at lower 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.212. 2

 Kahane, C.J., An Evaluation of Windshield Glazing and Installation Methods for Passenger Cars, NHTSA

Technical Report No. DOT HS 806 693, Washington, 1985, p. 3; Federal Register 33 (August 16, 1968): 11652, 41

(August 30, 1976): 36493, 42 (July 5, 1977): 34288. 3

 Please see the chapter on FMVSS 205, earlier in this report. 4 Ibid., pp. 8 and 11-17.

120
cost, with acceptable durability, water- and sound-proofing. GM began using the tape on some

1963 Buick Specials and Oldsmobile F-85’s, and on all their domestic passenger cars by 1968, 

well before the FMVSS 212 effective date. In 1973, GM shifted from butyl tape to a 

polyurethane sealant, perhaps an even stronger adhesive bond. Ford began adhesive bonding in 

1965 on full-sized cars but continued using rubber gaskets on some car models through 1977; 

Chrysler started in 1969 but continued gaskets on some models through 1976. Obviously, the 

cars with rubber gaskets from 1970 onwards could and did meet FMVSS 212: the American 

rubber-gasket installation was hardly a “pop-out” windshield. 

Overseas manufacturers mostly continued to use rubber gaskets until the late 1970’s. However, 

Volkswagen (and perhaps other German manufacturers) had loose enough bonds that specific 

actions were needed to meet FMVSS 212. VW began to install continuous plastic clips between 

the gasket and the frame’s pinchweld flange in 1970. It appears that Japanese manufacturers had 

shifted to adhesive bonding, or to a rubber gasket installation as tight as adhesive bonding by 

MY 1980, and European manufacturers at most a few years after that.5

Pickup trucks, vans and SUVs also kept rubber gaskets during most of the 1970’s, and in many 

cases after FMVSS 212 was extended to light trucks (September 1, 1978). Manufacturers may 

have been especially concerned that operation on rough roads could accelerate deterioration of 

adhesive bonds, as compared to rubber gaskets. Adhesive bonding was gradually phased in 

during approximately 1978-85.6

 The final transition to adhesive bonding may have been spurred 

by anticipation of safety benefits, cost advantages with the second-generation sealants, and a 

1976 rule allowing NHTSA to conduct the FMVSS 212 test in a wider range of temperatures, 

from 15 to 110 degrees Fahrenheit: the performance of rubber gaskets can vary widely with 

temperature, adhesive bonding, less so.7

Expected benefits; concerns about a possible increase in lacerations Windshields installed in 

domestic cars with adhesive bonding ought to have a lower percentage of bond separation, in 

frontal crashes, at any speed, than windshields mounted with rubber gaskets in those domestic 

make-models. Similarly, German cars meeting FMVSS 212, with plastic clips between the 

rubber gasket and the frame, ought to have less bond separation than pre-FMVSS 212 German 

cars also with rubber gaskets, but without the clips. 

As a consequence, drivers and front-seat passengers should have a significantly lower risk of 

ejection via the windshield portal – in domestic cars after they switched to adhesive bonding, and 

in German cars after they got plastic clips in the rubber gaskets. Since an ejected occupant has 

substantially higher risk of fatality and serious injury than a non-ejected occupant under the same

crash conditions, that will result in a reduction of fatalities and serious injuries. 

 

5

 Mazda and Volvo used adhesive bonding from 1970 (Ibid., p. 14); Ebay.com offers extensive “windshield seals,” 

“windshield gaskets,” “windshield rubber” or “windshield weatherstrips” for domestic cars in model years when

they had rubber gaskets, and for imported cars in the 1970’s, but few after 1980; a recent analysis of NCSS data 

suggests that Japanese cars of the 1970’s with rubber gaskets had about the same probability of ≥ 25 % bond

separation in frontal crashes as domestic cars with adhesive bonding. 6 Richard Humphrey of General Motors (retired) advised the author that GM phased adhesive bonding into their 

trucks specifically during MY 1978-85; Ebay.com offers rubber gaskets for a wide variety of LTVs up to

approximately MY 1985, but after that only for SUVs with removable windshields (such as Jeep Wrangler). 7 Federal Register 41 (August 30, 1976): 36493. 

121
Conversely, if adhesive bonding makes windshields less prone to “give” or “pop out” upon head 

impacts by occupants, it is conceivable that facial lacerations could increase. Specifically, a 

1968 statistical study by Fargo of cars with pre-HPR windshields showed significantly higher 

laceration rates with adhesive bonding than with rubber gaskets.8

 At that time, there were 

insufficient crash cases of cars with HPR windshields to compare laceration rates with rubber 

gaskets vs. adhesive bonding. 

Effect on windshield bond separation in crashes NHTSA’s 1985 analysis uses data from the 

National Crash Severity Study (NCSS), a predecessor of NASS.9

 Investigators measured the 

percentage of bond separation and computed the Delta V in actual towaway crashes. Linear 

regression calibrated the average percentage of bond separation, as a function of Delta V, in 

frontal crashes, by windshield installation method. For example, in frontal crashes with Delta V 

= 30 mph, the average percentage of bond separation was: 

 Windshield Average Bond 

Country of Installation Pre or Post Separation at 

Manufacture Method FMVSS 212? ∆V 30 mph (%) 

United States rubber gasket pre 22 

 post 23 

 butyl tape pre 16 

 post 15 

 polyurethane post 14 

Germany rubber gasket pre 59 

 post 37 

In domestic cars, both types of adhesive bonding substantially reduced bond separation at 30 

mph, relative to rubber gaskets. Within each method, separation rates were about the same

before and after FMVSS 212. In German cars, the plastic clips added to the rubber gaskets in 

response to FMVSS 212 greatly reduced bond separation, although to a level that was still higher 

than pre-standard domestic cars. Similarly, at all other speeds, adhesive bonding reduced the 

percentage of bond separation in domestic cars, and the plastic clips reduced it in German cars. 

Effect on occupant ejection via the windshield portal Combining the 1977-79 NCSS with 

1968-78 Multidisciplinary Accident Investigations (MDAI) generates a large data file with 

information on the windshield installation method of each case vehicle. It specifies whether 

 

8

 Fargo, R.B., Windshield Glazing as an Injury Factor in Automobile Accidents, Cornell Aeronautical Laboratory, 

Buffalo, 1968. 9

 Kahane (1985 Windshields), pp. 143-154; Kahane, C.J., Smith, R.A. and Tharp, K.J., “The National Crash

Severity Study,” Report on the Sixth International Technical Conference on Experimental Safety Vehicles, NHTSA 

Report No. DOT HS 802 501, Washington, 1977, pp. 493-515. 

122
occupants were ejected and, if so, via what portal. The rate of ejection via the windshield portal 

per 100 crash-involved front-seat occupants was 68 percent lower in domestic cars with adhesive 

bonding than in domestic cars with rubber gaskets. However, after examining the rates of 

ejection via other portals, which also decreased to some extent in the later-model cars for reasons 

obviously unrelated to the windshield installation method, the evaluation concluded that, more 

realistically, a 50 percent reduction of ejection via the windshield portal could be attributed to 

adhesive bonding. Similarly, in German cars, the installation of plastic clips within the rubber 

gaskets reduced ejection via the windshield portal by an estimated 50 percent.10

Fatality reduction – passenger cars The great advantage of preventing ejection is that, all else 

being equal, an occupant is safer remaining inside the vehicle than being ejected from it. Yet, 

not every ejection prevented is a life saved. A portion of ejectees would have sustained fatal 

injuries from interior components even if they had stayed within the car. This is especially true 

of the windshield portal, where an estimated 70 percent of the fatally injured ejectees in the 

NCSS-MDAI data had already received mortal wounds from the steering assembly, instrument 

panel, windshield header and/or other components before the ejection, and would have died even 

if they had not been ejected. In other words, reducing ejection-fatality cases by 100 means 

saving 30 lives (the other 70 would still not survive). The 50 percent reduction of ejection 

attributed to adhesive bonding in domestic cars, and to plastic clips in German cars corresponds 

to saving 15 percent of the fatalities who were ejected via the windshield portal before these 

safety improvements. Using 1982 as the “baseline” year, the evaluation estimated that adhesive 

bonding would be saving 105 lives per year in domestic cars, and plastic clips, 7 lives per year in 

German cars by the time all cars built before these safety improvements had been phased out.11

Serious injury reduction – passenger cars Likewise, 30 percent of the people ejected via the 

windshield portal who survived, but sustained one or more serious, nonfatal AIS 3-5 injuries 

received all of these injuries after exiting the vehicle, while 70 percent suffered at least one such 

injury prior to the ejection. Thus, as above, a 50 percent reduction of ejection corresponds to a 

15 percent injury reduction. Again using 1982 as the “baseline” year, the evaluation estimated 

that adhesive bonding would eventually save 160 people from AIS 3-5 injury per year in 

domestic cars, and plastic clips, 11 AIS 3-5 casualties per year in German cars. 

Effect on lacerations – passenger cars As stated above, if adhesive-bonded windshields “give” 

less upon head impacts by occupants, facial lacerations could increase. Fargo’s 1968 study of 

pre-HPR windshields showed significantly higher laceration rates with adhesive bonding than 

with rubber gaskets and raised a worry this could persist with HPR windshields (1966 and later). 

NHTSA extensively analyzed crash data from NCSS, New York (1974) and Texas (1972-74) on 

cars equipped with HPR windshields. Cars with adhesive bonding and rubber gaskets had 

equally low rates of facial lacerations and other type of minor-moderate injuries involving 

windshield contact. Windshield penetration by occupant impact was no more common with 

adhesive bonding than with rubber gaskets. NHTSA concluded that adhesive bonding does not 

have any side effect of increasing minor-moderate injuries in cars with HPR windshields. 

Incidentally, the NHTSA analysis confirmed Fargo’s finding that adhesive bonding was 

 

10 Kahane (1985 Windshields), pp. 154-161. 11 Ibid., pp. 161-163, 179-182 and 236-243; 90% confidence bounds for life-saving effectiveness: 7 to 22 percent;

for lives saved in domestic cars: 35 to 175. 

123
associated with higher injury rates in cars with pre-HPR windshields, now long phased out 

except for occasional “historic” vehicles.12

Effectiveness – light trucks NHTSA’s 1985 evaluation only addressed the performance of 

windshield bonding in passenger cars. However, since the kinematics of occupant ejection via 

the windshield portal are presumably similar in cars and light trucks, the estimated reduction (50 

percent) for this type of ejection from cars is probably appropriate for light trucks as well. 

 

12 Ibid., pp. 185-220. 

124
FMVSS 213: Child restraint systems

FMVSS 225: Child restraint anchorage systems

These two standards work together as a single unit to protect child passengers. FMVSS 213 

regulates child safety seats, safety equipment that is not part of the vehicle. FMVSS 225 

regulates vehicles, specifically the anchors whereby safety seats are secured in the vehicle. 

FMVSS 213 took effect on April 1, 1971, but FMVSS 225 did not begin to phase in until 

September 1, 1999. Three technologies to advance child passenger safety have been evaluated, 

or will be evaluated by NHTSA. A fourth “technology” that has always been available – riding 

in the back seat – is not related to any particular FMVSS but will be discussed here because it 

has important benefits for child passengers: 

• Child safety seats

• Upper tethers and anchorages (not yet evaluated)

• LATCH (lower anchors and tethers for children – not yet evaluated)

• Riding in the back seat

Child safety seats are the basic protection system for passengers who are too small to obtain full 

benefits from safety belts. Newborns start with rear-facing infant seats, graduate to forwardfacing toddler seats, booster seats and, finally, safety belts. Child seats have typically been 

secured in a vehicle at one place, by a lap belt; upper tethers secure them at a second place, 

significantly reducing the tendency of seats to move or rotate in crashes. LATCH supersedes the 

vehicle’s lap belts as a method of securing the seat in the vehicle; the new method will be more 

effective, more convenient and harder to misuse. The back seat is intrinsically safer than the 

front seat, given equal safety equipment, because there are a lot more severe frontals than rear 

impacts, and it is safer to sit further away from the point of impact. 

FMVSS 213 “specifies requirements for child restraint systems ... to reduce the number of 

children killed or injured.” FMVSS 225 “establishes requirements for child restraint anchorage 

systems to ensure their proper location and strength for the effective securing of child restraints, 

to reduce the likelihood of the anchorage systems’ failure, and to increase the likelihood that 

child restraints are properly secured and thus more fully achieve their potential effectiveness.”1

Child safety seats

History Early child seats and car beds, dating back to 1933, were designed for comfortable 

transportation, not crash protection. The first safety seats include the Ford Astro-Guard (1965) 

and Tot-Guard (1967) and the GM “Love” infant and child seats (1970). NHTSA issued 

FMVSS 213, effective April 1, 1971, to establish performance criteria for any device marketed 

as a “safety car seat,” and to discourage the marketing of non-safety devices for use in vehicles. 

This version of FMVSS 213 required that safety seats be designed for attachment within a car by 

car’s safety belts, and it set limits for forward motion under a static load, but it did not include a 

dynamic test simulating a crash. By the mid-1970’s, frontal 30 mph sled testing by the 

Consumers Union and others demonstrated that some seats offered substantially less protection 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Parts 571.213 and

571.225.

125
than others. NHTSA revised FMVSS 213, effective January 1, 1981, incorporating the 30 mph 

test. The seat must remain structurally intact during the test, limit the forward motion of the 

dummy, and also limit the Head Injury Criterion (HIC) to 1000 and chest acceleration to 60 g’s 

on the 3-year-old dummy. Ever since the mid-1970’s, several manufacturers of juvenile 

equipment have offered a selection of crashworthy seats for children of various ages.2

How safety seats work The goal of safety seats is to provide small children with the same

protection, or better, that adults obtain from safety belts and the other safety equipment built into 

a vehicle. They are designed to keep children within the vehicle and close to their original 

seating position, prevent contacts with harmful interior surfaces or other occupants and provide 

“ride-down” by gradually decelerating the child as the vehicle deforms and absorbs energy. Key 

terminology is the “excursion” of the head and knee, the greatest distance that those parts of a 

dummy extend forward from the seatback at any time during the 30 mph test. Excursion is 

allowed by the looseness of the devices that secure the seat to the vehicle and the dummy within 

the seat, and by the tendency of seats to tilt or rotate during the test. Obviously, the less the 

excursion, the lower the probability of contacting any part of the vehicle interior. 

Rear-facing infant seats are recommended from birth until an infant reaches a manufacturerspecified weight, often 20 pounds (typically before the first birthday), sometimes higher. These 

infants are not yet sitting up. The safety seat is like a cushioned box that holds the infant in a 

semi-recumbent position, with the head higher than the torso and legs. Since the seat faces 

rearwards, the infant’s entire body presses into the cushion during a frontal crash, and rides down 

with the vehicle. That is the safest way to absorb the infant’s kinetic energy, since force is not 

concentrated on one part of the body. It minimizes the risk of neck injury, to which infants are 

especially vulnerable. In side impacts, the infant presses against cushions on the side of the seat. 

A small harness keeps the infant within the seat in rollovers, rear impacts or multiple impacts. 

The vehicle’s lap belt secures the safety seat to the vehicle. A rear-facing seat must never be 

exposed to a deploying air bag, because the front of the seat is directly in the path of the 

deploying air bag. Infants must ride in the back seat, or if that is impossible but the vehicle has 

an on-off switch for the air bag, that switch must be turned off. 

Forward-facing child seats are recommended for a manufacturer-specified range of weights, 

often 20-40 pounds (typically ages 1-4). The safety seat is like an armchair. The child sits up in 

it; the child’s head and torso are protected in back and, to some extent, on each side by the seat’s

shell and cushion; the child’s legs hang down over the edge of the seat. Typically a 5-point 

harness, fitting over both shoulders, hips and abdomen, restrains the child in rollovers, frontals 

and side impacts, without concentrating force on one part of the body. Some place a cushioned 

 

2

 Radovich, V.G., “Development of Infant and Child Restraint Regulations and Their Application,” SAE Child

Injury and Restraint Conference Proceedings, Paper No. 831655, Society of Automotive Engineers Publication No. 

P-135, Warrendale, PA, 1983, pp. 101-111; Kahane, C.J., An Evaluation of Child Passenger Safety: The 

Effectiveness and Benefits of Safety Seats, NHTSA Technical Report No. DOT HS 806 890, Washington, 1986, pp. 

2-4; Federal Register 35 (September 23, 1970): 14778, 44 (December 13, 1979): 72131; Consumer Reports, Vol. 

37, August 1972, p. 484. 

126
shield in front of the child in addition to the harness, or sometimes instead of the harness. The 

back of the seat and its cushion protect the child from whiplash in rear impacts.3

Until August 31, 2002, the vehicle’s lap belt secured the safety seat to the vehicle. Belts were 

routed through the frame of the child seat, as specified by the manufacturer, or less frequently 

around the seat and the child. Beginning September 1, 2002, seats must have lower tethers for 

use in new vehicles equipped with LATCH anchorages, but must also be securable by lap belts 

in older vehicles. Starting September 1, 1999, all seats have to be equipped with upper tethers 

for an additional attachment to the vehicle. Before that, some seats were equipped with upper 

tethers on a voluntary basis dating back to 1970. The advantage of the upper tether is that it 

reduces the tilting or rotation of the seat during a crash, because it is firmly attached to the 

vehicle at the top as well as the bottom. 

Effective January 1, 1981, FMVSS 213 limited forward head excursion to 32 inches and knee 

excursion to 36 inches on the 30 mph frontal test, measured from the seatback pivot point. 

Those levels are sufficient to prevent contact with interior surfaces in an average-sized passenger 

car. Upper tethers improve performance: as of September 1, 1999, FMVSS 213 has further 

limited head excursion to 720 mm (28.35 inches), providing an additional margin of safety. 

FMVSS 213 also sets numerous other requirements for seats, including a limit of 1000 HIC and 

60 chest g’s on the 3-year-old dummy and maintenance of structural integrity in the 30 mph test, 

clear labeling of instructions it their use, convenient seat registration, and harness buckles that 

are convenient for adults but cannot be opened by small children.4

Convertible seats can be used in a rear-facing mode for an infant, and then tilted 90 degrees to 

become a forward-facing seat when the infant “graduates” to that type of seat. The floor of the 

infant seat becomes the back of the child seat, while the front of the infant seat becomes the 

bench of the child seat. 

Booster seats are recommended for a manufacturer-specified range of weights, often 40-80 

pounds (typically ages 4-8), or until a child is 4’9’’ tall. Booster seats essentially raise the child 

up high enough that the vehicle’s manual 3-point belt fits over one shoulder and diagonally 

across the thorax, as it would for an adult. The lap portion of the 3-point belt should fit snugly 

around the hips. When the 3-point belt is thus correctly positioned, it should provide similar 

benefits for these children as for adults. Some booster seats also have their own shields or 5-

point harnesses for use by children at the lower end of the weight range. Some booster seats 

have their own seatbacks, while others use the vehicle’s seatback.5

Safety seat use trends In 1979, NHTSA’s first national survey indicated that 45 percent of 

infants under age 1 and 9 percent of toddlers age 1-4 rode in some kind of child “seat.” Half of 

these “seats” were not secured by the car’s belt, hardly protecting the child (many of them were 

 

3 NHTSA Child Seat Safety Information, NHTSA, Washington, 2004 

(http://www.nhtsa.dot.gov/people/injury/childps/csr2001/csrhtml/safetyFeatures.html#forward); Kahane (1986), pp. 

19-26. 4 Code of Federal Regulations, Part 571.213 S5.1.3. and Figure 1B; the seatback pivot point is at the lower-rear edge

of the seatback; Kahane (1986), p. 3. 5 A Parent’s Guide to Booster Seats, NHTSA Publication No. DOT HS 808 671, Washington, 1998; Buying a Safer 

Car for Child Passengers 2003, NHTSA Publication No. DOT HS 809 545, Washington, 2003. 

127
probably not safety seats designed to FMVSS 213). However, Tennessee had recently become

the first State with a child passenger protection law, effective January 1, 1978. Rhode Island 

followed in 1980, West Virginia in 1981 and ten States in 1982. By June 1, 1985, every State 

and the District of Columbia had a law to protect child passengers. In NHTSA’s 19-City Study, 

safety seat use rose quickly during the 1980’s, exceeding 80 percent for infants and toddlers by 

the end of the decade. By 2002, NOPUS showed that 99 percent of infants and 94 percent of 

toddlers age 1-4 were in some kind of restraint (not necessarily age-appropriate or correctly 

used). Many of the laws initially allowed children to “graduate” too early from safety seats to 

the vehicle’s belts, but as of 2003, 44 States require children to be in a safety seat at least up to 

their fourth birthday.6

Safety seat misuse For full benefits, safety seats need to be installed correctly in the vehicle and 

children properly harnessed within the seat. Misuse is a potential problem because there are 

many styles of seats, and the mode of use can also vary by the age of the child, the type of

vehicle, or even by seat position within the same vehicle. NHTSA’s evaluation of child 

passenger safety reviewed 957 observations during 1984 of children age 0-4 riding in safety 

seats:

7

• 40 percent of the seats were correctly used, exactly as recommended by the manufacturer 

or very close to that. 

• 18 percent were “grossly” misused: the seat was not secured to the vehicle by a belt 

and/or the seat’s harness or shield was not used. In a crash, the child would immediately 

become a projectile and derive little or no protection from the seat. 

 

6

 Lawless, E.W. and Siani, T.A., “The State of the Art of Child Passenger Safety Legislation in North America,” 

SAE Child Injury and Restraint Conference Proceedings, Paper No. 831650, Society of Automotive Engineers 

Publication No. P-135, Warrendale, PA, 1983, pp. 229-242; Kahane (1986), pp. 4-5; Phillips, B.M., Safety Belt 

Usage Among Drivers, NHTSA Report No. DOT HS 805 398, Washington, 1980; Phillips, B.M., Restraint System

Usage in the Traffic Population, NHTSA Report No. DOT HS 806 424, Washington, 1983; Perkins, D.D., Cynecki,

M.J. and Goryl, M.E., Restraint System Usage in the Traffic Population, NHTSA Report No. DOT HS 806 582,

Washington, 1984; Goryl, M.E. and Cynecki, M.J., Restraint System Usage in the Traffic Population, NHTSA

Report No. DOT HS 806 714, Washington, 1985; Goryl, M.E., Restraint System Usage in the Traffic Population, 

NHTSA Report No. DOT HS 806 987, Washington, 1986; Goryl, M.E. and Bowman, B.L., Restraint System Usage 

in the Traffic Population, NHTSA Report No. DOT HS 807 080, Washington, 1987; Bowman, B.L. and Rounds, 

D.A., Restraint System Usage in the Traffic Population 1987 Annual Report, NHTSA Report No. DOT HS 807 342,

Washington, 1988; Bowman, B.L. and Rounds, D.A., Restraint System Usage in the Traffic Population 1988 Annual

Report, NHTSA Report No. DOT HS 807 447, Washington, 1989; Datta, T.K. and Guzek, P., Restraint System Use 

in 19 U.S. Cities 1989 Annual Report, NHTSA Report No. DOT HS 807 595, Washington, 1990; Datta, T.K. and 

Guzek, P., Restraint System Use in 19 U.S. Cities 1990 Annual Report, NHTSA Report No. DOT HS 808 147, 

Washington, 1991; Datta, T.K. and Guzek, P., Restraint System Use in 19 U.S. Cities 1991 Annual Report, NHTSA 

Report No. DOT HS 808 148, Washington, 1992; National Occupant Protection Use Survey: Controlled 

Intersection Study, NHTSA NCSA Research Note, Washington, 1995; National Occupant Protection Use Survey – 

1996: Controlled Intersection Study, NHTSA NCSA Research Note, Washington, 1997; Traffic Safety Facts 1999 –

Children, NHTSA Publication No. DOT HS 809 087, Washington, 2000, p. 5; Glassbrenner, D., The Use of Child

Restraints in 2002, NHTSA Research Note No. DOT HS 809 555, Washington, 2003; Child Restraint Laws,

Insurance Institute for Highway Safety, Arlington, VA, 2004

(http://www.hwysafety.org/safety%5Ffacts/state%5Flaws/restrain2.htm). 7

 Kahane (1986), pp. 30-47, especially p. 45. 

128
• 42 percent were “partially” misused, substantively differing from the method 

recommended by the manufacturer. Depending on the type of misuse, effectiveness 

could be slightly or seriously degraded. Typical misuse modes include: 

o Incorrectly routing the lap belt through/around the frame, where the frame is 

weaker or where it will allow more excursion. 

o Using a seat in the forward facing mode for an infant who should be in a rearfacing seat, or vice-versa. 

o Not attaching the upper tether, if one is available. 

NHTSA, other government and private organizations and the safety-seat manufacturers have 

made an effort to design seats that are easy to install and use correctly, to provide clear 

instructions that are prominently displayed on the seat, and to establish a national network of 

instructors who can advise people about the type of seat they need for their child and their 

vehicle, and show them how to install it correctly. The public may find an instruction station 

close to their home at http://www.nhtsa.dot.gov/CPS/CPSFitting/Index.cfm. 

A 1997 survey of 2,965 safety seats in actual use showed that gross misuse of seats had greatly 

decreased since 1984, but misuse of safety seats remained a problem. Approximately 2 percent 

were not secured by the vehicle’s belt and 3.3 percent did not have the safety seat’s harness 

connected (a big reduction from 18 percent gross misuse in the earlier survey). Misrouting of the 

vehicle’s belt, once quite common, had decreased to about 3 percent. On the other hand, 24 

percent of infant seats were used in a forward facing mode. Locking clips, a separate device 

employed in some vehicles to better secure lap-shoulder belts, were not used in over 60 percent 

of the vehicles where they were needed. Also common were improper use or fit of the vehicle’s 

belts or the seat’s harness.8

Expected benefits Correctly used safety seats ought to have the same types of benefits that 

safety belts have for adults, and probably more so, because they can do a better job preventing 

contacts with the vehicle interior, and because their typically 5-point harnesses will more evenly 

spread forces than a lap-shoulder belt. Persistent misuse of safety seats, however, is likely to 

diminish “as used” effectiveness – i.e., if the restrained population includes the actual mix of 

correctly used and misused seats, effectiveness will be lower than for the population consisting 

exclusively of children who are correctly restrained. “As used” effectiveness can increase over 

time if the proportion of correctly used seats increases. 

Fatality reduction – passenger cars In 1984, at about the same time that Evans developed a 

method to estimate belt effectiveness and called it “double-pair comparison analysis,” Partyka at 

NHTSA independently developed essentially the same method to estimate safety seat

effectiveness. NHTSA expanded and updated the analysis in its 1986 evaluation, in 1988, and 

finally in 1996. The last study provides NHTSA’s current estimates of the “as used” fatality 

reduction by child safety seats. It is based on 1988-94 FARS data. The analysis of safety seats 

resembles the procedures used to estimate the effectiveness of safety belts, especially back-seat 

safety belts (see the FMVSS 208 chapter). For example, in cars with unrestrained drivers, the 

fatality ratio of unrestrained children to their drivers is compared to the fatality ratio of children 

 

8

 Decina, L.E. and Knoebel, K.Y., “Child Safety Seat Misuse Patterns in Four States,” Accident Analysis and

Prevention, Vol. 29, January 1997, pp. 125-132.

129
in safety seats to their drivers. “Safety seat users” include those that FARS reported in “child 

safety seats” or “child safety seats used improperly.” Since the percentage of seats “used 

improperly” is far lower in FARS than in observational surveys, a substantial but unknown 

percentage of the children that FARS merely reported “in safety seats” were also in improperly 

used seats. Thus, the two groups have been combined to provide an overall, “as used” 

effectiveness estimate. For infants less than 1 year old, safety seats reduced overall fatality risk 

by a statistically significant 71 percent. For toddlers age 1-4, the seats reduced fatality risk by a 

statistically significant 54 percent.9

 

The preceding “as used” estimates include misused seats. In 1983, the Tennessee Highway 

Patrol estimated that correctly used safety seats could reduce fatality risk by 71 percent, an 

estimate widely quoted in the literature. It is not based on statistical analysis of fatalities to 

restrained vs. unrestrained children, but on a detailed case-by-case analysis of 51 unrestrained 

fatalities, judging what would have happened if the children had been protected by safety seats. 

However, it continues to appear plausible, especially given that the preceding “as used” 

estimates including misused seats are not much lower.10

Over the years, a moderate proportion of toddlers age 1-4, especially at the higher ages have only 

been restrained by the vehicle’s belts, not by a safety seat. The restraint is essentially a lap belt 

only, for even if the seat is equipped with a 3-point belt, the shoulder harness will not fit across 

the torso of a child that small, and it will offer little protection. NHTSA urges that children 

under 4’9’’, and especially in the 1-4 age group not be restrained with belts alone, but with a 

FMVSS 213 seat appropriate to their weight. Nevertheless, belts have some benefits for children 

age 1-4. NHTSA’s 1986 evaluation, based on double-pair comparison analysis of 1975-84 

FARS data, estimates that lap belts reduce fatality risk by 33 percent. That is substantially lower 

than the 54 percent “as used” effectiveness of the actual mix of correctly used and misused safety 

seats, let alone the effectiveness of correctly used safety seats. It is about the same as the 

effectiveness of lap belts for adults (27 percent in the front seat and 32 percent in the back seat – 

see the FMVSS 208 chapter).11

Fatality reduction – light trucks NHTSA’s 1996 study also showed statistically significant 

fatality reductions for child safety seats in LTVs. For infants less than 1 year old, safety seats 

reduced overall fatality risk by 58 percent. For toddlers age 1-4, the reduction was 59 percent. 

The study showed a 48 percent fatality reduction by lap belts for toddlers age 1-4. This is the 

same as the estimated effectiveness of lap belts for adults in the front seat.12 

 

9

 Partyka, S.C., Restraint Use and Fatality Risk for Infants and Toddlers, NHTSA National Center for Statistics and

Analysis, Washington, 1984; Kahane (1986), pp. 140-163; Partyka, S.C., Lives Saved by Child Restraints from 1982 

through 1987, NHTSA Technical Report No. DOT HS 807 371, Washington, 1988; Hertz, E.C., Revised Estimates 

of Child Restraint Effectiveness, NHTSA NCSA Research Note, Washington, 1996 (this is a summary report that 

does not show the detailed analyses, but they are set up the same way as in Partyka’s 1988 report). 10 51 Young Lives, HSL Report No. DOT HS 034 896, Tennessee Highway Patrol, Nashville, 1983; Kahane (1986),

pp. 96-99; National Child Passenger Safety Week: One-Minute Child Safety Seat Facts,

http://www.nhtsa.dot.gov/people/outreach/safesobr/OPlanner/ncpsw/kidseat3.html. 11 Kahane (1986), pp. 161-164; these data are entirely before 1986, when State buckle-up laws began to bias belt use 

reporting on FARS. 12 Hertz (1996).

130
Injury reduction – passenger cars NHTSA’s 1986 evaluation furnished three sets of estimates 

of injury reduction by safety seats in passenger cars. In a file that combined all available detailed 

investigations of crashes selected by probability sampling – the 1974-75 RSEP, the 1977-79 

NCSS, the 1979 pilot test of NASS at the NCSS sites, and the 1979-83 NASS – the rate of fatal 

or hospitalizing injuries per 100 children age 0-5 involved in towaway crashes was 56 percent 

lower for children in safety seats than for unrestrained children. The reduction was statistically 

significant. However, it is an overestimate of the overall “as used” effectiveness, because these 

investigators classified children in grossly misused seats as “unrestrained.” If they had been 

classified as safety seat users, injury reduction would have been an estimated 46 percent in 

1984.13

An analysis of 1981-83 Pennsylvania crashes computed injury rates per 100 children, adjusting 

for the child’s age and seat position. Compared to unrestrained children, safety seats reduced 

fatal-and-serious (K + A) injury risk by 43 percent, moderate-to-fatal (K + A + B) injury risk by 

45 percent, and overall (K + A + B + C) injury risk by 31 percent. Here, too, many children in 

grossly misused seats may have been classified as “unrestrained.” The 1986 report concludes 

that K + A + B injury reduction would have been closer to 37 percent if they had all been 

classified as safety seat users.14 

As part of the 1986 evaluation, NHTSA conducted 36 frontal or oblique-frontal sled tests, each 

with 3 or 4 3-year-old dummies, at speeds ranging from 11 to 35 mph. Dummies were 

unrestrained, or in safety seats of four different types – correctly used, grossly misused, or in 

various modes of partial misuse. NHTSA calibrated the probability of hospitalizing head or 

torso injury as a function of speed for the unrestrained dummy – and various seat types/use 

modes. A mathematical model computed overall effectiveness from the calibrated relationships. 

Correctly used, the various types of safety seats reduced the risk of hospitalizing injuries in 

frontal crashes by an average of 61 percent, relative to the unrestrained dummy. The average 

effectiveness of the partially misused seats was 38 percent. Not surprisingly, the dummies in 

grossly misused seats had the same injury risk as unrestrained dummies. When correct use, 

partial misuse and gross misuse were weighted by their frequency of occurrence in the 

observational survey, the average “as used” effectiveness of safety seats in frontal crashes was 

40 percent.15

Injury reduction – light trucks NHTSA has not estimated the injury reduction by safety seats 

for children who are occupants of LTVs. 

Upper tethers and anchorages

LATCH (lower anchors and tethers for children)

On March 5, 1999, NHTSA published a Final Rule amending FMVSS 213 to require safety seats 

to have upper and lower tethers, and establishing FMVSS 225 to require motor vehicles to have 

anchorages for attaching the tethers. On child safety seats (except certain types), upper tethers 

 

13 Kahane (1986), pp. xxxiv and 201-214. 14 Ibid., pp. xxxiv and 169-184; rates were adjusted for age and seat position by multidimensional contingency table 

analysis. 

15 Ibid., pp. 235-305, especially p. 301. 

131
were required on September 1, 1999 and lower tethers on September 1, 2002. In motor vehicles, 

the phase-in of upper tether anchorages extended from September 1, 1999 to September 1, 2000, 

and the lower anchorages from September 1, 2000 to September 1, 2002. The upper anchorages 

are required at all positions on the rear-most forward-facing row of seats (i.e., the back seat of a 

car, but the third seat of most minivans), and the lower anchorages at two of those positions. The 

objectives of the regulation are to secure seats more tightly in the vehicle, make their installation 

easier and more uniform, and reduce the probability of misuse.16

Safety seats with upper tethers have been available dating back to 1970. Upper tethers reduce 

the tilting or rotation of the seat during a crash, because they provide a second attachment of the 

seat to the vehicle (in addition to the lap belt or lower tethers). Sled testing shows unequivocally 

that tethered seats, when correctly used, have less head excursion than other types. However, 

observational surveys showed that most seats did not have tethers, and among those that did, 

only 15 percent of tethers were attached in 1984, in part because many vehicles did not have 

tether anchorages. The new regulation guarantees that every seat will have this performanceenhancing feature, and every vehicle will have a method of attaching it.17 

The method of securing a seat by the vehicle’s safety belts can vary considerably from seat to 

seat and from vehicle to vehicle, creating opportunities for misuse. The fit of the belts is often 

loose, especially when, more often than not, a locking clip needed to prevent spooling of the belt 

is not used. LATCH will establish a more uniform attachment system that does not rely on the 

safety belt. 

NHTSA will conduct an observational survey to find out if consumers are using upper tethers 

and LATCH system to install child safety seats, if they are easy to install, and the percentage that 

are being installed correctly. Subsequently, the agency will analyze crash data to see if upper 

tethers and LATCH have made safety seats more effective.18 

Safety benefits of riding in the back seat 

Why the back seat is safer The closer the occupant sits to the point of impact, the greater the 

risk of fatal injury. That is because fatal crashes often result in severe damage, but rarely to the 

entire vehicle. They can demolish the portion of the passenger compartment closest to the 

impact, while the furthest portion remains nearly intact. A frontal impact is twice as dangerous 

for front-seat occupants as back-seat occupants, whereas a rear impact is twice as dangerous for 

 

16 Federal Register 64 (March 5, 1999): 10786; Code of Federal Regulations, Title 49, Parts 571.213 S5.9 and 

571.225 S4. 17 Bayer, A.R., Jr. and Peterson, B.S., Child Restraint Systems Testing, NHTSA Report No. DOT HS 803 408,

Washington, 1978; Kelleher, B.J. and Walsh, M.J., “Sled Test Comparisons of Child Restraint Performance,”

Twenty-Second Stapp Car Crash Conference, Paper No. 780903, Society of Automotive Engineers, Warrendale, PA, 

1978; Kelleher, B.J., Walsh, M.J , Dance, D.M. and Gardner, W.T., “An Experimental Study of the Effects of Child

Restraint Improper Installation and Crash Protection for Larger Size Children,” SAE Child Injury and Restraint 

Conference Proceedings, Paper No. 831602, Society of Automotive Engineers Publication No. P-135, Warrendale, 

PA, 1983, pp. 31-51; Radovich, op. cit.; Kahane (1986), pp. xliv, 30-47 and 106-134. 18 National Highway Traffic Safety Administration Evaluation Program Plan, Calendar Years 2004-2007, NHTSA

Report No. DOT HS 809 699, Washington, 2004, pp. 9-10. 

132
the back-seat occupants.19 But this is not a trade-off. High-speed frontal impacts are far more 

common than high-speed rear impacts, resulting in greater overall fatality risk to front-seat 

occupants: 

• Collisions with fixed objects are frontal, unless the vehicle has yawed out of control, and 

even then they are rarely rear impacts. 

• When two vehicles collide, usually at least one of them, and sometimes both have frontal 

damage, but rear-to-rear collisions are rare. 

• Head-on collisions often involve a dangerous closing speed because the two vehicles are 

moving in opposite directions; rear impacts are often of low severity because both 

vehicles are moving in the same direction. 

A second advantage for the unrestrained back-seat occupant in a frontal crash is that he or she 

will contact the back of the front seat, a more benign surface than the steering assembly, 

instrument panel, or windshield header contacted by the unrestrained front-seat occupant. This 

advantage may be lost if both occupants are correctly restrained. Nevertheless, a back-seat 

occupant, restrained or unrestrained, ought to have lower fatality risk than a front-seat occupant 

with the same safety equipment. For many years, however, the front-seat has been the first place 

to get new safety equipment (3-point belts), and sometimes the only place (air bags). 

Fatality reduction Evans demonstrated that unrestrained drivers and adult right-front passengers 

of passenger cars have almost exactly the same fatality risk in a crash. In other words, in crashes 

where both seats were occupied by people of the same age and gender, the ratio of driver to RF 

fatalities was 1:1. But back-seat outboard occupants have 26 percent lower fatality risk than 

drivers and RF passengers of the same age and gender. Back-seat center occupants have 37 

percent lower fatality risk than drivers and RF passengers: the rear-center seat is the safest place 

in a car, because it is far away from the sides as well as the front of the car. These are the results 

for unrestrained occupants of passenger cars without air bags, age 16 and older.20

Children, too, are substantially safer in the back seat. In NHTSA’s 1986 evaluation, double-pair 

comparison analyses of 1975-84 FARS data showed that an unrestrained child age 0-4 had 27 

percent lower fatality risk in the back seat than in the front seat. For a child in a safety seat, the 

fatality risk was 20 percent lower in the back seat than in the front seat.21

These benefits have persisted in vehicles without air bags. Three NHTSA publications in 1996-

97 cite an analysis of 1988-94 FARS data showing that both restrained children and unrestrained 

children experienced a 26 [or 27] percent reduction in fatality risk in the back seat relative to the 

front seat.22 

 

19 Evans, L., Traffic Safety and the Driver, Van Nostrand Reinhold, New York, 1991, pp. 47-51. 20 Ibid. 21 Kahane (1986), pp. xxxiv and 164-167; in the double-pair comparison, the fatality ratio of children to their drivers 

is compared for children in the front seat and children in the back seat. 22 Hertz (1996); Federal Register 62 (November 21, 1997): 62406, Footnote 23; Air Bags & On-Off Switches, 

NHTSA Publication No. DOT HS 808 629, Washington, 1997; the supporting analysis is not available, and it is 

unknown if it included children age 0-4 or 0-12, or if it was limited to passenger cars or included LTVs. 

