U.S. Department of Transportation

National Highway Traffic

Safety Administration

National Automotive Sampling System

Crashworthiness Data System

1993 -1995
National Automotive Sampling System/Crashworthiness Data System 1993-1995 i

Contents

Page

Executive Summary ...................................................... v

1. Introduction .......................................................... 1

Background ......................................................... 1

Objective ............................................................ 1

Vehicles Under Consideration ........................................... 1

CDS Estimates ....................................................... 2

2. Perspective ........................................................... 3

3. Vehicle Crash Data .................................................... 5

Car Size ............................................................ 5

Car Crash Modes and Areas of Damage ................................... 5

Car Crash Severity .................................................... 8

Seating Position of Car Occupants ...................................... 10

Functional Class and Size of Light Trucks ................................. 11

Light Truck Crash Modes and Areas of Damage ........................... 12

Light Truck Crash Severity ............................................. 14

Seating Position of Light Truck Occupants ................................ 15

4. Occupant Injury Data .................................................. 17

Crash-Involved Occupants by Injury Severity .............................. 17

Use of Restraints .................................................... 20

Effect of Restraint Use on Injury Risk .................................... 22

Injury Severity and Outcome ........................................... 23

Effect of Alcohol Use on Injury Risk ...................................... 27

Body Regions Injured in Traffic Crashes .................................. 30

Restraint Use and Body Regions Injured .................................. 35

Injury Contacts ...................................................... 38

Occupant Ejection and Entrapment ...................................... 43

Appendixes

A. Glossary ......................................................... 49

B. NASS/CDS Sample Design ......................................... 53
Contents

ii National Automotive Sampling System/Crashworthiness Data System 1993-1995

Tables Page

1. Crash-Involved Towed Cars by Weight Class, 1993-1995 ..................... 5

2. Distribution of Towed Car Crash Modes and Areas of Damage, 1993-1995 ....... 6

3. Distribution of Towed Cars by Crash Severity (delta-v) and Area of Damage: 

Average per Year, 1993-1995 ........................................... 8

4. Occupant Seating Positions in Towed Cars, 1993-1995 ....................... 10

5. Distribution of Towed Light Trucks by Vehicle Class and Size, 1993-1995 ........ 11

6. Distribution of Towed Light Truck Crash Modes and Areas of Damage, 

1993-1995 ........................................................... 12

7. Distribution of Towed Light Trucks by Crash Severity (delta-v) and 

Area of Damage: Average per Year, 1993-1995 ............................. 14

8. Occupant Seating Positions in Towed Light Trucks, 1993-1995 ................. 15

9. Distribution of Crash-Involved Car Occupants 

by Maximum Injury Severity: Average per Year, 1993-1995 .................... 18

10. Distribution of Crash-Involved Light Truck Occupants 

by Maximum Injury Severity: Average per Year, 1993-1995 .................... 18

11. Distribution of Crash-Involved Car Occupants by Restraint Use 

and Maximum Injury Severity: Average per Year, 1993-1995 ................... 20

12. Distribution of Crash-Involved Light Truck Occupants by Restraint Use 

and Maximum Injury Severity: Average per Year, 1993-1995 ................... 21

13. Distribution of Crash-Involved Car Occupants by Treatment 

and Maximum Injury Severity: Average per Year, 1993-1995 .................... 24

14. Distribution of Crash-Involved Light Truck Occupants by Treatment 

and Maximum Injury Severity: Average per Year, 1993-1995 .................... 25

15. Distribution of Crash-Involved Car Drivers by Age Group 

and Alcohol Use: Average per Year, 1993-1995 .............................. 28

16. Distribution of Crash-Involved Light Truck Drivers by Age Group 

and Alcohol Use: Average per Year, 1993-1995 .............................. 28

17. Distribution of Crash-Involved Car Drivers by Alcohol Use 

and Maximum Injury Severity: Average per Year, 1993-1995 .................... 29

18. Distribution of Crash-Involved Light Truck Drivers by Alcohol Use 

and Maximum Injury Severity: Average per Year, 1993-1995 .................... 29

19. Distribution of All Injuries to Crash-Involved Car Occupants 

by Body Region and Severity: Average per Year, 1993-1995 .................... 30

20. Distribution of All Injuries to Crash-Involved Light Truck Occupants 

by Body Region and Severity: Average per Year, 1993-1995 .................... 32

21. Distribution of All Injuries to Crash-Involved Car Occupants 

by Injury Contact and Severity: Average per Year, 1993-1995 ................... 38

22. Distribution of All Injuries to Crash-Involved Light Truck Occupants 

by Injury Contact and Severity: Average per Year, 1993-1995 ................... 40

23. Occupant Ejection and Entrapment in Crash-Involved Towed Cars 

by Degree of Ejection, Crash Mode, and Area of Damage: 

Average of Nationally Weighted Counts per Year, 1993-1995 ................... 43

24. Occupant Ejection and Entrapment in Crash-Involved Towed Light Trucks 

by Degree of Ejection, Crash Mode, and Area of Damage: 

Average of Nationally Weighted Counts per Year, 1993-1995 ................... 44
Contents

National Automotive Sampling System/Crashworthiness Data System 1993-1995 iii

Page

25. Injury-Weighted Occupant Ejection and Entrapment Rates for Crash-Involved 

Towed Cars by Degree of Ejection, Crash Mode, and Area of Damage: 

Average of Nationally Weighted Counts per Year, 1993-1995 ................... 46

26. Injury-Weighted Occupant Ejection and Entrapment Rates for Crash-Involved 

Towed Light Trucks by Degree of Ejection, Crash Mode, and Area of Damage: 

Average of Nationally Weighted Counts per Year, 1993-1995 ................... 47

Figures

1. Crash-Involved Vehicles in the United States, Average per Year, 1993-1995 ....... 3

2. Distribution of Towed Car Crash Modes and Areas of Damage, 1993-1995 ........ 7

3. Distribution of Towed Car Crashes by Crash Severity and Area of Damage, 

1993-1995 ............................................................ 9

4. Distribution of Crash Modes and Areas of Damage: Comparison of Cars 

vs. Light Trucks, 1993-1995 .............................................. 13

5. Distribution of Crash-Involved Occupant Injuries by Maximum Injury Severity: 

Cars vs. Light Trucks, 1993-1995 ......................................... 19

6. Injury Rates for Crash-Involved Car Occupants by Maximum Injury Severity as a 

Function of Restraint Use, 1993-1995 ...................................... 22

7. Annual Incidence of Injured Crash-Involved Car Occupants by Maximum Injury 

Severity and Treatment, 1993-1995 ........................................ 26

8. Distribution of Injuries to Crash-Involved Car Occupants by Affected Body Region 

and Severity of Injury, 1993-1995 ......................................... 34

9. Distribution of Injuries by Body Region to Crash-Involved Car Occupants 

by Restraint Usage: Weighted Average per Year, 1993-1995 ................... 36

10. Distribution of Injuries by Body Region to Crash-Involved Light Truck Occupants 

by Restraint Usage: Weighted Average per Year, 1993-1995 ................... 37

11. Distribution of Injuries to Crash-Involved Car Occupants by Injury Contact 

and Severity of Injury, 1993-1995 ......................................... 42

12. Towed Car Occupant Ejection Rates by Crash Mode and Degree of Ejection, 

1993-1995 ............................................................ 45

13. Ejection-Induced Occupant Injury Rates for Crash-Involved Towed Cars by 

Degree of Ejection and Crash Mode, 1993-1995 ............................. 48
National Automotive Sampling System/Crashworthiness Data System 1993-1995 v

Executive Summary

During the period 1993 through 1995, an estimated 11.4 million vehicles each year

were involved in police-reported traffic crashes. Approximately 93 percent of these

were automobiles, pickup trucks, vans, and sport/utility vehicles, collectively referred to

as passenger vehicles. Pickup trucks, vans, and utility vehicles are collectively referred

to as light trucks. Most of these vehicles were not seriously damaged: only 26 percent of

them were towed from the crash scene due to damage sustained in the crash.

Approximately 47,000 passenger vehicles were involved in fatal crashes each year.

This report focuses attention on occupants of those passenger vehicles that were

towed from the crash scene. NHTSA's National Automotive Sampling System (NASS)/

Crashworthiness Data System (CDS) collects detailed information on towed passenger

vehicle crashes, employing trained, professional crash investigation teams. The indepth data collection, scientific protocols, and professionalism of those involved make

the NASS/CDS database a valuable resource to many in the traffic safety community.

NASS data are used by government, industry, and the private sector to conduct

research, identify injury patterns and mechanisms, provide a basis for regulatory

decisionmaking, and provide a means of evaluating the association between occupant

injury and various crash-related characteristics.

Some highlights of the report include:

 !Passenger cars comprise the largest segment (about 73 percent) of the passenger

vehicles found in the NASS/CDS, and hence, in police-reported towaway crashes. In

the report, cars are treated separately from the remaining vehicles, which have been

grouped together as light trucks.

 !Occupancy patterns for towed crash-involved cars and light trucks were very similar:

about two-thirds (about 66 percent) of the time, the only occupant of a towed crashinvolved car or light truck was the driver. A front-seat passenger was present in the

car about 21.0 percent of the time, with passengers in the second and further seats

about 13.5 percent of the time. For occupants of light trucks, front-seat passengers

were present 18.0 percent of the time, with passengers in the second and further

seats about 16.4 percent of the time.

 !One of the health-care consequences of motor vehicle crashes is the burden on

emergency and health services. About 230,000 occupants of passenger vehicles

were hospitalized each year as a result of police-reported traffic crashes. Another

1,200,000 occupants were transported to a medical facility and released, and

296,000 occupants were treated at the scene of the crash.

 !Contact with the steering assembly accounted for about 10 percent of the minor

injuries (AIS 1-2) but about 15 percent of the serious-maximum (AIS 3+) injuries. A

similar pattern was observed for contact with the interior side surface, comprising 8

percent of the minor injuries and 18 percent of serious and greater injuries.
Executive Summary

vi National Automotive Sampling System/Crashworthiness Data System 1993-1995

 !Approximately 172,000 injuries to occupants resulted from contacting an air bag.

Around 97 percent were minor injuries, and about 3 percent were serious injuries.

 !About 5 percent of the towed cars in crashes rolled over, compared with 14 percent

of the towed light trucks.

 !Eight percent of car occupants in rollover crashes were ejected; the remaining crash

types exhibited ejection rates in the range of 0.2 to 1.3 percent.

 !The restraint use rate for all occupants of passenger vehicles was about 76 percent.