133
The following analysis of MY 1981-95 passenger cars without air bags in 1991-99 FARS data 

supplies more detailed results. Children of all ages and adolescents, restrained as well as 

unrestrained, obtained a substantial benefit for riding in a rear-outboard seat rather than the rightfront seat, and an even larger fatality reduction if they traveled in the rear-center seat. 

Specifically, children age 0-12, both restrained and unrestrained, experienced statistically 

significant fatality reductions close to 30 percent for moving from the front-right seat to a rear 

outboard seat, and close to 45 percent for moving from the front-right seat to the rear-center seat: 

CARS WITHOUT Fatality Reduction Relative to Right-Front Seat (%) 

AIR BAGS 

Rear-Outboard Seat Rear-Center Seat 

Age Group Restrained Unrestrained Restrained Unrestrained 

 0 – 4 36 26 46 29 

5 – 12 29 36 47 59 

0 – 12 33 31 46 47 

13 – 15 11 30 49 44 

Air bags have made it much more important for children to ride in the back seat, less so for 

adolescents and adults. The benefits of air bags for right front passengers age 13 and older have 

narrowed the difference between the front and back seats for those groups. But children are 

much safer in the back seat, without air bags, than in the front seat of a car with air bags. For 

example, air bags with 1990’s technology were estimated to increase the fatality risk of an infant 

RF passenger in a rear-facing safety seat by a factor of approximately 51⁄2 (see the FMVSS 208 

chapter). Thus, the fatality reduction for moving that infant to the back seat is not merely 36-46 

percent, as shown in the above table, but close to 90 percent. Similarly, these air bags may have 

increased the fatality risk of a toddler in a forward-facing safety seat by approximately 70 

percent; that toddler will be 62 percent safer in a rear-outboard seat, and 68 percent safer in the 

rear-center seat than in the right-front seat.23

More children are riding in the back seat Since the mid-1990’s, NHTSA, the manufacturers 

and the safety community have campaigned to inform the public about the hazard of air bags to 

children and the need for children to ride in the back seat of vehicles with air bags. Moreover, 

the campaigns make it clear that the back seat is the safest place for a child in all vehicles, 

including those without air bags.24

 

23 For example, if the fatality risk of an infant in the RF seat of a car without air bags is 1, the risk with air bags is 

5.5; the risk in the rear-center seat is 1 - .46 = .54; the reduction is 1 - .54/5.5 = 90 percent. 24 Air Bag & Seat Belt Safety Campaign, Air Bag & Seat Belt Safety Tips, National Safety Council, Chicago,

November 17-30, 2003, http://www.nsc.org/partners/safetips.htm; Air Bags & On-Off Switches, op. cit.; Buckle-Up 

America Child Passenger Safety Week, February 10-16, 2002, Talking Points, NHTSA, 

http://www.nhtsa.dot.gov/people/injury/airbags/buckleplan/CPS%20Week%20Planner_files/talking1.html.

134
The public has responded. Substantially fewer children age 0-7 rode in the front seat in 2001 

than in 1995. NHTSA analyzed State crash data from Florida, Maryland and Utah for 1995-

2001. The distribution of seat positions of the 363,579 child passengers in these mostly lowseverity crashes is probably about the same as in the general, non-crash-involved traffic stream. 

In 2001, only 8 percent of 0-3 year old infants and toddlers still rode in the front seat, down from 

26 percent in 1995, and the proportion of 4-7 year old children in the front seat decreased to 19 

percent from 33 percent. However, the proportion of 8-12 year old children in the front seat only 

declined to 35 percent from 39 percent.25

When a child is the only passenger in the vehicle, the driver may be reluctant to have the child 

ride alone in the back seat. But even here, there were dramatic changes between 1995 and 2001 

for children age 7 or younger (but not for 8-12 year olds). Fewer children are riding in the front 

seat, not only in vehicles with passenger air bags, but even in vehicles without air bags: 

Vehicles with Only One Passenger, a Child Age 0-12 

Percent in Front Seat 

Age 0-3 Age 4-7 Age 8-12 

All vehicles 

1995 52 78 88 

2001 17 43 79 

Vehicles with 

 dual air bags 1995 49 75 88 

2001 14 36 76 

Vehicles without 

 air bags 1995 52 78 88 

2001 22 54 84 

 

25 Kindelberger, J. and Starnes, M., Moving Children from the Front Seat to the Back Seat: The Influence of Child 

Safety Campaigns, NHTSA Research Note No. DOT HS 809 698, Washington, 2003. 

135
FMVSS 214: Side impact protection 

This standard is associated with two vehicle modifications whose safety benefits have been 

evaluated by NHTSA and two recent innovations that the agency is just beginning to evaluate: 

• Side door beams

• Voluntary (pre-1994) TTI(d) improvements in 2-door cars

• Side impact protection, dynamic test standard, passenger cars (not yet evaluated)

• Side air bags (not yet evaluated)

Before 1969, the side doors of passenger cars were nearly empty shells of sheet metal, and 

offered little protection to occupants in side impacts. Side door beams, running longitudinally 

inside the door, were a first step to provide some crush resistance and structural strength, but 

they were not enough to resist a high-speed impact by another vehicle. NHTSA, the 

manufacturers and the safety community researched additional structural improvements to resist 

crush and padding to cushion the occupant. They developed a dynamic crash test, a dummy, and 

an injury criterion TTI(d) to measure how well a vehicle protects its occupants. Side air bags 

provide additional cushioning for the occupant and they improve TTI(d) performance. 

The second paragraph of FMVSS 214 says, “The purpose of this standard is to reduce the risk of 

serious and fatal injury ... in side impact crashes by specifying vehicle crashworthiness 

requirements in terms of accelerations measured on anthropomorphic dummies in test crashes 

[and] by specifying strength requirements for side doors.”1

 That’s exactly what it has done, but 

in reverse chronological order. First, FMVSS 214 set strength requirements for doors, effective 

January 1, 1973 in passenger cars and extended to pickup trucks, vans, buses and SUVs up to 

10,000 pounds GVWR, effective September 1, 1993. Subsequently, it added a dynamic crash 

test requirement, phased in for passenger cars from September 1, 1993 to September 1, 1996, and 

effective for LTVs up to 6,000 pounds GVWR on September 1, 1998. 

Side door beams

History During the 1960’s, the manufacturers conducted research and tests to improve side 

impact protection. Hedeen and Campbell at GM developed side door beams, and the company 

also developed a static test for measuring a door’s crush resistance. The beams were installed in 

MY 1969 full-size GM cars. The test procedure became Society of Automotive Engineers’ 

Recommended Practice J367 in March 1970, but it did not specify pass-fail criteria. NHTSA 

announced its intention to regulate side door strength with an ANPRM in October 1968, 

followed by several NPRMs. The Final Rule issued in October 1970, with an effective date of 

January 1, 1973, built upon the SAE practice and added pass-fail criteria. A rigid steel cylinder 

is gradually forced into the middle of the door, its top nearly level with the bottom of the 

window. The cylinder must encounter an average crush resistance of at least 2,250 pounds 

during the first 6 inches of crush, an average of 3,500 pounds over the first 12 inches, and a peak 

of at least 7,000 pounds or twice the vehicle’s curb weight (whichever is less) somewhere in the 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.214. 

136
first 18 inches. Most domestic cars were equipped with the beams at some point during MY 

1969-73 and, of course, all cars had them after January 1, 1973 (mid-MY 1973).2

LTVs, with their higher sills and more rigid construction, are more robust than cars when they 

are hit in the side by another vehicle, but they share cars’ vulnerability in side impacts with fixed 

objects. As part of its effort to bring safety requirements for LTVs up to the same level as cars, 

NHTSA extended the static strength test of FMVSS 214 to LTVs, effective September 1, 1993. 

Most LTVs received side door beams in MY 1994, but a few make-models in MY 1991, 1992 or 

1993.3

What they are and how they work The side door beam “is a metal bar of channel design, 

typically 8 inches wide and with channels 2 inches deep. It is located inside [each side] door, 

close to the outside surface, about 10 inches above the sill. It runs the length of the door, being 

attached to the door frame vertical members at the hinge and latch ends of the door. ... In some

vehicles, the beam is accompanied by a beam cover, stiffener, ... mounting flanges ... [and/or] a 

local reinforcement of the B pillar at the floor level.”4

 “Channel design” resembles fluting or 

corduroy, running from the front to the rear of the beam, and it is a feature that adds strength to 

metal structures. In MY 1979-81, the weight of the beams ranged from 5 to 7 pounds per door in 

4-door cars, and 10 to 21 pounds per door in 2-door cars.5

In a direct side impact by another vehicle, the front of that vehicle will push the door structure 

inwards until it hits the occupant’s torso at close to that vehicle’s original impact speed. Injury 

risk is high. Therefore, any structure that engages the striking vehicle is welcome. By putting 

some crush on the front of the striking vehicle and/or transmitting force to the remainder of the 

struck vehicle and accelerating it sideways, the structure can reduce the amount of intrusion 

toward the occupant and slow down the rate of that intrusion. 

Whereas any added strength is welcome, it is obvious that a 5-21 pound beam, stretching from

one end of the door to the other without much support in the middle, has limited power to resist a 

severe and perpendicular impact into the middle of the door by a 2,000-5,000 pound vehicle. 

The 10-inch gap between the beam and the sill is an additional weak point. The beams might be 

somewhat effective in lower-speed impacts. NHTSA’s 1982 evaluation found that side door 

beams reduced the depth of maximum crush from an average of 10 inches to 8 in compartmentcentered towaway impacts by another vehicle.6

 

2

 Kahane, C.J., An Evaluation of Side Structure Improvements in Response to Federal Motor Vehicle Safety

Standard 214, NHTSA Technical Report No. DOT HS 806 314, Washington, 1982, pp. 100-108; Hedeen, C.E. and 

Campbell, D.D., Side Impact Structures, Paper No. 690003, Society of Automotive Engineers, New York, 1969; 

Federal Register 33 (October 5, 1968): 14971, 33 (December 11, 1968): 18386, 35 (January 21, 1970): 813, 35 

(April 23, 1970): 6513, 35 (October 30, 1970): 16801; 1971 SAE Handbook, Society of Automotive Engineers, New 

York, 1971, pp. 962-963. 3

 Walz, M.C., Evaluation of FMVSS 214 Side Impact Protection for Light Trucks: Crush Resistance Requirements

for Side Doors, NHTSA Technical Report No. DOT HS 809 719, Washington, 2004; Federal Register 56 (June 14, 

1991): 27427. 4

 Kahane (1982 FMVSS 214), p. 106. 5 Ibid., p. 380. 6 Ibid., p. 301.

137
The beam ought to be considerably more effective when the impact has a strongly frontal 

component of force, especially in typical side impacts with fixed objects where a vehicle is 

traveling forward and skidding off the road at the same time. The side of the vehicle contacts the 

pole or tree, but the direction of force is oblique frontal. Rather than merely absorbing energy, 

the beam acts like an internal “guard rail” to deflect the vehicle and allow it to slide past the pole 

or tree, with a longer, shallower crush pattern and, ultimately, a lower Delta V. Furthermore, the 

simultaneous contact of the fixed object with the high beam and the low sill, rather than just the 

sill, keeps the vehicle upright and reduces the risk of damage to the “greenhouse” area of the 

occupant compartment. Indeed, NHTSA’s 1982 evaluation showed that side door beams 

significantly changed damage patterns in side impacts with fixed objects. The ratio of the 

maximum depth of crush to the width of crush decreased from .24 to .15. There was less damage 

to the occupant compartment and more to the fenders. There was less greenhouse damage. 

Integrity of the side doors was better preserved.7

Expected benefits Given the effects of side door beams on damage patterns and severity, it will 

not be a surprise if beams are found to reduce fatalities in single-vehicle crashes, but not in 

multivehicle crashes. They may reduce nonfatal injuries in the less severe multivehicle crashes. 

Since the beams affect the overall damage pattern to the vehicle in single-vehicle crashes, and 

help reduce the severity of the crash, they may benefit the farside as well as the nearside 

occupants. Because there is a beam in every side door on a vehicle, drivers, front-seat 

passengers and back-seat passengers can benefit. 

Fatality reduction – passenger cars NHTSA’s analysis, published in 1982, was based on 1975-

81 FARS data.8

 These data are best suited for comparing overall fatality risk of occupants of 

outboard seats (i.e., next to a door: drivers; right-front, left-rear and right-rear passengers) in side 

impacts, before and after the installation of side door beams, relative to a control group of 

fatalities in frontal impacts. In one analysis, the data encompassed cars of the first 2 model years 

with beams (e.g., 1969-70 Chevrolet Impala, 1973-74 Chevrolet Nova) vs. cars of the same or 

equivalent make-models in the last two model years before beams (e.g., 1967-68 Chevrolet 

Impala, 1971-72 Chevrolet Nova). Frontal crashes are an acceptable control group because there 

were few innovations that affect fatality risk in frontal during those model years; specifically, 

every car in the analysis was equipped with energy-absorbing steering assemblies. The 1975-81 

FARS statistics for fatalities in single-vehicle crashes were9

: 

SINGLE-VEHICLE Frontal Side Impact 

CRASHES Fatalities Fatalities 

Last 2 MY before beams 4,325 2,505 

First 2 MY with beams 4,303 2,137 

 

7 Ibid., pp. 33-43 and 281-329. 8 Ibid., pp. 22-25 and 143-182. 9 Ibid., p. 157.

138
This is a statistically significant 14 percent fatality reduction in single-vehicle side impacts with 

side door beams: 1 – [(2,137/2,505) / (4,303/4,325)] = .143.10

Analyses by other techniques confirmed the 14 percent fatality reduction.11 Effectiveness was 

nearly identical in nearside impacts (14 percent) and farside impacts (15 percent). When “singlevehicle side impacts” were limited to collisions with a single fixed object (and impacts by trains, 

rollovers with principally side damage and complex off-road excursions were excluded), 

effectiveness rose to 23 percent.12

Using 1980 as the “baseline” year, the evaluation estimated that side door beams would 

eventually save 480 lives per year in single-vehicle crashes of passenger cars, when all cars on 

the road were equipped with them. When NHTSA added the dynamic crash test for FMVSS 

214, the agency retained the static test requirement, in part, to assure that the benefits of side 

door beams in single-vehicle crashes would be preserved.13

By contrast, none of the analyses showed a statistically significant effect for side door beams on 

fatalities in multivehicle crashes. Point estimates were close to zero. 

Fatality reduction – light trucks Similar analyses were performed with 1989-2001 FARS data 

to estimate the effect of side door beams in light trucks, where they were introduced in MY 1994 

or shortly before that. In single-vehicle side impacts, side door beams reduced fatality risk by a 

statistically significant 19 percent. The reduction was larger in nearside impacts (25 percent) 

than in farside impacts (11 percent). Using 1999-2002 as the “baseline” years, the evaluation 

estimated that side door beams would eventually save 151 lives per year in single-vehicle side 

impacts of LTVs, when all LTVs on the road have the beams.14

This evaluation, too, did not show a statistically significant effect for side door beams on 

fatalities in multivehicle crashes. Point estimates by all analysis methods were close to zero. 

Injury reduction – passenger cars NHTSA’s 1982 evaluation used data from the National 

Crash Severity Study (NCSS), the predecessor of NASS. The injury rate – the number of fatal or 

hospitalizing injuries per 100 occupants involved in side-impact towaway crashes – was 

computed for cars with side door beams and compared to the rate in cars without the beams. 

These injury rates were controlled for belt use, rural/urban, speed limit, frame or unibody 

construction, or other factors by multidimensional contingency table analysis, a predecessor of 

the logistic regression method widely used today. Also, in some analyses, the data were limited 

to cars produced 2 (or 5) model years just before and after the make-model was equipped with 

the beams.15

 

10 90% confidence bounds: 7 to 21 percent. 11 Other techniques included: limiting the data to the first year with beams and the last year without them; regression

of the ratio of side to frontal fatalities by beam status, vehicle age and other factors. 12 Ibid., pp. 157 and 354. 13 Ibid., pp. 385-388; 90% confidence bounds: 300-660. 14 Walz (2004); 95% confidence bounds for effectiveness: 4 to 32 percent; for lives saved per year: 22-285. 15 Kahane (1982 FMVSS 214), pp. 183-266; Kahane, C.J., Smith, R.A. and Tharp, K.J., “The National Crash

Severity Study,” Report on the Sixth International Technical Conference on Experimental Safety Vehicles, NHTSA 

Report No. DOT HS 802 501, Washington, 1977, pp. 493-515. 

139
In single-vehicle side impact crashes, the analyses showed a statistically significant 25 percent 

reduction of fatal or hospitalizing injuries for side door beams.16 

At the nonfatal level, beams were also effective in some multivehicle crashes. When a vehicle 

was struck in the side by another vehicle and the damage was centered in the occupant 

compartment area, side door beams reduced nearside occupants’ rate of hospitalizing injuries by 

a statistically significant 25 percent. But for farside occupants in all multivehicle crashes, and 

for nearside occupants when the damage was not centered on the compartment, the effect of side 

door beams was close to zero.17

Using 1980 as the “baseline” year, the evaluation estimated that side door beams would prevent 

4,550 nonfatal hospitalizations per year in single-vehicle crashes and 4,920 in multivehicle 

crashes when all cars on the road are equipped with the beams. That adds up to 9,470 nonfatal 

hospitalizations prevented per year.18

Injury reduction – light trucks NHTSA has not analyzed the effect of side door beams on 

nonfatal injuries in LTVs. 

Voluntary (pre-1994) TTI(d) improvements in 2-door cars

History of the FMVSS 214 upgrade By the late 1970’s, if not earlier, researchers suspected that 

side door beams alone were insufficient to significantly attenuate intrusion in a severe side 

impact by another vehicle and reduce fatality risk to the nearside occupant of the struck car. At a 

public Side Impact Conference on January 31, 1980, NHTSA outlined its plans to upgrade 

FMVSS 214 with a dynamic test.19

Unlike the early FMVSS that largely incorporated other organizations’ test procedures and 

existing safety technologies, the FMVSS 214 upgrade necessitated many years of research, 

analysis and testing by NHTSA and the safety community to develop comprehensive and selfsufficient science:20

• A review of crash data indicated that a typical side impact fatality involved a fast-moving 

vehicle striking a slow-moving car in the door, at a right angle – e.g., at an intersection. 

• Injury data indicated that nearside occupants’ life-threatening injuries often involved 

contact between the sides of their torsos and the interior side surface (most frequently the 

door) of the car. 

• The Thoracic Trauma Index (TTI) was found to be an excellent predictor of thoracic 

injury severity in experimental impacts to cadavers. TTI = 1⁄2 (GR + GLS), where GR is the 

 

16 Kahane (1982 FMVSS 214), pp. 12 and 25-33; 90% confidence bounds: 11 to 35 percent. 17 Ibid., pp. 10, 12, 25-33 and 186; 90% confidence bounds: 6 to 38 percent; damage to the side of a car is “centered 

on the compartment” if the centerpoint of the damage (CRASH program parameter D) is in a range from 15 inches

behind to 45 inches ahead of the longitudinal centerpoint of the car. 18 Ibid., pp. 15, and 388-397; 90% confidence bounds: 4,300 to 14,700 hospitalizations prevented. 19 Side Impact Conference, NHTSA Report No. DOT HS 805 614, Washington, 1980. 20 Kahane, C.J., Evaluation of FMVSS 214 - Side Impact Protection: Dynamic Performance Requirement; Phase 1:

Correlation of TTI(d) with Fatality Risk in Actual Side Impact Collisions of Model Year 1981-1993 Passenger Cars,

NHTSA Technical Report No. DOT HS 809 004, Washington, 1999, pp. 1-4. 

140
greater of the peak accelerations of either the upper or the lower rib, expressed in g’s and 

GLS is the lower spine (T12 vertebra) peak acceleration. Pelvic g’s are an additional 

injury criterion. 

• A Side Impact Dummy (SID) was developed that reliably registered TTI and pelvic g’s in 

side impact tests. The injury score measured on the dummy is called TTI(d). 

• A Moving Deformable Barrier (MDB) was developed to represent a generic 3000-pound 

passenger vehicle. The test procedure simulates an MDB moving 30 mph hitting, at a 

right angle, the door area of a subject vehicle, traveling 15 mph. (It is accomplished by 

having the MDB travel at 33.5 mph at an angle of 63 degrees with the longitudinal 

centerline of a stationary test vehicle. The wheels of the MDB are “crabbed” 27 degrees 

toward the rear of the test vehicle to obtain a right-angle contact.) 

• The baseline distribution of TTI(d) was learned by testing of a variety of production MY 

1980-88 passenger cars, and monitored by testing other cars up to MY 1993, just before 

the phase-in period for the new FMVSS 214. 

• Two technologies were demonstrated that, singly or in combination could significantly 

reduce TTI(d) from its baseline levels in production vehicles: 

o Structure modifications such as substantially strengthening pillars, sills, roof rails, 

seats or cross-members of a car, and stronger overlap between doors and pillars, sills, 

etc., to slow down and reduce the extent of door intrusion into the passenger 

compartment. 

o Padding capable of absorbing significant energy at a force-deflection rate safe for 

occupants. It is thick plastic foam - not a soft pad. 

• Regulatory analysis estimated the lives saved by reducing TTI(d) to various levels and 

the extent of vehicle modifications needed to secure those levels – and, finally – 

• NHTSA promulgated the new FMVSS 214 in 1990, allowing TTI(d) up to 90 in 2-door 

cars and up to 85 in 4-door cars, with phase-in scheduled for MY 1994-97.21

Voluntary improvements before model year 1994 The 1980-93 development of FMVSS 214 

was an iterative process with feedback between NHTSA and the manufacturers, and extensive 

public participation. Manufacturers could test TTI(d) in their existing vehicles and compare it to 

levels proposed for FMVSS 214 or achieved by competitors in tests by public organizations. 

TTI(d) in 2-door cars averaged 110 for those MY 1981-90 cars that were tested and the results 

made public, and it ranged as high as 131. Manufacturers had voluntarily improved that to an 

average 97 by MY 1993, the year before the phase-in for FMVSS 214 – much closer to the 90 

allowed by the future standard. The best score among the pre-standard 2-door cars was 82. 

There was relatively less improvement in 4-door cars: from 80 in 1981-90 to 74 in 1993; 

furthermore, even the earlier average is better than the 85 eventually permitted by the future 

standard. Two-door cars are intrinsically more vulnerable than 4-door cars in side impacts, 

because the door of a 2-door car is usually much longer than the front door of a 4-door car. 

Impacting vehicles are less likely to strike pillar(s), more likely to hit the long, weakly supported 

door area between pillars. In any case, manufacturers took steps to redesign some of the worst 

performers, especially among 2-door cars, before FMVSS 214 took effect. For example, one 

 

21 Federal Register 55 (October 30, 1990): 45752.

141
manufacturer ran a cross member across the A-pillars through the dash, reinforced the B-pillar at 

the sill level and added some floor stiffeners.22

Fatality reduction NHTSA’s 1999 evaluation used a cross-sectional approach, rather than 

“before-after” analysis, to estimate the benefit of TTI(d) improvements. It compared the sideimpact fatality risk of cars with good TTI(d) scores to cars with poor scores. NHTSA has TTI(d) 

scores, from the test configuration subsequently used in FMVSS 214, for 43 pre-standard (MY 

1980-92) make-model-model year combinations, 17 2-door and 26 4-door. The evaluation 

gathered 1980-98 FARS cases of front-outboard occupant fatalities in each of these 43 makemodel-MY combinations, including cars from earlier/later model years and corporate “twins” of 

essentially identical design. “Side-impact fatality risk” is the ratio of occupant fatalities in side 

impact crashes (where the principal impact is at a 2-4:00 or 8-10:00 location) to fatalities in 

purely frontal crashes (where the principal impact is at a 12:00 location and the most harmful 

event is not a subsequent rollover). Purely frontal crashes are an acceptable control group 

because cars of the 1980’s did not substantially change their technologies for occupant protection 

in frontal crashes (cars with air bags or automatic belts were excluded from the analysis). The 

data file comprised 10,983 cases of occupant fatalities in side impacts and 12,019 in frontals.23 

 

Separate analyses were performed for the 2-door cars and the 4-door cars. Analysis techniques 

included: 

• Correlation of TTI(d) with side-impact fatality risk across the various make-model-MY 

groups.24

• Comparing the fatality risk of the cars with the best TTI(d) scores to the cars with the 

poorest scores.25

• Logistic regression of the probability that a fatality is in a side impact (and not in a 

frontal), as a function of TTI(d), curb weight, driver age and other variables.26

In the 2-door cars, all three analysis methods showed significantly lower fatality risk in the cars 

with lower TTI(d) scores. For example, cars with TTI(d) > 115 had more fatalities in side 

impacts than in pure frontals, whereas cars with TTI(d) < 102 had substantially fewer27: 

 

22 Kahane (1999), pp. vii, 6 and 19-23. 23 Ibid., pp. 11-18 and 24-31. 

24 Ibid., pp. 31-45. 25 Ibid., pp. 47-71. 26 Ibid., pp. 73-103. 27 Ibid., p. 51.

142
2-DOOR CARS Purely Frontal Side Impact 

 Fatalities Fatalities

Models with TTI > 115 (average = 123) 760 812 

Models with TTI < 102 (average = 94) 654 528 

This is a statistically significant 24 percent reduction of side impact fatalities with lower TTI(d): 

1 – [(528/654) / (812/760)] = .244. More precisely, a logistic regression estimated that fatality 

risk was reduced by a statistically significant 0.927 percent per unit reduction of TTI(d). Thus, 

the reduction from the 1981-90 “baseline average” TTI(d) of 110 to the “pre-standard bestpractices” score of 82 corresponds to a 23 percent reduction in the risk of side-impact fatalities. 

Importantly, unlike the preceding results on side door beams, this reduction is not limited to 

single-vehicle crashes, but is about equally large in multivehicle and single-vehicle crashes. In 

fact, the highest effect, a 39 percent reduction, was observed for nearside occupants of 2-door 

cars that were hit in the side by another passenger car.28

Corresponding analyses of 4-door cars, however, did not show statistically significant 

relationships between TTI(d) and side-impact fatality risk. Unlike the 2-door cars, a large 

portion of the crash data involved cars with TTI(d) scores clustered in a relatively narrow range 

from 78 to 94, making it statistically more difficult to find correlations between TTI(d) and risk. 

Direct comparisons of the fatality risk in 4-door cars with the best and worst TTI(d) scores 

(analogous to the preceding table for 2-door cars) showed 5-15 percent fatality reductions for the 

cars with the better scores, but these reductions were not statistically significant.29 

Side impact protection, dynamic test standard, passenger cars 

On October 39, 1990, NHTSA issued the Final Rule amending FMVSS 214 to phase in a 

dynamic test of side impact protection. It required at least 10 percent of passenger cars produced 

between September 1, 1993 and August 31, 1994 to meet the standard; at least 25 percent of cars 

produced between September 1, 1994 and August 31, 1995; at least 40 percent of cars between 

September 1, 1995 and August 31, 1996; and all cars after September 1, 1996. Effective 

September 1, 1998, LTVs up to 6,000 pounds GVWR were also required to meet the dynamic 

test. The upgraded FMVSS 214 aims especially to reduce fatal thoracic injuries when a car is 

struck in the side by another vehicle. The preceding section describes the rationale, development 

and requirements of the dynamic test.30 

Recognizing the intrinsically greater vulnerability of 2-door cars, FMVSS 214 allows TTI(d) up 

to 90 in 2-door cars, but limits 4-door cars and LTVs to 85. In compliance or research tests of 

actual cars, TTI(d) improved from an average of 97 in 2-door cars of MY 1993, the last year 

before the phase-in, to 74 in MY 1997, the first year that all cars had to meet FMVSS 214. In 

 

28 Ibid., pp. viii, 84 and 91-100; 1 – (1 – .00927) 110 – 82 = 23 percent. 29 Ibid., pp. ix, 37-45, 63-71 and 85-87. 30 Federal Register 55 (October 30, 1990): 45752, 60 (July 28, 1995): 38749; manufacturers also had the option of

100 percent of their cars meeting the standard beginning on September 1, 1994 and no requirement before that date. 

143
other words, average performance improved from a score that would not have been permitted 

under FMVSS 214 to a score that was well within the limits of FMVSS 214. In 4-door cars, 

TTI(d) improved by a smaller amount, from an average of 74 in 1993 to 65 in 1997; both 

averages are within the limit of 85 permitted by the standard.31

As described above, structural modifications and padding are the principal technologies used to 

meet FMVSS 214. The manufacturers have provided NHTSA with detailed lists and diagrams

showing what changes were made to achieve compliance during the phase-in period. This 

information suggests that make-models accounting for approximately 56 percent of new cars 

received substantial structural modifications, usually accompanied with padding, during MY 

1994-97; 27 percent of the fleet received padding only, or padding with minor structural 

modifications; whereas 17 percent of cars remained essentially unchanged from previous years, 

implying that even the pre-1994 models of these cars could have met FMVSS 214. In addition, 

side air bags began to appear on some cars in MY 1996.32 

NHTSA’s 1999 evaluation report includes an analysis plan for FMVSS 214. The agency will 

estimate the change in side-impact fatality risk after FMVSS 214 vs. just before the standard: for 

all cars, by car type (2-door vs. 4-door), by type of vehicle modification (structure, padding, side 

air bags, combinations of these), and as a function of how much the test criterion TTI(d) was 

reduced when the standard was implemented in a make-model. This will be a high-priority 

evaluation for NHTSA.33

Side air bags 

During the 1990’s, manufacturers and suppliers developed side air bags that deploy from the seat 

or the door to provide an energy-absorbing cushion between the occupant’s torso and the 

vehicle’s side structure during lateral impacts. Volvo made them standard on all their MY 1996 

cars, while Audi, BMW and Cadillac began to offer them in 1997. By MY 2001, 22 percent of 

new cars and LTVs were equipped with side air bags. NHTSA believes they are a promising 

safety technology, as evidenced by substantial reductions in TTI(d). NHTSA’s annual Buying a 

Safer Car brochures inform the public what make-models are equipped with side air bags. This, 

too, will be a high-priority evaluation for NHTSA.34

 

31 Kahane (1999), pp. vii, 19-23 and 139; the peak lateral acceleration of the pelvis shall not exceed 130 g’s in any 

vehicle. 32 Ibid., pp. vii and 139-143. 33 Ibid., pp. 143-155; National Highway Traffic Safety Administration Evaluation Program Plan, Calendar Years

2004-2007, NHTSA Report No. DOT HS 809 699, Washington, 2004, p. 5. 34 Ibid., p. 223 shows TTI(d) reduced from 72 to 52 in one make-model; Buying a Safer Car 2000, NHTSA 

Publication No. DOT HS 809 046, Washington, 2000; Buying a Safer Car 2001, NHTSA Publication No. DOT HS

809 152, Washington, 2000; Buying a Safer Car 2002, NHTSA Publication No. DOT HS 809 409, Washington, 

2002; Buying a Safer Car 2003, NHTSA Publication No. DOT HS 809 546, Washington, 2003; NHTSA Evaluation 

Program Plan, CY 2004-2007, p. 13. 

144
FMVSS 216: Roof crush resistance

This standard is associated in the public mind with one vehicle modification whose safety 

benefits have been evaluated by NHTSA: 

• Redesign of true hardtops as pillared hardtops or sedans

In fact, FMVSS 216 is a performance standard limiting the amount of crush allowed when a 

static load is applied to the roof of a vehicle. The first paragraph of FMVSS 216 says, “The 

purpose of this standard is to reduce deaths and injuries due to the crushing of the roof into the 

occupant compartment in rollover crashes.”1

 FMVSS 216 took effect for passenger cars on 

September 1, 1973. It was extended to most pickup trucks, vans and SUVs up to 6,000 pounds 

GVWR, effective September 1, 1993.2

Most passenger cars built since September 1, 1973 have easily complied with FMVSS 216, and 

it is also believed most cars built before that date could have met the standard. It was primarily 

full-sized true hardtops of the late 1960’s and early 1970’s that had typically borderline or worse 

performance This body style was phased out – redesigned as a pillared hardtop or sedan – a few 

years before or after FMVSS 216 took effect. Although some true hardtops were built after 1973 

and did meet FMVSS 216, they were pretty much gone by the late 1970’s. NHTSA evaluated 

the safety benefits of the redesign, regardless of FMVSS 216’s role in motivating it. 

As for light trucks, NHTSA believes they met FMVSS 216 well before 1993, and that there were 

no substantial changes in roof design around that time. For that reason, NHTSA does not plan to 

evaluate FMVSS 216 for light trucks. 

Regulatory history In October 1967, almost six years before the eventual effective date of 

FMVSS 216, NHTSA issued an ANPRM broaching possible limits on the intrusion of a 

vehicle’s roof, front, side and rear structures into the passenger compartment during crashes. 

The roof intrusion portion of the ANPRM was a starting point for FMVSS 216. The industry 

developed a procedure for measuring static roof crush resistance, SAE Recommended Practice 

J374, dated December 1968, without defining specific pass-fail levels. Soon after, the new 

generation of hardtops with more vulnerable roof structures spurred NHTSA to issue FMVSS 

216, with a Notice of Proposed Rulemaking in January 1971, a Final Rule in December 1971 and 

an effective date of September 1, 1973. The FMVSS largely incorporates the J374 procedure 

and sets a 5-inch limit on crush given a load of 11⁄2 times the curb weight, or 5,000 pounds, 

whatever is less, applied to one of the sides of the roof, at the forward edge.3

A rather simple static test was preferred to a staged rollover crash because there was no

repeatable, standardized rollover test that would have worked for all make-models. However, 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.216. 2 Federal Register 36 (December 8, 1971): 23299, 56 (April 17, 1991): 15510. 3

 Kahane, C.J., An Evaluation of Door Locks and Roof Crush Resistance of Passenger Cars – Federal Motor

Vehicle Safety Standards 206 and 216, NHTSA Technical Report No. DOT HS 807 489, Washington, 1989, pp. 4-8;

Federal Register 32 (October 13, 1967): 14278, 36 (January 6, 1971): 166, 36 (December 8, 1971): 23299; 1973

SAE Handbook, Society of Automotive Engineers, New York, 1973, p. 1172. 

145
the application of the load in the static test to the front and side of the roof resembles many 

rollover crashes. A car is required to support 11⁄2 times its weight, rather than just its own 

weight, because rollovers involve an additional dynamic load when the car flips onto its top. 

However, cars weighing over 3,333 pounds need only support a 5,000 pound load, less than 11⁄2 

times their weight, and are essentially held to a less strict FMVSS 216 requirement, since they 

are much less rollover-prone than light cars. 

How it works One obvious danger in rollover crashes is that when a vehicle flips or bounces 

onto its roof, that impact could push the roof into the compartment far enough to contact and 

harm an occupant. However, it is uncertain what proportion of the fatalities in rollover crashes 

involved occupant contact with the roof and could have been avoided if the roof had not been 

crushed. For the unrestrained occupant, injuries from being ejected or tossed against interior 

surfaces are far more common, especially if the rollover is just one event in a sequence of 

impacts. In fact, some of the early research doubted that roof crush strength had any practical 

correlation with injury risk. Nevertheless, at least intuitively, a weak enough roof in a severe 

enough rollover is likely to collapse and harm occupants. In more recent years, when higher belt 

use has reduced the risk of ejection in rollovers, roof crush surely has become more important.4

The principal structures that resist roof crush are the roof itself, its side, front and back rails, and 

the two, three or four pillars on each side that hold it up. The A-pillars are on both sides of the 

windshield. In a sedan, the B-pillars are prominently visible between the front and back sidewindows; in a true hardtop, the B-pillar extends only from the floor to where the windows begin, 

and does not support the roof; in a “pillared hardtop,” the B-pillar extends fully to the roof, 

somewhat hidden in the metal between the front side-window and the “opera” window. The Cpillars are behind the rear side-windows. Station wagons also have D-pillars on both sides of the 

tailgate. 

Four design factors increase roof crush resistance. One, obviously, is thicker or stronger 

materials in the roof, rails or pillars. A second is to have as many pillars as possible, specifically 

a full B-pillar. A third is to build a smaller car, reducing the unsupported surface area of the roof 

and the distance between pillars. A fourth is to arch the roof and angle the pillars inward, an 

intrinsically better weight-bearing design. The last three factors are the exact opposite of the 

popular “look” in the late 1960’s and early 1970’s, featuring the largest cars ever, true hardtops 

with continuous glass along the side, and a “lower, longer, wider” profile with a wide, flat roof. 

It is not surprising that large hardtops of the 1968-75 era were, on the average, the worst 

performers on roof crush tests. The manufacturers phased out true hardtops, not all at once but 

year-by-year as they restyled their various model lines, either by redesigning them as pillared 

hardtops (e.g., Chevrolet Monte Carlo in 1973, Ford Mustang in 1974) or by completely 

dropping the hardtop option from their catalogs (e.g., Dodge Aspen in 1976, GM full-sized cars 

in 1977). By the later 1970’s, downsizing was in and the “lower, longer, wider” look was passé. 

 

4

 Kahane (1989 Door Locks/Roof Crush Resistance), pp. 32-36; Hight, P.V., Siegel, A.W. and Nahum, A.M., 

“Injury Mechanisms in Rollover Collisions,” Proceedings of Sixteenth Stapp Car Crash Conference, Society of 

Automotive Engineers, New York, 1972; Huelke, D.F., Marsh, J.C. IV and Sherman, H.W., “Analysis of Rollover

Accident Factors and Injury Causation,” Proceedings of the Sixteenth Conference of the American Association for

Automotive Medicine, American Association for Automotive Medicine, Morton Grove, IL, 1972; Huelke, D.F. and 

Compton, C., “Injury Frequency and Severity in Rollover Car Crashes as Related to Occupant Ejection, Contacts 

and Roof Damage,” Accident Analysis and Prevention, Vol. 15, October 1983. 

146
Expected benefits Improved roof crush resistance ought to reduce fatality risk in rollover 

crashes for occupants who were not ejected from the vehicle. It could benefit occupants at any 

seat position. 

Evaluation findings NHTSA’s study, published in 1989, includes roof crush testing by the 

FMVSS 216 procedure on cars built before and after the standard took effect; statistical analyses 

of average roof-crush depth in actual crashes; and statistical analyses of fatality risk for nonejected occupants in rollover crashes. The analyses compare true hardtops to cars with full Bpillars, taking into account vehicle size and before/after FMVSS 216. 

Roof-crush tests Compliance test results for 108 cars of model years 1974-85 were 

supplemented by running the FMVSS 216 test procedure on 14 pre-standard cars of model years 

1964-72, selected from make-models that matched 1974-75 compliance tests. Most cars passed 

easily: 80 percent of them had less than half the crush allowed by FMVSS 216. Larger cars had 

significantly greater roof crush than smaller cars. Full-sized and intermediate hardtops had 

significantly more crush than sedans of those sizes. The worst performers were full-sized 

hardtops of the 1968-75 era: 10 were tested, only 2 had less than half the crush allowed by 

FMVSS 216, and they accounted for 4 of the 6 worst scores among all the cars.5

Roof-crush depth in rollover crashes The 1982-86 NASS, the 1977-79 National Crash Severity 

Study6

 (NCSS), and 1968-78 Multidisciplinary Accident Investigations (MDAI) were combined 

with appropriate case weighting. They generated a file of roof-damage rollover crashes with 

information on roof crush (as measured by the extent zone in the Collision Deformation 

Classification7

) and the make-model and body style of each case vehicle. After adjusting for car 

size, the average extent of roof crush in cars with full B-pillars (sedans, coupes, pillared 

hardtops, hatchbacks, station wagons) changed very little between model years 1964 and 1982. 

Up until 1967, true hardtops had about the same roof crush as cars with full B-pillars. However, 

in 7 of the 8 model years between 1968 and 1975, the hardtops had more average crush than 

pillared cars of the same size – a statistically significant difference. After 1975, there are only a 

few true hardtops in the data.8

 

Fatality reduction NHTSA evaluated the risk of a non-ejection fatality in a rollover crash, based 

on logistic regression using 1975-86 FARS data. The ratio of non-ejection rollover fatalities to 

non-ejection frontal-fixed-object fatalities in model-year 1966-81 cars was calibrated by B-pillar 

status (true hardtop, full B-pillar), FMVSS 216 status (pre-1971, 1971-74 transition, post-1974), 

track width and curb weight. This ratio was a statistically significant 15 percent higher in true 

hardtops than in pillared cars of the same size, before 1976. In other words, phasing out the true 

hardtops has saved lives. The analysis showed little or no effect for FMVSS 216 in cars with full 

B-pillars – i.e., the safety benefit derived from phasing out true hardtops, not from any changes 

within the pillared cars. After controlling for car size, the average non-ejection rollover fatality 

 

5

 Kahane (1989 Door Locks/Roof Crush Resistance), pp. 39-69. 6

 Kahane, C.J., Smith, R.A. and Tharp, K.J., “The National Crash Severity Study,” Report on the Sixth International

Technical Conference on Experimental Safety Vehicles, NHTSA Report No. DOT HS 802 501, Washington, 1977, 

pp. 493-515. 7

 1985 SAE Handbook, Vol. 4, Society of Automotive Engineers, Warrendale, PA, 1985, Recommended Practice 

No. J224 MAR 80. 8

 Kahane (1989 Door Locks/Roof Crush Resistance), pp. 71-86. 

147
risk in cars of the late 1970’s, nearly all equipped with full B-pillars, was 7.4 percent lower than 

in cars of the early 1970’s, a near 50-50 mix of hardtops and sedans.9

 Using 1982 as the 

“baseline” year, the evaluation estimated the phasing out of true hardtops saved approximately 

110 lives per year.10

 

9

 Ibid., pp. 159-167. 10 Ibid., pp. 214-217. 

148
FMVSS 301: Fuel system integrity

FMVSS 301 is a performance standard that limits the amount of fuel allowed to spill from a 

vehicle after a crash test impact from any one of several directions, or during a static rollover 

test. The standard was substantially upgraded in 1975-77; that upgrade was accompanied by 

substantive vehicle modifications and it was evaluated by NHTSA: 

• 1975-77 upgrade: rollover, rear-impact and lateral-impact tests

The first paragraph of FMVSS 301 says, “The purpose of this standard is to reduce deaths and 

injuries occurring from fires that result from fuel spillage during and after motor vehicle 

crashes.”

1

 Approximately 29,000 cars and LTVs per year catch fire after being involved in a 

crash.2

 The 2001 FARS indicates that 1,447 occupants of these 29,000 cars and LTVs were 

fatally injured (not necessarily from burns, but possibly due to interior impacts, ejection, or other 

reasons). 

Regulatory history FMVSS 301 is one of NHTSA’s initial safety standards, with an effective 

date of January 1, 1968 for passenger cars. Originally, cars only had to pass a frontal impact test, 

into a rigid barrier at 30 mph. Fuel spillage after the impact is not allowed to exceed 1 ounce 

while the car is still in motion and 5 ounces during the first 5 minutes after the car comes to a 

stop. During the next 25 minutes, fuel spillage may not exceed 1 ounce during any 1-minute 

interval.3

Cost analyses by the agency did not show any substantive changes from model year 1967 to 

1968 needed to meet the original FMVSS 301.4

 Statistical analyses of post-crash fire rates did 

not show a significant difference between pre-1968 and MY 1968+ cars.5

 NHTSA believes that 

cars sold in the United States generally would have been capable of meeting the FMVSS 301 

frontal impact test for some years before the regulation was proposed or issued.6

During the 1970’s, FMVSS 301 was significantly upgraded over a three-year phase-in period. 

Effective September 1, 1975, passenger cars had to meet a static rollover test. Immediately after 

the frontal test, the damaged vehicle is slowly rotated 90 degrees, 180 degrees (upside-down) and 

270 degrees, holding at each of these positions for 5 minutes. Fuel spillage may not exceed 1 

ounce during any 1-minute interval in this process. 

 

1 Code of Federal Regulations, Title 49, Government Printing Office, Washington, 2002, Part 571.301. 2

 Parsons, G.G., Motor Vehicle Fires in Traffic Crashes and the Effects of the Fuel System Integrity Standard, 

NHTSA Technical Report No. DOT HS 807 675, Washington, 1990, pp. xvii and 3-25 – 3-28. 3 Ibid.; Federal Register 32 (February 3, 1967): 2414. 4

 McLean, R.F., Eckel, C. and Cowan, D., Cost Evaluation for Four Federal Motor Vehicle Standards, Volume I, 

NHTSA Report No. DOT HS 803 871, Washington, 1978, pp. 63-77. 5

 Reinfurt, D.W., A Statistical Evaluation of the Effectiveness of FMVSS 301: Fuel System Integrity, NHTSA Report 

No. DOT HS 805 969, Washington, 1981; Flora, J.D., Beitler, P., Bromberg, J., Goldstein, N., and O’Day, J., An 

Evaluation of FMVSS 301 – Fuel System Integrity, Report No. UM-HSRI-79-42, UMTRI, University of Michigan, 

Ann Arbor, 1979. 6

 Parsons, G.G., Evaluation of Federal Motor Vehicle Standard 301-75, Fuel System Integrity: Passenger Cars, 

NHTSA Technical Report No. DOT HS 806 335, Washington, 1983, p. 3.

149
Effective September 1, 1976, cars had to meet 30 mph frontal, oblique-frontal and rear-impact 

tests, plus a 20 mph lateral test, each followed by a static rollover test, with the same limits on 

fuel spillage as in the original frontal test. The rear and lateral impacts involve a 4,000-pound 

moving barrier striking a stationary vehicle. Rear and lateral impacts are, in a sense, more 

stringent tests than the frontal impact, because they come closer to the location of the fuel tank in 

most vehicles. LTVs with GVWR less than or equal to 6,000 pounds had to meet 30 mph frontal 

and rear-impact tests followed by static rollover. LTVs with GVWR 6,000-10,000 pounds 

(including small LTV-based school buses) had to meet the frontal test without static rollover. 

Effective September 1, 1977, all LTVs up to 10,000 pounds (including small school buses) had 

to meet the same requirements as passenger cars: frontal, oblique-frontal, rear and lateral tests 

with subsequent rollover. (Also, on April 1, 1977, the requirements were extended to large 

school buses with GVWR over 10,000 pounds, but excluding the subsequent rollover tests.)7

Vehicle modifications in the mid-1970’s The type and extent of modifications near the time of 

the 1975-77 upgrade varied greatly by make-model. Strategies used by the manufacturers 

include: 

• Strengthening the fuel tank or other components of the fuel delivery system. 

• Strengthening the structures that hold the fuel tank in place. 

• Shielding the fuel tank and delivery system from other parts of the vehicle. 

• Relocating parts of the fuel system further away from other parts of the vehicle or areas 

likely to be damaged during impacts. 

• Relocating other parts of the vehicle further away from the fuel system, or reshaping 

them to make them less likely to damage the fuel system.

8

Expected benefits Improved fuel system integrity ought to reduce the number of post-crash fires 

that are primarily sustained by fuel spillage. The measures used to improve fuel system integrity 

might not be effective in certain crashes that are far more severe than the levels tested in FMVSS 

301. Not all fatalities in vehicles with post-crash fires are due to the fire; occupants primarily 

injured by interior components, or due to ejection, could have had the same injury severity even 

without the fire. 

Post-crash fire reduction – passenger cars NHTSA’s evaluation, published in 1990, is based on 

1982-87 State crash data from Maryland, Michigan and Ohio. Crash-involved cars are grouped 

by model year and calendar year. The proportion of crashes accompanied by post-crash fires is 

analyzed by a linear regression, with FMVSS 301 (MY 1976+ = post-standard) and vehicle age 

as the dependent variables. (Fire rates increased strongly as cars aged, but the rates were 

uncorrelated with curb weight.) The analysis indicated that post-standard cars had 14 percent 

fewer fires than pre-standard cars, after controlling for vehicle age.9

 The reduction is statistically 

 

7 Parsons (1990), p. 1-3; Federal Register 39 (March 21, 1974): 10588, 39 (November 21, 1974): 40857, 40 (August 

6, 1975): 33036, 40 (October 10, 1975): 47790. 8 Ibid., pp. 4-11 – 4-22. 9

 95% confidence bounds: 7 to 21 percent 

150
significant. Using 1982-87 as the “baseline” years, the evaluation estimated that there would be 

3,900 fewer fires annually when the entire car fleet meets FMVSS 301.10

Post-crash fire reduction – light trucks A similar analysis was performed on the proportion of 

LTV crash involvements with fires (except that here MY 1977+ = post-standard). However, this 

analysis did not show a statistically significant reduction of post-crash fires with FMVSS 301.11

Fatality reduction – passenger cars A similar analysis was also performed on 1975-88 FARS 

data: a regression on the proportion of fatal crash involvements followed by fires. After 

controlling for vehicle age, the observed effect of FMVSS 301 was close to zero and not 

statistically significant. NHTSA was unable to conclude that FMVSS 301 has had any effect on 

fatal fires. Another analysis, based on direct comparison of the fire rates N model years before 

vs. after FMVSS 301, also showed little or no effect for FMVSS 301 after controlling for vehicle 

age.12 “No reduction in fire-related fatalities was found; the force levels encountered in fatal fire 

crashes may generally exceed the levels set by the Standard.”

13 That suggests the 14 percent 

overall reduction of fires, discussed above, happened primarily in the less severe, nonfatal 

crashes. 

The probability of fire increases with vehicle age. During 1975-88 people began to hold onto 

their vehicles longer and scrap them later. As the median age of vehicles increased, the number 

of fatal crash involvements followed by fires grew from 1,300 in 1975 to 1,800 in 1988.14

Fatality reduction – light trucks Similar analyses were performed on the proportion of fatal 

LTV crash involvements with fires (except that here MY 1977+ = post-standard). They did not 

show a statistically significant effect for FMVSS 301.15

Future FMVSS 301 upgrade On April 12, 1995 NHTSA issued an ANPRM to consider 

upgrading FMVSS 301, possibly including changes in the system performance tests, new tests of 

individual components, and criteria to address environmental and vehicle-aging effects on the 

integrity of the fuel system.

16 After reviewing the research and the public comments to the 

ANPRM, NHTSA issued, on November 6, 2000, an NPRM limiting, for now, the upgrade to 

more stringent rear- and lateral-impact test procedures for vehicles up to 10,000 pounds GVWR. 

The NPRM proposes to replace the current rear-impact test (30 mph by a 4,000-pound rigid 

barrier and 100 percent overlap) with a 50 mph impact by a 3,000-pound deformable barrier at 

70 percent overlap with the test vehicle. The lateral impact (currently 20 mph by a 4,000-pound 

rigid barrier) would be replaced by the FMVSS 214 test configuration: a 33.5 mph impact by a 

3,000-pound deformable barrier. For most vehicles, the new tests would be substantially more 

stringent. NHTSA concluded these changes would prevent fire-related fatalities and injuries.17

The Final Rule was issued on December 1, 2003. It phases in the new standard for 40 percent of 

 

10 Ibid., pp. xix, 2-1 – 2-33, and 4-2. 11 Ibid., pp. xx and 2-63 – 2-82. 12 Ibid., pp. xx and 2-53 – 2-62. 13 Ibid., p. xxiv. 14 Ibid., p. xviii. 15 Ibid., pp. xx and 2-91 – 2-98. 16 Federal Register 60 (April 12, 1995): 18566. 17 Federal Register 65 (November 13, 2000): 67693. 

151
cars and LTVs produced from September 1, 2006 to August 31, 2007; 70 percent of cars and 

LTVs produced from September 1, 2007 to August 31, 2008; and all cars and LTVs produced on 

or after September 1, 2008.18

 

18 Federal Register 68 (December 1, 2003): 67068 

152
NCAP: New Car Assessment Program

NHTSA’s New Car Assessment Program (NCAP) is not a regulation or a standard, but a 

program of testing the crashworthiness and crash avoidance capabilities of new cars and LTVs 

and publishing the results for the public. NCAP began in 1978 with frontal crash testing of MY 

1979 passenger cars. LTVs were first tested in MY 1983. NCAP expanded to side impact 

testing in MY 1997, and it began to provide information on the rollover resistance of vehicles in 

MY 2001. NCAP information, and any vehicle modifications in response to it, may be divided 

into four categories. So far, only the first has been evaluated by NHTSA: 

• Frontal NCAP-related improvements in cars without air bags 

• Frontal NCAP in vehicles with air bags (not yet evaluated)

• Side NCAP (not yet evaluated)

• Rollover-resistance NCAP (not yet evaluated)

NCAP’s frontal impact test is conducted at 35 mph. That is 5 mph faster than the test speed in 

FMVSS 204, 208, 212, 219 and 301, the NHTSA regulations that set basic performance 

requirements in frontal impacts. Similarly, NCAP’s side-impact test is 5 mph faster than the 

dynamic test in FMVSS 214. One purpose of NCAP, of course, is to enable consumers to 

compare the performance of different vehicles they might want to buy. In addition, NCAP 

specifies tests above and beyond the minimum requirements of the FMVSS. Manufacturers 

know what they are, and they have the option to design their vehicles for optimum performance 

in these tests. Even though NCAP has no “pass-fail” criteria, manufacturers have improved 

performance over the years by introducing, modifying or fine-tuning safety equipment. For 

example, voluntary introductions of technologies such as pretensioners and load-limiters for 

safety belts or side/head air bags (not required by any FMVSS as of October 2004) have 

improved performance on NCAP tests. When consumers and manufacturers respond to the 

information, the end result is a fleet of vehicles with better test performance. 

Frontal NCAP-related improvements in cars without air bags

NCAP history and procedure Title II of the Motor Vehicle Information and Cost Savings Act of 

1973 authorized NHTSA to develop consumer information on the crashworthiness of passenger 

vehicles. The agency developed a 35 mph frontal impact test into a rigid barrier with belted 

dummies at the driver’s and right-front seats. The test setup was essentially identical to the one 

used in NHTSA’s basic frontal crashworthiness standards, except 5 mph faster. The same injury 

criteria – originally the Head Injury Criterion (HIC), chest g’s and femur load – were measured 

on the dummies.1

In MY 1979, the first year of testing, fewer than 25 percent of the cars were able to meet the 

FMVSS 208 criteria (HIC < 1,000, chest g’s < 60 and femur load < 2,500 pounds on each leg) in 

the 35 mph test. (Of course, the only requirement of FMVSS 208 at that time was for vehicles 

with automatic occupant protection to meet those criteria at 30 mph.) By MY 1986-91, over 60 

percent of passenger cars met the FMVSS 208 criteria at 35 mph. Manufacturers had begun 

 

1 The Motor Vehicle Information and Cost Savings Act of 1973, Public Law 92-513, as amended, 15 United States 

Code 1912-2012. 

153
“designing to 35 mph” a large proportion of their vehicles. Specifically, during the first four 

years of NCAP, 1979-82, HIC averaged 1,052 and chest g’s 54.9. By MY 1983, modifications 

that improved NCAP performance had worked their way through the production cycle. In 1983-

86, average HIC had dropped to 915 and chest g’s even more so, to 46.8. In 1987-91 HIC 

continued to improve to 827, while chest g’s remained about the same, at 46.5.2

Vehicle modifications, and their purpose NHTSA’s films and other data from NCAP tests are 

public information. Manufacturers, if they chose, had the opportunity to study results of the 

initial NCAP tests of their MY 1979-81 cars. They could identify the contacts that were driving 

up HIC or chest g’s on the dummies and they could test out a variety of remedies by running 

their own 35 mph impacts. Subsequent modifications were not limited to a single, specific 

technology, but included adjusting the belt system, the steering assembly, the instrument panel 

and the seat structure, taking into account how belted dummies interacted with those systems in 

35 mph tests. For example, manufacturers: 

• Reduced spool-out of the safety belts in crashes. Excessive spool-out allowed head 

impacts with frontal components. Strategies to reduce spool-out included adding a weblocking mechanism, relocating the D-ring, modifying the retractor or shortening the belts. 

• Found ways to reduce upward movement of the steering assembly in crashes and keep it 

away from the driver’s head. 

• Reduced dashboard intrusion into the occupant compartment. 

• Stiffened the front seat cushion. 

• Realigned the seats relative to the steering assembly and instrument panel to provide 

additional ride-down space for occupants.3

 

Expected benefits Strategies to optimize the performance of belted dummies in 35 mph frontal 

barrier impacts are likely to have the largest benefits for belted occupants in frontal crashes, 

generally, and especially in frontal crashes that have velocity change somewhere near 35 mph 

(i.e., severe, but not extreme) and resemble an impact with a flat barrier (hitting a wide object or 

another vehicle, with plenty of overlap). 

Fatality reduction – passenger cars In 1994, NHTSA published a study of the Correlation of 

NCAP Performance with Fatality Risk in Actual Head-On Collisions. It was based on 1979-92 

FARS data, specifically head-on collisions of two MY 1979-91 passenger cars, each with a 

belted driver, resulting in a fatality to one or to both of the drivers. A head-on collision is a 

special type of highway crash ideally suited for studying frontal crashworthiness differences 

between two cars. Both cars are in essentially the same frontal collision. It doesn't matter if one 

of them had a "safe" driver and the other, an "unsafe" driver; at the moment they collide head-on, 

 

2

 Kahane, C.J., Correlation of NCAP Performance with Fatality Risk in Actual Head-On Collisions, NHTSA

Technical Report No. DOT HS 808 061, Washington, 1994, pp. 1-2. 3

 Hackney, J. and Quarles, V., “The New Car Assessment Program – Status and Effect,” Ninth International

Technical Conference on Experimental Safety Vehicles, NHTSA Report No. DOT HS 806 341, Washington, 1983, 

pp. 809-824; Hackney, J. and Ellison, C., “A Review of the Effects of Belts Systems, Steering Assemblies, and 

Structural Design on the Safety Performance of Vehicles in the New Car Assessment Program,” Tenth International 

Technical Conference on Experimental Safety Vehicles, NHTSA Report No. DOT HS 806 916, Washington, 1983, 

pp. 380-413. 

154
how safely they were driving before the crash is nearly irrelevant to what happens in the crash. 

Which driver dies and which survives depends primarily on the intrinsic relative crashworthiness 

of the two cars, their relative weights, and the age and gender of the two drivers (vulnerability to 

injury). 

If car 1 and car 2 weigh exactly the same, and both drivers are the same age and gender, the 

likelihood of a driver fatality in a head-on collision would be expected to be equal in car 1 and 

car 2. When vehicle weight or driver age/gender are not the same, the expected fatality risk for 

each driver was calibrated from the FARS data by a logistic regression. The expected fatality 

risk for driver 1 was 

 exp[.616 - 5.427(log W 1 - log W 2 ) + .0531(A 1 -A 2 ) + .34(F 1 -F 2 )] 

1 + exp[.616 - 5.427(log W 1 - log W 2 ) + .0531(A 1 -A 2 ) + .34(F 1 -F 2 )] 

where W 1 is the curb weight of car 1, A 1 is the age of driver 1 and F 1 is 1 if driver 1 was female, 

0 if male. The expected fatality risk for driver 2 was 

 exp[.616 + 5.427(log W 1 - log W 2 ) - .0531(A 1 -A 2 ) - .34(F 1 -F 2 )] 

1 + exp[.616 + 5.427(log W 1 - log W 2 ) - .0531(A 1 -A 2 ) - .34(F 1 -F 2 )] 

For example, given 100 fatal head-on collisions between 3000 pound cars driven by belted, 20-

year-old males and 2500 pound cars driven by belted, 50-year-old females, the formulas predict 

9 deaths among the young males in the heavier cars and 97 deaths among the older females in the 

lighter cars (for a total of 106 fatalities in the 100 collisions, since some of them resulted in 

fatalities to both drivers). 

Cars with average crashworthiness will experience an actual number of fatalities close to what is

predicted by the formulas. If a group of cars consistently experiences fewer driver fatalities than 

expected in their head-on collisions, then this group of cars is more crashworthy than the average 

car of similar mass. More generally, given a set of head-on collisions between one group of cars 

A and another group of cars B, it is possible to compare the crashworthiness of the two groups. 

For example, if the actual fatalities in the crashes and the sums of the expected probabilities of 

fatality (based on the formulas) are as follows: 

 Head-On Collisions between Groups A and B 

 Car Group A Car Group B 

Actual fatalities 60 100 

Expected fatalities 68 92 

Then the fatality reduction for Group A relative to Group B is 

1 - [ (60/68) / (100/92) ] = 18.8 percent 

Specifically, NHTSA’s evaluation compares actual and expected fatalities when Group A 

consists of cars with good scores on one or more NCAP parameters and Group B consists of cars 

155
with poor scores. For example, in 125 head-on collisions between cars with chest g’s ≤ 56 on the 

NCAP test (a group averaging 44.6 chest g’s on the test) and cars with chest g’s > 56 (averaging 

63.4 chest g’s), with both drivers belted, the actual number of driver fatalities relative to the 

expected was 18.7 percent lower in the cars with the good scores than in the cars with the poor 

scores. The evaluation also considered many other sets of head-on collisions between groups of 

make-models with good and poor NCAP scores, where “good” and “poor” were defined on the 

basis of a single injury criterion – HIC, chest g’s or femur load – or on various combinations of 

those criteria. Consistently, the actual fatality risk (relative to expected – i.e., after controlling 

for vehicle weight, driver age and gender) was significantly lower in the make-models the better 

NCAP scores.4

As stated above, the average NCAP performance of new cars improved substantially between 

MY 1979 and MY 1991, with the largest improvement coming around 1983-86. Therefore, we 

would expect a corresponding reduction over time of fatality risk in head-on collisions. Indeed, 

NHTSA’s evaluation showed that MY 1983-86 cars had a statistically significant 20 percent 

reduction of fatality risk, relative to MY 1979-82 cars, for belted drivers in car-to-car head-on 

collisions.5

 

NHTSA’s evaluation is based entirely on analyses of belted drivers in head-on crashes between 

two cars. The data were limited almost entirely to cars without air bags. It is unknown if the 20 

percent fatality reduction in these crashes would extend to other types of crashes. Quite 

probably, there would be a similar effect for belted drivers in frontal impacts with the side or rear 

of another passenger car (i.e., car-to-car, but not head-on). More tenuously, in frontal impacts 

with LTVs, heavy trucks or fixed objects, all of which are usually more rigid than cars. The 

results are least likely to extend to unbelted drivers, or any kind of non-frontal impacts. Also, 

these results for drivers of cars without air bags need not apply to passengers, or to drivers of 

cars with air bags. 

Frontal NCAP in vehicles with air bags 

The proportion of new vehicles equipped with air bags increased greatly from 1990 onwards. 

The relationship between NCAP scores and fatality risk in actual head-on collisions in vehicles 

with air bags may be different from the result found in NHTSA’s 1994 evaluation of MY 1979-

91 cars, mostly without air bags, described above. Other developments in frontal NCAP not 

considered in the 1994 evaluation include the extensive test results and crash data now available 

on LTVs, and the five-star rating system initiated in 1994 to make NCAP results more useful to 

the public. The agency is considering an updated evaluation of frontal NCAP, based on crash 

data involving head-on collisions of cars and LTVs equipped with driver or dual air bags, using 

the five-star rating system, among other criteria, to distinguish between “good” and “poor” 

NCAP performance.6

 

 

4

 Kahane (1994 NCAP), pp. 79-118. 5

 Ibid., 1994, pp. xvi and 129-142. 6

 Hackney, J.R. and Kahane, C.J., The New Car Assessment Program: Five Star Rating System and Vehicle Safety 

Performance Characteristics, Technical Paper No. 950888, Society of Automotive Engineers, Warrendale, PA, 

1995; New Car Assessment Program: Response to the NCAP FY 1992 Congressinal Requirements, Report to the 

Congress, NHTSA, Washington, 1993; National Highway Traffic Safety Administration Evaluation Program Plan, 

Calendar Years 2004-2007, NHTSA Report No. DOT HS 809 699, Washington, 2004, p. 26. 

156
Side NCAP

After September 1, 1996, when all cars were required to meet a dynamic side impact test as part 

of FMVSS 214, NHTSA also expanded NCAP to provide consumer information on vehicle 

performance in side impacts. The agency uses a five-star rating system for front-outboard and 

rear-outboard occupants. In the NCAP tests, the moving deformable barrier (MDB) strikes the 

side of the target vehicle at 38.5 mph, 5 mph faster than in the FMVSS 214 test. As part of its 

ongoing evaluation of side impact protection, NHTSA plans to study the correlation between test 

results on Side NCAP and fatality risk in actual side-impact crashes.7

Rollover-resistance NCAP 

In MY 2001, NHTSA expanded NCAP with ratings of one to five stars for rollover resistance, 

based on the Static Stability Factor. The SSF equals one half of the track width divided by the 

height of the center of gravity above the road. This measurement identified the location of the 

center of gravity of the vehicle and correlated this to the risk of a tripped rollover crash. Linear 

and logistic regressions were run in 2000, using MY 1994 to 1998 vehicles, to determine and 

verify the relationship between SSF and rollover rate. SSF has a remarkably strong relationship 

to the rate rollovers per 100 single vehicle crashes. NHTSA has planned an evaluation of the 

long-term trend of the SSF for various types of cars, pickup trucks, SUVs and vans. Starting 

with 2004 model year vehicles, NHTSA has issued rollover resistance star ratings that combine 

the SSF (based on measurements of stationary vehicles) and the tip or no-tip results of a new, 

dynamic maneuvering rollover test.8

 

7 NHTSA Evaluation Program Plan, Calendar Years 2004-2007, p. 5. 8 Federal Register 66 (January 12, 2001): 3388; NHTSA Evaluation Program Plan, Calendar Years 2004-2007, pp. 

14-15.

157
SUMMARY TABLES FOR PART 1

Tables 1-2, 1-3 and 1-4 summarize the effectiveness estimates for safety technologies obtained in 

past evaluation reports, as discussed in the preceding chapters of Part 1. Table 1-2 summarizes 

the estimated percentage reductions in fatalities; Table 1-3, nonfatal injuries; and Table 1-4, 

crashes (always specifying to what group of crashes/injuries/fatalities these percentages apply – 

but for more detail, refer back to the preceding chapters). The effectiveness estimates in Table 1-

2 are also used in this report’s model to assess lives saved by the FMVSS in 1960-2002. When 

NHTSA has evaluated a safety technology more than once (e.g., Center High Mounted Stop 

Lamps), the latest estimates are the ones shown in Tables 1-2, 1-3 and 1-4. 

Tables 1-3 and 1-4 also summarize the estimated annual benefits of nonfatal injury reduction and 

crash avoidance, as stated in NHTSA’s evaluation reports. However, those estimates of benefits, 

in general, are not directly comparable and do not add up to the overall crash avoidance and 

injury reduction by all the FMVSS in, say, 2002. NHTSA does not have enough “building 

blocks” to develop models for overall crash avoidance and injury reduction comparable to the 

analysis of fatal crashes in Part 2 of this report. 

158
TABLE 1-2: ESTIMATES OF FATALITY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY 

Vehicle Type Fatality-Reducing Effectiveness Estimate(s) 

105: Hydraulic brake systems 

Dual master cylinders 

Cars and LTVs 0.7 % reduction of all fatal crash involvements 

Front disc brakes 

Cars and LTVs 0.17 % reduction of all fatal crash involvements 

 Rear-wheel ABS 

LTVs No significant overall effect 

 4-wheel ABS 

Cars and LTVs No significant overall effect 

24 % reduction of multivehicle involvements on 

wet roads 

27 % reduction of collisions with non-occupants (in 

1989-93 only?) 

28 % increase in run-off-road crashes (in 1989-93

only?) 

Electronic stability control 

Cars 30 % reduction of single-vehicle run-off-road 

crashes (preliminary estimate) 

LTVs 63 % reduction of single-vehicle run-off-road 

crashes (preliminary estimate) 

108: Lamps, reflective devices 

Side marker lamps 

Cars and LTVs No significant effect 

Center High Mounted Stop Lamps 

Cars and LTVs No significant effect 

 Retroreflective tape 

Heavy trailers 29 % reduction of cars and LTVs hitting the side or 

rear of a heavy trailer in the dark 

159
 TABLE 1-2 (Continued): ESTIMATES OF FATALITY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY 

Vehicle Type Fatality-Reducing Effectiveness Estimate(s) 

201: Occupant protection in interior impact 

Voluntary mid and lower instrument panel improvements 

Cars and LTVs 15.9 % in frontal crashes, for unrestrained RF 

passengers 

202: Head restraints 

Head restraints for front seat 

Cars and LTVs No significant effect 

203: Impact protection from the steering control; 204: Steering control rearward displacement 

Energy-absorbing steering assemblies 

Cars and LTVs 12.1 % in frontal crashes, for drivers 

205: Glazing materials 

 HPR windshields 

Cars and LTVs No significant effect 

 Glass-plastic windshields 

 Cars No significant effect 

206: Door locks and retention components 

Improved locks for side doors 

Cars 15.38 % reduction of ejection fatalities in rollovers 

(excluding occupants riding outside the passenger 

compartment) 

LTVs 9.8 % reduction of ejection fatalities in rollovers 

(excluding occupants riding outside the passenger 

compartment) 

207: Seating systems 

 Seatback locks 

2-door cars No significant effect 

160
TABLE 1-2 (Continued): ESTIMATES OF FATALITY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY 

Vehicle Type Fatality-Reducing Effectiveness Estimate(s) 

208: Occupant crash protection; 209: Seat belt assemblies; 210: Seat belt assembly anchorages 

Lap belts for front seat (age 5+) 

Cars 27 % overall fatality reduction 

LTVs 48 % overall fatality reduction 

Lap belts for back seat (age 5+) 

Cars 32 % overall fatality reduction 

LTVs 63 % overall fatality reduction 

Lap belts for child passengers age 1-4 (front or back seat) 

Cars 33 % overall fatality reduction 

LTVs 48 % overall fatality reduction 

3-point belts for front seat (age 5+) 

Cars 45 % overall fatality reduction 

LTVs 60 % overall fatality reduction 

3-point belts for back seat (age 5+) 

Cars 44 % overall fatality reduction 

LTVs 73 % overall fatality reduction 

Automatic 2-point belts (age 5+) 

Cars 32 % overall fatality reduction 

 Frontal air bags 

Cars and LTVs 10.8 % overall fatality reduction for belted drivers 

14 % overall fatality reduction for unbelted drivers 

11.9 % overall fatality red. for belted RF age 13+ 

15.4 % overall fatality red. for unbelted RF age 13+ 

22 % fatality increase for child passengers age 0-12 

(varies considerably depending on age/restraint use) 

161
TABLE 1-2 (Continued): ESTIMATES OF FATALITY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY 

Vehicle Type Fatality-Reducing Effectiveness Estimate(s) 

208: Occupant crash protection (continued) 

On-off switches for air bags 

Pickup trucks 86 % of switches were turned off for infants in a 

rear-facing child seat in the RF seat of the truck 

74 % of switches turned off for children age 1-6 

83 % of switches turned on for adults (age 13+) 

212: Windshield mounting 

Adhesive windshield bonding 

Cars and LTVs 15 % fatality reduction for people ejected through 

the windshield portal 

213: Child restraint systems; 225: Child restraint anchorage systems 

 Child safety seats 

Cars 71 % overall fatality reduction for infants (age 0) 

54 % overall fatality reduction for toddlers (age 1-4) 

LTVs 58 % overall fatality reduction for infants (age 0) 

59 % overall fatality reduction for toddlers (age 1-4) 

Riding in the back seat, children age 0-12 

Cars w/o air bags 33 % reduction for restrained in the rear-outboard

seat relative to restrained in the right-front seat 

31 % reduction for unrestrained in the rear-outboard 

seat relative to unrestrained in the right-front seat 

46 % reduction for restrained in the rear-center seat 

relative to restrained in the right-front seat 

47 % reduction for unrestrained in the rear-center 

seat relative to unrestrained in the right-front seat 

162
TABLE 1-2 (Concluded): ESTIMATES OF FATALITY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY 

Vehicle Type Fatality-Reducing Effectiveness Estimate(s) 

214: Side impact protection 

Side door beams 

Cars 14 % fatality reduction for occupants of outboard 

seats in single-vehicle side impacts 

LTVs 19 % fatality reduction for occupants of outboard 

seats in single-vehicle side impacts 

Voluntary (pre-1994) TTI(d) improvements 

2-door cars 23 % fatality reduction for front-outboard occupants 

in all side impacts 

216: Roof crush resistance 

Eliminate true hardtops 

Cars 7.4 % reduction of non-ejection fatalities in rollover 

crashes (excluding occupants riding outside the 

passenger compartment) 

301: Fuel system integrity 

1975-77 upgrade: rollover, rear- and lateral-impact tests 

Cars and LTVs No significant effect 

NCAP: New Car Assessment Program 

Frontal NCAP-related improvements 

Cars w/o air bags 20 % fatality reduction for MY 1986 and later cars, 

relative to MY 1979 cars, for belted drivers in 

frontal collisions with other passenger cars 

163
TABLE 1-3: ESTIMATES OF INJURY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Injury-Reducing Effectiveness Estimate(s) 

Vehicle Type Injuries Prevented Per Year When All Vehicles on 

the Road Have the Technology 

105: Hydraulic brake systems 

Dual master cylinders 

Cars and LTVs 0.7 % reduction of all injury crash involvements 

24,000 injuries of any severity prevented per year 

(computation used 1979-80 as the baseline year) 

Front disc brakes 

Cars and LTVs 0.17 % reduction of all injury crash involvements 

5,700 injuries of any severity prevented per year 

(computation used 1979-80 as the baseline year) 

 Rear-wheel ABS 

LTVs 30 % reduction of injuries in nonfatal rollovers 

20 % reduction of injuries in nonfatal side impacts 

with fixed objects 

No significant effect in multivehicle crashes 

 4-wheel ABS 

Cars 28 % reduction of injuries in multivehicle 

involvements on wet roads 

19 % increase of injuries in run-off-road crashes (in 

1989-93 only?) 

164
TABLE 1-3 (Continued): ESTIMATES OF INJURY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Injury-Reducing Effectiveness Estimate(s) 

Vehicle Type Injuries Prevented Per Year When All Vehicles on 

the Road Have the Technology 

108: Lamps, reflective devices 

Side marker lamps 

Cars and LTVs 21 % reduction of injury-producing nighttime angle 

collisions when both vehicles in a crash have the 

lamps 

93,000 injuries of any severity prevented per year 

(computation used 1979-80 as the baseline year) 

Center High Mounted Stop Lamps 

Cars and LTVs 4.3 % reduction of injuries to people involved in 

front-to-rear collisions 

58,000-70,000 injuries of any severity prevented per 

year (computation used 1994 as the baseline year) 

 Retroreflective tape 

Heavy trailers 29 % reduction of cars and LTVs hitting the side or 

rear of a heavy trailer in the dark 

3,100-5,000 injuries of any severity prevented per 

year (computation used 2001 as the baseline year) 

201: Occupant protection in interior impact 

Voluntary mid and lower instrument panel improvements 

Cars 29 % reduction of AIS ≥ 2 injuries from instrument 

panel contact in frontal crashes, for RF passengers 

 8,000 AIS ≥ 2 injuries prevented per year 

(computation used 1982 as the baseline year) 

165
TABLE 1-3 (Continued): ESTIMATES OF INJURY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Injury-Reducing Effectiveness Estimate(s) 

Vehicle Type Injuries Prevented Per Year When All Vehicles on 

the Road Have the Technology 

202: Head restraints 

Head restraints for front seat 

Cars 16.9 % injury reduction in rear-impact crashes with 

fixed or integral head restraints 

10.4 % injury reduction in rear-impact crashes with 

adjustable head restraints 

85,000 injuries of any severity prevented per year 

with a fleet of fixed or integral head restraints 

(computation used 1979 as the baseline year) 

52,000 injuries of any severity prevented per year 

with a fleet of adjustable head restraints 

(computation used 1979 as the baseline year) 

LTVs 6.1 % injury reduction in rear-impact crashes with 

any type of head restraint 

14,900 injuries of any severity prevented per year 

(computation used 1999 as the baseline year) 

203: Impact protection from the steering control; 204: Steering control rearward displacement 

Energy-absorbing steering assemblies 

Cars 38.4 % reduction of fatal or hospitalizing injuries 

due to contact with the steering assembly in frontal 

crashes 

 23,000 nonfatal hospitalizations prevented per year 

(computation used 1978 as the baseline year) 

166
TABLE 1-3 (Continued): ESTIMATES OF INJURY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Injury-Reducing Effectiveness Estimate(s) 

Vehicle Type Injuries Prevented Per Year When All Vehicles on 

the Road Have the Technology 

205: Glazing materials 

 HPR windshields 

Cars 74 % reduction of AIS ≥ 2 lacerations due to 

windshield contact 

56 % reduction of AIS 2-4 facial fractures due to 

windshield contact 

72 % reduction of AIS 2-4 injuries of the eyes, nose 

and mouth due to windshield contact 

25 % reduction of AIS 1 lacerations due to 

windshield contact 

 39,000 AIS ≥ 2 lacerations prevented per year 

(computation used 1982 as the baseline year) 

8,000 AIS 2-4 facial fractures 

The preceding 47,000 AIS 2-4 injuries include 

19,000 injuries to the eyes, nose or mouth 

 Glass-plastic windshields 

 Cars No significant effect 

207: Seating systems 

 Seatback locks 

2-door cars No significant effect 

167
TABLE 1-3 (Continued): ESTIMATES OF INJURY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Injury-Reducing Effectiveness Estimate(s) 

Vehicle Type Injuries Prevented Per Year When All Vehicles on 

the Road Have the Technology 

208: Occupant crash protection; 209: Seat belt assemblies; 210: Seat belt assembly anchorages 

Lap belts for front seat 

Cars 33 % overall AIS ≥ 3 injury reduction 

22 % overall AIS ≥ 2 injury reduction 

 8 % overall AIS ≥ 1 injury reduction 

Lap belts for back seat 

Cars 37 % overall fatal-and-serious (K + A) injury 

reduction 

33 % overall moderate-to-fatal (K + A + B) injury

reduction 

11 % overall (K + A + B + C) injury reduction 

3-point belts for front seat 

Cars 45 % overall AIS ≥ 3 injury reduction 

46 % overall AIS ≥ 2 injury reduction 

13 % overall AIS ≥ 1 injury reduction 

 Frontal air bags 

Cars and LTVs 12 % overall AIS ≥ 3 injury reduction for belted 

occupants age 13+ 

 4 % overall AIS ≥ 2 injury reduction for belted 

occupants age 13+ 

21 % overall AIS ≥ 3 injury reduction for unbelted 

occupants age 13+ 

21 % overall AIS ≥ 2 injury reduction for unbelted 

occupants age 13+ 

168
TABLE 1-3 (Concluded): ESTIMATES OF INJURY REDUCTION 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Injury-Reducing Effectiveness Estimate(s) 

Vehicle Type Injuries Prevented Per Year When All Vehicles on 

the Road Have the Technology 

212: Windshield mounting 

Adhesive windshield bonding 

Cars and LTVs 15 % AIS 3-5 injury reduction for people ejected 

through the windshield portal 

171 AIS 3-5 injuries prevented per year 

(computation used 1982 as the baseline year) 

213: Child restraint systems; 225: Child restraint anchorage systems 

 Child safety seats 

Cars 46 % overall reduction of fatal or hospitalizing 

injuries for children age 0-5 

31 % reduction of overall (K + A + B + C) injuries

214: Side impact protection 

Side door beams 

Cars 25 % reduction of fatal or hospitalizing injuries for 

occupants of outboard seats in single-vehicle side 

impacts 

25 % reduction of fatal or hospitalizing injuries for 

nearside occupants in side impacts by another 

vehicle, centered in the occupant compartment area 

9,470 nonfatal hospitalizations prevented per year 

(computation used 1980 as the baseline year) 

301: Fuel system integrity 

1975-77 upgrade: rollover, rear- and lateral-impact tests 

Cars 14 % reduction in all post-crash fires

3,900 fires prevented per year (unknown number of 

injuries; computation used 1982-87 as the baseline 

years) 

 LTVs No significant effect 

169
TABLE 1-4: ESTIMATES OF CRASH AVOIDANCE 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Crash-Reducing Effectiveness Estimate(s) 

Vehicle Type Crashes Avoided Per Year When All Vehicles on 

the Road Have the Technology 

103: Windshield defrosting and defogging 

Rear-window defoggers 

 Cars No significant effect 

105: Hydraulic brake systems 

Dual master cylinders 

Cars and LTVs 0.7 % reduction of all crash involvements 

40,000 police-reported crashes avoided per year 

(computation used 1979-80 as the baseline year) 

Front disc brakes 

Cars and LTVs 0.17 % reduction of all injury crash involvements 

9,800 police-reported crashes avoided per year 

(computation used 1979-80 as the baseline year) 

 Rear-wheel ABS 

LTVs 30 % reduction of nonfatal rollovers 

20 % reduction of nonfatal side impacts with fixed 

objects 

No significant effect in multivehicle crashes 

 4-wheel ABS 

Cars 28 % reduction of multivehicle involvements on 

wet roads 

19 % increase of run-off-road crashes (in 1989-93

only?) 