 !The alcohol involvement rate for drivers of passenger cars in traffic crashes is

highest for the age group 25-34 years. In comparison, for drivers of light trucks, the

alcohol involvement rate is highest for drivers 35-44 years old.

 !The alcohol involvement rate for all drivers of light trucks in traffic crashes is almost

twice that for drivers of passenger cars.
National Automotive Sampling System/Crashworthiness Data System 1993-1995 1

1. Introduction

Background

The National Automotive Sampling System (NASS)—formerly, the National Accident

Sampling System—is the mechanism through which the National Highway Traffic

Safety Administration (NHTSA) collects nationally representative data on motor vehicle

traffic crashes to aid in the development, implementation, and evaluation of motor

vehicle and highway safety countermeasures. The NASS was originally designed and

implemented in 1979 to support highway and motor vehicle safety programs. The

NASS program was reevaluated in the mid-1980s. The evaluation team concluded that

the program should be redesigned to focus on enhanced in-depth analyses of

passenger vehicle crash protection performance. This reevaluation resulted in changes

that were implemented by NHTSA's National Center for Statistics and Analysis (NCSA)

in January 1988.

To enhance its applicability in addressing crashworthiness issues, the NASS was

divided into two parts: (1) the General Estimates System (GES), which collects data on

an annual sample of approximately 55,000 police-reported traffic crashes; and (2) the

Crashworthiness Data System (CDS), which collects additional detailed information on

an annual sample of approximately 5,000 police-reported traffic crashes involving

passenger vehicles towed from the crash scene due to damage resulting from the

crash. In this report, the term passenger vehicles is used to refer to all cars, pickup

trucks, vans, and sport/utility vehicles with a gross vehicle weight rating (GVWR) of

10,000 pounds or less. The term light trucks is used to refer to pickup trucks, vans, and

sport/utility vehicles.

Unlike the CDS, the GES does not investigate crashes. Its only source of information is

the police crash report. It does provide the data needed for assessments of the state of

and trends in motor vehicle and traffic safety. An annual report is published each year

that describes the data availability from the NASS/GES and the Fatality Analysis

Reporting System (FARS). The FARS is a census of all fatal crashes that occur in the

United States and Puerto Rico.

Objective

The objective of this report is to illustrate the availability, resolution, and applicability of

crash, vehicle, occupant, and casualty attributes for the characterization of vehicle

crash protection performance on U.S. roads during the years 1993 through 1995,

based on the NASS/CDS records for those years.

Vehicles Under Consideration

This report addresses towed passenger cars, pickup trucks, vans, and sport/utility

vehicles under 10,000 pounds GVWR. Sport/utility vehicles include jeeps, truck-based

station wagons, utility vehicles, and other van- or truck-based motor vehicles under

10,000 pounds GVWR that are not cars, pickups, or vans. Motorcycles, bicycles, horsedrawn carriages, etc., are not included.
Introduction

2 National Automotive Sampling System/Crashworthiness Data System 1993-1995

CDS Estimates

Unless otherwise noted, all the CDS statistics presented in this report are estimates—

not exact counts—generated from a sample of crashes that occurred in the 3-year

period from 1993 through 1995. Descriptions of the CDS sample design and the

procedure used to obtain the data shown in the tables are contained in Appendix B.

Since the CDS is a probability sample, the sampling error of every CDS statistic can be

estimated. Approximate sampling errors for the weighted average counts over the

1993-1995 period are provided in Appendix G.
National Automotive Sampling System/Crashworthiness Data System 1993-1995 3

2.

Note: For those vehicles where tow status is unknown it is

assumed that the vehicles were not towed. While all vehicles

are addressed by NASS/GES, only towed passenger vehicles

are addressed by NASS/CDS.

Source: NASS/CDS and NASS/GES, 1993-1995.

Non-towed: 684,797 89.1%

Towed: 83,385 10.9%

6.7%

768,182

Other/Unknown:

Non-towed: 340,049 75.8%

Towed: 108,826 24.2%

3.9%

448,875

Vehicles:

Sport Utility

Non-towed: 527,496 81.2%

Towed: 129,998 19.8%

5.8%

657,494

Vans:

Non-towed: 1,329,280 76.3%

Towed: 413,231 23.7%

15.3%

1,742,511

Pickups:

Non-towed: 5,649,038 72.6%

Towed: 2,131,330 27.4%

68.3%

7,780,368

Cars

100%

11,397,430

All Vehicles:

Figure 1

Crash-Involved Vehicles in the Unites States,

Average per Year, 1993-1995

Perspective

A perspective on crash-involved vehicles is illustrated in Figure 1, which shows annual

incidence averaged over the years 1993-1995.

The number of all vehicle body types involved in police-reported crashes each year in

the United States is about 11,400,000; about 93.0 percent of these are passenger cars,

pickups, vans, and sport/utility vehicles. In this report, pickups, vans, and sport/utility

vehicles are collectively referred to as “light trucks.” Each of these body types is

subdivided into towed and non-towed vehicles.
Perspective

4 National Automotive Sampling System/Crashworthiness Data System 1993-1995

The towed vehicles shown in Figure 1 are investigated in the NASS/CDS, because of

interest in the crashworthiness of vehicles involved in the more severe crashes. These

are the subject of the following analyses and illustrations, with emphasis on cars.

During the period 1993-1995, the average number of registered passenger vehicles per

year, as reported by R.L. Polk & Co., was 181,624,854, of which 122,097,953 (67.2

percent) were passenger cars and 59,526,901 (32.8 percent) were light trucks.
National Automotive Sampling System/Crashworthiness Data System 1993-1995 5

3.

Table 1

Crash-Involved Towed Cars by Weight Class, 1993-1995

Weight Class Total Sample

Annual Average

Percent Count

Small (<2,500 lbs) 5,032 35.1 824,647 

Mid-Size (2,500-3,000 lbs) 4,388 32.4 761,361 

Large (>3,000 lbs) 4,734 31.0 728,035 

Unknown Size 281 1.6 37,292 

 Total 14,435 100.0 2,351,335 

Examples of Weight Class:

 Small—Ford Tempo, Mercury Tracer, Saturn, Nissan Sentra, Honda Civic

 Mid-size—Plymouth Sundance, Ford Probe, Honda Prelude, Toyota Celica

 Large—Ford Taurus, Dodge Dynasty, BMW 3 series, Pontiac Grand Prix

Vehicle Crash Data

Car Size

About 2,351,000 cars are towed away from the scene of traffic crashes every year.

Table 1 shows the distribution of these cars by weight class. Passenger cars made up

about 77 percent of all NASS/CDS towed vehicles; the remaining 23 percent were light

trucks (see Table 5).

Car Crash Modes and Areas of Damage

Table 2 and Figure 2 show the distribution of towed cars among the primary crash

modes and areas of damage. Frontal damage in nonrollover car crashes is the most

frequent crash type, accounting for about 58 percent of all towed car crashes. Side

damage and all other nonrollover crash types account for 29 percent and 9 percent,

respectively. Rollover car crashes account for the remaining 4 percent.

These crash frequencies do not reflect the distribution of harmful outcomes to the car

occupants. Certain crash types are associated with higher proportions of injury. For

example, although rollover occurs in about 4 percent of towed car crashes, it is

responsible for about 12 percent of the harm-weighted injuries to car occupants in

towed crashes. On the other hand, car crashes with rear damage account for about 9

percent of the cases but are responsible for about 5 percent of the harm-weighted

injuries to occupants (see Table 25).
Vehicle Crash Data

6 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 2

Distribution of Towed Car Crash Modes and Areas of Damage, 1993-1995

Crash Mode and

Area of Damage Total Sample

Annual Average

Percent Count

Rollover

 1-3 Quarter Turns 631 2.8 66,217 

 4+ Quarter Turns 435 1.6 37,594 

 End Over End 46 0.1 2,975 

 Total Rollover 1112 4.5 106,786 

Nonrollover

 Single-Vehicle

 Frontal Damage 2,078 14.8 349,124 

 Side Damage 574 4.3 101,910 

 Rear, Top, or Under Damage 81 1.0 20,716 

 Total Single-Vehicle 2,733 20.1 471,750 

 Multiple-Vehicle

 Frontal Damage 6,106 43.1 1,014,544 

 Side Damage 3,503 24.3 571,762 

 Rear Damage 963 7.9 184,648 

 Top or Under Damage 17 0.1 1,845 

 Total Multiple-Vehicle 10,589 75.4 1,772,799 

 Total Nonrollover 13,322 95.5 2,244,549 

Total Towed Car Crashes 14,435 100.0 2,351,335 

Note: Damage Area “Unknown” has been imputed into the known damage areas.
Vehicle Crash Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 7

Note: The “Other” category for single-vehicle crashes includes rear, top, and

under damage. For multiple-vehicle crashes, “Other” includes top and under

damage.

Source: NASS/CDS, 1993-1995.

0% 10% 20% 30% 40% 50%

Frequency

Other

Rear

Side

Frontal

Other

Side

Frontal

Rollover

Nonrollover

Single-Vehicle

Multiple-Vehicles

Figure 2

Distribution of Towed Car Crash Modes

and Areas of Damage, 1993-1995
Vehicle Crash Data

8 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 3

Distribution of Towed Cars by Crash Severity (delta-v) and Area of Damage:

Average per Year, 1993-1995

Area of

Damage

Crash Frequency by Crash Severity*

1-10 mph 11-20 mph 21-30 mph 31-40 mph >40 mph Unknown Total

Front 187,068 318,708 42,095 4,964 1,175 397,404 951,414 

33.8% 57.5% 7.6% 0.9% 0.2% 41.8% 40.5% 

Side 116,670 111,404 12,830 1,206 118 238,763 480,990 

48.2% 46.0% 5.3% 0.5% 0.1% 49.6% 20.5% 

Rear 16,702 61,653 12,858 1,383 352 45,184 138,132 

18.0% 66.3% 13.8% 1.5% 0.4% 32.7% 5.9% 

Other NA NA NA NA NA 63,398 63,398 

-- -- -- -- -- 100.0% 2.7% 

Unknown 1,428 2,182 117 0 0 713,673 717,401 

38.3% 58.5% 3.1% 0.0% 0.0% 99.5% 30.5% 

 Total 321,867 493,947 67,899 7,553 1,645 1,458,422 2,351,335 

36.0% 55.3% 7.6% 0.8% 0.2% 62.0% 100.0% 

*For each area of damage and known crash severity, the first data row shows the number of

vehicles, and the second row shows the percentage of the total number of vehicles for which

crash severities were known. For the “Unknown” column, the second data row shows the

percentage of the total for each area of damage. For the “Total” column, the second data row

shows the percentage of the grand total. NA = not available.