Electronic stability control 

Cars 35 % reduction of single-vehicle run-off-road 

crashes (preliminary estimate) 

LTVs 67 % reduction of single-vehicle run-off-road 

crashes (preliminary estimate) 

170
TABLE 1-4 (Concluded): ESTIMATES OF CRASH AVOIDANCE 

NHTSA EVALUATIONS OF SAFETY TECHNOLOGIES

FMVSS 

 SAFETY TECHNOLOGY Crash-Reducing Effectiveness Estimate(s) 

Vehicle Type Crashes Avoided Per Year When All Vehicles on 

the Road Have the Technology 

108: Lamps, reflective devices 

Side marker lamps 

Cars and LTVs 16.8 % reduction of nighttime angle collisions when 

both vehicles in a crash have the lamps 

 106,000 police-reported crashes avoided per year 

(computation used 1979-80 as the baseline year) 

Center High Mounted Stop Lamps 

Cars and LTVs 4.3 % reduction of rear impacts 

 92,000-137,000 police-reported crashes plus 

102,000 unreported crashes avoided per year 

(computation used 1994 as the baseline year) 

 Retroreflective tape 

Heavy trailers 29 % reduction of cars and LTVs hitting the side or 

rear of a heavy trailer in the dark 

7,800 police-reported crashes avoided per year 

(computation used 2001 as the baseline year) 

171

PART 2 

LIVES SAVED BY THE FEDERAL MOTOR VEHICLE SAFETY STANDARDS 

AND OTHER VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

SUMMARY OF THE ESTIMATION METHOD 

During 1960-2002, nearly 2,000,000 people died in motor vehicle crashes in the United States. 

Starting in 1975, the Fatality Analysis Reporting System (FARS) has furnished detailed 

information on over 1,200,000 of these fatality cases. Using the FARS data, we have built a 

model from which we can estimate how many additional people would have died had it not been 

for the Federal Motor Vehicle Safety Standards (FMVSS) and other vehicle safety technologies 

affecting passenger cars and light trucks. We can also estimate how many lives have been saved 

by each technology, year-by-year, from 1960 through 2002. 

Each 100 actual fatality cases on FARS represent a potentially even greater number of fatalities 

that could have happened if the vehicles had not met any of the FMVSS. The actual fatality 

cases are the starting point for a model to estimate the lives saved by the FMVSS. The model is 

similar to the technique that NHTSA has been using since 1993 to estimate the number of lives 

saved each year by safety belts, air bags and child safety seats.1

 That technique is essentially 

expanded to the other safety standards. 

For example, FARS might have records of 100 driver fatalities, wearing safety belts, in model 

year 1999 cars equipped with air bags, in frontal multivehicle crashes with primary impact point 

12:00 (i.e., directly frontal). Air bags reduce fatality risk for belted drivers by 25.3 percent in 

12:00 frontal crashes. Thus, if the cars had not been equipped with air bags, there would have 

been not 100 but 

100/(1 – .253) = 134 potential fatalities. 

In other words, the existence of these 100 actual fatality cases with air bags on FARS implies 

that the MY 1999 vehicles were involved in 134 crashes potentially fatal to their drivers. 

However, 34 of those potentially fatal crashes did not become FARS fatality cases because the 

air bag saved the driver’s life. 

Three-point safety belts reduce drivers’ fatality risk by 42 percent in multivehicle frontal

impacts. If safety belts as well as air bags had been removed from those cars, the number of 

potential fatalities would have increased from 134 to 

134/(1 – .42) = 231 potential fatalities. 

 

1 Traffic Safety Facts 2002 – Occupant Protection, NHTSA Publication No. DOT HS 809 610, Washington, 2003;

Kahane, C.J., Fatality Reduction by Air Bags, NHTSA Technical Report No. DOT HS 808 470, Washington, 1996, 

pp. 19-20.

173
That implies the use of safety belts saved 231 – 134 = 97 lives. But the benefits of the FMVSS 

do not stop here. Even after stripping the air bags and 3-point belts, these MY 1999 cars would 

still have had energy-absorbing steering assemblies to protect their drivers. Those assemblies 

reduce drivers’ fatality risk in frontal collisions by 12.1 percent. If the energy-absorbing steering 

assemblies in these cars had been replaced by pre-1968 rigid columns, there would have been not 

231 but 

231/(1 – .121) = 263 potential fatalities. 

The energy-absorbing columns saved an implicit 263 – 231 = 32 lives. The 100 actual fatality 

cases on FARS imply the existence of 263 potentially fatal crash cases. They imply that the 

three safety technologies (air bags, safety belts, energy-absorbing columns) saved a combined 

total of 163 lives: 34 by air bags, 97 by safety belts and 32 by energy-absorbing columns. 

The process works the same in reverse: consider a population of MY 1966 cars, not equipped 

with energy-absorbing columns, 3-point belts or air bags, involved in 12:00 frontal multivehicle 

crashes, resulting in fatalities to 263 drivers. If these cars had been equipped with energyabsorbing columns (introduced in 1967-68) but not yet 3-point belts (introduced primarily in 

1974) or air bags (introduced in 1985-97), the columns would have reduced the fatalities by 12.1 

percent, from 263 to 231. If, in addition, the cars had been equipped with 3-point belts and the 

drivers had buckled up, the belts would have reduced those fatalities by 42 percent, from 231 to 

134. Finally, the addition of air bags would have reduced the remaining fatalities by 25.3 

percent, from 134 to 100. 

In other words, the model begins with the actual FARS fatality cases and inflates them step-bystep, using the effectiveness estimates from the NHTSA evaluations documented in Part 1 of this 

report2

, until all FMVSS and safety technologies applicable to this type of crash have been 

“removed” from the vehicle – until the vehicle has been degraded to a level of safety 

performance characteristic of the 1950’s rather than its actual model year. The safety 

technologies are “removed” in the reverse chronological order that they were historically 

introduced into vehicles. Starting, say, with an MY 2002 vehicle, we first “remove” the safety 

device most recently introduced, in 2001, and downgrade the vehicle to the MY 2000 level of 

safety; next, the device introduced in 1991, diminishing the vehicle to the MY 1990 level, and so 

on until the vehicle is degraded to 1950’s technologies without any of the modern safety devices. 

At each step into the past, the model tallies the lives saved by the latest safety technology – i.e., 

the additional fatalities that would have occurred if that technology had been removed. 

The model produces unbiased estimates of the lives saved by the various technologies, and it is 

not an exercise in double counting, because each of the effectiveness estimates in Part 1 is based 

on analyses of vehicles produced just after vs. just before the FMVSS in question.3

 For 

 

2

 Except electronic stability control (ESC) systems; they did not begin to appear in the late 1990’s, and NHTSA has 

so far only conducted a preliminary evaluation. 3

 Even though the analyses are based on vehicles produced just after vs. just before the FMVSS, they usually include 

crashes involving these vehicles over a number of calendar years after the FMVSS. Specifically, in the case of 

crash-avoidance standards, vehicles have been on the road long enough for drivers to adapt to the technologies, if

that is an issue. 

174
example, the evaluation of air bags was limited to data on MY 1985 and later cars, some without 

air bags and some with air bags, but all equipped with 3-point belts and energy-absorbing 

columns. Thus, the above effectiveness estimate is no more than the incremental effect of air 

bags, given that a car already has energy-absorbing columns and that the driver buckled up. 

Similarly, the effectiveness estimate for 3-point belts was based on MY 1975-86 cars always 

equipped with energy-absorbing columns but almost never with air bags. It measured the 

incremental effect of belts, given that cars already had the columns, but not air bags. The 

evaluation of energy-absorbing columns was limited to data on MY 1966-68 cars, without air 

bags or 3-point belts, and measured the effect of the column for an (almost always) unrestrained 

driver of a pre-standard car. In other words, these effectiveness estimates are each incremental, 

and may be applied in sequence, as shown above, to estimate the total fatality reduction for the 

combination of the three technologies.4

One factor that simplifies the model is that rarely more than a few FMVSS apply to any specific 

crash situation. For example, the energy-absorbing column only benefits drivers in frontal 

crashes, and its effect will never need to be combined with, say, the benefit of back-seat belts. In 

addition, the safety technologies that have little or no effect on fatalities, such as head restraints 

or Center High Mounted Stop Lamps, do not need to be addressed in this model. 

The model requires enough information about each FARS case of an occupant fatality in a 

passenger car or light truck to determine which safety technologies were present in the vehicle, 

and what effect, if any, each of these technologies would have had, given the type of crash and 

the type of occupant. In other words, the following data elements are needed to apply the model 

to an individual fatality case: 

Vehicle 

• Vehicle type: car or light truck (pickup, SUV, minivan or full-size van) 

• Model year 

• Make-model, if possible 

• Impact locations – principal and initial 

• Most harmful event 

Occupant 

• Seat position 

• Age 

• Restraint system use 

• Ejected? 

Crash 

• Calendar year 

• Single- or multivehicle 

 

4 Kahane (1996), pp. 7-9; Kahane, C.J., Fatality Reduction by Safety Belts for Front-Seat Occupants of Cars and

Light Trucks, NHTSA Technical Report No. DOT HS 809 199, Washington, 2000, pp. 5-10; Kahane, C.J., An 

Evaluation of Federal Motor Vehicle Safety Standards for Passenger Car Steering Assemblies, NHTSA Technical 

Report No. DOT HS 805 705, Washington, 1981, pp. 197-203. 

175
• First harmful event/manner of collision 

Crash-avoidance technologies are more complicated because their life-saving benefits are not 

limited to the occupants of the vehicles equipped with them. Dual master cylinders and front 

disc brakes in passenger cars and light trucks will, in addition, benefit the pedestrians, bicyclists 

and motorcyclists who, as a result, are not struck by those vehicles. Conspicuity tape has only 

been installed on heavy truck trailers, but it saves occupants of cars and LTVs (light trucks and 

vans, including pickup trucks, SUVs, minivans and full-size vans) who, as a consequence, did 

not hit the trailers. This “full” accounting of the benefits of the FMVSS and other safety 

technologies for cars and LTVs includes not only the lives saved in cars and LTVs by car/LTV 

technologies or child safety seats (which turn out to be 99 percent of the total), but also the nonoccupants and motorcyclists saved by car/LTV technologies and the car/LTV occupants saved by 

technologies in other vehicles (heavy trailers) – any technology where cars/LTVs produce and/or 

receive benefits. For that purpose it is necessary to know, for each non-occupant or motorcyclist 

fatality, the model year/type of the vehicle that hit it, and for each car/LTV occupant fatality in 

impacts with heavy trucks, the model year and impact location on the heavy truck, and the light 

conditions at the time of the crash. 

The model does not address the benefits of safety technologies in vehicles other than cars and 

LTVs, except for the benefits to occupants of the cars/LTVs struck by those other vehicles. For 

example, it does not include motorcycle occupant lives saved by motorcycle helmets. 

The model also does not estimate fatality reductions (or increases) due to shifts between existing 

vehicle types or seat positions such as: between cars and LTVs, large cars and small cars, 2-door 

and 4-door cars, or between the front seat and the back seat. They are not “new safety 

technologies” but shifts between existing vehicle designs. However, the effects of these shifts on 

safety may account for some of the year-to-year changes in the “base” of actual and potential 

fatalities. 

The model consists of three principal sections: 

Preprocessor to adjust for missing data elements The model needs complete information on a 

core group of data elements, listed above, to determine what safety equipment was in the case 

vehicle and what effect, if any, this equipment had on fatality risk, given the type of crash, the 

occupant’s seat position, and other factors. But FARS cases may have “unknown” codes for one 

or more of these data elements. The original FARS data need to be transformed to a file that has 

complete information on the core data elements, and whose case weights add up to the same

number of fatalities as on the original file. Two strategies adjust for missing data: 

Vehicle type and vehicle model year are rarely missing (well under 1 percent in occupant fatality 

cases). But when they are missing, the remaining data elements rarely provide clues for an 

educated guess at the vehicle type or model year. The strategy here is to omit the cases with 

missing data and to give the leftover cases a weight factor slightly higher than 1, in order that 

their weights add up to the original fatality total.

176
More frequently unknown are the vehicle impact location/crash type (2 percent of car/LTV 

occupant fatalities), occupant seat position (2 percent) and restraint use (14 percent). Here, 

however, other variables can help you determine, case-by-case, the likely distributions of the 

unknowns. For example, if the “manner of collision” is front-to-rear (multivehicle), the impact 

location/crash type is most likely a frontal or a rear impact, rarely a side impact or rollover; but if 

the most harmful event is a collision with a tree, the impact location is very likely frontal, 

possibly a side impact, rarely a rear impact. A passenger with unknown seat location was more 

likely to have been in the back seat if he or she was a child, than if an adult; more likely to have 

occupied an “unenclosed part of the vehicle” if the vehicle was a pickup truck than if it was a 

minivan. An adult with unknown restraint use was quite possibly belted if the crash happened in 

2002, much less so if it happened in 1980. 

Several regression analyses estimate the distribution of impact type, seat position and belt use as 

a function of other core variables, based on the calibration dataset of cases with known values on 

all the core variables. For example, when the fatality is a non-ejected driver age 50 or older, the 

vehicle is a passenger car, and the first harmful event is an impact with a tree or highway sign, 

the distribution of these fatalities by impact type is 76 percent frontal, 19 percent side, 3 percent 

rollover and 2 percent rear/other. The strategy here is to replace the FARS fatality case of the 

50+ year-old car driver who hit a tree with unknown vehicle-impact location by four new cases, 

each of which retain the values of the other core variables: one with a frontal impact, one with a 

side impact, one rollover and one rear/other impact. If the original case had a weight factor of 1, 

the new cases will have weight factors of .76, .19, .03 and .01, respectively. 

The two strategies generate a file of fatality cases with non-missing values on all the core 

variables. Data inconsistencies are also corrected – e.g., “lap and shoulder belts used” is 

changed to “lap belt used” if a seat was only equipped with lap belts. 

Calculation of lives saved, 1975-2002 The model runs through each of the actual fatality cases, 

removes the safety technologies from the vehicle in the reverse chronological order that they 

were implemented in the fleet, inflating the case weight factor as each technology is removed. In 

the example at the beginning of this discussion, if the case of the belted driver fatality in the MY 

1999 car in a directly frontal, multivehicle crash has a case weight of 1, that case weight would 

have been inflated to 1.34 after removing the air bag, 2.31 after removing the safety belts, and 

2.63 after removing the energy-absorbing column: because the combination of energy-absorbing 

columns, safety belts and air bags are estimated to reduce 2.63 fatalities to 1 fatality in this type 

of crash. Thus, this actual fatality case contributes evidence of .34 lives saved by air bags, .97 by 

safety belts and .32 by energy-absorbing columns, totaling up to 1.63 lives saved by all the 

FMVSS. Benefits are summed and tabulated by safety standard/technology, by vehicle type, by 

calendar year, and by whether the technology was mandated by a standard already in effect or 

was voluntarily furnished by the manufacturer at the time the vehicle was built. 

The chronological order of the safety technologies is based on their median implementation 

dates, generally the first model year in which 50 percent or more of new vehicles were equipped 

with the technology. It is a sort of “average” introduction year for the technology. Table 2-1 

shows the chronological order of the 22 safety improvements for passenger cars, evaluated to 

date, that significantly reduced fatalities. 

177
TABLE 2-1

INSTALLATION DATES OF SAFETY TECHNOLOGIES IN PASSENGER CARS

 First Median FMVSS 

 Offered Installation Effective 

 In Year5 Date 

208A Lap belts for front-outboard occupants 1956 1962 1/1/68 

208B Lap belt use by children age 1-4 1956 1964 1/1/68 

206 Improved door locks 1962 (?) 1965 1/1/68 

208C Lap belts for back-outboard occupants 1961 (?) 1965 late 1/1/68 

212 Adhesive windshield bonding 1963 1966 early 1/1/706

208D Lap belts for front-center occupants 1961 (?) 1966 1/1/68 

105A Dual master cylinders 1962 1966 late 1/1/68 

208E Lap belts for back-center occupants 1961 (?) 1967 early 1/1/68 

203 Energy-absorbing steering assemblies 1967 1967 1/1/68 

201 Voluntary instrument panel improvements 1967 (?) 1968 1/1/687

105B Front disc brakes 1965 1971 1/1/76 

214A Side door beams 1969 1973 early 1/1/73 

216 Roof crush strength, eliminate hardtops 1970 1973 9/1/73 

208F 3-point belts for front-outboard occupants 1963 1974 9/1/73 

NCAP NCAP-related improvements (w/o air bags) 1982 1984 early N.A. 

213 Child safety seats Pre-19708 19859 4/1/71 

208G 3-point belts for back-outboard occupants 1971 1989 12/11/89 

208H Automatic 2-point belts 197510 199111 9/1/86-9/1/89 

214B Voluntary12 TTI(d) reductions in 2-door cars 1986 (?) 1993 N.A. 

208I Frontal air bags 1985 1994 9/1/86-9/1/89 

108 Conspicuity tape – heavy trailers 1991 (?) 199613 12/1/9314

208J 3-point belts for back-center occupants Pre-1995 2001 9/2005-2007 

 

5

 Unless otherwise noted, it is the first model year that over 50 percent of new vehicles were equipped with this

safety technology. “Early” = close to 50 percent were already equipped in the preceding year and/or much more 

than 50 percent were equipped in this year or the following year. “Late” = far fewer than 50 percent were equipped 

in the preceding year and/or barely over 50 percent were equipped in this year and the following year. 6

 FMVSS 212 did not specifically require adhesive bonding; some cars continued to have rubber gaskets (meeting 

FMVSS 212) after the effective date. 7

 FMVSS 201 did not require these improvements to mid- and lower instrument panels; these improvements were 

not necessarily introduced before the effective date. 8

 Effective child safety seats were offered before 1970; child passenger protection laws took effect in all States, 

1978-85. 9

 Safety seat use first exceeded 50 percent in 1985. 10 Phased out of new cars after 1996. 11 Never reached 50 percent of new vehicles; 1991 was the peak installation year. 12 Pre-1994, prior to the phase-in of the dynamic test requirement of FMVSS 214. 13 First calendar year when over 50 percent of heavy trailers on the road were equipped with the tape. 14 FMCSA retrofit requirement effective 6/1/2001. 

178
For example, lap belts for front-outboard occupants were offered on some new cars as early as 

1956, and were required on all new cars after FMVSS 208 took effect on January 1, 1968. 

However, NCSS and NASS data show that 1962 is the first model year in which over 50 percent 

of new cars were equipped with lap belts. A description, regulatory history and effectiveness 

estimate for every safety improvement in Table 2-1 may be found in Part 1 of this report, within 

the chapter whose FMVSS number matches the code number for that technology (or in the 

“NCAP” chapter). 

NHTSA’s initial safety standards took effect on January 1, 1968 but, in many cases, the 

manufacturers had already implemented the safety technologies several years earlier. Threepoint belts and side door beams were the major innovations of the 1970’s. Automatic occupant 

protection and several other standards date to the late 1980’s and the 1990’s. The most recent 

technologies, including the dynamic side impact standard, and the head injury protection upgrade 

are not included in the model, because NHTSA has not yet evaluated their effectiveness. 

Two of the 22 technologies are not applied to the cars themselves. Child safety seats are add-on 

equipment, while conspicuity tape is applied to heavy trailers and helps car drivers see the 

trailers at night and not hit them. For these two, the analog to “median installation year” is: the 

first calendar year when over 50 percent of children age 0-4 rode in safety seats (1985), and the 

first calendar year when over 50 percent of heavy trailers on the road were treated with tape 

(1996). 

“Reverse chronological order” is just one of several general methods that could have been used 

to allocate lives saved among the safety technologies in those crashes where more than one 

technology is beneficial (e.g., air bags, safety belts and energy-absorbing columns for drivers in 

frontal crashes). Furthermore, “median installation year” is just one of several specific methods 

that could have been used to order the standards chronologically. However, in considering other 

allocation methods or orderings, it is important to note that all methods should produce the same 

estimate of overall lives saved (the primary objective of this report), only changing the allocation 

of the lives saved among the individual standards. In the example at the beginning of this 

section, all methods would agree that the combination of air bags, safety belts, and energyabsorbing columns saved 163 lives in the crashes where drivers were protected by all three. 

They would only differ on how to allocate these 163 lives among air bags, belts and energyabsorbing columns – a more theoretical issue because these drivers are being saved by the 

combination of all three devices, and there is no obvious way to pinpoint who was saved by 

what. 

The reverse-chronological method is intuitively straightforward. It views each (at that time) new 

safety technology as building upon the baseline of previously existing technologies, and it 

allocates to the new technology only the benefits relative to that baseline: it computes how many 

lives are saved if technology X is added to cars that already have Y and Z. Another advantage is 

that the effectiveness estimates in NHTSA evaluations are computed on that basis, and enter 

directly into the model this report uses to estimate total lives saved. 

A less attractive feature of the reverse-chronological method is that the allocation between 

technologies depends on their chronological order. In general, moving a standard earlier in the 

179
chronological order will increase the benefits allocated to that standard, and take some away 

from the standards that follow (leaving unchanged, however, the total lives saved by the 

combination of these standards). Two technologies might, in some intuitive way, be equally 

effective, but the model could allocate more lives saved to the earlier one. 

An alternative approach that could allocate independently of chronological order is based on the 

effectiveness of each technology acting alone. For example, X alone might reduce fatality risk 

by 30 percent and Y alone by 10 percent. If the combination of X and Y saves 1,000 lives, 750 

of them are allocated to X and 250 to Y (based on the ratio of their free-standing effectiveness 

estimates). That approach is feasible if there are data on vehicles that have only X and other 

vehicles that have only Y (e.g., safety belts without air bags, and air bags with unrestrained 

drivers). But it is essentially impossible for most of the non-belt technologies in this report, 

because they were introduced in nearly all vehicles in the same sequence: first X, then Y. For 

example, we know the effectiveness of energy-absorbing columns without air bags, but it is 

impossible to estimate, from crash data, the effectiveness of air bags without energy-absorbing 

columns, because there are no vehicles with air bags and rigid columns. 

Even within the reverse-chronological method, there are alternatives to using the median 

installation year. The median year is fine if technologies X and Y were each introduced over 

relatively short, non-overlapping timeframes – e.g., energy-absorbing columns (1967-68) and air 

bags (1985-96). It works for the non-belt technologies in Tables 2-1 and 2-2 (because even 

though some technologies were introduced at about the same time, those usually do not apply to 

the same occupant or crash type – e.g., energy-absorbing columns for drivers and improved 

instrument panels for passengers). 

A problem arises with safety belts, whose use has gradually increased over the years. Some

people began to buckle up long before cars had air bags, others only started a few years ago. 

Theoretically, at least, we should ascertain when each individual started buckling up to decide 

the “order” of safety belts and air bags for that individual. FARS, however, only tells us if a 

fatality was belted, but it does not say in what year that person first started buckling up. We only 

know that 3-point belts became available in new cars in model year 1974, that most States had 

buckle-up laws by 1987, and that on-the-road belt use exceeded 50 percent by 1991. Whatever 

year we use as the “median” implementation year for safety belts, it is before the median 

implementation year for air bags (1994) and after the median implementation years for all the 

early “built-in” safety technologies up to side door beams, preserving the sequence in Table 2-1. 

Table 2-2 shows the chronological order of the 18 life-saving improvements for LTVs. They are 

the same improvements as for cars, but excluding automatic belts (never installed in LTVs), roof

crush strength, NCAP improvements and TTI(d) reductions (not evaluated for LTVs). Many 

FMVSS were not extended to LTVs until several years after they had been in effect for cars. As 

a result, the chronological order of the technologies in LTVs is slightly different from cars. In 

both vehicles, though, 3-point belts were installed before air bags but after energy-absorbing 

columns and voluntary instrument panel improvements. 

180
TABLE 2-2

INSTALLATION DATES OF SAFETY TECHNOLOGIES IN LTVs 

 First Median FMVSS 

 Offered Installation Effective 

 In Year15 Date 

208A Lap belts for front-outboard occupants 1956 (?) 1964 7/1/71 

208B Lap belt use by children age 1-4 1956 (?) 1966 7/1/71 

105A Dual master cylinders 1962 (?) 1966 late 9/1/83 

206 Improved door locks 1962 (?) 1967 1/1/72 

208C Lap belts for back-outboard occupants ? 1968 7/1/71 

208D Lap belts for front-center occupants 1965 (?) 1968 7/1/71 

208E Lap belts for back-center occupants ? 1968 7/1/71 

105B Front disc brakes 1965 (?) 1971 9/1/83 

201 Voluntary instrument panel improvements 1969 (?) 1972 9/1/8116

203 Energy-absorbing steering assemblies 1970 1976 early 9/1/81 

208F 3-point belts for front-outboard occupants 1969 1976 9/1/76 

212 Adhesive windshield bonding 1978 (?) 1980 9/1/7817

213 Child safety seats Pre-197018 198519 4/1/71 

208G 3-point belts for back-outboard occupants 1987 1990 9/1/91 

214A Side door beams 1991 1994 9/1/93 

208I Frontal air bags 1991-92 1995 9/1/94-9/1/97 

108 Conspicuity tape – heavy trailers 1991 (?) 199620 12/1/9321

208J 3-point belts for back-center occupants Pre-1995 > 2001 9/2005-2007 

 

15 Unless otherwise noted, it is the first model year that over 50 percent of new vehicles were equipped with this

safety technology. “Early” = close to 50 percent were already equipped in the preceding year and/or much more 

than 50 percent were equipped in this year or the following year. “Late” = far fewer than 50 percent were equipped 

in the preceding year and/or barely over 50 percent were equipped in this year and the following year. 16 FMVSS 201 did not require these improvements to mid- and lower instrument panels. 17 FMVSS 212 did not specifically require adhesive bonding; some LTVs continued to have rubber gaskets (meeting 

FMVSS 212) after the effective date. 18 Effective child safety seats were offered before 1970; child passenger protection laws took effect in all States, 

1978-85. 19 Safety seat use first exceeded 50 percent in 1985. 20 First calendar year when over 50 percent of heavy trailers on the road were equipped with the tape. 21 FMCSA retrofit requirement effective 6/1/2001. 

181
If two technologies were implemented at the same time, and benefited the same people in the 

same types of crashes, there is a danger of double-counting the benefits – i.e., attributing the joint 

benefit to each of the individual technologies. However, the history of the safety measures, as 

shown in Tables 2-1 and 2-2 and the analysis methods in most NHTSA evaluations (with control 

groups) minimize that danger. Major technologies usually came in several years apart, but even 

when two were introduced at once, they did not benefit the same people because: 

• They applied at different seat positions (e.g., front seat belts and rear seat belts). 

• They applied in different crash types (e.g., side impacts and frontal impacts). 

• Belt technologies only benefit belted occupants, while other technologies can benefit 

unrestrained occupants. 

• 100-series FMVSS can be evaluated for their crash avoidance benefits, while 200-series 

FMVSS do not have such benefits. 

Postprocessor: estimate lives saved in 1960-74 FARS data only exist from 1975. However, the 

FMVSS date back to 1968 and some of them incorporate technologies available well before that. 

The postprocessor extends the estimation model back to the years before FARS existed, 

specifically 1960-74. 

The National Safety Council’s Accident Facts tally the number of fatalities in motor vehicle 

crashes each year in the United States and apportion the fatalities among car occupants, “truck” 

occupants, motorcyclists, pedestrians/bicyclists and several other categories.22 For CY 1975-80, 

when FARS and Accident Facts are both available, it is possible to compare the total fatalities 

for the two data sources (which use slightly different definitions of “motor vehicle crash 

fatality”) and the number in each category, and establish ratios of FARS to Accident Facts case 

counts. These ratios are applied to the Accident Facts counts for each earlier year to estimate the 

“number of FARS fatality cases if FARS had existed that year.” 

The postprocessor essentially recreates a FARS file for each year from 1960-74, with just the 

core variables needed to operate the model. It runs these files through the basic model to 

estimate how many additional people would have died had it not been for the FMVSS and other 

vehicle safety technologies affecting passenger cars and light trucks. 

The core variables are the number of vehicles in the crash (1, 2+); the vehicle’s impact type 

(front, side, rollover, rear/other) and model year; and the occupant’s age group (0, 1-4, 5+), seat 

position, belt/safety seat use and ejection status. The joint distribution of the core variables is 

inferred from 1975-80 FARS. Specifically, all the variables except model year, belt use and 

safety seat use are assumed to have the same distribution in earlier years as on 1975-80 FARS. 

The distribution of vehicle age is also assumed not to change, and the distribution of vehicles by 

model year is obtained by noting that 

MY = CY – vehicle age 

 

22 For example, Accident Facts 1978 Edition, National Safety Council, Chicago, 1978, pp. 56 and 58. 

182
Belt use depends on the vehicle’s model year and the occupant’s seat position, based on trends 

seen in 1975-80 FARS data; safety seat use depends on the child’s age and the calendar year. 

The various assumptions add uncertainty to this part of the model, but it does not matter so much 

because, as we shall see, less than 5 percent of the lives saved in 1960-2002 were saved during 

1960-1974. A file is created with one cell for each possible combination of values of the core 

variables, and with cell fatality counts that add up to the “number of FARS cases if FARS had 

existed that year.” 

For example, suppose this process had created a cell count of 100 “would-have-been” FARS 

cases of unbelted drivers in frontal crashes of MY 1968 cars in CY 1972. All MY 1968 cars 

were equipped with energy-absorbing steering assemblies that reduce drivers’ fatality risk in 

frontal collisions by 12.1 percent. If the energy-absorbing steering assemblies in these cars had 

been replaced by pre-1968 rigid columns, there would have been not 100 but 

100/(1 – .121) = 114 potential fatalities. 

The energy-absorbing columns saved an implicit 114 – 100 = 14 lives in this cell. 

Appendix A of this report contains step-by-step descriptions of the preprocessor, the main model 

and the postprocessor, and it discusses the auxiliary programs needed to run the model. 

183

FINDINGS 

Estimate of lives saved 

Table 2-3 shows that safety technologies regulated by the Federal Motor Vehicle Safety 

Standards or introduced on a voluntary basis saved an estimated 328,551 lives in 1960-2002. 

The annual number of lives saved grew from 115 in 1960, when a small number of people used 

lap belts, to 24,561 in 2002, when most cars and LTVs were equipped with numerous modern 

safety technologies and belt use on the road achieved 75 percent. The number of lives saved 

grew every year except 1974 and 1981-82, when, among other things, external events (an energy 

crisis and a recession) substantially reduced baseline crashes from the previous year. 

The total of 328,551 includes 44,483 lives saved by voluntary improvements and 284,069 saved 

by FMVSS that were in effect at the time. “Voluntary” improvements include those introduced 

before the actual effective date of a FMVSS (e.g., energy-absorbing steering assemblies before 

January 1, 1968) and distinct technologies that were never required for meeting a FMVSS (such 

as the improvements to the mid- and lower instrument panels). On the other hand, improvements 

directly pursuant to a specific FMVSS in effect at the time are credited to the “FMVSS in 

effect,” even if the manufacturer exceeded the minimum requirements of the FMVSS. For 

example, lives saved by a frontal air bag in a 1998 car are credited to the air bag FMVSS, 

regardless of whether that car scored a HIC of 1000 (the minimum requirement) or 200 

(exceptionally good performance) on the FMVSS 208 test. 

Of course, before January 1, 1968, every life saved was due to a “voluntary” improvement – or at 

least one not required by the Federal government, although some States required safety belts in 

new cars well before 1968. After 1968, lives saved by voluntary improvements have remained 

close to 1,000 per year, comprising modifications to instrument panels, TTI(d) reductions before 

the FMVSS 214 upgrade, NCAP-related changes, and numerous improvements made a few years 

before a FMVSS took effect. For example, the energy-absorbing columns in MY 1967 cars, 

produced before the January 1, 1968 effective date, started generating “voluntary” benefits in 

late 1966, when those cars first began to sell, and continued to generate them as long as any of 

those cars were still on the road, even in 2002. 

By contrast, the number of lives saved by FMVSS in effect has grown dramatically from a 

modest start of 107 in 1968, and they accounted for 22,999 of the 24,561 total lives saved in 

2002. 

Any non-belt technology “built into” new cars or LTVs takes years to build up substantial 

benefits. At first, only the newest vehicles on the road have the technology. Only after 6-8 years 

are they in the majority of vehicles on the road. By contrast, any program to increase belt use, 

such as buckle-up laws, can have an immediate large effect on lives saved. The belts are already 

in the vehicles; the program immediately increases the number of people who use them. 

185
TABLE 2-3: LIVES SAVED BY VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

(Car and LTV occupants saved, 

plus non-occupants and motorcyclists saved by car/LTV brake improvements) 

 L I V E S S A V E D 

 BY VOLUNTARY BY FMVSS 

 CY TOTAL IMPROVEMENTS IN EFFECT 

1960 115 115 0 

1961 117 117 0 

1962 135 135 0 

1963 160 160 0 

1964 203 203 0 

1965 251 251 0 

1966 339 339 0 

1967 509 509 0 

1968 816 709 107 

1969 1,179 831 348 

1970 1,447 866 581 

1971 1,774 957 817 

1972 2,226 1,096 1,130 

1973 2,576 1,168 1,408 

1974 2,518 1,005 1,513 

1975 3,058 1,073 1,986 

1976 3,240 1,089 2,151 

1977 3,671 1,156 2,515 

1978 4,040 1,185 2,855 

1979 4,299 1,198 3,101 

1980 4,539 1,218 3,322 

1981 4,455 1,167 3,288 

1982 4,057 1,044 3,013 

1983 4,248 986 3,262 

1984 4,835 956 3,879 

1985 6,389 1,073 5,316 

1986 8,523 1,207 7,316 

1987 9,973 1,224 8,748 

1988 11,265 1,291 9,974 

1989 11,487 1,291 10,197 

1990 11,711 1,272 10,439 

1991 12,194 1,252 10,942 

1992 12,483 1,266 11,217 

1993 13,796 1,319 12,477 

1994 15,154 1,411 13,744 

1995 16,117 1,469 14,648 

1996 17,813 1,553 16,260 

1997 18,560 1,591 16,969 

1998 19,380 1,550 17,830 

1999 19,942 1,521 18,420 

2000 21,789 1,569 20,220 

2001 22,605 1,527 21,078 

2002 24,561 1,562 22,999 

 =========== =========== =========== 

 328,551 44,483 284,069 

186
Figure 2-1 graphs the year-by-year trend in lives saved (the first column in Table 2-3). It took 

until 1969 to reach 1,000. Throughout the 1970’s, new vehicles meeting the early FMVSS 

gradually superseded the older on-road fleet, contributing to steady growth in lives saved, but 

that was offset by declining belt use in the late 1970’s, in the wake of the unsuccessful ignition 

interlock and prior to national buckle-up campaigns. The largest gains in both absolute and 

relative terms came with the buckle-up laws: lives saved rose from 4,835 in 1984 to 11,265 in 

1988. Since then, continued increases in belt use, air bags and other recent FMVSS, and a 

steadily escalating “base” of more vehicles and more VMT (vehicle miles of travel) have helped 

the fatality reduction grow steadily, reaching 24,561 in 2002. 

Table 2-4 compares the lives saved, year-by-year, by vehicle or person type. Car occupants are 

the largest group, comprising 232,255 of the 328,551 lives saved. However, commensurate with 

the growth in LTVs (light trucks and vans, including pickup trucks, SUVs, minivans and fullsize vans), the number of lives saved in LTVs has accelerated in recent years, reaching 10,331 in 

2002, compared to 14,175 car occupants. By contrast, in 1980, safety technologies saved only 

608 LTV occupants vs. 3,848 car occupants. 

The effect of car/LTV braking improvements on pedestrian, bicyclist and motorcyclist fatalities 

is small relative to the effect of all the FMVSS on car/LTV occupants. Non-occupants accounted 

for 1,782 and motorcyclists, 398 of the 328,551 lives saved. Once dual master cylinders and 

front disc brakes were in most of the cars and LTVs on the road, in the mid-1970’s, nonoccupant and motorcyclist lives saved stopped increasing and have, in fact, declined as the 

“base” of pedestrian and motorcyclist exposure decreased. A revival of motorcycle popularity 

reversed the decreasing trend after 1999. 

Net effectiveness for car/LTV occupants 

Table 2-5 concentrates on the occupant fatalities in cars and LTVs. The first column is the actual 

number of occupant fatalities. There were an estimated 1,443,030 actual occupant fatalities in 

cars and LTVs in 1960-2002.1

 The next column estimates how many fatalities would have 

happened in 1960-2002 if none of the safety technologies had existed: 1,769,401.2

 The third 

column, equal to column 2 minus column 1, is the lives saved by the safety technologies: 

326,371 in 1960-2002. The fourth column is the overall effectiveness of the existing safety 

technologies in each calendar year: the lives saved divided by the number of fatalities there 

would have been without any safety improvements. The effectiveness grew in every year from

1960 to 2002, from a humble 0.40 percent in 1960 to a very substantial 42.81 percent fatality 

reduction in 2002. There were 32,737 actual car/LTV occupant fatalities in 2002, but there 

would have been 57,242 without the safety technologies. The 24,506 lives saved are 42.81 

percent of the potential fatalities. 

 

1

 This is the sum of the ORIGWT values in the programs LS2004 and OLDFA24. 2

 This is the sum of WEIGHTFA in LS2004 and OLDFA24, the inflated values of ORIGWT after all the safety 

technologies are “removed,” one-by-one, from the vehicles.

187
FIGURE 2-1: LIVES SAVED BY VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

 ‚ 

25000 ˆ 

 ‚ belt use O 

 ‚ keeps 

 ‚ increasing O 

 ‚ O 

 ‚ + air bags 

 ‚ 

20000 ˆ + more vehicles O 

 ‚ and VMT O 

 ‚ O 

 ‚ O 

 ‚ 

 ‚ O 

 ‚ 

15000 ˆ O 

 ‚ 

 ‚ O 

 ‚ 

 ‚ O O 

 ‚ O O O 

 ‚ 

10000 ˆ O BUCKLE 

 ‚ 

 ‚ O UP 

 ‚ 

 ‚ LAWS 

 ‚ O 

 ‚ 

 5000 ˆ O 

 ‚ energy O O O O O O 

 ‚ crisis O O declining belt use 

 ‚ O O O 

 ‚ O early non-belt 

 ‚ O O O technologies phase in 

 ‚ O O 

 0 ˆO O O O O O O 

 ______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

188
TABLE 2-4: LIVES SAVED BY VEHICLE SAFETY TECHNOLOGIES, 1960-2002 

BY VEHICLE/PERSON TYPE 

 CAR LTV PEDESTRIANS MOTOR- 

 CY TOTAL OCCUPANTS OCCUPANTS BICYCLISTS CYCLISTS 

1960 115 92 22 0 0 

1961 117 95 22 0 0 

1962 135 110 25 0 0 

1963 160 131 28 1 0 

1964 203 168 34 1 0 

1965 251 211 38 2 0 

1966 339 288 46 4 1 

1967 509 444 55 9 1 

1968 816 719 80 15 2 

1969 1,179 1,042 114 21 2 

1970 1,447 1,279 136 28 4 

1971 1,774 1,574 161 35 4 

1972 2,226 1,984 194 42 6 

1973 2,576 2,282 238 48 8 

1974 2,518 2,220 244 45 9 

1975 3,058 2,723 272 53 10 

1976 3,240 2,852 324 54 11 

1977 3,671 3,190 409 58 14 

1978 4,040 3,501 462 60 16 

1979 4,299 3,657 561 64 18 

1980 4,539 3,848 608 65 18 

1981 4,455 3,758 614 64 18 

1982 4,057 3,394 585 62 16 

1983 4,248 3,534 641 57 15 

1984 4,835 3,943 815 60 17 

1985 6,389 5,196 1,118 59 17 

1986 8,523 6,827 1,620 59 17 

1987 9,973 7,783 2,115 60 15 

1988 11,265 8,733 2,457 61 14 

1989 11,487 8,677 2,741 58 12 

1990 11,711 8,684 2,957 58 12 

1991 12,194 8,943 3,188 53 11 

1992 12,483 9,007 3,417 50 9 

1993 13,796 9,916 3,818 52 10 

1994 15,154 10,626 4,469 50 9 

1995 16,117 11,115 4,942 51 9 

1996 17,813 12,076 5,679 50 9 

1997 18,560 12,146 6,356 49 9 

1998 19,380 12,325 6,998 48 9 

1999 19,942 12,401 7,486 45 9 

2000 21,789 13,052 8,682 43 11 

2001 22,605 13,532 9,016 45 12 

2002 24,561 14,175 10,331 44 12 

 =========== =========== =========== =========== =========== 

 328,551 232,255 94,117 1,782 398 

189
TABLE 2-5: ACTUAL OCCUPANT FATALITIES, POTENTIAL FATALITIES WITHOUT 

THE VEHICLE SAFETY TECHNOLOGIES, AND LIVES SAVED IN CARS/LTVs 

 CAR+LTV OCCUPANT FATALITIES 

 W/O SAFETY LIVES PERCENT 

 CY ACTUAL TECHS. SAVED SAVED 

1960 28,183 28,298 115 0.40 

1961 28,087 28,204 117 0.41 

1962 30,544 30,679 135 0.44 

1963 32,664 32,823 159 0.49 

1964 35,603 35,805 202 0.56 

1965 36,518 36,767 249 0.68 

1966 39,130 39,465 334 0.85 

1967 39,327 39,826 499 1.25 

1968 41,019 41,818 799 1.91 

1969 42,117 43,273 1,156 2.67 

1970 39,556 40,972 1,415 3.45 

1971 38,916 40,651 1,735 4.27 

1972 40,103 42,281 2,178 5.15 

1973 38,739 41,258 2,520 6.11 

1974 31,145 33,608 2,463 7.33 

1975 31,361 34,355 2,995 8.72 

1976 32,222 35,398 3,176 8.97 

1977 33,173 36,772 3,599 9.79 

1978 34,988 38,951 3,964 10.18 

1979 35,108 39,325 4,217 10.72 

1980 35,097 39,554 4,456 11.27 

1981 33,911 38,284 4,373 11.42 

1982 29,855 33,834 3,979 11.76 

1983 29,209 33,384 4,176 12.51 

1984 30,177 34,935 4,758 13.62 

1985 30,044 36,357 6,314 17.37 

1986 32,380 40,827 8,447 20.69 

1987 33,306 43,203 9,898 22.91 

1988 34,217 45,407 11,190 24.64 

1989 33,709 45,127 11,418 25.30 

1990 32,830 44,470 11,640 26.18 

1991 30,928 43,060 12,131 28.17 

1992 29,542 41,966 12,424 29.60 

1993 30,182 43,917 13,735 31.27 

1994 30,979 46,075 15,096 32.76 

1995 32,057 48,113 16,056 33.37 

1996 32,534 50,289 17,755 35.31 

1997 32,501 51,003 18,502 36.28 

1998 31,940 51,263 19,323 37.69 

1999 32,151 52,038 19,887 38.22 

2000 32,234 53,968 21,734 40.27 

2001 32,009 54,558 22,548 41.33 

2002 32,737 57,242 24,506 42.81 

 =========== =========== =========== 

 1,443,030 1,769,401 326,371 

190
Two graphs help to illustrate the trends in actual fatalities, potential fatalities and effectiveness. 

Figure 2-2 compares the actual car/LTV occupant fatalities (A) to the potential fatalities that

could have happened without the safety technologies (P). Actual fatalities remained fairly level, 

usually in the low 30,000’s, throughout 1960-2002. Only in 1968-72, when large numbers of 

baby-boomers were young drivers, did they crest just over 40,000. By contrast, potential 

fatalities have doubled from 28,298 in 1960 to 57,242 in 2002. They have experienced a longterm rising trend, with some exceptions such as the energy crisis in the mid-1970’s, the recession 

in the early 1980’s, and a smaller dip in 1990-92 perhaps associated with a high public emphasis 

on health and safety as the baby-boomers reached their 40’s. Periods of prosperity such as the 

later 1980’s and most of the 1990’s saw large rises in potential fatalities, commensurate with 

rising VMT, vehicle sales, and trips for both work and recreation. 

Until the mid-1970’s, there is little distance between the A’s and the P’s on Figure 2-2. Then a 

gap opens between them, and it really widens after buckle-up laws were enacted in the mid1980’s. From that time onward, the potential fatalities continue to grow, but the FMVSS and 

other safety technologies have held the line on actual fatalities, working a little harder each year, 

keeping them in the low 30,000’s year after year. 

Figure 2-3 graphs the percentage of potential fatalities saved by the safety technologies. It looks 

a lot like Figure 2-1, a graph of the absolute number of lives saved. The difference is that Figure 

2-3 essentially controls for VMT and other factors that make the “base” grow or shrink. The 

trend of the effectiveness of the vehicle safety technologies becomes even clearer: 

• Not much effect until the late 1960’s. 

• Steady growth in the early-to-mid 1970’s as new vehicles meeting the early FMVSS 

gradually phased in. 

• Little progress in 1978-82, when belt use declined, in the wake of the unsuccessful 

ignition interlock and prior to national buckle-up campaigns. 

• The largest absolute and relative gains came with the buckle-up laws in the mid-to-late 

1980’s. 

• Steady progress since the late 1980’s thanks to continued increases in belt use, air bags 

and other recent FMVSS. 

191
FIGURE 2-2: ACTUAL VS. POTENTIAL CAR/LTV OCCUPANT FATALITIES 

(“A” = actual fatalities; “P” = potential fatalities without the vehicle safety technologies) 

 60000 ˆ 

 ‚ 

 ‚ potential P 

 55000 ˆ fatalities P 

 ‚ P 

 ‚ P P P 

 50000 ˆ P keep rising 

 ‚ P 

 ‚ P 

 45000 ˆ P P P 

 ‚ P P P P 

 ‚ A A P P P P 

 40000 ˆ P A A P A P P P FMVSS start to 

 ‚ baby- A A A P P make a big difference 

 ‚ boomers A energy P recession P 

 35000 ˆ start A crisis P P A A A P A 

 ‚ A P A A P P A A A A A A 

 ‚ driving A A A A A A A A A A A 

 30000 ˆ A A A A A A A 

 ‚A A 

 ‚ The FMVSS hold the line! 

 25000 ˆ 

 ‚ 

 ‚ 

 20000 ˆ 

 ‚ 

 ‚ 

 15000 ˆ 

 ‚ 

 ‚ 

 10000 ˆ 

 ‚ 

 ‚ 

 5000 ˆ 

 ‚ 

 ‚ 

 0 ˆ 

 ‚ 

 _______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

192
FIGURE 2-3: PERCENT OF POTENTIAL FATALITIES SAVED BY VEHICLE SAFETY

TECHNOLOGIES, 1960-2002 

 45 ˆ 

 ‚ 

 ‚ O 

 ‚ more belt use O 

 40 ˆ O 

 ‚ + air bags O 

 ‚ O 

 ‚ O 

 35 ˆ O 

 ‚ O 

 ‚ O 

 ‚ O 

 30 ˆ O 

 ‚ O 

 ‚ 

 ‚ O 

 25 ˆ O O 

 ‚ 

 ‚ O 

 ‚ O 

 20 ˆ 

 ‚ buckle-up 

 ‚ O laws 

 ‚ 

 15 ˆ 

 ‚ O 

 ‚ O 

 ‚ O O O O 

 10 ˆ O O declining belt use 

 ‚ O O 

 ‚ O early 

 ‚ O non-belt 

 5 ˆ O FMVSS 

 ‚ O O phase in 

 ‚ O O 

 ‚ O O O 

 0 ˆO O O O O 

 ‚ 

 ______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

193
Car/LTV occupant fatalities per 100,000,000 VMT 

A detailed analysis of fatality rates per 100,000,000 VMT comparing the strength of vehicle, 

behavioral, environmental and demographic factors is beyond the scope of this report, which 

concentrates on estimating the lives saved by vehicle safety technologies. Nevertheless, it is 

interesting to look at the trends in occupant fatality rates per 100,000,000 VMT – with and 

without the safety technologies. 

Table 2-6 shows the VMT of passenger cars + LTVs in 1960-2002 and computes the rates of 

actual and potential fatalities per 100,000,000 miles in each calendar year.3

 America has been an 

increasingly mobile society, and VMT has grown every year except the energy-crisis years of

1974 and 1979-80, when it barely decreased. The actual fatality rate of car/LTV occupants has 

dramatically fallen from 4.26 fatalities per 100,000,000 miles in 1960 to 1.25 in 2002. Without 

the vehicle safety technologies, the potential fatality rates would have been 4.28 in 1960 and 2.18 

in 2002. 

Figure 2-4 shows the difference in the trends of the actual and potential fatality rates. From 1960 

to the mid-1970’s there was little difference between the actual and potential rates, because the 

vehicle technologies were not yet saving that many lives. There were large changes in the 

fatality rate for reasons unrelated to the FMVSS. From 1960 to 1964, the fatality rate actually 

increased as the first great cohort of baby-boomers, born immediately after World War 2, began 

to drive. From 1966 to 1977, the actual and potential rates fell dramatically (the potential rate 

from 4.61 to 2.70), partly because of major infrastructure improvements such as the Interstate 

Highway System, but also because of demographic and external factors that began to act at 

various times, such as: 

• An increasingly urbanized and suburban population, with an increasing share of the VMT 

involved in relatively low-risk commuting and urban trips. 

• A rising proportion of female drivers, who have lower fatal crash rates. 

• In the 1970’s, the first cohort of baby-boomers passed age 25, their most dangerous 

driving years behind them. 

• Toward the end of that period, the energy crisis, the 55 mph speed limit and a recession. 

From about 1983 onwards, the paradigm shifts. The potential fatality rate has stayed rather flat 

at about 2.1, whereas the actual fatality rate improved from 1.92 to 1.25. In other words, in the 

absence of vehicle safety technologies including increased belt use, if all other factors 

influencing the fatality rate had stayed the same, the fatality rate would also have stayed about 

the same. 

 

3 Traffic Safety Facts 2002, NHTSA Report No. DOT HS 809 620, Washington, 2004, p. 22 specifies VMT for cars 

in 1975-2002 and p. 24 for LTVs; add them to obtain the left column of Table 2-6. VMT estimates were obtained 

from the Federal Highway Administration (FHWA). P. 15 shows VMT for all vehicles on the road in 1966-2002,

also obtained from FHWA. In 1975-80, cars + LTVs accounted for 92.4 percent of total VMT, and this percentage 

is assumed also for years before 1975. Accident Facts 1974 Edition, National Safety Council, Chicago, 1974, p. 59

tabulates VMT back to 1960 and earlier, also obtained from FHWA but with a slightly different definition. In 1966-

73 the Traffic Safety Facts VMT is 99.6 percent of the Accident Facts VMT, and this percentage is also assumed for 

years before 1966. 

194
TABLE 2-6: ACTUAL AND POTENTIAL OCCUPANT FATALITIES

IN CARS/LTVs PER 100,000,000 MILES VMT 

 POTENTIAL FATALITIES 

 ACTUAL FATALITIES W/O SAFETY TECHNOLOGIES 

 VMT 

 CY (108 MILES) N RATE N RATE 

1960 6,617 28,183 4.26 28,298 4.28 

1961 6,791 28,087 4.14 28,203 4.15 

1962 7,058 30,544 4.33 30,679 4.35 

1963 7,408 32,664 4.41 32,823 4.43 

1964 7,794 35,603 4.57 35,805 4.59 

1965 8,172 36,518 4.47 36,767 4.50 

1966 8,560 39,131 4.57 39,465 4.61 

1967 8,911 39,327 4.41 39,825 4.47 

1968 9,392 41,019 4.37 41,818 4.45 

1969 9,817 42,117 4.29 43,273 4.41 

1970 10,260 39,556 3.86 40,972 3.99 

1971 10,898 38,916 3.57 40,650 3.73 

1972 11,647 40,103 3.44 42,280 3.63 

1973 12,137 38,739 3.19 41,258 3.40 

1974 11,841 31,145 2.63 33,608 2.84 

1975 12,347 31,360 2.54 34,356 2.78 

1976 13,040 32,222 2.47 35,397 2.71 

1977 13,598 33,173 2.44 36,772 2.70 

1978 14,259 34,988 2.45 38,952 2.73 

1979 14,055 35,108 2.50 39,325 2.80 

1980 14,025 35,098 2.50 39,554 2.82 

1981 14,297 33,911 2.37 38,284 2.68 

1982 14,679 29,855 2.03 33,834 2.30 

1983 15,227 29,209 1.92 33,384 2.19 

1984 15,850 30,177 1.90 34,934 2.20 

1985 16,378 30,043 1.83 36,357 2.22 

1986 16,941 32,380 1.91 40,828 2.41 

1987 17,729 33,306 1.88 43,204 2.44 

1988 18,725 34,217 1.83 45,407 2.42 

1989 19,377 33,709 1.74 45,127 2.33 

1990 19,828 32,830 1.66 44,470 2.24 

1991 20,076 30,929 1.54 43,060 2.14 

1992 20,784 29,542 1.42 41,965 2.02 

1993 21,205 30,182 1.42 43,917 2.07 

1994 21,707 30,979 1.43 46,075 2.12 

1995 22,283 32,057 1.44 48,114 2.16 

1996 22,864 32,534 1.42 50,289 2.20 

1997 23,533 32,501 1.38 51,003 2.17 

1998 24,179 31,940 1.32 51,263 2.12 

1999 24,701 32,151 1.30 52,038 2.11 

2000 25,233 32,233 1.28 53,968 2.14 

2001 25,715 32,009 1.24 54,557 2.12 

2002 26,248 32,737 1.25 57,243 2.18 

195
FIGURE 2-4: ACTUAL AND POTENTIAL OCCUPANT FATALITIES

IN CARS/LTVs PER 100,000,000 MILES VMT 

(“A” = actual fatalities; “P” = potential fatalities without the vehicle safety technologies) 

 5.0 ˆ 

 ‚ 

 ‚ 

 ‚enter A A 

 4.5 ˆthe A P P great decline 

 ‚ A A A A P not due to FMVSS 

 ‚A A 

 ‚ A Interstates/better roads 

 4.0 ˆbaby- P 

 ‚boomers A urbanization/more female drivers 

 ‚ P 

 ‚ A P baby-boomers growing up 

 3.5 ˆ A 

 ‚ P energy crisis 

 ‚ A 

 ‚ recession 

 3.0 ˆ 

 ‚ P P 

 ‚ P P P P P 

 ‚ A P recession 

 2.5 ˆ A A A A A A without the FMVSS, the rate 

 ‚ A P P P P would have stayed flat at 2.1 

 ‚ the FMVSS P P P P P P 

 ‚ start to make P P P P P P P P P P 

 2.0 ˆ a visible A P 

 ‚ difference A A A A A A 

 ‚ A 

 ‚ A 

 1.5 ˆ A A 

 ‚ A A A A A A 

 ‚ A A A A 

 ‚ with the FMVSS, the rate 

 1.0 ˆ has continued to decrease 

 ‚ 

 ‚ 

 ‚ 

 0.5 ˆ 

 ‚ 

 ‚ 

 ‚ 

 0.0 ˆ 

 ‚ 

 ______________________________________________________________________________________

 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 

 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 

 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 

 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 

 CALENDAR YEAR 

196
• A reduction in the average mass of passenger cars on the road, as pre-downsized vehicles 

were retired, followed by an influx of rollover-prone and aggressive LTVs, may have 

contributed to increasing the rate. 

• An increasingly prosperous society, with more recreational driving destinations and a 

greater hurry to get there, may have increased the rate. 

But the steady increase in belt use, air bags, and other vehicle safety technology helped preserve 

the long-term downward trend in the fatality rate. 

Estimates of lives saved by each FMVSS 

Tables 2-7, 2-8 and 2-9 apportion the 328,551 lives saved in 1960-2002 among the various safety 

standards. Table 2-7 indicates that safety belts saved 168,524 occupants of cars and LTVs in 

1960-2002, including 14,570 in 2002. The estimate comprises safety belts of all types – 

lap/shoulder, lap only and automatic 2-point – at all seat positions, front and rear, outboard and 

center. Lap belts were saving about 500 lives a year in the early 1970’s. The transition to 3-

point belts in the mid-1970’s increased that to about 800. In the mid-1980’s, buckle-up laws had 

a huge impact, raising lives saved to 6,000 per year by 1988-90 and, for the first time since 1970, 

putting belts far ahead of any other FMVSS in number of lives saved. Since 1990, continuing, 

successful programs to increase belt use, and the expanding “base” of VMT, vehicles and 

potentially fatal crashes has kept the “saved by the belt” number growing every year. 

Furthermore, belts are especially effective in LTVs (because many potentially fatal crashes are 

rollovers and/or ejections), and the growing SUV population means belts are saving more 

people. The 168,524 lives saved by belts are just over half of the total of 328,551; the 14,570 

saved in 2002 are well over half of the total of 24,561 saved in that year. 

Frontal air bags saved 12,074 lives in 1986-2002, including 2,473 in 2002. They are one of the 

most recent safety technologies to appear. In CY 2002, 133 million cars and LTVs had driver air 

bags, comprising 63 percent of all cars and LTVs on the road.4

 Vehicles with air bags are 

gradually replacing the older fleet without air bags, and the number of lives saved by air bags has 

been growing, year by year, as the fleet with air bags grows. When the proportion of vehicles 

with air bags gets closer to 100 percent, air bags will climb to clear 2nd place, behind safety belts 

but ahead of all the other FMVSS, in lives saved per year. 

 

4 Traffic Safety Facts 2002 – Occupant Protection, NHTSA Publication No. DOT HS 809 610, Washington, 2004

states there were 133 million vehicles with driver air bags; Traffic Safety Facts 2002, op. cit., pp. 22 and 24 indicate 

there were 212 million cars and LTVs on the road in 2002. 

197

For example, during 1983-2002, there were some factors that tended to reduce the fatality rate 

while other offsetting factors increased it: 

• Effective programs to reduce drunk driving helped to reduce the fatality rate. 

• A growing and increasingly mobile population of crash-prone, physically vulnerable 

older drivers contributed to increasing the rate. 
TABLE 2-7: CAR + LTV OCCUPANTS SAVED BY SAFETY BELTS,

FRONTAL AIR BAGS, AND CHILD SAFETY SEATS, 1960-2002 

 CHILD 

 SAFETY AIR SAFETY 

 CY BELTS5 BAGS6 SEATS 

1960 115 0 0 

1961 116 0 0 

1962 129 0 0 

1963 140 0 0 

1964 160 0 0 

1965 174 0 0 

1966 195 0 0 

1967 205 0 0 

1968 240 0 1 

1969 298 0 1 

1970 332 0 4 

1971 379 0 9 

1972 470 0 14 

1973 546 0 19 

1974 591 0 20 

1975 843 0 36 

1976 755 0 17 

1977 791 0 34 

1978 797 0 24 

1979 707 0 49 

1980 706 0 43 

1981 666 0 70 

1982 657 0 73 

1983 823 0 112 

1984 1,151 0 131 

1985 2,370 0 166 

1986 3,976 1 157 

1987 5,066 2 209 

1988 5,967 3 226 

1989 6,187 8 239 

1990 6,367 43 233 

1991 6,912 75 252 

1992 7,251 103 283 

1993 8,222 207 278 

1994 9,118 308 326 

1995 9,443 538 331 

1996 10,563 764 393 

1997 11,017 984 372 

1998 11,535 1,233 346 

1999 11,687 1,485 396 

2000 12,915 1,781 427 

2001 13,373 2,065 328 

2002 14,570 2,473 335 

 =========== =========== =========== 

 168,524 12,074 5,954 

 

5

 Includes lives saved by NCAP-related voluntary improvements for belted car drivers (1,024 total in 1979-2002). 6

 Net lives saved by air bags: benefits for adults and adolescents (age 13+) are to a small extent offset by increased

risk to certain groups of child passengers (age 0-12); see Tables 2-38 – 2-40. 

198
but because more people are putting their children in the back seat, a safer place, and are also 

driving more safely. 

NHTSA’s National Center for Statistics and Analysis (NCSA) generates the agency’s official 

estimates of lives saved by safety belts, air bags and safety seats by the same general 

computational method.7

 NCSA’s and this report’s estimates are not identical because this report 

introduces slightly different computational procedures as it estimates the lives saved by all 

vehicle safety technologies, not just belts, air bags and safety seats. But the estimates are, on the 

average, very close – e.g., this report estimates 164,435 lives saved by belts in 1975-2002 while 

NCSA estimates 164,753. 

Tables 2-8 and 2-9 estimate the lives saved by all the vehicle technologies other than safety belts, 

air bags and safety seats, grouping them under the eight FMVSS associated with them. 

Importantly, the right column of Table 2-9 shows that, together, these “built-in,” non-belt 

technologies saved an estimated 142,000 lives in 1960-2002, a substantial portion of the 328,551 

lives saved by all the technologies. That column shows they were saving 3,000 lives per year by 

the late 1970’s, by which time most cars of the pre-FMVSS era had been retired. The savings 

continued to grow, reaching 7,183 in 2002, as some new technologies were introduced, most preFMVSS LTVs were retired, and above all as the “base” of vehicles, VMT and potentially fatal 

crashes continued to grow. The eight individual FMVSS generally exhibit similar growth in 

lives saved during 1980-2002. 

Braking improvements directly or indirectly associated with FMVSS 105 include dual master 

cylinders, implemented in the early-to-mid 1960’s, and front disc brakes, introduced during 

1965-1977. The first column of Table 2-8 shows these technologies began saving lives in 1962. 

Benefits grew rapidly in 1967-80 as vehicles with dual master cylinders replaced older vehicles 

without them in the on-road fleet. Benefits continued to grow after 1980 as the “base” of 

potentially fatal crashes kept expanding. They saved an estimated 13,053 lives in 1962-2002, 

including 538 in 2002. The people who owe their lives to these safety improvements are not 

limited to occupants of the cars and LTVs equipped with them. When a car or LTV, as a 

consequence of these improvements, avoids hitting another car/LTV, a pedestrian, bicyclist or 

motorcyclist, it may prevent a fatality among any of those groups. 

The life-saving technology associated with FMVSS 108 is the red-and-white conspicuity tape on 

heavy truck trailers. Although this device is furnished on heavy trailers, not cars or LTVs, it is 

the occupants of cars and LTVs who primarily benefit, because it helps them avoid hitting the 

trailers in the dark. The tape began to appear on substantial numbers of trailers by 1991, and it 

has saved an estimated 1,105 car/LTV occupants, including 159 in 2002. 

 

7 Traffic Safety Facts 2002 – Occupant Protection, op. cit.

199

Child safety seats have been saving 300-400 lives per year since the early 1990’s. They have 

been available and saving lives since the late 1960’s. Benefits really began to increase after the 

States enacted child passenger protection laws in 1978-85, and followed up with campaigns to 

increase use. Benefits were lower in 2001-2002 than in 1996-2000, not because use declined, 
TABLE 2-8: LIVES SAVED BY TECHNOLOGIES ASSOCIATED WITH 

FMVSS 105, 108, 201, 203 AND 206, 1960-2002 

 FMVSS 105 FMVSS 108 FMVSS 201 FMVSS 203 FMVSS 206 

 BRAKES HEAVY 

 (INCLUDES TRAILER INSTRUMENT STEERING DOOR 

 CY PEDS, MCs) CONSPICUITY PANEL ASSEMBLY LOCKS 

1960 0 0 0 0 0 

1961 0 0 0 0 0 

1962 2 0 0 0 4 

1963 4 0 0 0 15 

1964 7 0 0 0 34 

1965 9 0 0 0 60 

1966 24 0 1 3 98 

1967 54 0 14 68 141 

1968 92 0 45 201 198 

1969 129 0 88 346 258 

1970 157 0 128 449 293 

1971 189 0 179 563 337 

1972 232 0 247 706 396 

1973 262 0 305 808 427 

1974 242 0 307 760 378 

1975 278 0 366 894 385 

1976 300 0 408 989 435 

1977 330 0 458 1,113 566 

1978 360 0 528 1,262 620 

1979 377 0 548 1,334 753 

1980 387 0 600 1,381 838 

1981 380 0 602 1,351 795 

1982 344 0 535 1,231 692 

1983 338 0 522 1,210 702 

1984 357 0 553 1,294 730 

1985 369 0 605 1,469 763 

1986 407 0 700 1,614 908 

1987 428 0 733 1,718 1,012 

1988 448 0 782 1,834 1,098 

1989 442 0 792 1,877 1,036 

1990 438 0 793 1,887 1,045 

1991 420 9 767 1,821 1,026 

1992 408 20 766 1,805 980 

1993 427 32 792 1,924 992 

1994 443 50 808 2,032 1,059 

1995 462 69 851 2,162 1,110 

1996 479 81 885 2,243 1,156 

1997 485 113 916 2,306 1,153 

1998 487 129 876 2,345 1,179 

1999 492 154 832 2,330 1,238 

2000 508 158 900 2,440 1,298 

2001 516 132 882 2,592 1,292 

2002 538 159 930 2,657 1,398 

 =========== =========== =========== =========== =========== 

 13,053 1,105 21,043 53,017 28,902 

200
TABLE 2-9: LIVES SAVED BY TECHNOLOGIES ASSOCIATED WITH 

FMVSS 212, 214 AND 216, 1960-2002 

 FMVSS212 FMVSS214 FMVSS216 TOTAL 

 FOR 8 

 WINDSHIELD SIDE IMPACT ROOF CRUSH NON-BELT 

 CY BONDING PROTECTION STRENGTH FMVSS 

1960 0 0 0 0

1961 0 0 0 0

1962 0 0 0 6

1963 0 0 0 20

1964 2 0 0 43

1965 8 0 0 78

1966 18 0 0 144

1967 28 0 0 304

1968 39 0 0 576

1969 53 7 0 880

1970 62 21 2 1,112

1971 72 40 5 1,387

1972 86 63 11 1,742

1973 94 96 18 2,010

1974 83 115 22 1,907

1975 85 142 29 2,179

1976 94 209 34 2,468

1977 104 218 59 2,847

1978 119 259 70 3,219

1979 121 308 103 3,543

1980 133 335 116 3,790

1981 133 343 115 3,719

1982 126 297 102 3,327

1983 131 311 98 3,312

1984 149 370 99 3,553

1985 169 370 108 3,853

1986 208 419 131 4,389

1987 238 429 137 4,695

1988 268 490 151 5,070

1989 259 504 144 5,053

1990 265 504 136 5,067

1991 262 512 138 4,956

1992 247 489 133 4,847

1993 263 525 134 5,088

1994 278 585 148 5,402

1995 294 708 147 5,804

1996 300 789 160 6,093

1997 298 767 150 6,187

1998 306 788 156 6,266

1999 315 860 154 6,374

2000 322 892 148 6,666

2001 333 944 148 6,839

2002 347 994 161 7,183

 =========== =========== =========== =========== 

 6,710 14,703 3,466 142,000 

201
Improvements to mid- and lower instrument panels, not actually required by FMVSS 201 but 

historically and functionally associated with that standard to some extent, began to appear in cars 

in the later 1960’s and in LTVs a few years after that. They have saved an estimated 21,043 

right-front passengers in frontal crashes, including 930 in 2002. 

Energy-absorbing steering assemblies meeting FMVSS 203 and 204 were one of the most 

important “built-in” early safety technologies. They significantly reduced the fatality risk of 

drivers in frontal crashes, and have saved an estimated 53,017 lives in cars and LTVs, including 

2,657 in 2002. Energy-absorbing column and well-designed instrument panels continue to be 

important components of the overall occupant protection system in today’s vehicles with air 

bags, and they continue to save lives. Specifically, as explained in the “Summary of the 

Estimation Method,” our model first computes by how much fatalities would increase if the most 

recent technologies such as air bags were “removed” from today’s vehicles, and then by how 

much more they would increase if the earlier technologies such as energy-absorbing columns 

were also “removed.” 

Improvements to door locks, latches, hinges and other components regulated by FMVSS 206 

have significantly reduced door ejections in rollover crashes, saving an estimated 28,902 lives in 

1962-2002, including 1,398 in 2002. Recent increases in the population of relatively rolloverprone LTVs have expanded the “base” of potentially fatal crashes addressed by this technology. 

FMVSS 212, windshield bonding, is the first standard addressed in Table 2-9. The introduction 

of adhesive windshield bonding extended from 1963 in some cars until approximately 1985 in 

some LTVs. As a result, the benefits for FMVSS 212 built up more gradually than some other 

standards. Adhesive bonding has significantly reduced occupant ejections via the windshield 

portal, saving an estimated 6,710 lives in 1964-2002, including 347 in 2002. 

The estimates of benefits associated with FMVSS 214, side impact protection, are based on three 

technologies that entered at different times: side door beams for passenger cars (1969-73), 

voluntary TTI(d) reductions in 2-door cars before the dynamic test requirement went into effect 

(1986-93) and side door beams for LTVs (mostly 1994). Each new technology increased 

benefits, reaching 994 lives saved in 2002, and a total of 14,703 in 1969-2002. The most recent 

technologies – the 1994-97 upgrade in response to the new dynamic test, and side air bags – have 

not yet been evaluated and are not included in these estimates. 

FMVSS 216, roof crush strength, is associated with the redesign of true hardtops as pillared 

hardtops or sedans during the 1970’s. The elimination of these hardtops with low, flat, 

vulnerable roofs saved lives; if cars were still built that way there would have been 3,466 

additional fatalities, including an estimated 161 in 2002. 

Ranked by their estimates of lives saved in 1960-2002, the 11 groups of safety technologies line 

up as follows: 

202
Lives Saved in 1960-2002 

208/209/210 Safety belts 168,524 

203/204 Energy-absorbing steering assemblies 53,017 

206 Door locks, latches and hinges 28,902 

201 Instrument panels 21,043 

214 Side impact protection 14,703 

105 Dual master cylinders/front disc brakes 13,053 

208 Air bags (frontal) 12,074 

212 Adhesive windshield bonding 6,710 

213 Child safety seats 5,954 

216 Roof crush resistance 3,466 

108 Trailer conspicuity tape 1,105

 328,551 

Safety belts are first by far, followed by three of the early occupant protection standards dating 

back to January 1, 1968 for passenger cars. However, some of the technologies were later 

arrivals and have not had as many years of accumulated benefits. Ranked by their estimates of 

lives saved in 2002 alone, the 11 FMVSS line up as follows: 

Lives Saved in 2002 

208/209/210 Safety belts 14,570 

203/204 Energy-absorbing steering assemblies 2,657 

208 Air bags (frontal) 2,473 

206 Door locks, latches and hinges 1,398 

214 Side impact protection 994 

201 Instrument panels 930 

105 Dual master cylinders/front disc brakes 538 

212 Adhesive windshield bonding 347 

213 Child safety seats 335 

216 Roof crush resistance 161 

108 Trailer conspicuity tape 159

 24,561 

Safety belts and air bags account for a much large proportion of the total in recent years. Air 

bags moved up to 3rd place on the list and are likely to have moved to 2nd in 2003, as older 

vehicles without air bags continued to be retired. 

As stated in the “Summary of the Estimation Method,” our model comprises any technology 

where cars/LTVs produce and/or receive benefits: not only (1) the lives saved in cars and LTVs 

by car/LTV technologies (plus child safety seats), but also (2) the non-occupants and 

motorcyclists saved by car/LTV technologies and (3) the car/LTV occupants saved by 

203
technologies in other vehicles (heavy trailers). We can now estimate the sizes of these three 

groups: 99 percent of the benefits estimated by the model are car/LTV occupant lives saved by 

car/LTV technologies (plus child safety seats)8

: 

Car/LTV occupant lives saved by car/LTV technologies 325,266 

Non-occupant/motorcyclist lives saved by car/LTV brake improvements 2,180 

Car/LTV occupant lives saved by heavy-trailer conspicuity tape 1,105

328,551

Benefits for occupants of passenger cars 

Table 2-10 is a summary of the benefits of safety technologies for passenger car occupants. 

Actual fatalities in passenger cars increased from 24,689 in 1960 to an all-time high of 36,406 in 

1969. They have rather steadily declined since then to 20,489 in 2002, reflecting cars’ gradual 

loss of market share to LTVs. But safety improvements greatly contributed to the decline; 

without them, fatalities would only have fallen from 37,449 in 1969 to 34,664 in 2002. Safety 

technologies saved 232,255 car occupants in 1960-2002, including 14,175 in 2002. Voluntary 

improvements such as better instrument panels, TTI(d) reductions in 2-door cars and designs to 

new FMVSS before their effective date have been saving between 600 and 1,100 lives a year 

since 1968; however, most of the lives saved (200,156) are by safety technologies directly 

associated with FMVSS in effect at that time. 

The proportion of potential fatalities saved by safety technologies has grown from 0.37 percent 

in 1960, when 92 car occupants were saved by lap belts, to 40.89 percent in 2002. The largest 

boost (from 14.32 to 25.35 percent) came in 1984-88, when buckle-up laws took effect in most 

of the States, but there have been continued, steady gains since with belt use increasing and air 

bags phasing in. 

 

8

 The non-occupant/motorcyclist lives saved are the sum of the last two columns (1,782 + 398) on Table 2-4; the

car/LTV occupant lives saved by trailer conspicuity tape is the total for FMVSS 108 in Table 2-8. (Trailer 

conspicuity tape also has the potential to save lives of motorcyclists and heavy-truck occupants, but these are not

tallied by our model, as explained in the “Summary of the Estimation Method.”) 

204
TABLE 2-10: PASSENGER CAR SUMMARY – ACTUAL OCCUPANT FATALITIES, 

POTENTIAL FATALITIES WITHOUT THE SAFETY TECHNOLOGIES, AND LIVES 

SAVED 

 CAR OCCUPANT FATALITIES LIVES SAVED 

 W/O SAFETY BY VOLUNTARY BY FMVSS PERCENT 

 CY ACTUAL TECHS. IMPROVEMENTS IN EFFECT TOTAL SAVED 

1960 24,689 24,782 92 0 92 0.37 

1961 24,605 24,699 95 0 95 0.38 

1962 26,757 26,867 110 0 110 0.41 

1963 28,614 28,745 131 0 131 0.46 

1964 31,189 31,357 168 0 168 0.54 

1965 31,991 32,202 211 0 211 0.66 

1966 34,346 34,634 288 0 288 0.83 

1967 34,542 34,986 444 0 444 1.27 

1968 35,720 36,439 614 105 719 1.97 

1969 36,406 37,449 700 342 1,042 2.78 

1970 34,051 35,331 711 568 1,279 3.62 

1971 33,463 35,036 778 796 1,574 4.49 

1972 34,444 36,427 899 1,084 1,984 5.45 

1973 32,874 35,155 957 1,325 2,282 6.49 

1974 26,103 28,322 809 1,411 2,220 7.84 

1975 26,601 29,325 873 1,851 2,723 9.29 

1976 26,803 29,655 864 1,988 2,852 9.62 

1977 27,337 30,527 881 2,310 3,190 10.45 

1978 28,438 31,940 878 2,624 3,501 10.96 

1979 28,069 31,725 857 2,800 3,657 11.53 

1980 27,709 31,557 839 3,009 3,848 12.20 

1981 26,945 30,703 789 2,970 3,758 12.24 

1982 23,390 26,783 686 2,708 3,394 12.67 

1983 22,932 26,466 646 2,889 3,534 13.35 

1984 23,596 27,538 626 3,317 3,943 14.32 

1985 23,217 28,413 684 4,512 5,196 18.29 

1986 24,966 31,794 826 6,001 6,827 21.47 

1987 25,098 32,881 835 6,948 7,783 23.67 

1988 25,720 34,453 879 7,854 8,733 25.35 

1989 25,020 33,697 874 7,803 8,677 25.75 

1990 24,089 32,773 859 7,825 8,684 26.50 

1991 22,338 31,281 855 8,088 8,943 28.59 

1992 21,303 30,310 866 8,141 9,007 29.72 

1993 21,543 31,459 913 9,004 9,916 31.52 

1994 21,949 32,575 962 9,664 10,626 32.62 

1995 22,342 33,457 1,026 10,088 11,115 33.22 

1996 22,495 34,571 1,082 10,994 12,076 34.93 

1997 22,142 34,288 1,121 11,025 12,146 35.42 

1998 21,210 33,535 1,072 11,253 12,325 36.75 

1999 20,902 33,303 1,034 11,367 12,401 37.24 

2000 20,712 33,765 1,094 11,958 13,052 38.66 

2001 20,324 33,856 1,087 12,445 13,532 39.97 

2002 20,489 34,664 1,083 13,092 14,175 40.89 

 =========== =========== =========== =========== =========== 

 1,137,471 1,369,726 32,099 200,156 232,255 

205
VMT data are available for passenger cars in 1975-2002.9

 They make it possible to compute 

occupant fatality rates per 100,000,000 VMT, as shown in Table 2-11 and Figure 2-5. Without 

the safety technologies, the fatality rate would potentially have remained nearly flat, close to 2.2, 

from about 1983 onward (with possibly a rising trend in the mid-1980’s as new, downsized cars 

continued to replace the pre-downsized fleet). But thanks to the safety improvements, the actual 

fatality rate trended steadily downward from 1.93 in 1983 to 1.27 in 2002. Specifically, the 

buckle-up laws enacted in the mid-1980’s more than cancelled any upward trend in the potential 

fatality rate.

At this point, we can review the lives saved by 22 individual safety technologies for passenger 

cars. Table 2-1 lists them in a chronological order based on the “median installation year”: the 

first year that at least 50 percent of new cars had the technology. Our presentation will follow 

the same order, from oldest to newest (even though the computer models generating the 

estimates actually analyze the technologies in reverse chronological order). Table 2-12 covers 

the two earliest technologies, 208A – lap belts for front-outboard occupants (age 5 and older), 

and 208B – lap belt use (at any seat position) by children age 1-4. 

Lap belts at the driver and right-front seats were offered in some new cars as early as 1956 and 

were retrofitted into some cars even older than that. (Part 1 of this report discusses the 

availability and effectiveness of each safety technology, in this case the section on “lap belts for 

front-seat occupants” in the chapter on FMVSS 208.) By model year 1962, over half of new cars 

were equipped with lap belts; States were passing laws requiring lap belts on new cars sold there. 