Car Crash Severity

Crash severity (delta-v in miles per hour) for cars varies generally in the range from 1 to

50 mph. Table 3 shows the distribution of towed cars by severity and area of damage.

No crash severity, in terms of delta-v, can be defined for rollover crashes. Figure 3

illustrates the primary aspects of this distribution.

Crash frequency rises sharply to a peak located between 11 and 20 mph, as shown in

Figure 3. This frequency drops sharply following the peak; cumulative frequency

beyond 40 mph is about 0.2 percent. The same general pattern holds for all areas of

damage in nonrollover crashes: front, side, and rear.

Great caution is recommended in the use and interpretation of crash severity data, for

two reasons: (a) the large number of unknowns; and (b) the sharp reduction in the

number of available cases as crash severity increases. For “Unknown” area of damage

in Table 3, crash severity was calculated using the missing vehicle reconstruction

algorithm (see Appendix E, “CRASHPC and OLDMISSPC Summary”). Area of damage

“other” includes top and undercarriage, which are outside the scope of the

reconstruction algorithm.
Vehicle Crash Data

10 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 4

Occupant Seating Positions in Towed Cars, 1993-1995

Car Occupants Total Sample

Annual Average

Percent Count

Drivers 14,392 65.4 2,340,829 

Right Front Passengers 5,179 21.1 754,599 

Second Seat Passengers 3,349 12.1 433,661 

Other Passengers 348 1.4 50,596 

 Total 23,268 100.0 3,579,685 

Seating Position of Car Occupants

Every year, approximately 3.6 million people are involved in crashes as occupants of

towed cars. Table 4 shows the distribution of occupant seating positions for towed cars

from 1993 through 1995.

The distribution pattern—about 65 percent drivers, 21 percent right front passengers,

and 12 percent all other—is roughly the same as for all cars regardless of crash

involvement.
Vehicle Crash Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 11

Table 5

Distribution of Towed Light Trucks by Vehicle Class and Size, 1993-1995

Vehicle Category and Size Total Sample

Annual Average

Percent Count

Compact Pickup 1,272 28.9 202,515 

Standard Pickup 1,228 24.7 172,783 

Unknown Size Pickup 45 0.8 5,524 

Minivan 635 12.3 86,355 

Standard Van 408 9.1 63,601 

Unknown Size Van 46 0.6 4,231 

Compact Utility Vehicle 902 19.4 136,211 

Standard Utility Vehicle

Unknown Size Utility Vehicle

243 

11 

3.9

0.2 

27,599 

1568 

 Total 4,790 100.0 700,387 

Functional Class and Size of Light Trucks

About 700,000 light trucks (pickup trucks, vans, and sport/utility vehicles) under 10,000

pounds gross vehicle weight rating are towed away from the scene of traffic crashes

every year. Table 5 shows the distribution of these vehicles by functional class and

size. The annual average for these vehicles is 23 percent of all NASS/CDS towed

vehicles. The remaining 77 percent are cars.
Vehicle Crash Data

12 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 6

Distribution of Towed Light Truck Crash Modes and Areas of Damage, 1993-1995

Crash Mode and

Area of Damage Total Sample

Annual Average

Percent Count

Rollover

 1-3 Quarter Turns 537 8.5 59,695 

 4+ Quarter Turns 418 5.4 37,808 

 End Over End 23 0.1 782 

 Total Rollover 978 14.0 98,285 

Nonrollover

 Single-Vehicle

 Frontal Damage 639 16.7 116,716 

 Side Damage 116 2.6 18,307 

 Rear, Top, or Under Damage 22 0.9 6,039 

 Total Single-Vehicle 777 20.1 141,062 

 Multiple-Vehicle

 Frontal Damage 2,203 44.0 308,035 

 Side Damage 641 18.1 126,917 

 Rear Damage 188 3.7 26,045 

 Top or Under Damage 3 0.0 43 

 Total Multiple-Vehicle 3,035 65.8 461,040 

 Total Nonrollover 3,812 86.0 602,102 

Total Crashes 4,790 100.0 700,387 

Light Truck Crash Modes and Areas of Damage

Crash mode and area of damage distributions for towed light trucks involved in crashes

are generally similar to those for towed cars, except for rollover crashes. The proportion

of rollovers for light trucks is 3 times that for passenger cars. Table 6 shows the

distribution of towed light trucks among the primary crash modes and areas of damage.
Vehicle Crash Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 13

Note: The “Other” category for single-vehicle crashes includes rear, top, and

under damage. For multiple-vehicle crashes, “Other” includes top and under

damage.

0% 10% 20% 30% 40% 50%

Frequency

Other

Rear

Side

Frontal

Other

Side

Frontal

Rollover

Nonrollover

Single-Vehicle

Multiple-Vehicle

Light Trucks

Cars

Figure 4

Distribution of Crash Modes and Areas of Damage:

Comparison of Cars vs. Light Trucks, 1993-1995

Figure 4 shows the distribution of crash modes and areas of damage for towed light

trucks, compared with the distribution for towed cars for the years 1993 through 1995.

Most of the observations for car crash frequencies and injury as a function of crash

mode and area of damage are also valid for these vehicles. Rollover is the major

exception: rollover crashes for light trucks are both more frequent than car rollover

crashes (14 percent and 5 percent, respectively) and result in a greater proportion of

harmful outcomes to the vehicle occupants (39 percent and 14 percent, respectively).

The proportion of harm-weighted injuries (39 percent) associated with rollover crashes

is the average for three vehicle classes—pickups, vans, and sport/utility vehicles (see

Table 26). For these three classes the proportion of harmful outcomes varies

significantly: approximately 39 percent for pickups, 28 percent for vans, and 49 percent

for

sport/

utility

vehicl

es.
Vehicle Crash Data

14 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 7

Distribution of Towed Light Trucks by Crash Severity (delta-v)

and Area of Damage: Average per Year, 1993-1995

Area of

Damage

Crash Frequency by Crash Severity*

1-10 mph 11-20 mph 21-30 mph 31-40 mph >40 mph Unknown Total

Front 42,419 81,303 11,734 2,461 453 127,295 265,664 

30.7% 58.8% 8.5% 1.8% 0.3% 47.9% 37.9% 

Side 29,886 16,056 2,124 64 0 58,350 106,480 

62.1% 33.4% 4.4% 0.1% 0.0% 54.8% 15.2% 

Rear 3,858 4,749 106 44 0 8,033 16,790 

44.1% 54.2% 1.2% 0.5% 0.0% 47.9% 2.4% 

Other NA NA NA NA NA 34,178 34,178 

-- -- -- -- -- 100.0% 4.9% 

Unknown 0 155 10 0 0 277,110 277,275 

0.0% 94.2% 5.9% % 0.0% 99.9% 39.6% 

 Total 76,162 102,263 13,973 2,569 453 504,967 700,387 

39.0% 52.3% 7.2% 1.3% 0.2% 72.1% 100.0% 

*For each area of damage and known crash severity, the first data row shows the number of

vehicles, and the second row shows the percentage of the total number of vehicles for which

crash severities were known. For the “Unknown” column, the second data row shows the

percentage of the total for each area of damage. For the “Total” column, the second data row

shows the percentage of the grand total. NA = not available.

Light Truck Crash Severity

Table 7 shows the distribution of towed light truck crashes by crash severity (delta-v in

miles per hour) and area of damage. Most of the observations made for towed car

crash frequencies and injuries to occupants as a function of crash severity are also

valid for these vehicles; the same general patterns are observed. For example, for

frontal impact, the injury proportions (not shown) in the five crash severity intervals

used in Table 7 are 6 percent, 33 percent, 32 percent, 18 percent, and 10 percent for

frontal impacts, and the corresponding crash proportions are 31 percent, 59 percent, 9

percent, 2 percent, and about 0 percent.

A large majority of the injuries to occupants in towed light truck crashes occur at crash

severities under 40 mph. For example, in frontal impacts 90 percent of the injuries

occur at severities under 40 mph. The cumulative injury proportion under 40 mph is 100

percent for both side and rear impacts.

The comment made in connection with car crash severities is even more important for

these vehicles: great caution is recommended in the use and interpretation of crash

severity data, for two reasons: (a) the large number of unknowns; and (b) the sharp

reduction of the number of available cases as crash severity increases. For “Unknown”

area of damage in Table 7, crash severity was calculated using the missing vehicle

reconstruction algorithm.
Vehicle Crash Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 15

Table 8

Occupant Seating Positions in Towed Light Trucks, 1993-1995

Vehicle Occupants Total Sample

Annual Average

Percent Count

Drivers 4,774 65.6 697,432 

Right Front Passengers 1,608 18.0 191,661 

Second Seat Passengers 720 7.0 74,980 

Other Passengers 630 9.4 99,644 

 Total 7,732 100.0 1,063,717 

Seating Position of Light Truck Occupants

Approximately 1,064,000 people are involved in crashes as occupants of towed light

trucks every year. Table 8 shows the distribution of occupant seating positions for these

vehicles from 1993 through 1995.

The distribution pattern—about 66 percent drivers, 18 percent right front passengers,

and 16 percent all other—is roughly the same as for all light trucks regardless of crash

involvement. It is also similar to the corresponding distribution for towed car crashes

(Table 4).
National Automotive Sampling System/Crashworthiness Data System 1993-1995 17

4. Occupant Injury Data

Crash-Involved Occupants by Injury Severity

Approximately 3,580,000 occupants are involved in towed car crashes every year.

About 51 percent of them are uninjured, and 49 percent are injured at various severity

levels. Similarly, about 1,064,000 occupants are involved in towed light truck crashes

per year, with about 57 percent uninjured and 43 percent injured.

Given that each injured occupant usually has more than one injury, the severity of the

occupant's most harmful injury is used to characterize the seriousness of the injuries

resulting from the crash. The Abbreviated Injury Scale (AIS) is used to compare injury

severities, as follows:

AIS Severity of Injury

0 Not injured

1 Minor

2 Moderate

3 Serious

4 Severe

5 Critical

6 Maximum 

7 Injured, Severity

Unknown

The AIS scale reflects primarily the threat to life: approximately 99 percent for AIS=6;

about 58 percent for AIS=5; about 33 percent for AIS=4; declining rapidly to 0 percent

for AIS=1. However, the scale is also used to reflect the gravity of consequences for

survivors.

The distribution of injury severities for injured crash-involved occupants is shown in

Table 9 for cars and in Table 10 for light trucks. The two distributions are compared in

Figure 5, where it is evident that there are no major differences at any given level of

injury severity.