Lap belts reduce fatality risk by an average of 27 percent. FMVSS 208, like other initial safety 

standards, went into effect on January 1, 1968. Any lap-belt installation before January 1, 1968 

– i.e., before mid-model year 1968 – is considered a “voluntary” installation, at least from a 

Federal point of view (although State laws might have required it), and any life saved by belts in 

a pre-MY 1968 or early-MY 1968 car is counted as a voluntary save in Table 2-12. Voluntary 

saves grow from 92 in 1960 to 176 in 1968 as more cars became equipped with belts. These 

cars, however, remained on the road after 1968 and their lap belts continued to accrue voluntary 

saves every year up to and including 2002, but in ever dwindling numbers as more and more 

were retired. 

Most cars built from January 1, 1968 until August 31, 1973 had separate lap and shoulder belts. 

Here, our model counts fatality reductions among people who wore only the lap belt as “saved 

by the lap belt” and tallies them in the “Post-FMVSS” column of Table 2-12. But fatality 

reductions among people who wore both belts are counted with “saved by lap/shoulder belts” in 

Table 2-18, technology 208F. The number of post-FMVSS saves grew from 12 in 1968 to 233 

in 1973 and generally declined after that as the MY 1968-73 cars were retired. The sum of 

voluntary and post-FMVSS saves, in the third column of Table 2-12, peaked at 337 in 1973 and 

totaled 4,312 in 1960-2002. Relatively low use and low effectiveness limited the number of 

lives saved by lap belts. 

 

9 Traffic Safety Facts 2002, op. cit., pp. 22. 

206
TABLE 2-11

CARS: ACTUAL AND POTENTIAL OCCUPANT FATALITIES 

PER 100,000,000 MILES VMT 

 POTENTIAL FATALITIES 

 ACTUAL FATALITIES W/O SAFETY TECHNOLOGIES 

 VMT 

 CY (108 MILES) N RATE N RATE 

1975 10,304 26,601 2.58 29,325 2.85 

1976 10,707 26,803 2.50 29,655 2.77 

1977 11,027 27,337 2.48 30,527 2.77 

1978 11,365 28,438 2.50 31,940 2.81 

1979 11,117 28,069 2.52 31,725 2.85 

1980 11,071 27,709 2.50 31,557 2.85 

1981 11,221 26,945 2.40 30,703 2.74 

1982 11,458 23,390 2.04 26,783 2.34 

1983 11,878 22,932 1.93 26,466 2.23 

1984 12,265 23,596 1.92 27,538 2.25 

1985 12,490 23,217 1.86 28,413 2.27 

1986 12,776 24,966 1.95 31,794 2.49 

1987 13,285 25,098 1.89 32,881 2.48 

1988 13,840 25,720 1.86 34,453 2.49 

1989 14,152 25,020 1.77 33,697 2.38 

1990 14,272 24,089 1.69 32,773 2.30 

1991 14,117 22,338 1.58 31,281 2.22 

1992 14,360 21,303 1.48 30,310 2.11 

1993 14,451 21,543 1.49 31,459 2.18 

1994 14,592 21,949 1.50 32,575 2.23 

1995 14,784 22,342 1.51 33,457 2.26 

1996 14,991 22,495 1.50 34,571 2.31 

1997 15,284 22,142 1.45 34,288 2.24 

1998 15,559 21,210 1.36 33,535 2.16 

1999 15,668 20,902 1.33 33,303 2.13 

2000 15,805 20,712 1.31 33,765 2.14 

2001 15,935 20,324 1.28 33,856 2.12 

2002 16,085 20,489 1.27 34,664 2.16 

207
FIGURE 2-5: ACTUAL AND POTENTIAL OCCUPANT FATALITIES

IN CARS PER 100,000,000 MILES VMT 

(“A” = actual fatalities; “P” = potential fatalities without the vehicle safety technologies) 

 3.0 ˆ 

 ‚ 

 ‚ P P P 

 2.8 ˆ P P P 

 ‚ P 

 ‚ 

 2.6 ˆ A small cars 

 ‚ A A A A replace 

 ‚ A big P P P basically flat without the FMVSS 

 2.4 ˆ A cars P 

 ‚ P P 

 ‚ P P P P P 

 2.2 ˆ P P P P 

 ‚ P P P P P P 

 ‚ A 

 2.0 ˆ 

 ‚ A A A 

 ‚ A A A 

 1.8 ˆ A 

 ‚ 

 ‚ A 

 1.6 ˆ A 

 ‚ A A A 

 ‚ A A A 

 1.4 ˆ 

 ‚ continued A A A 

 ‚ reduction A A 

 1.2 ˆ with the 

 ‚ FMVSS 

 ‚ 

 1.0 ˆ 

 ‚ 

 ‚ 

 0.8 ˆ 

 ‚ 

 ‚ 

 0.6 ˆ 

 ‚ 

 ‚ 

 0.4 ˆ 

 ‚ 

 ‚ 

 0.2 ˆ 

 ‚ 

 ‚ 

 0.0 ˆ 

 ______________________________________________________________________________________

 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 

 CALENDAR YEAR 

208
TABLE 2-12: CAR OCCUPANT LIVES SAVED BY FRONT-OUTBOARD LAP BELTS 

AND LAP BELTS FOR CHILDREN AGE 1-4, 1960-2002 

 208A: LAP BELTS FOR FRONT-OUTBOARD OCCS 208B: LAP BELT USE BY CHILDREN AGE 1-4 

 (MEDIAN INSTALL YR 1962, FMVSS 1/1/68) (MEDIAN INSTALL YR 1964, FMVSS 1/1/68) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 92 0 92 1 0 1 

1961 94 0 94 1 0 1 

1962 104 0 104 1 0 1 

1963 114 0 114 1 0 1 

1964 131 0 131 1 0 1 

1965 142 0 142 1 0 1 

1966 160 0 160 1 0 1 

1967 169 0 169 1 0 1 

1968 176 12 188 2 0 2 

1969 168 48 216 1 0 2 

1970 145 83 228 1 1 2 

1971 130 118 249 1 1 2 

1972 122 180 303 1 1 2 

1973 104 233 337 1 1 2 

1974 72 194 266 1 1 2 

1975 64 188 253 0 1 1 

1976 44 140 184 0 2 3 

1977 33 109 142 0 3 3 

1978 30 95 125 1 2 3 

1979 21 62 83 1 3 4 

1980 15 45 59 1 5 5 

1981 7 39 46 0 4 4 

1982 10 25 34 0 7 7 

1983 7 22 28 0 7 8 

1984 8 23 30 0 11 11 

1985 11 35 46 0 14 14 

1986 20 51 71 0 23 23 

1987 17 41 58 0 27 27 

1988 17 36 53 0 28 28 

1989 16 23 40 0 30 30 

1990 12 26 38 0 20 20 

1991 8 19 27 0 19 19 

1992 8 16 24 0 25 25 

1993 9 14 23 0 26 26 

1994 11 15 26 0 42 42 

1995 4 12 16 0 30 30 

1996 7 13 20 0 33 33 

1997 5 8 13 0 29 29 

1998 5 10 15 0 34 34 

1999 6 9 15 0 18 18 

2000 6 6 12 0 15 15 

2001 5 6 11 0 22 22 

2002 7 23 30 0 17 17 

 =========== =========== =========== =========== =========== =========== 

 2,335 1,978 4,312 21 504 525 

209
Technology 208B counts any child age 1-4 saved by belts (but not in a child safety seat) at any 

seat position. It counts them as “saved by lap belts” regardless of whether that seat was equipped 

with a lap belt only, a 3-point belt, or separate lap and shoulder belts, because the shoulder 

portion of the belt is of little value to a small child who is not in a safety seat. Lap belts reduce 

the fatality risk of 1-4 year old children by an average of 33 percent. They are not nearly as 

effective as a correctly used safety seat. Belts, without a safety seat, are assumed to have little or 

no value for infants (age 0); the model calculates no savings for infants. Lives saved in cars built 

before January 1, 1968 are “voluntary” saves, and they can accrue as long as such cars remain in 

service; savings in cars built on or after January 1, 1968 are counted as “post-FMVSS.” This 

technology had quite limited benefits before States enacted child passenger protection laws in the 

early 1980’s. Since then, belts have been saving 15-42 lives a year. Some State laws 

specifically permit a belt in lieu of a safety seat if a child has reached a certain age; in other 

cases, the adults transporting the child may simply decide on their own to use belts rather than a 

safety seat. Belts have saved a total of 525 children age 1-4 in cars. 

Table 2-13 tallies savings by FMVSS 206 – improved door locks and by technology 208B – lap 

belts for rear-outboard occupants (age 5 and older). A series of improvements to door locks in 

approximately 1962-68 makes that the earliest non-belt technology evaluated by NHTSA. The 

evaluation estimated a 15 percent reduction of fatalities in rollovers. Benefits grew rapidly to 

about 500 lives saved per year as cars with the new technology replaced older cars; after that 

they gradually escalated to 704 in 2002 as the “base” of VMT and potentially fatal crashes grew 

larger and as smaller, more rollover-prone cars replaced full-size cars. As explained in the 

“Summary of the Estimation Method,” our model first “removes” all safety technologies that 

came after FMVSS 206, most importantly 3-point belts. The 704 lives saved in 2002 are an 

estimate of the difference between a hypothetical fleet of cars equipped only with technologies 

lap belts for front-outboard occupants, lap belts for children and improved door locks (208A, 

208B and 206) and another fleet that does not even have the improved door locks – specifically it 

is the benefit of FMVSS 206 in a fleet where nobody has 3-point belts. As with the other 

technologies, all lives saved in cars built before the January 1, 1968 effective date are 

“voluntary” saves. Improved door locks saved an estimated 19,504 car occupants in 1960-2002. 

Lap belts were available at the rear-outboard seats of most new cars by 1965-66 and were 

required effective January 1, 1968. In the 1980’s, 3-point belts increasingly superseded lap belts, 

and FMVSS 208 required lap/shoulder belts effective December 11, 1989. Lap belts are 

estimated to reduce fatality risk by an average of 32 percent for back-seat occupants age 5 and 

older. They achieved their largest benefit, 116 lives saved, in 1988, just before the shift to 3-

point belts but after buckle-up laws, although primarily applicable to front-seat occupants, began 

to have a favorable influence on the back-seat occupants as well. These lap belts saved an 

estimated 1,360 lives in 1960-2002. 

210
TABLE 2-13: CAR OCCUPANT LIVES SAVED BY IMPROVED DOOR LOCKS

AND LAP BELTS FOR REAR-OUTBOARD OCCUPANTS, 1960-2002 

 206: IMPROVED DOOR LOCKS 208C: LAP BELTS FOR REAR-OUTBOARD OCCS 

 (MEDIAN INSTALL YR 1965, FMVSS 1/1/68) (MEDIAN INSTALL YR LATE 65, FMVSS 1/1/68) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 4 0 4 0 0 0 

1963 13 0 13 0 0 0 

1964 30 0 30 1 0 1 

1965 52 0 52 2 0 2 

1966 86 0 86 3 0 3 

1967 123 0 123 4 0 4 

1968 152 21 173 4 0 5 

1969 157 67 224 4 1 6 

1970 143 110 253 4 2 6 

1971 139 151 291 4 3 7 

1972 141 199 340 4 6 10 

1973 129 232 361 4 9 13 

1974 95 221 316 3 10 13 

1975 74 248 322 5 12 17 

1976 68 290 357 2 13 15 

1977 69 392 461 4 21 25 

1978 60 445 505 3 20 22 

1979 53 536 589 0 12 12 

1980 41 609 650 0 10 10 

1981 29 590 619 1 13 13 

1982 24 506 530 0 13 13 

1983 20 511 532 0 29 30 

1984 15 533 549 0 30 30 

1985 15 553 568 0 65 65 

1986 12 653 664 0 87 88 

1987 10 711 721 1 88 89 

1988 9 769 778 1 115 116 

1989 5 703 708 1 108 109 

1990 5 704 709 0 83 83 

1991 5 676 681 0 77 77 

1992 3 626 629 1 64 65 

1993 2 630 632 0 65 65 

1994 3 651 655 2 64 66 

1995 2 679 681 1 67 68 

1996 2 688 689 0 47 47 

1997 2 644 646 0 42 42 

1998 1 639 640 0 39 39 

1999 1 667 668 0 18 18 

2000 1 677 679 0 39 39 

2001 1 669 670 0 15 15 

2002 0 703 704 0 11 11 

 =========== =========== =========== =========== =========== =========== 

 1,797 17,707 19,504 59 1,301 1,360 

211
Table 2-14 considers adhesive windshield bonding and lap belts for front-center occupants. 

Adhesive windshield bonding is a technology associated with FMVSS 212 but not explicitly 

required by that standard. Its introduction extended from MY 1963 through the effective date of 

January 1, 1970 until approximately 1980, although the majority of new cars had it by MY 1966. 

Adhesive bonding significantly reduces the risk of ejection through the windshield portal. Lives 

saved in cars built before January 1, 1970 are counted as voluntary saves, all others as postFMVSS saves. The number of lives saved has gradually risen over 200 per year as the “base” of

VMT and potentially fatal crashes has increased. Adhesive bonding saved an estimated 5,248 

lives in 1960-2002. 

The front-center seat, like all designated seat positions, had to be equipped with lap belts by 

January 1, 1968 and often was equipped before that. Many cars do not have a front-center seat; 

when they do, it is usually unoccupied; and belt use is low. Nevertheless, over four decades, an 

estimated 81 car occupants can thank this technology for saving their lives. 

Table 2-15 addresses dual master cylinders (105A) and lap belts for rear-center occupants (age 

5+). Both of these technologies were required effective January 1, 1968 and often introduced a 

few years before that. Dual master cylinders reduce the risk of a fatal crash involvement by an 

estimated 0.7 percent. As the “base” of potentially fatal crashes grew, benefits also grew to 235 

car occupants saved in 2002, and a total of 6,737 in 1960-2002. 

Lap belts reduce the fatality risk of rear-center occupants by about 32 percent. Benefits have 

increased in recent years as belt use increased and as more children age 5-12 moved to the back 

seat. However, especially since 1999, manufacturers have been phasing in 3-point belts in 

anticipation of Anton’s law, and the numbers for lap belts will dwindle. Lap belts saved an 

estimated 191 rear-center occupants in 1960-2002. 

Table 2-16 analyzes two basic “built-in” protections for front-seat occupants in frontal crashes: 

energy-absorbing/telescoping steering assemblies to protect drivers (FMVSS 203/204), and 

voluntary modifications to mid and lower instrument panels, protecting passengers (associated 

with FMVSS 201). Energy-absorbing columns were introduced in the majority of cars in MY 

1967 – i.e., late CY 1966 – and FMVSS 203 and 204 took effect on January 1, 1968. Thus, lives 

saved in the MY 1967 and early MY 1968 cars are counted as voluntary saves. The technology 

reduced drivers’ fatality risk in frontal crashes by an estimated 12.1 percent. NHTSA’s 

evaluation report, using 1978 as the baseline year, said FMVSS 203/204 would be saving 1,300 

lives per year when all cars on the road met the standards. In fact, estimated benefits reached 

1,300 in 1986 and since then have grown to 1,660 in 2002 as the base of VMT and potentially 

fatal crashes has expanded since 1978. Energy-absorbing and telescoping columns continue to 

be a critical component of the overall frontal energy-management and crash-protection system, 

even in today’s cars with air bags and high belt use. With 41,545 lives saved in 1966-2002, 

energy-absorbing steering assemblies clearly rank first in cumulative benefits among the nonbelt technologies for passenger cars. 

212
TABLE 2-14: CAR OCCUPANT LIVES SAVED BY ADHESIVE WINDSHIELD BONDING 

AND LAP BELTS FOR FRONT-CENTER OCCUPANTS, 1960-2002 

 212: ADHESIVE WINDSHIELD BONDING 208D: LAP BELTS FOR FRONT-CENTER OCCS 

 (MEDIAN INSTALL EARLY 66, FMVSS 1/1/70) (MEDIAN INSTALL YR 1966, FMVSS 1/1/68) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 2 0 2 0 0 0 

1965 8 0 8 0 0 0 

1966 18 0 18 0 0 0 

1967 28 0 28 0 0 0 

1968 39 0 39 0 0 1 

1969 53 0 53 1 0 1 

1970 56 6 62 0 1 1 

1971 55 17 72 0 1 2 

1972 56 31 86 0 1 2 

1973 52 41 94 0 2 2 

1974 40 42 83 0 2 2 

1975 37 48 85 1 3 4 

1976 35 58 94 0 3 3 

1977 33 71 104 0 2 2 

1978 31 87 118 0 3 3 

1979 23 92 115 0 1 1 

1980 20 104 124 0 2 2 

1981 12 110 122 0 1 1 

1982 10 103 113 0 2 2 

1983 8 107 115 0 1 1 

1984 7 120 127 0 1 1 

1985 5 133 138 0 3 3 

1986 5 164 170 0 2 2 

1987 4 183 187 0 2 2 

1988 3 206 209 0 3 3 

1989 2 196 197 0 4 5 

1990 1 196 198 0 4 4 

1991 1 194 195 0 3 3 

1992 1 184 185 0 2 2 

1993 1 193 194 0 3 3 

1994 1 201 202 0 3 3 

1995 1 210 211 0 3 3 

1996 0 214 214 0 4 4 

1997 0 208 208 0 4 4 

1998 1 207 208 0 3 3 

1999 0 209 210 0 2 2 

2000 1 214 214 0 2 2 

2001 0 221 221 0 2 2 

2002 0 229 229 0 1 1 

 =========== =========== =========== =========== =========== =========== 

 652 4,597 5,248 6 75 81 

213
TABLE 2-15: CAR OCCUPANT LIVES SAVED BY DUAL MASTER CYLINDERS 

AND LAP BELTS FOR REAR-CENTER OCCUPANTS, 1960-2002 

 105A: DUAL MASTER CYLINDERS 208E: LAP BELTS FOR REAR-CENTER OCCS 

 (MEDIAN INSTALL YR LATE 66, FMVSS 1/1/68) (MEDIAN INSTALL EARLY 67, FMVSS 1/1/68) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 1 0 1 0 0 0 

1963 3 0 3 0 0 0 

1964 5 0 5 0 0 0 

1965 6 0 6 0 0 0 

1966 16 0 16 0 0 0 

1967 37 0 37 0 0 0 

1968 51 10 61 0 0 0 

1969 53 32 85 0 0 0 

1970 47 53 100 0 0 0 

1971 46 73 119 0 0 0 

1972 47 96 143 0 0 1 

1973 45 112 157 0 0 1 

1974 34 107 141 0 0 1 

1975 32 132 164 0 0 0 

1976 29 146 175 0 0 0 

1977 23 163 186 0 1 1 

1978 19 182 201 3 1 4 

1979 15 188 203 0 0 1 

1980 12 194 205 0 0 0 

1981 9 192 201 0 0 0 

1982 7 170 176 0 4 4 

1983 5 170 176 0 1 1 

1984 4 180 184 0 5 5 

1985 4 186 190 0 6 6 

1986 3 209 212 0 4 4 

1987 2 218 220 0 10 10 

1988 2 229 231 0 4 4 

1989 2 225 227 0 10 10 

1990 1 219 221 0 10 10 

1991 1 210 211 0 7 7 

1992 1 204 205 0 8 8 

1993 1 212 213 0 5 5 

1994 1 220 220 0 8 8 

1995 0 226 226 0 10 10 

1996 0 234 234 0 17 17 

1997 0 232 233 0 14 14 

1998 0 227 228 0 13 13 

1999 0 226 226 0 10 10 

2000 0 229 229 0 14 14 

2001 0 230 230 0 9 9 

2002 0 235 235 0 14 14 

 =========== =========== =========== =========== =========== =========== 

 565 6,172 6,737 5 186 191 

214
TABLE 2-16: CAR OCCUPANT LIVES SAVED BY ENERGY-ABSORBING STEERING 

ASSEMBLIES AND VOLUNTARY INSTRUMENT PANEL IMPROVEMENTS, 1960-2002 

 203: ENERGY-ABSORBING 201: VOLUNTARY INSTRUMENT 

 STEERING ASSEMBLIES PANEL IMPROVEMENTS 

 (MEDIAN INSTALL YEAR 1967, FMVSS 1/1/68) (MEDIAN INSTALL YR 1968, FMVSS 1/1/68) 

 

 CY VOLUNTARY POST-FMVSS TOTAL TOTAL (VOLUNTARY) 

1960 0 0 0 0 

1961 0 0 0 0 

1962 0 0 0 0 

1963 0 0 0 0 

1964 0 0 0 0 

1965 0 0 0 0 

1966 3 0 3 1 

1967 68 0 68 14 

1968 140 60 201 45 

1969 154 192 346 87 

1970 136 313 448 125 

1971 131 431 562 172 

1972 135 569 704 234 

1973 133 663 795 286 

1974 106 630 735 283 

1975 100 764 864 339 

1976 98 846 944 371 

1977 78 964 1,043 410 

1978 65 1,106 1,171 462 

1979 54 1,168 1,222 475 

1980 43 1,204 1,247 510 

1981 31 1,178 1,209 510 

1982 25 1,049 1,073 451 

1983 19 1,029 1,047 439 

1984 15 1,088 1,103 457 

1985 13 1,211 1,224 502 

1986 10 1,328 1,339 578 

1987 8 1,388 1,396 593 

1988 6 1,462 1,468 636 

1989 6 1,460 1,466 626 

1990 4 1,447 1,451 614 

1991 5 1,373 1,377 591 

1992 3 1,358 1,360 595 

1993 2 1,428 1,430 612 

1994 2 1,485 1,487 620 

1995 2 1,533 1,535 645 

1996 1 1,592 1,592 646 

1997 2 1,601 1,603 677 

1998 1 1,589 1,590 621 

1999 1 1,544 1,545 587 

2000 1 1,575 1,576 617 

2001 0 1,657 1,658 608 

2002 1 1,660 1,660 631 

 =========== =========== =========== =========== 

 1,601 39,944 41,545 16,670 

215
FMVSS 201 at one time proposed to regulate the force-deflection characteristics of mid and 

lower instrument panels, but those proposals were not included in the final rule. Nevertheless, 

manufacturers voluntarily remodeled the panels, using newly available materials, to absorb 

passenger impacts at a safer and more controlled force level. That has resulted in a 15.9 percent 

fatality reduction for unrestrained right-front passengers in frontal impacts. It saved an estimated 

16,670 lives from late CY 1966 through 2002. The benefits for this technology are about onethird of the benefits for energy-absorbing steering assemblies principally because one-third of 

crash-involved cars have a right-front passenger, while all have a driver. 

Table 2-17 addresses front disc brakes (105B) and side door beams (214A). Front disc brakes 

are well suited for meeting tests added to FMVSS 105 effective January 1, 1976, but were never 

explicitly required by that standard. Consumers preferred them to drum brakes. Their 

introduction extended from MY 1965 until 1977, but the majority of new cars had them by 1971. 

Front disc brakes reduce the risk of a fatal crash involvement by an estimated 0.17 percent. They 

have been saving approximately 50 car occupants per year, and a total of 1,256 in 1960-2002. 

Side door beams were introduced in some cars as early as MY 1969, four years before the 

January 1, 1973 effective date of FMVSS 214. This technology aims to enhance crashworthiness 

and structural integrity in side impacts. While there are significant injury reductions in all types 

of side impacts, fatality reduction has been limited to single-vehicle crashes, such as side impacts 

with poles or trees after a car has run off the road and gone out of control. Side door beams 

reduce these fatalities by 14 percent, saving 450-500 lives per year, and an estimated total of 

11,207 in 1960-2002. 

Table 2-18 covers FMVSS 216, roof crush resistance and the big one: 3-point belts for frontoutboard occupants, age 5+ (208F). The visible change associated with FMVSS 216 was the 

redesign of true hardtops as pillared hardtops or sedans. Nevertheless, many hardtops could and 

did meet FMVSS 216. The transition to pillared hardtops and sedans extended from

approximately MY 1970 through the FMVSS 216 effective date of September 1, 1973 until 

about 1977. Pillared cars do a significantly better job of protecting non-ejected occupants in 

rollover crashes, saving an estimated 161 lives in 2002, and 3,466 in 1960-2002. 

FMVSS 208 has required manual, integral 3-point belts at the driver’s and right-front seats in all 

cars without automatic protection since September 1, 1973 and in all cars since September 1, 

1997. From January 1, 1972 until August 31, 1973, FMVSS 208 required lap and shoulder belts 

at these positions in all cars, but manufacturers could choose between integral 3-point belts or 

separate lap and shoulder belts. From January 1, 1968 until December 31, 1971, this

requirement applied only to cars where a lap belt was insufficient to prevent a dummy from

contacting the windshield header (but, in reality, manufacturers equipped all their cars with 

separate or integral lap/shoulder belts). 

216
TABLE 2-17: CAR OCCUPANT LIVES SAVED BY FRONT DISC BRAKES 

AND SIDE DOOR BEAMS, 1960-2002 

 105B: FRONT DISC BRAKES 214A: SIDE DOOR BEAMS 

 (MEDIAN INSTALL YEAR 1971, FMVSS 1/1/76) (MEDIAN INSTALL EARLY 73, FMVSS 1/1/73) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 1 0 1 0 0 0 

1968 1 0 1 0 0 0 

1969 3 0 3 7 0 7 

1970 4 0 4 21 0 21 

1971 7 0 7 40 0 40 

1972 11 0 11 63 0 63 

1973 15 0 15 75 21 96 

1974 15 0 15 61 54 115 

1975 19 0 19 66 76 142 

1976 21 2 23 84 125 209 

1977 21 6 27 65 153 218 

1978 21 11 32 69 190 259 

1979 19 16 35 68 240 308 

1980 18 19 37 69 266 335 

1981 15 22 38 53 290 343 

1982 12 22 34 45 251 297 

1983 11 24 35 41 270 311 

1984 10 28 37 39 330 370 

1985 8 32 40 23 347 370 

1986 8 37 45 25 390 415 

1987 6 42 47 20 398 418 

1988 5 46 50 13 452 465 

1989 3 46 50 9 456 465 

1990 3 46 49 9 445 454 

1991 2 45 47 6 448 454 

1992 2 44 45 6 414 420 

1993 1 46 47 4 422 426 

1994 1 48 49 3 426 429 

1995 1 50 50 3 481 484 

1996 1 52 52 1 493 494 

1997 1 51 52 1 454 454 

1998 0 50 51 2 450 452 

1999 0 50 51 1 456 457 

2000 0 51 51 1 459 460 

2001 0 51 51 0 465 466 

2002 0 52 53 1 488 489 

 =========== =========== =========== =========== =========== =========== 

 267 989 1,256 998 10,209 11,207 

217
TABLE 2-18: CAR OCCUPANT LIVES SAVED BY ROOF CRUSH STRENGTH 

AND 3-POINT BELTS FOR FRONT-OUTBOARD OCCUPANTS, 1960-2002 

 216: ROOF CRUSH STRENGTH - ELIMINATE HARDTOPS 208F: 3-POINT BELTS FOR FRONT-OUTBOARD OCCS 

 (MEDIAN INSTALL YR 1973, FMVSS 9/1/73) (MEDIAN INSTALL YR 1974, FMVSS 9/1/73) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 2 0 2 

1969 0 0 0 12 0 12 

1970 2 0 2 23 0 23 

1971 5 0 5 38 0 38 

1972 11 0 11 59 0 59 

1973 18 0 18 77 9 86 

1974 15 7 22 64 144 208 

1975 14 15 29 85 363 448 

1976 14 20 34 83 344 426 

1977 19 41 59 88 384 472 

1978 16 54 70 71 427 499 

1979 19 84 103 53 398 451 

1980 19 97 116 53 449 502 

1981 16 99 115 31 429 460 

1982 12 90 102 33 452 486 

1983 9 89 98 33 563 596 

1984 8 92 99 28 776 804 

1985 5 103 108 57 1,685 1,742 

1986 7 125 131 77 2,801 2,878 

1987 4 133 137 70 3,515 3,585 

1988 3 148 151 54 4,072 4,127 

1989 2 141 144 44 4,005 4,049 

1990 2 134 136 45 3,824 3,869 

1991 1 137 138 45 4,009 4,054 

1992 1 132 133 34 4,066 4,100 

1993 1 133 134 34 4,561 4,595 

1994 1 148 148 26 4,791 4,817 

1995 0 147 147 32 4,882 4,914 

1996 0 159 160 22 5,401 5,424 

1997 0 149 150 22 5,471 5,493 

1998 0 155 156 28 5,562 5,591 

1999 0 153 154 7 5,602 5,608 

2000 0 148 148 16 5,883 5,899 

2001 0 148 148 12 6,288 6,299 

2002 0 160 161 7 6,554 6,561 

 =========== =========== =========== =========== =========== =========== 

 225 3,241 3,466 1,466 87,710 89,176 

218
The model developed for this study counts as “voluntary” saves by technology 208F: 

• All people (age 5+) saved by integral 3-point belts installed before September 1, 1973 – 

primarily in European cars. 

• Lives saved among occupants who used both the lap and the shoulder belts, in cars with 

separate lap and shoulder belts built before September 1, 1973. 

However, as stated earlier, people who wore only the lap belt in cars with separate belts are 

counted as “saved by lap belts” (208A). 

The model counts as “post-FMVSS” saves by technology 208F: 

• All people (age 5+) saved by manual, integral 3-point belts installed on or after 

September 1, 1973, regardless of whether these integral belts were used correctly or 

incorrectly (e.g., wearing the shoulder portion of the belt behind the back, essentially 

obtaining protection from the lap portion only). 

• Lives saved by automatic 3-point belts. Although they are automatic belts, they have had 

use patterns and effectiveness nearly identical to manual 3-point belts. 

As stated above, any child age 1-4 saved by a belt, without a safety seat, is counted as “saved by 

lap belts” (208B), even if it was a 3-point belt, because the shoulder portion is intrinsically of 

little value to a child that small. 

Three-point belts are the most important available occupant protection in most crash modes, 

reducing fatality risk by an average of 45 percent in passenger cars, when they are used. They 

were saving about 500 lives per year in 1977-83 as declining belt use more or less offset the 

growing proportion of the fleet equipped with 3-point belts. Buckle-up laws in most States 

phenomenally increased the benefits of belts to 4,127 lives saved by 1988. Continued increases 

in belt use and moderate growth in the “base” of VMT and potentially fatal crashes have raised 

that to 6,561 lives saved in 2002, and a cumulative 89,176 saved in 1960-2002. Both numbers 

are somewhat under half the overall benefits of the FMVSS in passenger cars. 

Table 2-19 estimates lives saved by voluntary NCAP-related improvements and child safety 

seats (FMVSS 213). Since 1979, the New Car Assessment Program (NCAP) has advised the 

public about the injury performance of belted dummies in 35-mph frontal impact tests. During 

the early-to-mid 1980’s, manufacturers substantially improved NCAP performance, modifying 

belt systems, steering assemblies, instrument panels and/or seat structures. For cars without air 

bags, NHTSA’s evaluation estimated a 20 percent reduction of fatality risk for belted drivers in 

frontal impacts with other cars. NHTSA has not evaluated the relationship of NCAP scores with 

fatality risk in cars with air bags; the model limits its estimate of a benefit to cars without air 

bags. Lives saved by vehicle modifications associated with NCAP performance have saved an 

estimated 1,024 lives in 1983-2002; the estimates peaked at 79 in 1993 and have declined since 

then because almost all new cars have had driver air bags. Because NCAP is not a FMVSS, and 

any modifications to improve performance were voluntary on the part of the manufacturers, all 

benefits are counted as voluntary saves. 

219
TABLE 2-19: CAR OCCUPANT LIVES SAVED BY VOLUNTARY NCAP-RELATED 

IMPROVEMENTS AND CHILD SAFETY SEATS, 1960-2002 

 NCAP-RELATED VOLUNTARY IMPROVEMENTS 213: CHILD SAFETY SEATS 

 (USE EXCEEDED 50% IN 1985, 

 (MEDIAN IMPLEMENTATION EARLY 1984) FMVSS 4/1/71, STATE LAWS 1978-85) 

 

 CY TOTAL (VOLUNTARY) VOLUNTARY OBLIGATORY TOTAL 

1960 0 0 0 0 

1961 0 0 0 0 

1962 0 0 0 0 

1963 0 0 0 0 

1964 0 0 0 0 

1965 0 0 0 0 

1966 0 0 0 0 

1967 0 0 0 0 

1968 0 1 0 1 

1969 0 1 0 1 

1970 0 4 0 4 

1971 0 8 0 8 

1972 0 14 0 14 

1973 0 18 0 18 

1974 0 19 0 19 

1975 0 34 0 34 

1976 0 15 0 15 

1977 0 32 0 32 

1978 0 22 0 22 

1979 0 48 0 48 

1980 0 33 6 40 

1981 0 66 2 69 

1982 0 51 16 67 

1983 2 42 65 107 

1984 4 16 101 117 

1985 16 7 138 145 

1986 36 15 125 140 

1987 52 12 164 175 

1988 66 8 181 189 

1989 65 15 194 209 

1990 61 14 188 201 

1991 71 10 198 208 

1992 70 18 226 245 

1993 79 4 238 242 

1994 72 15 250 265 

1995 68 17 243 260 

1996 66 26 289 314 

1997 67 20 268 288 

1998 64 12 256 268 

1999 50 22 273 295 

2000 43 28 306 334 

2001 41 30 205 236 

2002 27 25 198 223 

 =========== =========== =========== =========== 

 1,024 723 4,131 4,854 

220
FMVSS 213 regulates the performance of child safety seats. However, the seats themselves are 

not part of a new vehicle. They must be purchased or acquired separately. At first, that was a 

voluntary decision for parents. During 1978-85, every State enacted laws requiring a safety seat 

for child passengers up to a certain age. The model counts as a “voluntary” save by child safety 

seats:

• Any child saved before a child passenger protection law was in effect in that State. 

• Any child saved who was older than the range of ages included in that State’s law. 

The model counts as an “obligatory” save: 

• Any child saved by a child safety seat in a State where a law was in effect, and that law 

required a child of that age to be in a safety seat.

However, any child saved by a belt, without a safety seat, is counted in one of the “saved by 

belts” categories, depending on the child’s age and seat position, and is not counted as saved by a 

safety seat. 

NHTSA’s evaluation estimates that safety seats reduce fatality risk in passenger cars by 71 

percent for infants and by 54 percent for toddlers. Safety seats saved an estimated 4,854 lives in 

1960-2002, of which 4,131 were children obligated by a State law to be in a safety seat, while 

723 were voluntary saves before State laws or involving older children. Benefits peaked at 334 

in 2000, but dropped in 2001-2002 because the exposure “base” of children in potentially fatal 

crashes shrank – in part because more and more children are placed in the safer back seat to 

avoid exposure to air bags, and because many children are now transported in minivans or SUVs 

rather than cars. 

Table 2-20 considers two of the more recent belt technologies: 3-point belts for rear-outboard 

occupants (208G) and automatic 2-point belts for front-outboard occupants (208H). FMVSS 208 

has required lap/shoulder belts at rear-outboard seats since December 11, 198910, and quite a few 

make-models were voluntarily equipped with 3-point belts a year or two or even many years 

before that date. Three-point belts are quite effective for back-seat occupants, reducing fatality 

risk by an average of 44 percent (as compared to 32 percent for the lap belt only). Belt use, 

occupancy of the back seat and the proportion of cars on the road equipped with 3-point belts 

have steadily increased since 1990, pushing benefits to 297 lives saved in 2002, and a total of 

2,224 in 1960-2002. 

 

10 A choice of 3-point belts or separate lap and shoulder belts was allowed from December 11, 1989 to August 31,

1990, whereas 3-point belts were required starting September 1, 1990; in reality, all cars have been equipped with 3-

point belts since before December 11, 1989.

221
TABLE 2-20: CAR OCCUPANT LIVES SAVED BY 3-POINT BELTS FOR REAROUTBOARD OCCUPANTS AND AUTOMATIC 2-POINT BELTS, 1960-2002 

 208G: 3-POINT BELTS FOR REAR-OUTBOARD OCCS 208H: AUTOMATIC 2-POINT BELTS 

 (MEDIAN INSTALL YR 1989, FMVSS 12/11/89) (PEAK YEAR 1991, PHASE-IN BEGAN 9/1/86) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 0 0 0 

1970 0 0 0 0 0 0 

1971 0 0 0 0 0 0 

1972 0 0 0 0 0 0 

1973 0 0 0 0 0 0 

1974 0 0 0 0 0 0 

1975 0 0 0 0 0 0 

1976 0 0 0 1 0 1 

1977 0 0 0 5 0 5 

1978 0 0 0 6 0 6 

1979 1 0 1 5 0 5 

1980 0 0 0 5 0 5 

1981 0 0 0 7 0 7 

1982 0 0 0 5 0 5 

1983 1 0 1 8 0 8 

1984 3 0 3 11 0 11 

1985 2 0 2 16 0 16 

1986 8 0 8 16 0 16 

1987 15 0 15 9 28 37 

1988 13 0 13 16 102 117 

1989 24 4 28 14 191 204 

1990 23 18 41 16 417 433 

1991 37 46 83 7 554 561 

1992 27 58 85 15 616 631 

1993 29 69 98 15 764 779 

1994 23 115 139 15 906 921 

1995 23 125 148 7 914 922 

1996 29 149 178 5 970 975 

1997 23 157 180 6 905 910 

1998 32 212 244 10 854 864 

1999 19 152 171 5 865 870 

2000 22 216 238 5 812 817 

2001 17 234 252 3 753 756 

2002 14 282 297 9 730 739 

 =========== =========== =========== =========== =========== =========== 

 386 1,838 2,224 241 10,380 10,621 

222
Automatic 2-point belts were introduced on a voluntary basis in the Volkswagen Rabbit (nonmotorized) starting in 1975 and the Toyota Cressida (motorized) starting in 1981. Quite a few 

make-models were equipped with them during the MY 1987-89 phase-in period for automatic 

protection under FMVSS 208 and in the early 1990’s. Consumers indicated a clear preference 

for the more effective combination of air bags and manual 3-point belts; automatic 2-point belts 

were gone from new cars by MY 1996, two years before FMVSS 208 required air bags and 

manual 3-point belts in all cars. 

Automatic 2-point belts are less effective than 3-point belts, in part because the manual lap belt 

that accompanies them is often not used. Fatality reduction is an estimated 32 percent with 

automatic 2-point belts (vs. 45 percent with 3-point belts). During the 1980’s the lower 

effectiveness was more than offset by a much higher use rate for the 2-point belts; by 2002, use 

of 3-point belts had largely caught up with the automatic use rate. Lives saved by automatic 2-

point belts peaked at 975 in CY 1996 and subsequently declined as no new cars were equipped 

with them. Through 2002, automatic 2-point belts had saved an estimated 10,621 lives. 

Table 2-21 assesses two of the most important recent safety technologies: voluntary TTI(d) 

reductions to improve side impact protection in 2-door cars (214B) and frontal air bags (208I). 

A dynamic test was added to FMVSS 214, with phase-in scheduled from September 1, 1993 to 

September 1, 1996, to improve occupant protection when a car is struck in the side by another 

vehicle. During the decade before the phase-in manufacturers tried out the test procedure and 

began to improve performance on the test criterion TTI(d) on a voluntary basis, especially in 2-

door cars (that are the most vulnerable in side impacts). Side structure improvements in 1986-93 

were similar to the additional improvements that many cars would receive during the phase-in 

period. If NHTSA had already evaluated the dynamic test standard itself, the model used in this 

report would have combined these voluntary improvements with the post-FMVSS improvements 

as a single technology; however, as of October 2004, NHTSA had only evaluated the fatality 

reduction associated with the voluntary improvements. They are estimated to reduce fatality risk 

in side impacts of 2-door cars by 23 percent over the time period they were introduced (1986-

93). That amounts to 2,795 lives saved in 1960-2002, including 359 in 2002. 

Frontal air bags are effective in reducing the fatality risk of adults and adolescents (age 13+) in 

frontal and partially frontal crashes. Benefits are to a small extent offset by increased risk to 

certain groups of child passengers (age 0-12). Table 2-21 presents net lives saved by air bags. 

At the end of this chapter, Tables 2-38 – 2-39 analyzes the effects of air bags separately by 

occupant age group and seat position. Mercedes offered air bags on a voluntary basis in MY 

1985-86. After the FMVSS 208 phase-in of automatic protection began on September 1, 1986, 

other manufacturers began to offer driver or dual air bags, building up to 100 percent of new cars 

by MY 1997. Only the 1985-86 Mercedes air bags are included in the voluntary saves on Table 

2-21. In all crashes, driver air bags reduce the fatality risk of belted occupants by an average of 

11 percent, and unbelted occupants by 14 percent. The number of lives saved by air bags has 

grown rapidly, commensurate with the proportion of registered cars equipped with air bags, 

reaching 1,642 in 2002. It will continue to grow as older cars are retired, because even in 2002, 

38 percent of the cars on the road still did not have any air bags, and 11 percent had only the 

driver air bag. Air bags saved an estimated 8,770 lives in passenger cars through 2002. 

223
TABLE 2-21: CAR OCCUPANT LIVES SAVED BY VOLUNTARY TTI(d) REDUCTIONS 

IN 2-DOOR CARS AND BY FRONTAL AIR BAGS, 1960-2002 

 214B: VOLUNTARY (PRE-1994) TTI(d) 208I: FRONTAL AIR BAGS 

 REDUCTIONS IN 2-DOOR CARS (MEDIAN INSTALL YR 1994, 

 (MEDIAN IMPLEMENTATION YEAR 1993) PHASE-IN BEGAN 9/1/86) 

 

 CY TOTAL (VOLUNTARY) VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 

1961 0 0 0 0 

1962 0 0 0 0 

1963 0 0 0 0 

1964 0 0 0 0 

1965 0 0 0 0 

1966 0 0 0 0 

1967 0 0 0 0 

1968 0 0 0 0 

1969 0 0 0 0 

1970 0 0 0 0 

1971 0 0 0 0 

1972 0 0 0 0 

1973 0 0 0 0 

1974 0 0 0 0 

1975 0 0 0 0 

1976 0 0 0 0 

1977 0 0 0 0 

1978 0 0 0 0 

1979 0 0 0 0 

1980 0 0 0 0 

1981 0 0 0 0 

1982 0 0 0 0 

1983 0 0 0 0 

1984 0 0 0 0 

1985 0 0 0 0 

1986 4 1 0 1 

1987 11 1 0 2 

1988 25 0 2 3 

1989 39 1 7 8 

1990 49 0 43 43 

1991 58 0 74 74 

1992 69 0 99 99 

1993 96 1 194 195 

1994 141 0 283 283 

1995 191 1 456 457 

1996 247 0 613 613 

1997 266 0 748 748 

1998 263 1 904 905 

1999 303 0 1,053 1,053 

2000 321 1 1,246 1,247 

2001 356 1 1,395 1,396 

2002 359 0 1,642 1,642 

 =========== =========== =========== =========== 

 2,795 11 8,759 8,770 

224
Table 2-22 analyzes the two latest technologies that save lives of car occupants for which 

NHTSA has evaluated effectiveness: conspicuity tape for heavy trailers and 3-point belts for 

rear-center occupants. FMVSS 108 has required conspicuity tape on new trailers since 

December 1, 1993. The Federal Motor Carrier Safety Administration required all trailers on the 

road, even those built before December 1, 1993 to be equipped or retrofitted with tape by June 1, 

2001. When trailers are equipped with tape, they are easier to see in the dark, and cars are 29 

percent less likely to hit them. 

The model11 counts as a “voluntary” save by conspicuity tape: 

• Any car occupant saved when his or her car, before June 1, 2001, avoided hitting a trailer 

built before December 1, 1993 yet equipped or retrofitted with tape. 

The model counts as a “post-standard” save: 

• Any car occupant saved when his or her car, at any time, avoided hitting a trailer built 

after December 1, 1993.

• Any car occupant saved when his or her car, after June 1, 2001, avoided hitting any

trailer. 

In 1991-93 conspicuity tape applied to trailers in advance of any Federal requirement began 

saving car occupants. From December 1, 1993 through May 31, 2001, lives were saved by a mix 

of trailers built after FMVSS 108 required the tape and older trailers voluntarily equipped or 

retrofitted with tape. After June 1, 2001, every save is a post-standard save, because FMCSA 

requires every trailer on the road to have the tape. This technology has saved a total of 683 car 

occupants through 2002, including 91 in 2002. 

Anton’s Law directs NHTSA to issue a regulation requiring the phase-in of 3-point belts at rearcenter seats between September 1, 2005 and August 31, 2007. However, manufacturers have 

already furnished this technology voluntarily on numerous make-models, especially from MY 

1999 onwards. Three-point belts reduce fatality risk, on the average, by 44 percent. It is 

estimated that they had saved 5 lives by the end of 2002. The safest place for a passenger to ride 

in a car is in the rear-center seat, protected by a 3-point belt, or by an age-appropriate safety seat 

if the passenger is a child too small for correct use of 3-point belts. 

 

11 Because FARS data do not report the MY of trailers, the model can only assess the probability of the following 

three scenarios based on the CY and month of the crash. 

225
TABLE 2-22: CAR OCCUPANT LIVES SAVED BY CONSPICUITY TAPE ON HEAVY 

TRAILERS AND 3-POINT BELTS FOR REAR-CENTER OCCUPANTS, 1960-2002 

 108: CONSPICUITY TAPE ON HEAVY TRAILERS 208J: 3-POINT BELTS FOR REAR-CENTER OCCS 

 (ON-ROAD FLEET EXCEEDED 50% IN 1996, (MEDIAN INSTALL YR 2001, 

 FMVSS 12/1/93, FMCSA RETROFIT 6/1/2001) FMVSS PHASE-IN TO BEGIN 9/2005) 

 

 CY VOLUNTARY POST-STANDARD TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 0 0 0 

1970 0 0 0 0 0 0 

1971 0 0 0 0 0 0 

1972 0 0 0 0 0 0 

1973 0 0 0 0 0 0 

1974 0 0 0 0 0 0 

1975 0 0 0 0 0 0 

1976 0 0 0 0 0 0 

1977 0 0 0 0 0 0 

1978 0 0 0 0 0 0 

1979 0 0 0 0 0 0 

1980 0 0 0 0 0 0 

1981 0 0 0 0 0 0 

1982 0 0 0 0 0 0 

1983 0 0 0 0 0 0 

1984 0 0 0 0 0 0 

1985 0 0 0 0 0 0 

1986 0 0 0 0 0 0 

1987 0 0 0 0 0 0 

1988 0 0 0 0 0 0 

1989 0 0 0 0 0 0 

1990 0 0 0 0 0 0 

1991 6 0 6 0 0 0 

1992 14 0 14 0 0 0 

1993 22 0 22 0 0 0 

1994 25 8 33 0 0 0 

1995 27 18 45 0 0 0 

1996 28 28 55 0 0 0 

1997 30 40 70 0 0 0 

1998 29 48 77 0 0 0 

1999 30 60 91 0 0 0 

2000 29 67 96 1 0 1 

2001 10 74 84 2 0 2 

2002 0 91 91 2 0 2 

 =========== =========== =========== =========== =========== =========== 

 248 435 683 5 0 5 

226
Benefits for occupants of LTVs 

Table 2-23 is a summary of the benefits of safety technologies for LTV occupants. Actual 

fatalities in LTVs have rather steadily increased from 3,494 in 1960 to 12,248 in 2002, reflecting 

the growing market share of LTVs. But without the safety improvements they would have 

increased much more, from 3,516 to 22,579. Safety technologies saved 94,117 LTV occupants 

in 1960-2002, including 10,331 in 2002. Most of the lives saved (82,302) are by safety 

technologies directly associated with FMVSS in effect at that time. Voluntary improvements 

such as better instrument panels and compliance with FMVSS before their effective date have 

been saving about 400 lives a year since the mid-1990’s. 

The proportion of potential fatalities saved has grown from 0.63 percent in 1960, when 22 LTV 

occupants were saved by lap belts, to 45.75 percent in 2002. The latter is even higher than the 

corresponding proportion saved in cars (40.89 according to Table 2-10). That is primarily 

because safety belts are even more effective in LTVs than in cars – because fatal crashes of 

LTVs are more likely to involve rollover and/or ejection, and belts are especially effective in 

those situations. 

Indeed, the largest boosts in the percent saved came in 1984-88 (from 11.02 to 22.43 percent), 

when buckle-up laws took effect in most of the States, and in 1995-2002 (from 33.72 to 45.75 

percent) when belt use, historically lower in LTVs, especially in pickup trucks, rapidly caught up 

to the use rate in cars. 

227
TABLE 2-23: LTV SUMMARY – ACTUAL OCCUPANT FATALITIES, POTENTIAL 

FATALITIES WITHOUT THE SAFETY TECHNOLOGIES, AND LIVES SAVED 

 LTV OCCUPANT FATALITIES LIVES SAVED 

 W/O SAFETY BY VOLUNTARY BY FMVSS PERCENT 

 CY ACTUAL TECHS. IMPROVEMENTS IN EFFECT TOTAL SAVED 

1960 3,494 3,516 22 0 22 0.63 

1961 3,482 3,504 22 0 22 0.63 

1962 3,787 3,812 25 0 25 0.65 

1963 4,050 4,078 28 0 28 0.70 

1964 4,414 4,448 34 0 34 0.76 

1965 4,527 4,565 38 0 38 0.83 

1966 4,785 4,831 46 0 46 0.95 

1967 4,785 4,839 55 0 55 1.13 

1968 5,299 5,379 80 0 80 1.49 

1969 5,711 5,824 114 0 114 1.95 

1970 5,505 5,641 136 0 136 2.41 

1971 5,453 5,614 159 2 161 2.87 

1972 5,659 5,853 173 21 194 3.31 

1973 5,865 6,103 184 54 238 3.90 

1974 5,042 5,286 172 72 244 4.61 

1975 4,759 5,031 173 98 272 5.40 

1976 5,419 5,742 199 125 324 5.64 

1977 5,836 6,245 248 161 409 6.55 

1978 6,550 7,012 279 183 462 6.59 

1979 7,039 7,600 311 249 561 7.38 

1980 7,389 7,997 350 258 608 7.60 

1981 6,966 7,581 351 263 614 8.10 

1982 6,465 7,051 332 253 585 8.30 

1983 6,277 6,918 317 324 641 9.27 

1984 6,581 7,396 308 507 815 11.02 

1985 6,826 7,944 368 750 1,118 14.07 

1986 7,414 9,034 364 1,256 1,620 17.93 

1987 8,208 10,323 374 1,740 2,115 20.49 

1988 8,497 10,954 399 2,058 2,457 22.43 

1989 8,689 11,430 406 2,335 2,741 23.98 

1990 8,741 11,697 402 2,555 2,957 25.28 

1991 8,591 11,779 388 2,800 3,188 27.07 

1992 8,239 11,655 393 3,024 3,417 29.31 

1993 8,639 12,458 400 3,418 3,818 30.65 

1994 9,030 13,500 443 4,026 4,469 33.11 

1995 9,715 14,657 438 4,504 4,942 33.72 

1996 10,039 15,718 468 5,212 5,679 36.13 

1997 10,359 16,715 467 5,890 6,356 38.03 

1998 10,730 17,728 475 6,523 6,998 39.48 

1999 11,249 18,735 485 7,001 7,486 39.96 

2000 11,521 20,203 473 8,209 8,682 42.97 

2001 11,685 20,701 439 8,577 9,016 43.55 

2002 12,248 22,579 478 9,853 10,331 45.75 

 =========== =========== =========== =========== =========== 

 305,559 399,675 11,814 82,302 94,117 

228
VMT data are available for LTVs in 1975-2002.12 Occupant fatality rates per 100,000,000 VMT 

are shown in Table 2-24 and Figure 2-6. The trends are somewhat different from cars, because 

LTVs are a less homogeneous group of vehicles. Originally, the majority of LTVs were pickup 

trucks. The introduction of minivans in the mid-1980’s, a new type of vehicle with exceptionally 

low fatality rates, helped to lower the average potential fatality rate for all LTVs from 2.32 in 

1987 to 1.81 in 1992; the actual fatality rate fell even more sharply, from 1.85 to 1.28. After 

1992, the market share for SUVs increased steadily relative to minivans and pickup trucks. 

Without the safety technologies, the potential fatality rate would have increased from 1.81 to 

2.22 in 2002, back to mid-1980’s levels. But thanks to safety improvements, above all increased 

belt use, the actual fatality rate dropped from 1.28 to 1.21. Essentially, increased belt use, air 

bags and other vehicle safety technologies made it possible to accommodate the shift to SUVs 

without an increase of actual fatality rates per 100,000,000 VMT. 

Lives saved by 18 individual safety technologies for LTVs will now be discussed in 

chronological order as listed in Table 2-2, based on the “median installation year.” Table 2-25 

covers the two earliest technologies, 208A – lap belts for front-outboard occupants (age 5 and 

older), and 208B – lap belt use (at any seat position) by children age 1-4. By model year 1964, 

over half of new LTVs were equipped with lap belts; FMVSS 208 required them in LTVs as of 

July 1, 1971. Lap belts are more effective in LTVs than in cars, reducing fatality risk by 48 

percent (vs. 27 percent in cars). Although some LTV make-models received 3-point belts in the 

early 1970’s, most kept lap belts through MY 1975 and some even until 1980. Some of those 

LTVs were still on the road in 2002. Thus, the number of lives saved by lap belts reached a peak 

of 110 in 1986, after buckle-up laws increased use, and it did not decline that much in the 

1990’s. In all, lap belts have saved an estimated 2,612 front-outboard occupants age 5 or older. 

Safety belts, without a safety seat, reduce the fatality risk of 1-4 year old children by an average 

of 48 percent in LTVs, and are assumed to have little or no value for infants (age 0). Belts have 

saved an estimated 295 children age 1-4, at all seat positions, in LTVs. 

Table 2-26 tallies the benefits of dual master cylinders (105A) and improved door locks (206). 

Dual master cylinders were not required until FMVSS 105 was extended to LTVs, effective 

September 1, 1983. But they were introduced much earlier, presumably at about the same time

as in cars, often a few years before 1968. They reduce the risk of a fatal crash involvement by an 

estimated 0.7 percent, saving a total of 2,379 LTV occupants in 1960-2002, including 157 in 

2002. The number of lives saved has grown year by year as the “base” of registered LTVs, their 

VMT and potentially fatal crashes continues to grow. 

 

12 Traffic Safety Facts 2002, op. cit., pp. 24. 

229
TABLE 2-24

LTVs: ACTUAL AND POTENTIAL OCCUPANT FATALITIES 

PER 100,000,000 MILES VMT 

 POTENTIAL FATALITIES 

 ACTUAL FATALITIES W/O SAFETY TECHNOLOGIES 

 VMT 

 CY (108 MILES) N RATE N RATE 

1975 2,043 4,759 2.33 5,031 2.46 

1976 2,334 5,419 2.32 5,742 2.46 

1977 2,571 5,836 2.27 6,245 2.43 

1978 2,895 6,550 2.26 7,012 2.42 

1979 2,938 7,039 2.40 7,600 2.59 

1980 2,955 7,389 2.50 7,997 2.71 

1981 3,076 6,966 2.26 7,581 2.46 

1982 3,220 6,465 2.01 7,051 2.19 

1983 3,349 6,277 1.87 6,918 2.07 

1984 3,586 6,581 1.84 7,396 2.06 

1985 3,888 6,826 1.76 7,944 2.04 

1986 4,165 7,414 1.78 9,034 2.17 

1987 4,444 8,208 1.85 10,323 2.32 

1988 4,884 8,497 1.74 10,954 2.24 

1989 5,225 8,689 1.66 11,430 2.19 

1990 5,557 8,741 1.57 11,697 2.11 

1991 5,959 8,591 1.44 11,779 1.98 

1992 6,424 8,239 1.28 11,655 1.81 

1993 6,754 8,639 1.28 12,458 1.84 

1994 7,115 9,030 1.27 13,500 1.90 

1995 7,500 9,715 1.30 14,657 1.95 

1996 7,873 10,039 1.28 15,718 2.00 

1997 8,249 10,359 1.26 16,715 2.03 

1998 8,620 10,730 1.24 17,728 2.06 

1999 9,033 11,249 1.25 18,735 2.07 

2000 9,429 11,521 1.22 20,203 2.14 

2001 9,781 11,685 1.19 20,701 2.12 

2002 10,164 12,248 1.21 22,579 2.22 

230
FIGURE 2-6: ACTUAL AND POTENTIAL OCCUPANT FATALITIES

IN LTVs PER 100,000,000 MILES VMT 

(“A” = actual fatalities; “P” = potential fatalities without the vehicle safety technologies) 

 3.0 ˆ 

 ‚ 

 ‚ 

 2.8 ˆ 

 ‚ P 

 ‚ 

 2.6 ˆ P 

 ‚ A 

 ‚ P P P 

 2.4 ˆ P P A 

 ‚ A A P minivans 

 ‚ A A A P 

 2.2 ˆ P P P P 

 ‚ P P P 

 ‚ P P P phase P P 

 2.0 ˆ A P P P 

 ‚ P SUVs phase in 

 ‚ A A A in P P 

 1.8 ˆ A P 

 ‚ A A 

 ‚ A 

 1.6 ˆ A 

 ‚ 

 ‚ A 

 1.4 ˆ 

 ‚ 

 ‚ A A A A A A A A 

 1.2 ˆ A A A 

 ‚ 

 ‚ The FMVSS hold the line despite SUVs 

 1.0 ˆ 

 ‚ 

 ‚ 

 0.8 ˆ 

 ‚ 

 ‚ 

 0.6 ˆ 

 ‚ 

 ‚ 

 0.4 ˆ 

 ‚ 

 ‚ 

 0.2 ˆ 

 ‚ 

 ‚ 

 0.0 ˆ 

 _____________________________________________________________________________________

 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 

 CALENDAR YEAR 

231
TABLE 2-25: LTV OCCUPANT LIVES SAVED BY FRONT-OUTBOARD LAP BELTS 

AND LAP BELTS FOR CHILDREN AGE 1-4, 1960-2002 

 208A: LAP BELTS FOR FRONT-OUTBOARD OCCS 208B: LAP BELT USE BY CHILDREN AGE 1-4 

 (MEDIAN INSTALL YR 1964, FMVSS 7/1/71) (MEDIAN INSTALL YR 1966, FMVSS 7/1/71) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 22 0 22 0 0 0 

1961 22 0 22 0 0 0 

1962 24 0 24 0 0 0 

1963 26 0 26 0 0 0 

1964 28 0 28 0 0 0 

1965 29 0 29 0 0 0 

1966 30 0 30 0 0 0 

1967 31 0 31 0 0 0 

1968 42 0 42 0 0 0 

1969 59 0 59 0 0 0 

1970 68 0 68 0 0 0 

1971 73 2 76 0 0 0 

1972 71 15 86 0 0 0 

1973 62 35 97 0 0 0 

1974 46 43 89 0 0 0 

1975 35 55 89 0 0 0 

1976 26 58 84 0 0 1 

1977 23 58 80 0 0 0 

1978 20 53 73 0 0 0 

1979 12 67 79 0 0 0 

1980 8 42 50 0 1 1 

1981 8 40 47 0 1 1 

1982 12 38 50 0 0 0 

1983 6 25 32 0 0 0 

1984 14 40 54 0 4 4 

1985 21 60 81 0 3 3 

1986 22 88 110 0 9 9 

1987 18 74 92 0 10 10 

1988 26 84 109 1 10 11 

1989 14 56 70 0 12 12 

1990 22 50 72 0 9 9 

1991 25 64 89 0 12 12 

1992 17 56 73 1 11 12 

1993 22 61 83 1 13 14 

1994 19 47 67 0 21 21 

1995 22 61 83 1 23 23 

1996 20 45 65 0 25 25 

1997 13 32 46 0 23 23 

1998 14 31 45 0 27 27 

1999 15 36 51 0 16 16 

2000 13 25 38 0 26 26 

2001 12 18 30 0 18 18 

2002 7 34 41 0 13 13 

 =========== =========== =========== =========== =========== =========== 

 1,118 1,494 2,612 7 288 295 

232
TABLE 2-26: LTV OCCUPANT LIVES SAVED BY DUAL MASTER CYLINDERS 

AND IMPROVED DOOR LOCKS, 1960-2002 

 105A: DUAL MASTER CYLINDERS 206: IMPROVED DOOR LOCKS 

 (MEDIAN INSTALL YR LATE 66, FMVSS 9/1/83) (MEDIAN INSTALL YR 1967, FMVSS 1/1/72) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1962 0 0 0 1 0 1 

1966 3 0 3 13 0 13 

1970 20 0 20 39 0 39 

1972 26 0 26 51 5 56 

1974 28 0 28 35 27 63 

1985 40 13 53 14 181 195 

1987 38 33 70 15 276 291 

1995 18 83 101 6 423 429 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1963 1 0 1 2 0 2 

1964 1 0 1 5 0 5 

1965 1 0 1 8 0 8 

1967 7 0 7 17 0 17 

1968 12 0 12 25 0 25 

1969 17 0 17 34 0 34 

1971 23 0 23 46 0 46 

1973 30 0 30 48 18 66 

1975 28 0 28 22 41 63 

1976 33 0 33 23 55 78 

1977 38 0 38 23 82 105 

1978 43 0 43 25 90 115 

1979 48 0 48 27 137 164 

1980 52 0 52 25 163 188 

1981 49 0 49 24 152 176 

1982 46 0 46 20 142 162 

1983 46 0 46 19 152 171 

1984 43 6 49 18 163 181 

1986 39 22 61 13 231 244 

1988 35 40 75 12 307 319 

1989 31 47 78 11 317 328 

1990 28 52 80 8 328 336 

1991 26 55 81 10 335 345 

1992 23 58 80 7 344 351 

1993 22 64 86 6 354 360 

1994 20 73 93 7 397 404 

1996 16 93 109 5 462 467 

1997 14 102 116 5 502 507 

1998 12 111 123 4 535 539 

1999 11 119 130 3 567 570 

2000 9 131 141 3 617 620 

2001 7 137 144 2 620 622 

2002 7 151 157 2 692 694 

 =========== =========== =========== =========== =========== =========== 

 989 1,390 2,379 681 8,717 9,398 

233
FMVSS 206 took effect on January 1, 1972 in LTVs, four years later than in cars. The model 

assumes that door lock improvements in LTVs started at about the same time as in cars, MY 

1962, but extended until MY 1972, the year the standard took effect. In cars, NHTSA’s 

evaluation estimated a 15 percent reduction of fatalities in rollovers. However, NCSS data show 

that the proportion of ejections that are through the door portal is smaller in LTVs than in cars. 

The effectiveness in LTVs is estimated to be 10 percent. Despite that lower effectiveness, the 

benefits of improved door locks in LTVs are estimated to be substantial, because so many 

potentially fatal LTV crashes involve rollover and ejection: 9,398 lives saved in 1960-2002, 

including 694 in 2002. 

Table 2-27 looks at the benefits of lap belts for occupants age 5+ at the rear-outboard (208C) and 

front-center (208D) seat positions. Lap belts were required at all designated seat positions in 

LTVs on July 1, 1971. FMVSS 208 required 3-point belts at the rear-outboard seats in LTVs 

starting September 1, 1991. Even lap belts alone are highly effective in the back seats of LTVs, 

reducing fatality risk by an average of 63 percent. They achieved their largest benefit, 80 lives 

saved, in 1993, just after the shift to 3-point belts, and have saved an estimated 978 lives in 

1960-2002. 

The front-center seat is more frequently occupied in pickup trucks, especially those that have a 

wide bench seat in the front and no back seats at all, than in cars. As a consequence, here is one 

technology that has saved more lives in LTVs (177) than in cars (81) during 1960-2002. 

Table 2-28 considers lap belts for rear-center occupants (208E) and front disc brakes (105B). 

Rear-center seats are occupied fairly often in vans and large SUVs, and lap belts are quite 

effective, reducing fatality risk by an estimated 63 percent. The belts saved 403 lives in 1960-

2002. 

 

The model assumes front disc brakes were introduced in LTVs at about the same time as in cars 

– i.e., during MY 1965-77 – even though FMVSS 105 did not apply to LTVs until September 1, 

1983.13 Front disc brakes reduce the risk of a fatal crash involvement by an estimated 0.17 

percent. They saved an estimated 501 LTV occupants in 1960-2002.

Table 2-29 analyzes voluntary modifications to mid and lower instrument panels and energyabsorbing steering assemblies, two basic “built-in” protections in frontal crashes. Instrument 

panels of LTVs were redesigned over several years, from about MY 1969 to 1976. That resulted 

in a 15.9 percent fatality reduction for unrestrained right-front passengers in frontal impacts. It 

saved an estimated 4,373 lives through CY 2002. 

FMVSS 203 and 204 were not extended to LTVs until September 1, 1981. However, energyabsorbing columns were introduced in some LTVs as early as 1970, and in the majority by MY 

1975-76, but in some not until MY 1982. Energy-absorbing steering assemblies have saved 

11,472 lives through CY 2002, including 997 in 2002. They rank first in cumulative benefits 

among the non-belt technologies for LTVs, as well as for passenger cars. 

13 Ward’s Automotive Yearbooks (Ward’s Communications, Detroit, annual publication) show nearly identical 

percentages of U.S. cars, U.S. trucks and imported cars with front disc brakes in MY 1975-77 and have no

information for U.S. trucks and imported cars before MY 1975.

234
TABLE 2-27: LTV OCCUPANT LIVES SAVED BY LAP BELTS FOR REAR-OUTBOARD 

OCCUPANTS AND LAP BELTS FOR FRONT-CENTER OCCUPANTS, 1960-2002 

 208C: LAP BELTS FOR REAR-OUTBOARD OCCS 208D: LAP BELTS FOR FRONT-CENTER OCCS 

 (MEDIAN INSTALL YR 1968, FMVSS 7/1/71) (MEDIAN INSTALL YR 1968, FMVSS 7/1/71) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1961 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1971 1 0 1 0 0 0 

1975 2 1 3 1 1 2 

1960 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 0 0 0 

1970 1 0 1 0 0 0 

1972 1 0 1 0 0 0 

1973 1 1 1 0 0 1 

1974 1 1 1 0 0 1 

1976 0 10 10 0 1 1 

1977 0 3 3 1 0 1 

1978 0 4 4 0 1 1 

1979 0 6 6 0 1 1 

1980 0 1 1 0 0 0 

1981 0 2 2 0 1 1 

1982 0 2 2 0 0 0 

1983 0 1 1 0 0 0 

1984 0 9 10 0 0 0 

1985 0 13 13 0 5 5 

1986 0 25 25 0 1 1 

1987 0 46 46 0 10 10 

1988 0 52 52 0 8 8 

1989 0 46 46 0 11 11 

1990 1 58 59 0 5 5 

1991 0 67 67 0 5 5 

1992 0 63 63 0 10 10 

1993 0 80 80 0 8 8 

1994 0 63 63 1 12 12 

1995 0 48 48 1 12 13 

1996 0 43 43 0 11 11 

1997 0 76 76 0 14 14 

1998 0 59 59 0 10 10 

1999 0 50 50 0 7 7 

2000 0 64 64 0 9 9 

2001 0 45 45 0 13 13 

2002 0 32 32 0 14 14 

 =========== =========== =========== =========== =========== =========== 

 9 969 978 6 171 177 

235
TABLE 2-28: LTV OCCUPANT LIVES SAVED BY LAP BELTS FOR REAR-CENTER 

OCCUPANTS AND FRONT DISC BRAKES, 1960-2002 

 208E: LAP BELTS FOR REAR-CENTER OCCS 105B: FRONT DISC BRAKES 

 (MEDIAN INSTALL YR 1968, FMVSS 7/1/71) (MEDIAN INSTALL YEAR 1971, FMVSS 9/1/83) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 1 0 1 

1970 0 0 0 1 0 1 

1971 0 0 0 2 0 2 

1972 0 0 0 2 0 2 

1973 0 0 1 3 0 3 

1974 0 0 1 4 0 4 

1975 0 0 0 4 0 4 

1976 1 0 1 5 0 5 

1977 0 4 4 7 0 7 

1978 0 7 7 8 0 8 

1979 0 2 2 9 0 9 

1980 0 0 0 10 0 10 

1981 0 0 0 10 0 10 

1982 0 0 0 9 0 9 

1983 0 0 0 9 0 9 

1984 0 0 0 9 1 10 

1985 0 2 2 8 3 11 

1986 0 3 3 8 5 13 

1987 0 5 5 8 8 15 

1988 4 10 14 7 9 17 

1989 0 11 11 7 11 18 

1990 0 10 10 6 12 18 

1991 0 18 18 5 13 18 

1992 0 14 14 5 13 18 

1993 0 13 13 5 15 20 

1994 0 16 16 4 17 21 

1995 0 18 18 4 19 23 

1996 0 19 19 4 22 25 

1997 0 39 39 3 24 27 

1998 0 36 36 3 26 28 

1999 0 31 31 2 28 30 

2000 0 65 65 2 30 32 

2001 0 30 30 2 32 33 

2002 0 44 44 1 35 37 

 =========== =========== =========== =========== =========== =========== 

 7 396 403 178 323 501 

236
TABLE 2-29: LTV OCCUPANT LIVES SAVED BY VOLUNTARY INSTRUMENT PANEL 

IMPROVEMENTS AND ENERGY-ABSORBING STEERING ASSEMBLIES, 1960-2002 

 201: VOLUNTARY INSTRUMENT 203: ENERGY-ABSORBING 

 PANEL IMPROVEMENTS STEERING ASSEMBLIES 

 (MEDIAN INSTALL YR 1972, FMVSS 9/1/81) (MEDIAN INSTALL EARLY 76, FMVSS 9/1/81) 

 

 CY TOTAL (VOLUNTARY) VOLUNTARY POST-FMVSS TOTAL 

1961 0 0 0 0 

1963 0 0 0 0 

1965 0 0 0 0 

1967 0 0 0 0 

1973 20 13 0 13 

1974 23 25 0 25 

1975 27 30 0 30 

1978 66 91 0 91 

1979 73 112 0 112 

1981 92 141 1 142 

1960 0 0 0 0 

1962 0 0 0 0 

1964 0 0 0 0 

1966 0 0 0 0 

1968 0 0 0 0 

1969 1 0 0 0 

1970 4 1 0 1 

1971 7 2 0 2 

1972 13 2 0 2 

1976 37 45 0 45 

1977 47 71 0 71 

1980 90 133 0 133 

1982 84 136 22 158 

1983 83 114 48 162 

1984 96 97 93 191 

1985 103 108 137 245 

1986 122 96 180 275 

1987 140 89 232 322 

1988 146 86 280 366 

1989 166 84 327 411 

1990 179 72 364 436 

1991 176 65 379 444 

1992 171 61 383 444 

1993 180 63 430 493 

1994 187 57 488 545 

1995 206 51 576 627 

1996 239 47 603 651 

1997 239 43 660 703 

1998 255 33 722 755 

1999 245 32 754 785 

2000 283 25 838 863 

2001 274 21 912 934 

2002 299 22 975 997 

 =========== =========== =========== =========== 

 4,373 2,066 9,407 11,472

237
Table 2-30 estimates the benefits of 3-point belts for front-outboard occupants (208F) and 

adhesive windshield bonding (212). FMVSS 208 required 3-point belts at the front-outboard 

seats of most LTVs on January 1, 1976 and on some not until September 1, 1981. However, 

some make-models received 3-point belts well before January 1, 1976. Safety belt use is 

critically important in LTVs, because a high proportion of potentially fatal crashes involve 

rollover and/or ejection, and because belts are also highly effective in the other crash modes. 

Three-point belts reduce fatality risk by an average of 60 percent in LTVs, when they are used. 

Fortunately, belt use is as high in SUVs and vans as in cars.14 Three-point belts saved an 

estimated 52,037 drivers and right-front passengers in 1960-2002, including 6,199 in 2002. Both 

of these numbers are more than half the overall benefits of all the LTV safety technologies in the

same time period, and so are the estimates for each individual year from 1988 to 2002.

Adhesive windshield bonding gradually superseded the older installation method using rubber 

gaskets during approximately 1978-85 in LTVs. The model assumes that adhesive bonding has 

the same effect on ejection fatalities in LTVs as in cars: NCSS data show that the proportion of 

ejections that are via the windshield portal was about the same in LTVs with rubber gaskets as in 

cars with rubber gaskets. Adhesive bonding has saved an estimated 1,462 lives in 1960-2002, 

including 118 in 2002. 

Table 2-31 considers child safety seats (213) and 3-point belts for rear-outboard occupants 

(208G). NHTSA’s evaluation estimates that safety seats reduce fatality risk in LTVs by 58 

percent for infants and by 59 percent for toddlers. Safety seats saved an estimated 1,100 lives in 

1960-2002, of which 934 were children obligated by a State law to be in a safety seat, while 165 

were voluntary saves before State laws or involving older children. 

FMVSS 208 has required lap/shoulder belts at rear-outboard seats of LTVs since September 1, 

1991, but most LTVs were voluntarily equipped with 3-point belts a few years before that date. 

Three-point belts are highly effective for back-seat occupants, reducing fatality risk by an 

average of 73 percent. Belt use, occupancy of the back seat and the proportion of LTVs on the 

road equipped with 3-point belts have increased rapidly, pushing benefits to 526 lives saved in 

2002, and a total of 2,499 in 1960-2002. 

Table 2-32 addresses side door beams (214A) and frontal air bags (208I). The side door strength 

test of FMVSS 214 was extended to LTVs effective September 1, 1993. Most LTVs were first 

equipped with side door beams in MY 1994, but on a few models they were voluntarily 

introduced in 1991-93. Side door beams reduce fatality risk in single-vehicle side impacts by 19 

percent. They saved an estimated 701 lives in 1960-2002; annual benefits have been rising as 

new LTVs with side door beams replace the pre-standard fleet. 

 

14 Glassbrenner, D., Safety Belt Use in 2003, NHTSA Technical Report No. DOT HS 809 646, Washington, 2003. 

238
TABLE 2-30: LTV OCCUPANT LIVES SAVED BY 3-POINT BELTS FOR FRONTOUTBOARD OCCUPANTS AND ADHESIVE WINDSHIELD BONDING, 1960-2002 

 208F: 3-POINT BELTS FOR FRONT-OUTBOARD OCCS 212: ADHESIVE WINDSHIELD BONDING 

 (MEDIAN INSTALL YR 1976, FMVSS 1/1/76) (MEDIAN INSTALL YR 1980, FMVSS 9/1/78) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 1 0 1 0 0 0 

1970 2 0 2 0 0 0 

1971 3 0 3 0 0 0 

1972 4 0 4 0 0 0 

1973 5 0 5 0 0 0 

1974 9 0 9 0 0 0 

1975 23 0 23 0 0 0 

1976 26 0 26 0 0 0 

1977 37 13 50 0 0 0 

1978 23 28 51 1 0 1 

1979 28 34 61 2 3 5 

1980 27 43 70 2 7 9 

1981 25 56 82 1 9 11 

1982 20 33 53 1 12 13 

1983 35 81 116 1 15 16 

1984 27 157 184 1 21 22 

1985 67 289 356 1 29 30 

1986 63 637 701 1 38 39 

1987 64 965 1,029 1 50 51 

1988 72 1,166 1,237 1 58 59 

1989 83 1,410 1,493 1 60 61 

1990 76 1,571 1,648 1 66 67 

1991 45 1,746 1,791 1 66 67 

1992 62 1,939 2,002 1 62 62 

1993 50 2,220 2,270 1 68 69 

1994 80 2,640 2,720 0 76 76 

1995 49 2,924 2,973 0 83 84 

1996 63 3,467 3,530 0 85 86 

1997 55 3,789 3,845 0 90 90 

1998 41 4,217 4,258 0 99 99 

1999 55 4,391 4,445 0 105 105 

2000 48 5,271 5,319 0 108 108 

2001 35 5,447 5,482 0 112 112 

2002 39 6,160 6,199 0 118 118 

 =========== =========== =========== =========== =========== =========== 

 1,342 50,695 52,037 20 1,441 1,462 

239
TABLE 2-31: LTV OCCUPANT LIVES SAVED BY CHILD SAFETY SEATS 

AND 3-POINT BELTS FOR REAR-OUTBOARD OCCUPANTS, 1960-2002 

 213: CHILD SAFETY SEATS 208G: 3-POINT BELTS FOR REAR-OUTBOARD OCCS 

 (USE EXCEEDED 50% IN 1985, 

 FMVSS 4/1/71, STATE LAWS 1978-85) (MEDIAN INSTALL YR 1990, FMVSS 9/1/91) 

 CY VOLUNTARY OBLIGATORY TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 0 0 0 

1970 0 0 0 0 0 0 

1971 0 0 0 0 0 0 

1972 1 0 1 0 0 0 

1973 1 0 1 0 0 0 

1974 1 0 1 0 0 0 

1975 2 0 2 0 0 0 

1976 3 0 3 0 0 0 

1977 2 0 2 0 0 0 

1978 2 0 2 0 0 0 

1979 1 0 1 0 0 0 

1980 3 0 3 0 0 0 

1981 1 0 1 0 0 0 

1982 3 3 6 0 0 0 

1983 3 2 5 0 0 0 

1984 3 10 13 0 0 0 

1985 5 16 20 0 0 0 

1986 0 17 17 0 0 0 

1987 2 32 34 0 0 0 

1988 2 35 37 8 0 8 

1989 3 27 30 6 0 6 

1990 3 29 32 6 0 6 

1991 4 39 44 28 0 28 

1992 9 29 38 26 43 69 

1993 2 34 36 24 57 80 

1994 5 56 61 22 105 127 

1995 8 63 71 16 88 105 

1996 9 70 79 12 96 108 

1997 15 68 84 16 208 224 

1998 7 70 77 31 202 233 

1999 17 85 101 35 287 322 

2000 12 82 93 9 304 313 

2001 13 79 92 14 332 346 

2002 24 88 112 10 515 526 

 =========== =========== =========== =========== =========== =========== 

 165 934 1,100 263 2,236 2,499 

240
TABLE 2-32: LTV OCCUPANT LIVES SAVED BY SIDE DOOR BEAMS 

AND FRONTAL AIR BAGS, 1960-2002 

 214A: SIDE DOOR BEAMS 208I: FRONTAL AIR BAGS 

 (MEDIAN INSTALL YR 1995, 

1998 3 70 73 52 277 329 

 (MEDIAN INSTALL YEAR 1994, FMVSS 9/1/93) PHASE-IN BEGAN 9/1/94) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 0 0 0 

1970 0 0 0 0 0 0 

1971 0 0 0 0 0 0 

1972 0 0 0 0 0 0 

1973 0 0 0 0 0 0 

1974 0 0 0 0 0 0 

1975 0 0 0 0 0 0 

1976 0 0 0 0 0 0 

1977 0 0 0 0 0 0 

1978 0 0 0 0 0 0 

1979 0 0 0 0 0 0 

1980 0 0 0 0 0 0 

1981 0 0 0 0 0 0 

1982 0 0 0 0 0 0 

1983 0 0 0 0 0 0 

1984 0 0 0 0 0 0 

1985 0 0 0 0 0 0 

1986 0 0 0 0 0 0 

1987 0 0 0 0 0 0 

1988 0 0 0 0 0 0 

1989 0 0 0 0 0 0 

1990 0 0 0 0 0 0 

1991 0 0 0 0 0 0 

1992 1 0 1 4 0 4 

1993 3 1 3 12 0 12 

1994 4 12 16 24 1 25 

1995 4 29 33 37 44 81 

1996 2 46 47 39 112 151 

1997 1 46 47 43 193 236 

1999 4 96 100 45 387 432 

2000 3 108 111 48 486 534 

2001 3 120 123 50 619 669 

2002 4 143 146 59 772 831 

 =========== =========== =========== =========== =========== =========== 

 31 670 701 414 2,890 3,304 

241
Frontal air bags are effective in reducing the fatality risk of adults and adolescents (age 13+) in 

frontal and partially frontal crashes. Benefits are to a small extent offset by increased risk to 

certain groups of child passengers (age 0-12). Furthermore, in pickup trucks with dual air bags 

and on-off switches, turning the switch “off” can prevent harm to a child passenger, but takes 

away the benefit of air bags from an adult passenger. Table 2-32 presents net lives saved by air 

bags in LTVs. At the end of this chapter, Tables 2-38 – 2-40 analyze the effects of air bags 

separately by occupant age group and seat position and investigates the effects of on-off 

switches. 