Occupants coded as “unknown if injured” have been excluded from the detail in Tables

9 through 14, but have been included in the “Total” rows to reflect the total number of

occupants involved in towed passenger vehicle crashes.
Occupant Injury Data

18 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 9

Distribution of Crash-Involved

Car Occupants by Maximum Injury Severity:

Average per Year, 1993-1995

Maximum AIS Rating Count Percent

Not Injured (0) 1,833,404 51.2 

Minor (1) 1,269,168 35.5 

Moderate (2) 142,915 4.0 

Serious (3) 62,230 1.7 

Severe (4) 13,393 0.4 

Critical (5) 8,479 0.2 

Maximum (6) 2,712 0.1 

 Total, Known Severity 3,332,301 93.1 

Injured, Severity Unknown

(7) 208,012 5.8 

 Total 3,579,685 100.0 

Table 10

Distribution of Crash-Involved

Light Truck Occupants by Maximum Injury Severity:

Average per Year, 1993-1995

Maximum AIS Rating Count Percent

Not Injured (0) 600,859 56.5 

Minor (1) 330,668 31.1 

Moderate (2) 53,268 5.0 

Serious (3) 13,092 1.2 

Severe (4) 4,343 0.4 

Critical (5) 2,546 0.2 

Maximum (6) 981 0.1 

 Total, Known Severity 1,005,757 94.5 

Injured, Severity Unknown

(7) 50,410 4.7 

 Total 1,063,717 100.0 
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 19

0%

10%

20%

30%

40%

50%

60%

Percent of Occupants

Not Injured Minor Moderate

(0) (1) (2)

Maximum AIS Rating

Cars

Light Trucks

Figure 5(a)

Distribution of Crash-Involved Occupant Injuries

by Maximum Injury Severity: Cars vs. Light Trucks, 1993-1995

0%

1%

1%

2%

2%

Percent of Occupants

Serious Severe Critical Maximum

(3) (5) (4)

Maximum AIS Rating

Cars

Light Trucks

(6)

Figure 5(b)

Distribution of Crash-Involved Occupant Injuries

by Maximum Injury Severity: Cars vs. Light Trucks, 1993-1995
Occupant Injury Data

20 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 11

Distribution of Crash-Involved Car Occupants by Restraint Use

and Maximum Injury Severity: Average per Year, 1993-1995

Restraint

Use

Frequency of Injury by Maximum AIS Rating*

Not Injured

(0)

Minor

(1)

Moderate

(2)

Serious

(3)

Severe

(4)

Critical

(5)

Maximum

(6)

Injured,

Severity

Unknown (7) Total

None 252,540 338,188 63,494 27,990 5,689 4,665 1,451 27,704 729,092 

16.6% 28.1% 47.0% 48.4% 45.1% 58.2% 63.9% 25.7% 23.8% 

Automatic

Belt

316,811 209,333 23,908 12,120 1,917 1,160 319 16,874 582,929 

20.8% 17.4% 17.7% 21.0% 14.5% 14.1% 15.4% 19.0% 

Manual Belt

894,254 648,004 47,670 17,644 4,886 2,167 486 64,776 

1,687,06

9 

58.8% 53.8% 35.3% 30.5% 38.7% 27.0% 21.4% 59.0% 55.0% 

Belt With

Child Seat

57,997 8,141 166 27 122 26 14 518 67,012 

3.1% 0.7% 0.1% 0.1% 1.0% 0.3% 0.6% 0.5% 2.2% 

 Total,

 Restrained

1,269,062 865,478 71,744 29,792 6,925 3,354 819 82,169 2,337,010 

83.4% 71.9% 53.1% 51.6% 54.9% 41.8% 36.1% 74.8% 76.2% 

 Total Known 1,521,602 1,203,667 135,238 57,782 12,614 8,018 2,270 109,873 3,066,102 

83.0% 94.8% 94.6% 92.9% 94.2% 94.6% 83.7% 52.8% 85.7% 

Unknown 311,802 65,501 7,677 4,448 779 460 442 98,139 513,583 

17.0% 5.2% 5.4% 7.1% 5.8% 5.4% 16.3% 47.2% 14.4% 

 Total 1,833,404 1,269,168 142,915 62,230 13,393 8,479 2,712 208,012 3,579,685 

51.2% 35.5% 4.0% 1.7% 0.4% 0.2% 0.1% 5.8% 100.0% 

*For each known belt use category, the first data row shows the number of injuries and the second row shows the

percentage of the “Total Known.” For the “Total Known” and “Unknown” belt use categories, the first row shows

the number of injuries and the second row shows the percentage of the column total. For the column totals, the

first row shows the number of injuries and the second row shows the percentage of the total number of injuries.

The row totals include the number of “unknown if injured”.

Use of Restraints

The annual distribution of injuries to crash-involved car occupants by maximum injury

severity and restraint use is shown in Table 11. A similar joint distribution is shown in

Table 12 for crash-involved light truck occupants.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 21

Table 12

Distribution of Crash-Involved Light Truck Occupants by Restraint Use

and Maximum Injury Severity: Average per Year, 1993-1995

Restraint

Use

Frequency of Injury by Maximum AIS Rating*

Not Injured

(0)

Minor

(1)

Moderate

(2)

Serious

(3)

Severe

(4)

Critical

(5)

Maximum

(6)

Injured,

Severity

Unknown (7) Total

None 114,522 114,705 22,855 8,073 3,358 2,117 360 12,319 283,217 

22.9% 36.2% 44.7% 65.7% 84.0% 85.9% 63.3% 40.7% 30.7% 

Automatic

Belt

2,480 1,148 104 10 0 0 0 0 3,742 

0.5% 0.4% 0.2% 0.1% -- -- -- -- 0.4% 

Manual Belt 373,292 199,590 28,118 4,166 642 346 209 17,820 624,577 

74.7% 63.1% 55.0% 33.9% 16.0% 14.1% 36.7% 58.9% 67.7% 

Belt With

Child Seat

9,786 1,107 69 32 0 0 0 112 11,106 

2.0% 0.4% 0.1% 0.3% -- -- -- 0.4% 1.2% 

 Total,

 Restrained

385,558 201,846 28,290 4,208 642 346 209 17,931 639,425 

77.1% 63.4% 55.3% 34.3% 16.1% 14.0% 36.7% 59.3% 69.3% 

 Total Known 500,080 316,551 51,145 12,281 4,000 2,464 569 30,250 922,642 

83.2% 95.7% 96.0% 93.8% 92.1% 96.8% 58.0% 60.0% 86.7% 

Unknown 100,778 14,117 2,123 811 343 82 412 20,161 141,075 

16.8% 4.3% 4.0% 6.2% 7.9% 3.2% 42.0% 40.0% 13.3% 

 Total 600,859 330,668 53,268 13,092 4,343 2,546 981 50,411 1,063,717 

56.5% 31.1% 5.0% 1.2% 0.4% 0.2% 0.1% 4.7% 100.0% 

*For each known belt use category, the first data row shows the number of injuries and the second row shows the

percentage of the “Total Known.” For the “Total Known” and “Unknown” belt use categories, the first row shows

the number of injuries and the second row shows the percentage of the column total. For the column totals, the

first row shows the number of injuries and the second row shows the percentage of the total number of injuries.

The row totals include the number of unknown injuries.

Overall, restraint use is approximately 76 percent for passenger car occupants and

69 percent for occupants of light trucks. These belt use rates are in agreement with the

belt use rates obtained by individual state surveys reported to NHTSA each year. Not

all states report belt usage rates each year. Therefore, to calculate the national safety

belt use rate from the individual state use rates, each state's most recent rate is

weighted by the state's proportion of the total U.S. population. Average state belt use

rates were reported as 66 percent in 1993, 67 percent in 1994, and 68 percent in 1995.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 23

Injury Severity and Outcome

As discussed above (see Table 9), not all crash deaths are associated with untreatable

injuries (AIS=6). Rather, the probability of death increases sharply with injury severity,

and many fatalities occur as a result of one or more injuries that are generally

considered survivable. Crash injury outcomes—fatality, hospitalization, needed

emergency medical care, first aid treatment, and no treatment needed—are generally a

function of the severity of an occupant's most severe injury, plus other factors, such as

the number, severity, and type of additional injuries; the person's age and overall

health; extrication time; etc.

The primary determinant of an outcome is the maximum injury severity. Table 13 shows

the distribution of injuries to crash-involved car occupants according to the AIS values

of maximum injury severity and the pertinent outcomes of maximum injury severities.

This table also includes the number of days an occupant was hospitalized for injuries

sustained in the crash as a result of the crash. An occupant may be hospitalized for

observation or due to a pre-existing medical condition, as directed by the attending

physician, without having received any injuries in the crash. Fatal injuries with AIS=1

are the result of incomplete medical information by which to code the data. A similar

distribution is shown in Table 14 for crash-involved light truck occupants.
Occupant Injury Data

24 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 13

Distribution of Crash-Involved Car Occupants by Treatment

and Maximum Injury Severity: Average per Year, 1993-1995

Treatment

Frequency of Injury by Maximum AIS Rating*

Not Injured

(0)

Minor

(1)

Moderate

(2)

Serious

(3)

Severe

(4)

Critical

(5)

Maximum

(6)

Injured,

Severity

Unknown (7) Total

None

1,753,110 268,663 937 0 0 0 0 28,453 

2,060,10

9 

85.1% 13.0% 0.0% -- -- -- -- 1.4% 57.6% 

Treated

at Scene

16,348 182,031 7,855 486 0 0 0 22,489 229,757 

7.1% 79.2% 3.4% 0.2% -- -- -- 9.8% 6.4% 

Transported

and Released

57,779 755,708 75,012 11,636 97 16 0 54,844 956,090 

6.0% 79.0% 7.8% 1.2% 0.0% 0.0% -- 5.7% 26.7% 

Hospitalized

 1-2 Days

2,879 39,285 28,609 15,774 1,589 470 0 5,022 93,628 

3.1% 42.0% 30.6% 16.8% 1.7% 0.5% -- 5.4% 2.6% 

 3-7 Days 320 9,993 23,586 18,445 2,771 671 0 376 56,163 

0.6% 17.8% 42.0% 32.8% 4.9% 1.2% -- 0.7% 1.6% 

 8-14 Days 43 274 3,644 10,199 1,813 991 0 360 17,325 

0.2% 1.6% 21.0% 58.9% 10.5% 5.7% -- 2.1% 0.5% 

 15-30 Days 0 615 917 2,501 910 1,246 0 34 6,224 

-- 9.9% 14.7% 40.2% 14.6% 20.0% -- 0.5% 0.2% 

 >30 Days 0 33 271 1,264 1,522 378 27 23 3,518 

-- 1.0% 7.7% 35.9% 43.2% 10.8% 0.8% 0.6% 0.1% 

Fatal 0 1,239 1,846 1,892 4,690 4,693 2,685 2,189 19,234 

-- 6.4% 9.5% 9.8% 24.2% 24.2% 13.8% 11.4% 0.5% 

Unknown 2,926 11,325 238 34 0 12 0 94,223 137,636 

2.1% 8.2% 0.2% 0.0% -- 0 -- 68.5% 3.8% 

 Total 1,833,404 1,269,168 142,915 62,230 13,393 8,479 2,712 208,012 3,579,685 

51.2% 35.5% 4.0% 1.7% 0.4% 0.2% 0.1% 5.8% 100.0% 

*For each treatment category, the first data row shows the number of injuries and the second row shows the

percentage of the row total.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 25