The FMVSS 208 phase-in period for automatic protection in LTVs extended from September 1, 

1994 to August 30, 1997. LTVs equipped with driver or dual air bags before September 1, 1994 

account for the voluntary saves on Table 2-32. NHTSA’s evaluation showed air bags are about 

equally effective in cars and LTVs: driver air bags reduce the fatality risk of belted occupants by 

an average of 11 percent, and unbelted occupants by 14 percent. Air bags saved 831 lives in 

2002; in that year, 41 percent of the LTVs on the road still did not have any air bags, and 11 

percent had only the driver air bag. The number of lives saved by air bags will continue to grow 

as older LTVs are retired. Air bags saved an estimated 3,304 lives in LTVs through 2002. 

Table 2-33 analyzes conspicuity tape for heavy trailers (108) and 3-point belts for rear-center 

occupants (208J). When heavy trailers are equipped with the red-and-white tape, they are easier

to see in the dark, and LTVs are 29 percent less likely to hit them. The tape has saved a total of 

422 LTV occupants through 2002, including 68 in 2002. 

 

Three-point belts began to appear on the rear-center seats of LTVs before 2002.15 Anton’s Law 

will require them on all rear-center seats by MY 2008. The model estimates 3 lives saved in 

LTVs by the end of 2002.

15 In a typical minivan, the two seats in the second row are considered “outboard” seats and have been equipped with

3-point belts since MY 1992 or earlier. Only the middle seat in the third row is considered a “center” seat. 

242
TABLE 2-33: LTV OCCUPANT LIVES SAVED BY CONSPICUITY TAPE ON HEAVY 

TRAILERS AND 3-POINT BELTS FOR REAR-CENTER OCCUPANTS, 1960-2002 

1973 0 0 0 0 0 0 

1999 21 42 63 0 0 0 

 108: CONSPICUITY TAPE ON HEAVY TRAILERS 208J: 3-POINT BELTS FOR REAR-CENTER OCCS 

 (ON-ROAD FLEET EXCEEDED 50% IN 1996, (MEDIAN INSTALL YR AFTER 2001, 

 FMVSS 12/1/93, FMCSA RETROFIT 6/1/2001) FMVSS PHASE-IN TO BEGIN 9/2005) 

 

 CY VOLUNTARY POST-STANDARD TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 0 0 0 0 0 0 

1967 0 0 0 0 0 0 

1968 0 0 0 0 0 0 

1969 0 0 0 0 0 0 

1970 0 0 0 0 0 0 

1971 0 0 0 0 0 0 

1972 0 0 0 0 0 0 

1974 0 0 0 0 0 0 

1975 0 0 0 0 0 0 

1976 0 0 0 0 0 0 

1977 0 0 0 0 0 0 

1978 0 0 0 0 0 0 

1979 0 0 0 0 0 0 

1980 0 0 0 0 0 0 

1981 0 0 0 0 0 0 

1982 0 0 0 0 0 0 

1983 0 0 0 0 0 0 

1984 0 0 0 0 0 0 

1985 0 0 0 0 0 0 

1986 0 0 0 0 0 0 

1987 0 0 0 0 0 0 

1988 0 0 0 0 0 0 

1989 0 0 0 0 0 0 

1990 0 0 0 0 0 0 

1991 3 0 3 0 0 0 

1992 6 0 6 0 0 0 

1993 11 0 11 0 0 0 

1994 12 4 17 0 0 0 

1995 14 9 23 0 0 0 

1996 13 13 26 0 0 0 

1997 19 25 43 0 0 0 

1998 19 32 52 0 0 0 

2000 19 43 62 0 0 0 

2001 5 43 48 0 0 0 

2002 0 68 68 3 0 3 

 =========== =========== =========== =========== =========== =========== 

 142 280 422 3 0 3 

243
Benefits for pedestrians, bicyclists and other non-occupants 

Table 2-34 is a summary of the non-occupant lives saved by car/LTV safety technologies, 

specifically braking improvements. The computation is straightforward: dual master cylinders 

reduce fatal crash involvements, including collisions with non-occupants by 0.70 percent, front 

disc brakes by 0.17 percent. Thus, when all cars and LTVs on the road are equipped with dual 

master cylinders and front disc brakes, 0.87 percent of potential non-occupant fatalities will be 

avoided. Indeed, the right column of Table 2-34 shows that the proportion of potential fatalities 

saved had reached 0.85 percent by 1987 and was converging on 0.87 percent by 2000-2002. For 

example, in 2002, there were 5,011 actual pedestrian, bicyclist and other non-occupant fatalities 

in collisions with cars or LTVs. Without the braking improvements there would have been 

5,055; the brakes prevented 44 fatalities, 0.87 percent of 5,055. 

Non-occupant fatalities in collisions with cars/LTVs peaked at 9,277 in 1972 and have greatly 

declined since then. That is primarily due to demographic factors: an increasingly suburban, 

aging and affluent population is less likely to walk, bike or ride a horse to work or to other 

destinations on public roads. Braking improvements in cars and LTVs have played a relatively 

small role in the decline. They have prevented an estimated 1,782 of 304,025 potential fatalities. 

Furthermore, the absolute number of lives saved has decreased from a peak of 65 in 1980 to 44 

in 2002 because the “base” of non-occupant exposure to potentially fatal crash situations had 

shrunk. Table 2-35 apportions the non-occupant lives saved between the two brake technologies: 

dual master cylinders saved an estimated 1,496 lives in 1960-2002; front disc brakes, 286. 

Benefits for motorcyclists 

Table 2-36 summarizes motorcyclist lives saved by car/LTV braking improvements. The 

computation is similar to Table 2-34: when all cars and LTVs on the road are equipped with dual 

master cylinders and front disc brakes, 0.87 percent of potential motorcyclist fatalities in 

collisions between cars/LTVs and motorcycles will be avoided. In 2002, for example, 1,366 

motorcyclists were actually killed in collisions with cars or LTVs. Without the braking 

improvements in the cars/LTVs there would have been 1,378; the brakes saved 12 lives, 0.87 

percent of 1,378. 

As the popularity of motorcycles has risen and fallen over the years, so have motorcyclist 

fatalities in collisions with cars/LTVs: rising from 388 in 1960 to 2,285 in 1980, falling to 1,000 

in 1996-97, and returning to 1,366 in 2002 as many baby-boomers have taken up cycling again. 

Motorcycle helmets (a safety technology outside the scope of this report) also have a major 

impact on fatalities. Braking improvements in cars and LTVs have played a relatively small 

role. They have prevented an estimated 398 of 58,349 potential fatalities. Table 2-37 shows that 

dual master cylinders in cars/LTVs saved an estimated 332 motorcyclists in 1960-2002; front 

disc brakes, 66. 

244
TABLE 2-34: PEDESTRIAN/BICYLIST SUMMARY 

ACTUAL NON-OCCUPANT FATALITIES IN COLLISIONS WITH CARS/LTVs,

POTENTIAL FATALITIES WITHOUT CAR/LTV BRAKING IMPROVEMENTS,

 AND LIVES SAVED BY CAR/LTV BRAKING IMPROVEMENTS 

 NON-OCCUPANT FATALITIES LIVES SAVED 

1970 8,805 8,834 17 11 28 0.32 

1998 5,477 5,524 2 45 48 0.87 

2000 4,963 5,006 2 42 43 0.87 

 W/O CAR/LTV BY VOLUNTARY BY FMVSS PERCENT 

 CY ACTUAL BRAKE TECHS. IMPROVEMENTS IN EFFECT TOTAL SAVED 

1960 6,447 6,447 0 0 0 0.00 

1961 6,407 6,407 0 0 0 0.00 

1962 6,604 6,604 0 0 0 0.00 

1963 6,918 6,919 1 0 1 0.01 

1964 7,587 7,588 1 0 1 0.02 

1965 7,469 7,470 2 0 2 0.02 

1966 7,901 7,905 4 0 4 0.05 

1967 7,941 7,949 9 0 9 0.11 

1968 8,334 8,349 13 2 15 0.18 

1969 8,334 8,355 15 6 21 0.25 

1971 9,002 9,037 18 17 35 0.39 

1972 9,277 9,319 21 22 42 0.46 

1973 9,159 9,207 23 26 48 0.52 

1974 7,626 7,671 20 25 45 0.59 

1975 7,882 7,935 22 31 53 0.67 

1976 7,599 7,653 21 33 54 0.70 

1977 7,828 7,886 22 36 58 0.73 

1978 7,776 7,836 22 38 60 0.77 

1979 8,088 8,152 22 42 64 0.78 

1980 8,077 8,142 22 43 65 0.80 

1981 7,879 7,943 20 45 64 0.81 

1982 7,472 7,533 20 42 62 0.82 

1983 6,835 6,891 18 39 57 0.82 

1984 7,116 7,176 17 43 60 0.83 

1985 6,911 6,969 16 43 59 0.84 

1986 6,975 7,035 13 47 59 0.84 

1987 6,982 7,042 12 48 60 0.85 

1988 7,117 7,179 10 51 61 0.85 

1989 6,706 6,763 9 49 58 0.85 

1990 6,692 6,750 8 49 58 0.86 

1991 6,084 6,137 7 46 53 0.86 

1992 5,746 5,796 5 45 50 0.86 

1993 5,974 6,026 5 47 52 0.86 

1994 5,729 5,778 5 45 50 0.86 

1995 5,908 5,960 4 47 51 0.86 

1996 5,681 5,730 3 46 50 0.86 

1997 5,621 5,670 3 46 49 0.86 

1999 5,185 5,230 2 43 45 0.86 

2001 5,119 5,164 1 44 45 0.87 

2002 5,011 5,055 1 43 44 0.87 

 =========== =========== =========== =========== =========== 

 302,243 304,025 456 1,326 1,782 

245
TABLE 2-35: NON-OCCUPANT LIVES SAVED BY 

CAR/LTV DUAL MASTER CYLINDERS AND FRONT DISC BRAKES, 1960-2002 

 (MEDIAN INSTALLATION YEAR LATE 1966, (MEDIAN INSTALLATION YEAR 1971, 

1971 16 17 33 2 0 2 

1990 6 40 47 2 9 11 

1996 3 37 40 1 9 10 

2001 1 35 36 0 8 9 

 105A: DUAL MASTER CYLINDERS 105B: FRONT DISC BRAKES 

 FMVSS 1/1/68 [CARS], 9/1/83 [LTVs]) FMVSS 1/1/76 [CARS], 9/1/83 [LTVs]) 

 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 1 0 1 0 0 0 

1964 1 0 1 0 0 0 

1965 2 0 2 0 0 0 

1966 4 0 4 0 0 0 

1967 9 0 9 0 0 0 

1968 13 2 15 0 0 0 

1969 15 6 21 1 0 1 

1970 16 11 27 1 0 1 

1972 17 22 39 3 0 3 

1973 18 26 44 4 0 4 

1974 16 25 40 5 0 5 

1975 16 31 47 6 0 6 

1976 14 33 47 6 0 7 

1977 15 35 50 7 1 8 

1978 15 36 51 7 2 9 

1979 16 38 54 7 3 10 

1980 15 39 54 7 4 11 

1981 14 40 54 6 5 11 

1982 14 37 51 6 5 11 

1983 13 34 47 5 5 10 

1984 12 37 49 5 6 11 

1985 12 36 48 4 7 11 

1986 9 39 48 3 8 11 

1987 9 40 49 3 8 11 

1988 7 42 50 3 9 11 

1989 7 40 47 2 9 11 

1991 5 37 43 1 9 10 

1992 4 36 40 1 8 10 

1993 4 38 42 1 9 10 

1994 4 37 40 1 9 10 

1995 3 38 42 1 9 10 

1997 2 37 40 1 9 9 

1998 2 37 39 0 9 9 

1999 2 35 36 0 8 9 

2000 1 34 35 0 8 8 

2002 1 34 35 0 8 8 

 =========== =========== =========== =========== =========== =========== 

 353 1,143 1,496 103 183 286 

246
TABLE 2-36: MOTORCYLIST SUMMARY 

ACTUAL MOTORCYCLIST FATALITIES IN COLLISIONS WITH CARS/LTVs,

POTENTIAL FATALITIES WITHOUT CAR/LTV BRAKING IMPROVEMENTS,

 AND LIVES SAVED BY CAR/LTV BRAKING IMPROVEMENTS 

 MOTORCYCLIST FATALITIES LIVES SAVED 

 W/O CAR/LTV BY VOLUNTARY BY FMVSS PERCENT 

 CY ACTUAL BRAKE TECHS. IMPROVEMENTS IN EFFECT TOTAL SAVED 

1960 388 388 0 0 0 0.00 

1962 414 414 0 0 0 0.00 

1964 569 569 0 0 0 0.02 

1970 1,189 1,193 2 1 4 0.31 

1974 1,654 1,664 5 5 9 0.57 

 

1961 362 362 0 0 0 0.00 

1963 465 465 0 0 0 0.01 

1965 827 827 0 0 0 0.02 

1966 1,111 1,112 1 0 1 0.05 

1967 1,034 1,035 1 0 1 0.11 

1968 982 984 2 0 2 0.18 

1969 1,008 1,011 2 1 2 0.24 

1971 1,137 1,142 2 2 4 0.37 

1972 1,396 1,402 3 3 6 0.44 

1973 1,603 1,611 4 4 8 0.51 

1975 1,569 1,579 5 6 10 0.65 

1976 1,602 1,613 5 6 11 0.69 

1977 1,957 1,971 6 8 14 0.72 

1978 2,136 2,152 7 9 16 0.75 

1979 2,238 2,256 7 10 18 0.78 

1980 2,285 2,303 7 11 18 0.79 

1981 2,188 2,205 7 11 18 0.80 

1982 2,019 2,036 6 10 16 0.81 

1983 1,864 1,879 6 10 15 0.81 

1984 2,040 2,057 6 11 17 0.83 

1985 2,003 2,020 5 12 17 0.84 

1986 2,017 2,034 4 13 17 0.83 

1987 1,803 1,818 3 12 15 0.84 

1988 1,682 1,696 3 11 14 0.85 

1989 1,385 1,396 2 9 12 0.85 

1990 1,448 1,460 2 10 12 0.86 

1991 1,219 1,229 2 9 11 0.85 

1992 1,043 1,052 1 8 9 0.86 

1993 1,125 1,135 1 8 10 0.86 

1994 1,034 1,043 1 8 9 0.86 

1995 1,041 1,050 1 8 9 0.87 

1996 1,000 1,009 1 8 9 0.86 

1997 1,000 1,009 1 8 9 0.87 

1998 1,004 1,013 1 8 9 0.87 

1999 1,068 1,078 0 9 9 0.87 

2000 1,271 1,282 0 11 11 0.87 

2001 1,405 1,417 0 12 12 0.87 

2002 1,366 1,378 0 12 12 0.87 

 =========== =========== =========== =========== =========== 

 57,951 58,349 114 284 398 

247
1967 1 0 1 0 0 0 

 CY VOLUNTARY POST-FMVSS TOTAL VOLUNTARY POST-FMVSS TOTAL 

1960 0 0 0 0 0 0 

1961 0 0 0 0 0 0 

1962 0 0 0 0 0 0 

1963 0 0 0 0 0 0 

1964 0 0 0 0 0 0 

1965 0 0 0 0 0 0 

1966 1 0 1 0 0 0 

1968 2 0 2 0 0 0 

1969 2 1 2 0 0 0 

1970 2 1 4 0 0 0 

1971 2 2 4 0 0 0 

1972 3 3 6 0 0 0 

1973 3 4 7 1 0 1 

1974 4 5 9 1 0 1 

1975 4 6 9 1 0 1 

1976 4 6 10 1 0 1 

1977 4 8 12 2 0 2 

1978 5 9 14 2 1 2 

1979 5 10 15 2 1 3 

1980 5 10 15 2 1 3 

1981 5 10 15 2 1 3 

1982 5 9 14 2 1 3 

1983 4 8 13 2 1 3 

1984 4 10 14 2 1 3 

1985 4 10 14 1 2 3 

1986 3 11 14 1 2 3 

1987 2 10 13 1 2 3 

1988 2 9 12 1 2 3 

1989 2 8 10 1 2 2 

1990 2 8 10 0 2 2 

1991 1 7 9 0 2 2 

1992 1 6 7 0 1 2 

1993 1 7 8 0 2 2 

1994 1 7 7 0 2 2 

1995 1 7 7 0 2 2 

1996 1 6 7 0 2 2 

1997 1 6 7 0 2 2 

1998 0 7 7 0 2 2 

1999 0 7 8 0 2 2 

2000 0 9 9 0 2 2 

2001 0 10 10 0 2 2 

2002 0 9 10 0 2 2 

 =========== =========== =========== =========== =========== =========== 

 88 244 332 26 40 66 

248

TABLE 2-37: MOTORCYCLIST LIVES SAVED BY 

CAR/LTV DUAL MASTER CYLINDERS AND FRONT DISC BRAKES, 1960-2002 

 105A: DUAL MASTER CYLINDERS 105B: FRONT DISC BRAKES 

 FMVSS 1/1/68 [CARS], 9/1/83 [LTVs]) FMVSS 1/1/76 [CARS], 9/1/83 [LTVs]) 

 (MEDIAN INSTALLATION YEAR LATE 1966, (MEDIAN INSTALLATION YEAR 1971, 
Effect of air bags, by seat position, occupant age and on-off switch availability 

The analysis model developed for this report permits more detailed estimate of the net effect of 

air bags on various population subgroups. Tables 2-7, 2-21 and 2-32 show that air bags had 

saved a net total of 12,074 lives by the end of CY 2002, including 8,770 in passenger cars and 

3,304 in LTVs. Table 2-38 shows that 10,349 of the lives saved were drivers. The computation 

of benefits is simpler for drivers than for right-front passengers. Even though NHTSA’s Special 

Crash Investigations (SCI) show individual cases where air bags have harmed drivers, the 

statistical analysis of FARS data estimates a net fatality reduction for every age/gender group 

and vehicle type. The model applies these effectiveness estimates – ranging from 33 percent for 

unbelted drivers in directly frontal impacts (12:00) down to 5 percent for belted drivers in side 

impacts partially frontal force (10:00 or 2:00) to zero in entirely non-frontal impacts – to the 

actual FARS cases of driver fatalities in vehicles equipped with air bags, inflating these cases to 

determine how many additional fatalities there would have been without air bags. Table 2-38 

estimates that air bags saved 7,394 car drivers and 2,955 LTV drivers. The number of lives 

saved has grown year by year, as vehicles with driver or dual air bags replace older vehicles

without air bags. 

Drivers account for a very large proportion (10,349 of 12,074) of the lives saved by air bags 

because: 

• The right-front seat is occupied in only 1 of every 3 vehicles, but the driver’s seat is 

always occupied. 

• There are many vehicles with driver air bags only, and they have been in service longer 

than the more recent vehicles with dual air bags. 

Table 2-39 estimates the effects of passenger air bags in vehicles without on-off switches for 

those air bags, including cars, SUVs, minivans, most large vans, and some pickup trucks with 

full crew cabs. Table 2-39 has two sections. The upper half considers adults and adolescents 

age 13 or older. Here, air bags are beneficial; in fact, they are slightly more effective than for 

drivers. The computation is similar to the analysis of drivers in Table 2-38. Passenger air bags 

saved an estimated 1,743 adults and adolescents, in vehicles without on-off switches, in 1987-

2002. 

The lower half of Table 2-39 estimates the net effect of air bags on child passengers age 0-12. In 

this group, SCI has identified 154 individual cases (CY 1993-2002 crashes reported to SCI as of 

October 1, 2004) where air bags resulted in fatal injuries to children in vehicles without on-off 

switches, but there conceivably have been other crashes where the air bags prevented a fatality. 

A negative number in Table 2-39 indicates a fatality increase. The computations in Table 2-39 

are: 

249
TABLE 2-38

 LIVES SAVED BY DRIVER AIR BAGS 

 CY TOTAL IN CARS IN LTVs 

1984 0 0 0 

1988 3 3 0 

1991 72 71 0 

1997 851 630 221 

LIVES SAVED BY DRIVER AIR BAGS IN CARS AND LTVs, 1984-2002 

1985 0 0 0 

1986 1 1 0 

1987 2 2 0 

1989 8 8 0 

1990 43 43 0 

1992 101 97 4 

1993 199 187 12 

1994 291 266 25 

1995 478 399 79 

1996 692 543 149 

1998 1,052 752 300 

1999 1,261 877 384 

2000 1,494 1,026 468 

2001 1,749 1,153 595 

2002 2,051 1,334 717 

 =========== =========== =========== 

 10,349 7,394 2,955 

250
TABLE 2-39

ESTIMATED EFFECT OF PASSENGER AIR BAGS ON ADULTS (AGE 13+) AND 

CHILDREN (AGE 0-12) IN CARS AND LTVs WITHOUT ON-OFF SWITCHES, 1987-2002 

 ADULTS (AGE 13+) SAVED BY PASSENGER AIR BAGS 

 CY TOTAL IN CARS IN LTVs W/O SWITCHES 

1987 0 0 0 

1988 0 0 0 

1989 0 0 0 

1990 0 0 0 

1991 3 3 0 

1992 2 2 0 

1993 8 8 0 

1994 21 20 1 

1995 67 64 2 

1996 92 84 8 

1997 144 131 13 

1998 192 167 25 

1999 222 189 33 

2000 277 234 43 

2001 305 258 46 

2002 411 322 89 

 =========== =========== =========== 

 1,743 1,482 261 

 NET EFFECT ON CHILD PASSENGERS (AGE 0-12) 

 (Negative numbers indicate a net increase in fatalities) 

 CY TOTAL IN CARS IN LTVs W/O SWITCHES 

1987 0 0 0 

1988 0 0 0 

1990 0 0 0 

1992 0 0 0 

1998 -18 -14 -4 

1989 0 0 0 

1991 0 0 0 

1993 -0 -0 0 

1994 -4 -3 -1 

1995 -6 -6 0 

1996 -19 -14 -5 

1997 -13 -13 -1 

1999 -15 -13 -1 

2000 -17 -13 -4 

2001 -19 -16 -3 

2002 -18 -14 -4 

 =========== =========== =========== 

 -130 -106 -23 

251
• Strictly based on the same type of statistical model used to compute the benefits of air 

bags for people age 13 or older. In other words, 

o The [often negative] effect of air bags was estimated by double-pair comparison 

analysis of FARS data, and it depends on the age of the child, restraint use, and 

vehicle impact location.

o The negative effectiveness estimates are applied to the actual FARS cases of child 

passenger fatalities in vehicles equipped with dual air bags, deflating these cases 

to determine how many fewer fatalities there would have been without air bags. 

• Information from SCI cases was not used at all in generating these estimates (except, of

course, many of the SCI cases are also FARS cases). 

• Because NHTSA has not yet statistically evaluated the redesign of air bags circa 1998, 

this analysis assumes the same effectiveness for frontal air bags before and after the 

redesign. If the later air bags are less harmful for children, the numbers for 1998-2002 

may be overstated, and the numbers for 1994-97 understated. 

Based on this statistical approach, the model estimates that passenger air bags are associated with

a net increase of 130 FARS-reportable child passenger fatalities through 2002, in vehicles 

without on-off switches. “FARS-reportable” means, among other things, that the crash happened 

on a public road. This statistical estimate is quite compatible with the count of 154 SCI cases, 

considering that the count includes some crashes on private property such as parking lots, and 

makes no allowance for lives that air bags may have saved in other crashes (it is not a net effect). 

Table 2-39 allows a year-by-year comparison of the estimated fatality reduction for adults and 

adolescents (age 13+) and the fatality increase for children (age 0-12). In 1996, air bags saved 

92 adults, but child passenger fatalities increased by 19. That is a ratio of 4.8 adults saved per 

child passenger fatality. In 2002, a much larger number of vehicles with dual air bags on the 

road saved 411 adult lives, but child passenger fatalities had decreased to 18. That is a ratio of 

22.8 adults saved per child passenger fatality. Because our statistical model assumes the same

effects for earlier and later air bags – it does not adjust the effectiveness for the air bag redesign 

circa 1998 – the enormous improvement in the ratio can be attributed to one factor alone: the 

public, to a large extent, has moved child passengers to the back seat, and the exposure of small 

children to air bags has been greatly reduced. 

Table 2-40 estimates the effects of passenger air bags in pickup trucks with on-off switches, and 

also the effect of the switches. Like Table 2-39, it has two sections. Ideally, switches would 

always be “on” for passengers age 13 and older, securing for them the benefits of air bags, and 

they would always be “off” for child passengers up to age 12, assuring that children would never 

be exposed to air bags. If that were the case, the first column of the top half of Table 2-40 would 

be identical to the second column, showing air bags achieving their full potential to protect adults 

(147 lives saved); the first column of the lower section of Table 2-40 would show air bags 

having no effect at all on child passengers (because they are always turned off) and it would be 

entirely filled with zeros. 

252
TABLE 2-40

ESTIMATED EFFECT OF PASSENGER AIR BAGS ON ADULTS (AGE 13+) AND 

CHILDREN (AGE 0-12) IN PICKUP TRUCKS WITH ON-OFF SWITCHES, 1995-2002 

(Positive numbers indicate lives saved; negative numbers indicate net increases in fatalities. 

Block print indicates actual effects of air bags with switches ‘on’; 

italics indicate hypothetical effects; 

bold italics indicate children saved by turning switches ‘off’) 

 EFFECT ON ADULT PASSENGERS (AGE 13+) 

 ACTUAL LIVES SAVED LIVES SAVED IF POTENTIAL SAVINGS LOST

 BY AIR BAGS WITH ALL SWITCHES BECAUSE SWITCHES 

 CY SWITCHES ‘ON’ HAD BEEN ‘ON’ WERE TURNED OFF

1995 0 0 0

1996 0 0 0

1997 2 3 -0

1998 9 11 -2

1999 17 21 -4

2000 27 35 -7

2001 32 40 -8

2002 31 38 -7

 =========== =========== =========== 

 117 147 -30 

 EFFECT ON CHILD PASSENGERS (AGE 0-12) 

 NET EFFECT ON CHILDREN NET EFFECT IF CHILDREN SAVED

 BY AIR BAGS BECAUSE ALL SWITCHES BECAUSE SWITCHES 

 CY SWITCHES WERE ‘ON’ HAD BEEN ‘ON’ WERE TURNED OFF

1995 0 0 0

1996 0 0 0

1997 -0 -1 0

1998 -1 -6 4

1999 -1 -2 2

2000 -1 -2 1

2001 -1 -6 4

2002 -2 -8 6

 =========== =========== =========== 

 -6 -24 18 

253
In reality, though, NHTSA’s survey in 2000 indicated that switches were turned off, for example, 

for 22 percent of 13-15 year olds, 15 percent of adults age 20-59, and 56 percent of people age 

70 or older. Switches were turned on for 14 percent of infants, 26 percent of 1-6 year olds, and 

70 percent of 11-12 year olds. The statistical model for this report factors in the probability that

the switch was on and the effectiveness of air bags, given the occupant’s age and the vehicle’s 

impact location, to estimate how the actual number of fatalities in FARS would have changed: 

• If the trucks had passenger air bags and no switches – or if they did have switches, but 

they were left on all the time (these are the same). 

• If the trucks did not have passenger air bags – or if they did have air bags and the 

switches were left off all the time (these are the same). 

The upper half of Table 2-40 estimates that passenger air bags in pickup trucks with switches 

actually saved 117 occupants age 13 or older. In other words, the switches were left on for these 

occupants; the air bags deployed and saved their lives. However, if in these same trucks the 

switch had been correctly left on for every occupant age 13 or older (or if pickup trucks had 

passenger air bags and no switches), the number of lives (age 13+) saved by air bags would have 

been 147 rather than 117. In other words, 30 of the 147 potential saves were lost because an air 

bag was turned off for a person age 13 or older. There are two ways of looking at these statistics. 

On the one hand, it could be said that inappropriate use of the switches cost 30 lives. On the 

other, it could be argued that, without some device such as the switches to protect child 

passengers, dual air bags simply could not have been mandated in pickup trucks without a back 

seat; in that sense, the switches saved 117 adults who, otherwise, would not have had the 

protection of air bags. 

In the lower half of Table 2-40, the statistical method used by our model estimates air bags netincreased child passenger fatalities by 6 in trucks with the switches left on. In fact, on October 1, 

2004, there were 5 SCI cases of children with fatal injuries from air bags in pickup trucks where 

the switches were left on. 

The statistical model also considers the hypothetical situation that all switches had been left on 

(or that all the trucks had air bags but no switches). The model estimates that air bags would 

have increased child passenger fatalities by 24 rather than 6. In other words, 18 potential 

fatalities to children were avoided because air bags were turned off. Essentially, the switch was 

turned off in three-quarters of the situations (18 of 24) where it needed to be off – i.e., especially 

for infants and toddlers. 

The statistics for adults and children – the two halves of Table 2-40 – can be compared: 

• As actually used by the public in 1995-2002, the combination of passenger air bags with 

on-off switches saved an estimated 117 adults at a cost of 6 child passenger fatalities. 

That is a ratio of 19.5 adult lives saved per child passenger fatality: not too different from

the 22.8 ratio, in 2002, in cars, vans and SUVs (where children can escape harm from air 

bags simply by riding in the back seat, an option not available in pickup trucks without 

back seats).

254
• Air bags without switches, hypothetically, would have saved an estimated 147 adults at a 

cost of 24 child passenger fatalities. That would have been a ratio of 6.1 adult lives saved 

per child passenger fatality: not too different from the 4.8 ratio, in 1996, in cars, vans and 

SUVs, before the public became well aware of the risks of air bags to small children. 

• If pickup trucks had not been equipped with passenger air bags, the statistics would have 

been, of course, zero adults saved and zero children harmed. 

• If the public had been fully aware of the correct way to use the switches, or if the manual 

switches were superseded by advanced systems that automatically trigger or suppress 

deployment depending on the size and location of the occupant, the statistics could have 

been 147 adults saved and zero children harmed. 

Finally, the statistics in Table 2-39 for vehicles other than pickup trucks can be combined with 

the estimates for pickup trucks in Table 2-40. 

• In all vehicles, passenger air bags saved 1,743 + 117 = 1,860 people age 13 or older in 

1987-2002. 

• Child passenger fatalities increased by 130 + 6 = 136. 

• Net lives saved by passenger air bags were 1,860 – 136 = 1,724. 

255

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Federal Register Notices: 

31 (March 8, 1966): 4091, GSA proposes safety standards for Federally purchased 

vehicles. 

31 (July 15, 1966): 9631, GSA Final Rule, safety standards for Federally purchased 

vehicles. 

31 (December 3, 1966): 15212, NPRM for the initial FMVSS. 

32 (February 3, 1967): 2414, Final Rule for the initial FMVSS, including among others 

FMVSS Nos. 103, 105, 108, 201, 203, 204, 205, 206, 207, 208, 209, 210 and 301. 

32 (October 13, 1967): 14278, ANPRM to consider regulations to limit roof crush and 

intrusion. 

32 (December 16, 1967): 18033, Final Rule extending FMVSS 108 to cars and LTVs. 

32 (December 28, 1967): 20865, NPRM to establish FMVSS 202 for passenger cars.

33 (February 14, 1968): 2945, Final Rule establishing FMVSS 202 for passenger cars. 

33 (August 16, 1968): 11652, Final Rule establishing FMVSS 212 for passenger cars. 

33 (October 5, 1968): 14971, ANPRM announcing the intention to regulate side door 

strength. 

33 (December 11, 1968): 18386, first NPRM proposing FMVSS 214. 

34 (January 24, 1969): 1150, Final Rule extending FMVSS 206 to trucks, buses and 

multipurpose passenger vehicles. 

34 (July 2, 1969): 11148, initial ANPRM to consider air bags or other automatic 

protection. 

260
35 (January 21, 1970): 813, second NPRM proposing FMVSS 214. 

35 (April 23, 1970): 6513, third NPRM proposing FMVSS 214. 

35 (May 7, 1970): 7187, initial NPRM for automatic occupant protection, did not become

a Final Rule. 

35 (September 23, 1970): 14778, Final Rule establishing FMVSS 213. 

35 (September 30, 1970): 15222, Final Rule extending the original FMVSS 208 to LTVs. 

35 (September 25, 1970): 14936, NPRM proposing to add a knee impact test to FMVSS 

201, never became a Final Rule. 

35 (October 30, 1970): 16801, Final Rule establishing FMVSS 214 (side door strength, 

passenger cars). 

35 (November 11, 1970): 17345, original NPRM to establish FMVSS 105a for passenger 

cars, effective October 1, 1972. 

36 (January 6, 1971): 166, NPRM to establish FMVSS 216 for passenger cars. 

36 (March 10, 1971): 4600, Final Rule amending FMVSS 208 to require shoulder belts 

and warning buzzers in all cars, and to permit automatic occupant protection. 

36 (December 2, 1971): 22902, Final Rule extending FMVSS 207 to LTVs. 

36 (December 8, 1971): 23299, Final Rule establishing FMVSS 216 for passenger cars. 

37 (September 2, 1972): 17970, original Final Rule establishing FMVSS 105a in 

passenger cars and LTVs, effective September 1, 1974 (subsequently revised). 

38 (May 18, 1973): 13017, delays FMVSS 105a to September 1, 1975 (subsequently 

revised). 

38 (June 20, 1973): 16072, Final Rule amending FMVSS 208 to require integral 3-point 

belts and ignition interlocks in passenger cars. 

39 (February 22, 1974): 6708, renames FMVSS 105a to FMVSS 105-75 and limits it to 

passenger cars (subsequently revised). 

39 (March 19, 1974): 10268, NPRM proposing to upgrade FMVSS 202, including fixed 

head restraints for drivers, never became a Final Rule. 

39 (March 21, 1974): 10588, Final Rule adding lateral and rear impact tests to FMVSS 

301 and extending the standard to LTVs. 

261
39 (October 31, 1974): 38380, Final Rule amending FMVSS 208 to delete the interlock 

requirement. 

39 (November 21, 1974): 40857, minor revisions to FMVSS 301 Final Rule of March 21, 

1974. 

39 (December 6, 1974): 42692, Final Rule amending FMVSS 208 to require a 4-8 second 

audible warning on belt use. 

40 (June 9, 1975): 24525, Final Rule for FMVSS 105-75 in passenger cars, effective 

January 1, 1976. 

40 (July 9, 1975): 28805, Final Rule amending FMVSS 208, extending 3-point belts to 

LTVs. 

40 (August 6, 1975): 33036, revises fuel spillage requirements in FMVSS 301 Final Rule 

of March 21, 1974. 

40 (October 10, 1975): 47790, revises effective dates in FMVSS 301 Final Rule of March 

21, 1974. 

41 (August 30, 1976): 36493, Final Rule extending FMVSS 212 to LTVs and also 

amending the standard, allowing NHTSA to test at a wider range of temperatures. 

42 (July 5, 1977): 34288, postpones until September 1, 1978 the effective date of the 

extension of FMVSS 212 to LTVs. 

42 (July 5, 1977): 34289, Final Rule requiring automatic occupant protection, rescinded 

in 1981 before its effective date. 

46 (February 19, 1981): 13193, Executive Order 12291 – Federal Regulation. 

44 (November 29, 1979): 68470, Final Rule extending FMVSS 201, 203 and 204 to 

LTVs. 

44 (December 13, 1979): 72131, Final Rule adding a 30 mph test to FMVSS 213. 

46 (January 2, 1981): 55, Final Rule extending FMVSS 105 to LTVs 

46 (January 8, 1981): 2064, Final Rule amending FMVSS 208 to add comfort and 

convenience standards for safety belts. 

46 (October 29, 1981): 53419, rescission of 1977 Final Rule requiring automatic 

occupant protection. 

262
48 (October 18, 1983): 48235, Final Rule amending FMVSS 108 to require Center High 

Mounted Stop Lamps on passenger cars. 

48 (November 16, 1983): 52065, Final Rule amending FMVSS 205 to permit the optional 

use of glass-plastic glazing. 

49 (July 17, 1984): 28962, Final Rule amending FMVSS 208 to require automatic 

occupant protection in passenger cars. 

50 (August 23, 1985): 34152, Final Rule amending FMVSS 208 to postpone belt comfort 

and convenience standards to September 1, 1986. 

54 (June 14, 1989): 25275, Final Rule amending FMVSS 208 to require 3-point belts at 

the rear-outboard seats of cars. 

54 (September 25, 1989): 39183, Final Rule extending FMVSS 202 to LTVs. 

54 (November 2, 1989): 46257, Final Rule amending FMVSS 208 to require 3-point belts 

at the rear-outboard seats of LTVs. 

55 (January 17, 1990): 1586, NHTSA evaluation plan for automatic occupant protection. 

55 (October 30, 1990): 45752, Final Rule upgrading FMVSS 214, adding a dynamic side 

impact test for passenger cars. 

56 (March 26, 1991): 12472, Final Rule amending FMVSS 208 to extend automatic 

protection to LTVs. 

56 (April 17, 1991): 15510, Final Rule extending FMVSS 216 to LTVs. 

56 (April 19, 1991): 16015, Final Rule amending FMVSS 108 to require Center High 

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56 (June 14, 1991): 27427, Final Rule extending FMVSS 214 side door strength 

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57 (December 10, 1992): 58406, Final Rule amending FMVSS 108 to require conspicuity 

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58 (September 2, 1993): 46551, Final Rule amending FMVSS 208 to require manual 3-

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58 (October 4, 1993): 51735, Executive Order 12866 – Regulatory Planning and Review. 

59 (January 4, 1994): 281, ANPRM asking for information about the effectiveness and 

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263
60 (April 12, 1995): 18566, ANPRM to consider upgrading FMVSS 301. 

60 (May 23, 1995): 27233, Final Rule amending FMVSS 208 to allow on-off switches 

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60 (July 12, 1995): 35889, Notice of public meeting to discuss potential upgrades to 

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60 (July 28, 1995): 38749, Final Rule extending the FMVSS 214 dynamic side impact

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60 (August 18, 1995): 43031, Final Rule upgrading FMVSS 201. 

60 (September 28, 1995): 50124, Final Rule extending FMVSS 206 to the back doors of 

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61 (July 12, 1996): 36698, ANPRM deferring indefinitely the ABS requirement. 

62 (March 19, 1997): 12960, Final Rule modifying the FMVSS 208 test to permit air 

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62 (November 21, 1997): 62406, sets up procedures enabling the public to obtain 

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63 (August 4, 1998): 41451, Final Rule reducing the FMVSS 201 test speed from 15 mph 

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64 (March 5, 1999): 10786, Final Rule establishing FMVSS 225 and amending FMVSS 

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64 (March 31, 1999): 15587, Federal Motor Carrier Safety Regulation (Final Rule) 

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65 (May 12, 2000): 30679, Final Rule amending FMVSS 208 to require advanced air 

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65 (November 13, 2000): 67693, NPRM to upgrade the rear- and lateral-impact test 

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66 (January 4, 2001): 967, NPRM to upgrade FMVSS 202. 

66 (January 12, 2001): 3388, establishes NHTSA’s rollover resistance ratings based on 

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264
68 (December 1, 2003): 67068, Final Rule upgrading the rear- and lateral-impact test 

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