Table 14

Distribution of Crash-Involved Light Truck Occupants by Treatment

and Maximum Injury Severity: Average per Year, 1993-1995

Treatment

Frequency of Injury by Maximum AIS Rating*

Not Injured

(0)

Minor

(1)

Moderate

(2)

Serious

(3)

Severe

(4)

Critical

(5)

Maximum

(6)

Injured,

Severity

Unknown (7) Total

None 575,362 74,232 159 0 0 0 0 12,204 662,555 

86.8% 11.2% 0.0% -- -- -- -- 1.8% 62.3% 

Treated

at Scene

14,647 44,565 3,061 166 0 0 0 3,920 66,433 

22.0% 67.1% 4.6% 0.3% -- -- -- 5.9% 6.2% 

Transported

and Released

8,696 197,499 26,913 1,341 0 0 0 8,757 243,231 

3.6% 81.2% 11.1% 0.6% -- -- -- 3.6% 22.9% 

Hospitalized

 1-2 Days

201 11,149 10,969 3,317 526 214 0 1,924 28,348 

0.7% 39.3% 38.7% 11.7% 1.9% 0.8% -- 6.8% 2.7% 

 3-7 Days 42 1,917 8,919 4,149 1,324 78 0 58 16,487 

0.3% 11.6% 54.1% 25.2% 8.0% 0.5% -- 0.4% 1.5% 

 8-14 Days 0 121 1,233 2,142 551 154 0 4 4,205 

-- 2.9% 29.3% 50.9% 13.1% 3.7% -- 0.1% 0.4% 

 15-30 Days 0 34 1,571 1,347 313 128 0 35 3,428 

-- 1.0% 45.8% 39.3% 9.1% 3.7% -- 1.0% 0.3% 

 >30 Days 0 56 160 226 237 175 0 85 939 

-- 6.0% 17.1% 24.1% 25.2% 18.6% -- 9.1% 0.1% 

Fatal 0 446 247 386 1,392 1,797 981 1,154 6,404 

-- 7.0% 3.9% 6.0% 21.7% 28.0% 15.3% 18.0% 0.6% 

Unknown 1,911 650 36 18 0 0 0 22,268 31,687 

6.0% 2.1% 0.1% 0.1% 0.0% 0.0% 0.0% 70.3% 3.0% 

 Total 600,859 330,668 53,268 13,092 4,343 2,546 981 50,410 1,063,717 

56.5% 31.1% 5.0% 1.2% 0.4% 0.2% 0.1% 4.7% 100.0% 

*For each treatment category, the first data row shows the number of injuries and the second row shows the

percentage of the row total.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 27

Effect of Alcohol Use on Injury Risk

The presence of alcohol in a motor vehicle driver increases (a) the likelihood of being

involved in a crash, and (b) the severity of the crash. In this report, alcohol reporting is

based on the police officer's assessment at the time of the crash.

Table 15 shows that, for drivers of passenger cars, those whose age is between 25 and

34 have the highest alcohol use rate, followed by the 21 through 24 age range and then

the 35- through 44-year-old drivers. Table 16 shows that, for drivers of light trucks,

those whose age is between 35 and 44 have the highest alcohol use rate, followed by

drivers 25 through 34 years old and then by those 45 through 64 years old. Drivers of

light trucks have almost twice the alcohol use rate of passenger car drivers. These

percentages are based on the “Total Known.”

Table 17 shows that, for drivers of passenger cars, as the severity of the injury

increases so does the presence of alcohol. Drivers in towed passenger cars with

alcohol present had MAIS 3-6 injury rates 4 times those for drivers with no alcohol

present. Approximately 30 percent of the MAIS 6 injuries are the result of alcohol

involvement, followed by 26 percent of the MAIS 4 injuries and 22 percent of the MAIS

5 injuries. Table 18 describes the same pattern for drivers of towed light trucks. Drivers

in towed light trucks with alcohol present had MAIS 3-6 injury rates at least twice those

for drivers with no alcohol present.
Occupant Injury Data

28 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 15

Distribution of Crash-Involved Car Drivers

by Age Group and Alcohol Use: Average per Year, 1993-1995

Police-Reported

Alcohol Use

Age Group (Years)

15-20 21-24 25-34 35-44 45-64 $65 Unknown Total

No Alcohol Present 421,354 284,272 440,281 345,570 307,384 192,995 11,058 2,002,915 

21.0% 14.2% 22.0% 17.3% 15.3% 9.6% 0.6% 85.6% 

Alcohol Present 16,083 28,019 62,648 26,999 19,894 5,454 1,694 160,793 

10.0% 17.4% 39.0% 16.8% 12.4% 3.4% 1.1% 6.9% 

Not Reported 32,057 19,539 27,551 19,540 16,058 8,784 15,458 138,986 

23.1% 14.1% 19.8% 14.1% 11.6% 6.3% 11.1% 5.9% 

Not Coded 5,496 8,816 7,880 3,057 1,941 578 10,213 37,981 

14.5% 23.2% 20.7% 8.0% 5.1% 1.5% 26.9% 1.6% 

 Total 474,991 340,646 538,360 395,166 345,278 207,812 38,423 2,340,675 

20.3% 14.6% 23.0% 16.9% 14.8% 8.9% 1.6% 100.0% 

*For each police-reported alcohol category, the first data row shows the number of drivers and the second row

shows the percentage of the row total.

Table 16

Distribution of Crash-Involved Light Truck Drivers

by Age Group and Alcohol Use: Average per Year, 1993-1995

Police-Reported

Alcohol Use

Age Group (Years)

15-20 21-24 25-34 35-44 45-64 $65 Unknown Total

No Alcohol Present 92,461 58,303 143,877 130,541 104,691 28,421 1,563 559,857 

16.5% 10.4% 25.7% 23.3% 18.7% 5.1% 0.3% 80.2% 

Alcohol Present 9,672 10,029 23,306 24,233 22,744 1,914 860 92,757 

10.4% 10.8% 25.1% 26.1% 24.5% 2.1% 0.9% 13.3% 

Not Reported 2,893 2,048 13,493 4,307 5,246 1,190 1,018 30,195 

9.6% 6.8% 44.7% 14.3% 17.4% 3.9% 3.4% 4.3% 

Not Coded 1,898 1,341 2,975 1,141 1,034 622 6,680 15,690 

12.1% 8.5% 19.0% 7.3% 6.6% 4.0% 42.6% 2.2% 

 Total 106,924 71,720 183,651 160,222 133,715 32,147 10,120 698,500 

15.3% 10.3% 26.3% 22.9% 19.1% 4.6% 1.4% 100.0% 

*For each police-reported alcohol category, the first data row shows the number of drivers and the second row

shows the percentage of the row total.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 29

Table 17

Distribution of Crash-Involved Car Drivers by Alcohol Use

and Maximum Injury Severity: Average per Year, 1993-1995

PoliceReported

Alcohol Use

Frequency of Injury by Maximum AIS Rating*

Not

Injured

(0)

Minor

(1)

Moderate

(2)

Serious

(3)

Severe

(4)

Critical

(5)

Maximum

(6)

Injured,

Severity

Unknown (7) Total

No Alcohol

Present

1,009,373 747,479 82,095 31,010 4,962 3,043 667 118,348 2,002,915 

50.4% 37.3% 4.1% 1.5% 0.2% 0.2% 0.0% 5.9% 85.6% 

Alcohol

Present

61,565 60,038 12,940 8,866 2,337 1,198 534 11,595 160,793 

38.3% 37.3% 8.0% 5.5% 1.5% 0.7% 0.3% 7.2% 6.9% 

Not Reported 50,752 58,276 7,785 1,946 628 558 413 7,351 138,986 

36.5% 41.9% 5.6% 1.4% 0.5% 0.4% 0.3% 5.3% 5.9% 

Not Coded 14,208 10,152 1,236 1,645 971 731 149 1,780 37,981 

37.4% 26.7% 3.3% 4.3% 2.6% 1.9% 0.4% 4.7% 1.6% 

 Total 1,135,898 875,945 104,057 43,467 8,898 5,530 1,762 139,074 2,340,675 

48.5% 37.4% 4.4% 1.9% 0.4% 0.2% 0.1% 5.9% 100.0% 

*For each police-reported alcohol use category, the first data row shows the number of drivers involved and the

second row shows the percentage of the row total.

Table 18

Distribution of Crash-Involved Light Truck Drivers by Alcohol Use

and Maximum Injury Severity: Average per Year, 1993-1995

PoliceReported

Alcohol Use

Frequency of Injury by Maximum AIS Rating*

Not

Injured

(0)

Minor

(1)

Moderate

(2)

Serious

(3)

Severe

(4)

Critical

(5)

Maximum

(6)

Injured,

Severity

Unknown (7) Total

No Alcohol

Present

301,223 198,401 21,095 6,745 1,907 802 237 29,128 559,857 

53.8% 35.4% 3.8% 1.2% 0.3% 0.1% 0.0% 5.2% 80.2% 

Alcohol

Present

53,548 27,021 4,356 1,887 752 506 73 3,747 92,757 

57.7% 29.1% 4.7% 2.0% 0.8% 0.5% 0.1% 4.0% 13.3% 

Not Reported 14,908 5,939 7,243 247 81 79 78 1,555 30,195 

49.4% 19.7% 24.0% 0.8% 0.3% 0.3% 0.3% 5.2% 4.3% 

Not Coded 2,961 2,895 546 606 174 290 416 1,865 15,690 

18.9% 18.4% 3.5% 3.9% 1.1% 1.8% 2.7% 11.9% 2.2% 

 Total 372,640 234,256 33,240 9,485 2,914 1,677 804 36,295 698,500 

53.4% 33.5% 4.8% 1.4% 0.4% 0.2% 0.1% 5.2% 100.0% 

*For each police-reported alcohol use category, the first data row shows the number of drivers involved and the

second row shows the percentage of the row total.
Occupant Injury Data

30 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 19

Distribution of All Injuries to Crash-Involved Car Occupants

by Body Region and Severity: Average per Year, 1993-1995

Body Region

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Head (Brain) 33,730 57,157 16,584 10,096 6,602 708 0 124,877 

27.0% 45.8% 13.3% 8.1% 5.3% 0.6% -- 

0.9% 19.3% 14.2% 39.4% 50.2% 23.9% -- 

Head (Skull) 0 2,901 5,536 1,906 0 506 0 10,850 

-- 26.7% 51.0% 17.6% -- 4.7% -- 

-- 1.0% 4.7% 7.4% -- 17.1% -- 

Head (Other) 0 383 21 46 50 0 10,227 10,728 

-- 3.6% 0.2% 0.4% 0.5% -- 95.3% 

-- 0.1% 0.0% 0.2% 0.4% -- 48.3% 

Face 73,189 18,092 3,205 0 0 0 0 94,487 

77.5% 19.1% 3.4% -- -- -- -- 

1.9% 6.1% 2.7% -- -- -- -- 

Neck 335,298 206 162 70 42 22 79 335,879 

99.8% 0.1% 0.0% 0.0% 0.0% 0.0% 0.0% 

8.8% 0.1% 0.1% 0.3% 0.3% 0.7% 0.4% 

Chest 25,818 23,406 31,165 10,167 3,750 1,128 6,694 102,129 

25.3% 22.9% 30.5% 10.0% 3.7% 1.1% 6.6% 

0.7% 7.9% 26.7% 39.7% 28.5% 38.1% 31.6% 

Shoulder and Back 159,783 51,673 4,930 0 0 0 0 216,387 

73.8% 23.9% 2.3% -- -- -- -- 

4.2% 17.5% 4.2% -- -- -- -- 

*For each body region, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.

Body Regions Injured in Traffic Crashes

There are about 2,351,000 cars towed away from traffic crashes every year. The

incidence of crash-involved occupants in these cars is about 3,580,000 per year. Of

these, about 1,746,000 car occupants per year are injured, incurring about 4,280,000

injuries of various severities, in various body regions, and by various injury contacts.

Table 19 shows the distribution of all injuries incurred by injured occupants of crashinvolved cars (as opposed to each occupant's most severe injury, reported in Tables 9-

18) as a function of injury severity and injured body region. Table 20 shows the same

distribution for injured occupants of light trucks.

The numbers for “injured, severity unknown” (AIS=7) are lower in these tables than in

tables using maximum AIS (MAIS), because of the level of information available for

coding the injuries. An AIS of 7 is assigned to an injury when there is not sufficient

information about the injury available. An MAIS of 7 is assigned to an occupant when it

is known that the occupant was injured, but no information about the injury is available.

Therefore, an occupant with an MAIS of 7 may not have any associated injuries coded.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 31

Table 19 (Continued)

Distribution of All Injuries to Crash-Involved Car Occupants

by Body Region and Severity: Average per Year, 1993-1995

Body Region

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Abdomen 704 21,821 4,721 2,714 1,929 0 4,175 36,065 

2.0% 60.5% 13.1% 7.5% 5.3% -- 11.6% 

0.0% 7.4% 4.0% 10.6% 14.7% -- 19.7% 

Spine 0 0 523 444 763 169 0 1,900 

-- -- 27.5% 23.4% 40.2% 8.9% -- 

-- -- 0.4% 1.7% 5.8% 5.7% -- 

Upper Extremities 49,134 36,858 20,542 0 0 0 0 106,534 

46.1% 34.6% 19.3% -- -- -- -- 

1.3% 12.5% 17.6% -- -- -- -- 

Pelvis 0 15,510 6,635 40 8 0 0 22,192 

-- 69.9% 29.9% 0.2% 0.0% -- -- 

-- 5.2% 5.7% 0.2% 0.1% -- -- 

Lower Extremities 41,907 63,001 22,337 78 0 0 0 127,322 

32.9% 49.5% 17.5% 0.1% -- -- -- 

1.1% 21.3% 19.1% 0.3% -- -- -- 

Skin 3,085,15

7 

4,464 269 0 7 427 0 3,090,325 

99.8% 0.1% 0.0% -- 0.0% 0.0% -- 

81.1% 1.5% 0.2% -- 0.1% 14.4% -- 

All Other 11 0 219 33 0 0 0 262 

4.2% -- 83.4% 12.5% -- -- -- 

0.0% -- 0.2% 0.1% -- -- -- 

 Total 3,804,731 295,473 116,851 25,594 13,151 2,961 21,176 4,279,937 

*For each body region, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.
Occupant Injury Data

32 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 20

Distribution of All Injuries to Crash-Involved Light Truck Occupants

by Body Region and Severity: Average per Year, 1993-1995

Body Region

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Head (Brain) 15,980 24,355 5,575 3,653 2,303 173 0 52,038 

30.7% 46.8% 10.7% 7.0% 4.4% 0.3% -- 

1.5% 23.1% 18.0% 40.7% 61.7% 14.7% -- 

Head (Skull) 0 2,592 2,110 925 0 293 0 5,921 

-- 43.8% 35.6% 15.6% -- 5.0% -- 

-- 2.5% 6.8% 10.3% -- 24.8% -- 

Head (Other) 0 2 0 39 0 0 2,951 2,992 

-- 0.1% -- 1.3% -- -- 98.6% 

-- 0.0% -- 0.4% -- -- 55.8% 

Face 18,247 7,612 1,419 0 0 0 0 27,278 

66.9% 27.9% 5.2% -- -- -- -- 

1.7% 7.2% 4.6% -- -- -- -- 

Neck 72,729 45 13 0 0 4 0 72,791 

99.9% 0.1% 0.0% -- -- 0.0% -- 

6.6% 0.0% 0.0% -- -- 0.3% -- 

Chest 4,197 7,224 5,879 2,882 766 361 1,252 22,562 

18.6% 32.0% 26.1% 12.8% 3.4% 1.6% 5.5% 

0.4% 6.9% 19.0% 32.1% 20.5% 30.6% 23.7% 

Shoulder and Back 45,225 16,952 1,656 0 0 0 0 63,833 

70.8% 26.6% 2.6% -- -- -- -- 

4.1% 16.1% 5.3% -- -- -- -- 

*For each body region, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 33

Table 20 (Continued)

Distribution of All Injuries to Crash-Involved Light Truck Occupants

by Body Region and Severity: Average per Year, 1993-1995

Body Region

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Abdomen 312 7,162 1,208 1,127 408 33 1,090 11,340 

2.8% 63.2% 10.7% 9.9% 3.6% 0.3% 9.6% 

0.0% 6.8% 3.9% 12.6% 10.9% 2.8% 20.6% 

Spine 0 0 159 308 114 17 0 598 

-- -- 26.5% 51.5% 19.1% 2.9% -- 

-- -- 0.5% 3.4% 3.1% 1.4% -- 

Upper Extremities 13,667 14,330 4,087 0 0 0 0 32,085 

42.6% 44.7% 12.7% -- -- -- -- 

1.2% 13.6% 13.2% -- -- -- -- 

Pelvis 0 4,011 3,058 0 89 0 0 7,159 

-- 56.0% 42.7% -- 1.2% -- -- 

-- 3.8% 9.9% -- 2.4% -- -- 

Lower Extremities 9,735 18,714 5,708 25 0 0 0 34,182 

28.5% 54.7% 16.7% 0.1% -- -- -- 

0.9% 17.7% 18.4% 0.3% -- -- -- 

Skin 921,450 2,441 97 0 28 300 0 924,317 

99.7% 0.3% 0.0% -- 0.0% 0.0% -- 

83.7% 2.3% 0.3% -- 0.8% 25.4% -- 

All Other 0 0 32 15 22 0 0 69 

-- -- 46.4% 21.4% 32.2% -- -- 

-- -- 0.1% 0.2% 0.6% -- -- 

 Total 101,542 105,440 31,002 8,974 3,731 1,182 5,293 1,257,164 

*For each body region, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 35

Restraint Use and Body Regions Injured

Figure 9 shows the distribution of crash-involved car occupants by injured body region

and belt usage. An occupant may receive more than one injury to a given body region;

however, this figure represents one injury per body region per occupant. An occupant

may also receive injuries across more than one body region. Therefore, the number for

each body region will add up to more than the number of injured occupants. For

example, an occupant may have a contusion to the left side of the brain and a

laceration to the right side of the brain. The figure counts only one of the injuries to the

brain. If the occupant in the example sustained a contusion to the left side of the brain

and a skull fracture, then both injuries would be included in the figure, and one injury

would be counted in the brain body region while the other injury would be counted in the

skull body region. To determine the percent of belted occupants who sustained a brain

injury, divide the number of occupants with a brain injury by the total number of

occupants using a restraint system. The same methodology applies to the unbelted

occupants. The percentages will not add to 100 percent, because the total number of

occupants includes those who were not injured. Figure 10 shows a similar distribution

of crash-involved occupants of light trucks by belt usage.
Occupant Injury Data

36 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Figure 9

Distribution of Injuries by Body Region to Crash-Involved

Car Occupants by Restraint Usage: Average per Year, 1993-1995

Restrained Unrestrained

Brain: 43,132 (3.0%) Brain: 53,792 (7.4%)

Other Head: 3,583 (0.3%) Other Head: 4,968 (0.7%)

Face: 31,550 (2.2%) Face: 34,879 (4.8%)

Chest: 54,333 (3.7%) Chest: 23,913 (3.3%)

 Upper Upper

Extremities: 55,068 (3.8%) Extremities: 31,129 (4.3%)

Abdomen: 11,806 (0.8%) Abdomen: 10,446 (1.4%)

Skin: 818,033 (56.0%) Skin: 393,239 (54.2%)

Skull: 4,270 (0.3%) Skull: 4,175 (0.6%)

Neck: 246,137 (16.9%) Neck: 70,385 (9.7%)

 Shoulder Shoulder

and Back: 130,979 (9.0%) and Back: 50,933 (7.0%)

Spine: 509 (0.0%) Spine: 1,196 (0.2%)

Pelvis: 5,795 (0.4%) Pelvis: 9,158 (1.3%)

 Lower Lower

Extremities: 55,503 (3.8%) Extremities: 36,888 (5.1%)

Total Total

Restrained Unrestrained

Occupants: Occupants:

1,460,711 725,200
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 37

Figure 10

Distribution of Injuries by Body Region to Crash-Involved

Light Truck Occupants by Restraint Usage: Average per Year, 1993-1995

Restrained Unrestrained

Brain: 14,391 (4.1%) Brain: 28,524 (11.4%)

Other Head: 906 (0.3%) Other Head: 1,976 (0.8%)

Face: 6,796 (1.9%) Face: 10,711 (4.3%)

Chest: 7,664 (2.2%) Chest: 9,083 (3.6%)

 Upper Upper

Extremities: 16,976 (4.8%) Extremities: 8,420 (3.4%)

Abdomen: 2,666 (0.8%) Abdomen: 3,786 (1.5%)

Skin: 199,846 (57.0%) Skin: 137,034 (54.8%)

Skull: 474 (0.1%) Skull: 3,333 (1.3%)

Neck: 50,553 (14.4%) Neck: 17,497 (7.0%)

 Shoulder Shoulder

and Back: 35,554 (10.1%) and Back: 15,821 (6.3%)

Spine: 141 (0.0%) Spine: 335 (0.1%)

Pelvis: 1,458 (0.4%) Pelvis: 2,970 (1.2%)

 Lower Lower

Extremities: 13,049 (3.7%) Extremities: 10,440 (4.2%)

Total Total

Restrained Unrestrained

Occupants: Occupants:

350,480 249,955
Occupant Injury Data

38 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 21

Distribution of All Injuries to Crash-Involved Car Occupants

by Injury Contact and Severity: Average per Year, 1993-1995

Injury Contact

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Steering Assembly 405,487 37,083 17,713 3,162 1,911 421 5,016 470,793 

86.1% 7.9% 3.8% 0.7% 0.4% 0.1% 1.1% 

10.7% 12.6% 15.2% 12.4% 14.5% 14.2% 23.7% 

Instrument Panel 592,272 43,588 16,720 1,303 553 405 764 655,605 

90.3% 6.6% 2.6% 0.2% 0.1% 0.1% 0.1% 

15.6% 14.8% 14.3% 5.1% 4.2% 13.7% 3.6% 

Windshield 346,890 21,536 4,750 1,516 492 106 2,425 377,716 

91.8% 5.7% 1.3% 0.4% 0.1% 0.0% 0.6% 

9.1% 7.3% 4.1% 5.9% 3.7% 3.6% 11.5% 

Interior Side

Surface

287,178 39,627 21,871 6,251 2,678 280 396 358,281 

80.2% 11.1% 6.1% 1.7% 0.7% 0.1% 0.1% 

7.5% 13.4% 18.7% 24.4% 20.4% 9.5% 1.9% 

Pillars 75,031 12,394 6,409 2,214 1,170 122 499 97,838 

76.7% 12.7% 6.6% 2.3% 1.2% 0.1% 0.5% 

2.0% 4.2% 5.5% 8.6% 8.9% 4.1% 2.4% 

Restraint (Belt)

System

450,005 14,388 7,362 839 382 12 1,000 473,988 

94.9% 3.0% 1.6% 0.2% 0.1% 0.0% 0.2% 

11.8% 4.9% 6.3% 3.3% 2.9% 0.4% 4.7% 

Child Seat 7,195 92 18 0 0 14 14 7,334 

98.1% 1.3% 0.2% -- -- 0.2% 0.2% 

0.2% 0.0% 0.0% -- -- 0.5% 0.1% 

Air Bag 167,344 2,425 1,056 375 431 42 346 172,020 

97.3% 1.4% 0.6% 0.2% 0.3% 0.0% 0.2% 

4.4% 0.8% 0.9% 1.5% 3.3% 1.4% 1.6% 

Head Restraints 31,816 5,212 496 297 25 0 95 37,942 

83.9% 13.7% 1.3% 0.8% 0.1% -- 0.3% 

0.8% 1.8% 0.4% 1.2% 0.2% -- 0.4% 

Seat Back 169,720 12,376 6,634 398 332 17 595 190,073 

89.3% 6.5% 3.5% 0.2% 0.2% 0.0% 0.3% 

4.5% 4.2% 5.7% 1.6% 2.5% 0.6% 2.8% 

Roof 77,033 13,051 5,603 2,408 1,655 224 630 100,603 

76.6% 13.0% 5.6% 2.4% 1.6% 0.2% 0.6% 

2.0% 4.4% 4.8% 9.4% 12.6% 7.6% 3.0% 

*For each injury contact, the first data row shows the number of injuries, the second row shows the percentage of

the row total, and the third row shows the percentage of the column total.

Injury Contacts

In addition to data on injured body regions, crash protection practitioners need data

concerning the various sources of injury (injury contacts). A summary of injury contacts

for injuries to crash-involved occupants is presented in Table 21 for cars and in Table

22 for light trucks. Table 21 shows the distribution of all crash-involved car occupant

injuries as a function of injury severity and injury contact. Table 22 shows the same

distribution for light truck occupants.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 39

Table 21 (Continued)

Distribution of All Injuries to Crash-Involved Car Occupants

by Injury Contact and Severity: Average per Year, 1993-1995

Injury Contact

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Floor 72,281 26,947 2,864 0 0 0 0 102,092 

70.8% 26.4% 2.8% -- -- -- -- 

1.9% 9.1% 2.5% -- -- -- -- 

Non-Contact

Injuries

469,875 3,083 516 69 33 0 793 474,370 

99.1% 0.6% 0.1% 0.0% 0.0% -- 0.2% 

12.3% 1.0% 0.4% 0.3% 0.2% -- 3.7% 

Fire in Vehicle 720 59 221 51 7 427 0 1,486 

48.5% 4.0% 14.9% 3.4% 0.5% 28.8% -- 

0.0% 0.0% 0.2% 0.2% 0.1% 14.4% -- 

Ground 32,174 5,489 2,563 1,116 334 156 565 42,397 

75.9% 12.9% 6.0% 2.6% 0.8% 0.4% 1.3% 

0.8% 1.9% 2.2% 4.4% 2.5% 5.3% 2.7% 

Exterior

(Occupant's

Vehicle)

2,968 1,555 757 413 249 192 194 6,327 

46.9% 24.6% 12.0% 6.5% 3.9% 3.0% 3.1% 

0.1% 0.5% 0.6% 1.6% 1.9% 6.5% 0.9% 

Exterior (Other

Vehicle or Exterior

Object)

7,560 3,512 3,162 1,571 949 145 88 16,987 

44.5% 20.7% 18.6% 9.2% 5.6% 0.9% 0.5% 

0.2% 1.2% 2.7% 6.1% 7.2% 4.9% 0.4% 

Side and Rear

Glazing

69,280 8,149 1,047 245 111 28 207 79,066 

87.6% 10.3% 1.3% 0.3% 0.1% 0.0% 0.3% 

1.8% 2.8% 0.9% 1.0% 0.8% 1.0% 1.0% 

All Others 164,071 8,705 3,054 575 156 34 843 177,438 

92.5% 4.9% 1.7% 0.3% 0.1% 0.0% 0.5% 

4.3% 2.9% 2.6% 2.2% 1.2% 1.1% 4.0% 

Unknown 375,831 36,202 14,037 2,790 1,683 335 6,705 437,582 

85.9% 8.3% 3.2% 0.6% 0.4% 0.1% 1.5% 

9.9% 12.3% 12.0% 10.9% 12.8% 11.3% 31.7% 

Total 3,804,731 295,473 116,851 25,594 13,151 2,961 21,176 4,279,937 

*For each injury contact, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.
Occupant Injury Data

40 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 22

Distribution of All Injuries to Crash-Involved Light Truck Occupants

by Injury Contact and Severity: Average per Year, 1993-1995

Injury Contact

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Steering Assembly 97,753 10,405 3,505 783 328 105 883 113,762 

85.9% 9.1% 3.1% 0.7% 0.3% 0.1% 0.8% 

8.9% 9.9% 11.3% 8.7% 8.8% 8.9% 16.7% 

Instrument Panel 165,185 17,336 5,786 122 141 19 83 188,671 

87.6% 9.2% 3.1% 0.1% 0.1% 0.0% 0.0% 

15.0% 16.4% 18.7% 1.4% 3.8% 1.6% 1.6% 

Windshield 84,331 5,981 836 304 197 20 859 92,527 

91.1% 6.5% 0.9% 0.3% 0.2% 0.0% 0.9% 

7.7% 5.7% 2.7% 3.4% 5.3% 1.7% 16.2% 

Interior Side

Surface

79,561 11,005 4,361 1,016 204 0 132 96,280 

82.6% 11.4% 4.5% 1.1% 0.2% -- 0.1% 

7.2% 10.4% 14.1% 11.3% 5.5% -- 2.5% 

Pillars 25,244 5,482 1,616 513 324 49 433 33,660 

75.0% 16.3% 4.8% 1.5% 1.0% 0.1% 1.3% 

2.3% 5.2% 5.2% 5.7% 8.7% 4.2% 8.2% 

Restraint (Belt)

System

99,875 4,022 1,087 204 0 0 221 105,410 

94.7% 3.8% 1.0% 0.2% -- -- 0.2% 

9.1% 3.8% 3.5% 2.3% -- -- 4.2% 

Child Seat 2,126 10 27 0 0 0 5 2,168 

98.0% 0.5% 1.3% -- -- -- 0.2% 

0.2% 0.0% 0.1% -- -- -- 0.1% 

Air Bag 11,211 1,362 22 0 0 0 0 12,594 

89.0% 10.8% 0.2% -- -- -- -- 

1.0% 1.3% 0.1% -- -- -- -- 

Head Restraints 3,371 71 23 0 0 0 21 3,486 

96.7% 2.0% 0.7% -- -- -- 0.6% 

0.3% 0.1% 0.1% -- -- -- 0.4% 

Seat Back 37,120 4,070 352 159 53 0 19 41,773 

88.9% 9.7% 0.8% 0.4% 0.1% -- 0.0% 

3.4% 3.9% 1.1% 1.8% 1.4% -- 0.4% 

Roof 50,661 7,915 1,646 493 278 172 503 61,668 

82.2% 12.8% 2.7% 0.8% 0.5% 0.3% 0.8% 

4.6% 7.5% 5.3% 5.5% 7.4% 14.5% 9.5% 

*For each injury contact, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 41

Table 22 (Continued)

Distribution of All Injuries to Crash-Involved Light Truck Occupants

by Injury Contact and Severity: Average per Year, 1993-1995

Injury Contact

Frequency of Injury by AIS Rating*

1 2 3 4 5 6 7 Total

Floor 13,742 5,801 435 0 0 0 0 19,979 

68.8% 29.0% 2.2% -- -- -- -- 

1.2% 5.5% 1.4% -- -- -- -- 

Non-Contact

Injuries

135,020 514 118 15 44 26 14 135,752 

99.5% 0.4% 0.1% 0.0% 0.0% 0.0% 0.0% 

12.3% 0.5% 0.4% 0.2% 1.2% 2.2% 0.3% 

Fire in Vehicle 196 15 27 0 27 300 0 565 

34.7% 2.6% 4.8% -- 4.7% 53.1% -- 

0.0% 0.0% 0.1% -- 0.7% 25.4% -- 

Ground 48,324 8,747 3,394 1,886 991 76 303 63,721 

75.8% 13.7% 5.3% 3.0% 1.6% 0.1% 0.5% 

4.4% 8.3% 10.9% 21.0% 26.6% 6.4% 5.7% 

Exterior

(Occupant's

Vehicle)

3,672 2,486 1,590 909 306 22 16 9,001 

40.8% 27.6% 17.7% 10.1% 3.4% 0.2% 0.2% 

0.3% 2.4% 5.1% 10.1% 8.2% 1.9% 0.3% 

Exterior (Other

Vehicle or Exterior

Object)

17,085 3,221 981 550 218 112 25 22,191 

77.0% 14.5% 4.4% 2.5% 1.0% 0.5% 0.1% 

1.6% 3.1% 3.2% 6.1% 5.9% 9.5% 0.5% 

Side and Rear

Glazing

26,812 1,594 641 44 4 0 102 29,197 

91.8% 5.5% 2.2% 0.2% 0.0% -- 0.3% 

2.4% 1.5% 2.1% 0.5% 0.1% -- 1.9% 

All Others 62,721 2,566 635 205 34 0 59 66,219 

94.7% 3.9% 1.0% 0.3% 0.1% -- 0.1% 

5.7% 2.4% 2.0% 2.3% 0.9% -- 1.1% 

Unknown 137,534 12,837 3,919 1,771 584 281 1,615 158,540 

86.8% 8.1% 2.5% 1.1% 0.4% 0.2% 1.0% 

12.5% 12.2% 12.6% 19.7% 15.6% 23.8% 30.5% 

Total 1,101,542 105,440 31,002 8,974 3,731 1,182 5,293 1,257,164 

*For each injury contact, the first data row shows the number of injuries, the second row shows the percentage

of the row total, and the third row shows the percentage of the column total.
Occupant Injury Data

42 National Automotive Sampling System/Crashworthiness Data System 1993-1995

0% 5% 10% 15% 20%

Car Occupant Injuries

All Others

Head Restraints

Ground

Side/Rear Glazing

Pillars

Floor

Airbag

Seat Back

Roof

Interior Side

Restraint System

Non-contact Injuries

WIndshield

Steering Assembly

Instrument Panel

Injury Contact

All Severities

Serious-Maximum

Figure 11

Distribution of Injuries to Crash-Involved Car Occupants

by Injury Contact and Severity of Injury, 1993-1995

It is evident from Tables 21 and 22 that the most frequent injury contacts for injuries of

all severities (AIS 1-7) are not necessarily the same as those that are most frequently

involved in serious to maximum injuries (AIS 3-6). This is illustrated in Figure 11, where

two distributions are shown: one for all severities and one for serious to maximum

severities, each adding up to 100 percent.

As can be seen in this figure, the instrument panel, windshield, and restraint system as

injury contacts have high frequencies in general but relatively low frequencies for

serious to maximum injuries. The converse is observed for the steering assembly,

interior side, roof, pillars, and ground.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 43

Table 23

Occupant Ejection and Entrapment in Crash-Involved Towed Cars

by Degree of Ejection, Crash Mode, and Area of Damage:

Average of Nationally Weighted Counts per Year, 1993-1995

Crash Mode and

Area of Damage

Complete

Ejection

Partial

Ejection Entrapment Total

Rollover 8,357 4,806 1,395 161,822 

5.2% 3.0% 0.9% 4.5% 

Nonrollover

 Single-Vehicle

 Front 1,124 3,941 3,891 533,892 

0.2% 0.7% 0.7% 14.9% 

 Side 2,105 1,103 930 158,026 

1.3% 0.7% 0.6% 4.4% 

 Rear, Top, or Under 21 18 5 25,391 

0.2% 0.2% 0.0% 0.7% 

 Multiple-Vehicle

 Front 418 1,202 2,761 1,505,070 

0.0% 0.1% 0.2% 42.0% 

 Side 2,306 2,410 2,932 878,177 

0.3% 0.3% 0.3% 24.5% 

 Rear 108 366 33 314,816 

0.0% 0.1% 0.0% 8.8% 

 Top or Under 0 0 14 2,491 

-- -- 0.6% 0.1% 

Total 14,439 13,846 11,952 3,579,685 

0.4% 0.4% 0.3% 100.0% 

*For each crash mode, the first data row shows the number of occupants ejected or entrapped and

the second row shows the percentage of the row total.

Note: Damage Area “Unknown” has been imputed into the known damage areas.

Occupant Ejection and Entrapment

Table 23 shows the rates of occupant ejections from and entrapment in crash-involved

towed cars. Two degrees of ejection are distinguished: complete and partial. The

results in Table 23 are shown by primary crash modes and areas of damage. Similar

data for light trucks are shown in Table 24. Ejection rates by degree of ejection are also

shown in Figure 12. Ejection occurs most frequently in rollover crashes, followed by

side impacts.
Occupant Injury Data

44 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 24

Occupant Ejection and Entrapment in Crash-Involved Towed Light Trucks

by Degree of Ejection, Crash Mode, and Area of Damage:

Average of Nationally Weighted Counts per Year, 1993-1995

Crash Mode and

Area of Damage

Complete

Ejection

Partial

Ejection Entrapment Total

Rollover 13,819 2,486 1,479 149,546 

9.2% 1.7% 1.0% 14.1% 

Nonrollover

 Single-Vehicle

 Front 563 555 606 165,495 

0.3% 0.3% 0.4% 15.6% 

 Side 435 467 150 26,224 

1.7% 1.8% 0.6% 2.5% 

 Rear, Top, or Under 3 0 0 20,447 

0% -- -- 2.0% 

 Multiple-Vehicle

 Front 596 448 696 491,007 

0.1% 0.1% 0.1% 46.2% 

 Side 996 164 271 172,879 

0.6% 0.1% 0.2% 16.3% 

 Rear 82 471 233 38,076 

0.2% 1.2% 0.6% 3.6% 

 Top or Under 0 0 10 43 

-- -- 14.5% 0.0% 

Total 16,495 4,590 3,445 1,063,717 

1.6% 0.4% 0.3% 100.0% 

*For each crash mode, the first data row shows the number of occupants ejected or entrapped and

the second row shows the percentage of the row total.

Note: Damage Area “Unknown” has been imputed into the known damage areas.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 45

0% 1% 2% 3% 4% 5% 6%

Frequency

All Crash Modes

Rear

Side

Frontal

Side

Frontal

Rollover

Nonrollover

Single-Vehicle

Multiple-Vehicles

Complete

Ejection

Figure 12

Towed Car Occupant Ejection Rates

by Crash Mode and Degree of Ejection, 1993-1995
Occupant Injury Data

46 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Table 25

Injury-Weighted Occupant Ejection and Entrapment Rates

for Crash-Involved Towed Cars

by Degree of Ejection, Crash Mode, and Area of Damage:

Average of Nationally Weighted Counts per Year, 1993-1995

Crash Mode and

Area of Damage

Complete

Ejection

Partial

Ejection Entrapment Total

Rollover 1,531,133 671,680 293,223 5,516,762 

27.8% 12.2% 5.3% 14.2% 

Nonrollover

 Single-Vehicle

 Front 222,454 467,101 533,625 5,810,600 

3.8% 8.0% 9.2% 15.0% 

 Side 346,712 172,150 237,727 2,435,085 

14.2% 7.1% 9.8% 6.3% 

 Rear, Top, or Under 100 5,909 109 186,513 

0.1% 3.4% 0.1% 0.5% 

 Multiple-Vehicle

 Front 188,112 256,410 841,635 11,756,619 

1.6% 2.2% 7.2% 30.3% 

 Side 351,630 631,691 792,494 11,680,407 

3.0% 5.4% 6.8% 30.1% 

 Rear 14,355 24,362 23,446 1,384,610 

1.0% 1.8% 1.7% 3.6% 

 Top or Under 0 0 10,376 21,391 

-- -- 48.5% 0.1% 

Total 2,654,495 2,229,303 2,732,634 38,791,987 

6.8% 5.7% 7.0% 100.0% 

*For each crash mode, the first data row shows the number of occupants ejected or entrapped and

the second row shows the percentage of the row total.

The ejection rates shown in Tables 23 and 24 are generally small, except in car

rollovers. However, due to the very harmful outcomes of occupant ejections, the rate of

injuries associated with occupant ejections is significantly higher, as shown in Tables

25 and 26, which show injury-weighted (using Harm—see Appendix E) ejection and

entrapment data for crash-involved towed vehicles, and Figure 13, which shows

ejection-induced injury rates for towed vehicles. Crashes that involve ejection are

generally more severe crashes; therefore, injuries to ejected occupants may be due to

higher crash forces as well as the ejection itself.
Occupant Injury Data

National Automotive Sampling System/Crashworthiness Data System 1993-1995 47

Table 26

Injury-Weighted Occupant Ejection and Entrapment Rates

for Crash-Involved Towed Light Trucks

by Degree of Ejection, Crash Mode, and Area of Damage:

Average of Nationally Weighted Counts per Year, 1993-1995

Crash Mode and

Area of Damage

Complete

Ejection

Partial

Ejection Entrapment Total

Rollover 2,178,170 493,318 343,590 4,372,254 

49.8% 11.3% 7.9% 38.9% 

Nonrollover

 Single-Vehicle

 Front 177,979 31,281 119,518 1,283,619 

13.9% 2.4% 9.3% 11.4% 

 Side 52,715 36,131 32,867 479,467 

11.8% 7.5% 6.9% 4.3% 

 Rear, Top, or Under 109 0 0 89,255 

0.1% -- -- 0.8% 

 Multiple-Vehicle

 Front 42,970 182,735 165,915 3,008,343 

1.4% 6.1% 5.5% 26.8% 

 Side 238,399 44,868 54,699 1,755,937 

13.6% 2.6% 3.1% 15.6% 

 Rear 312 1,765 921 231,765 

0.1% 0.8% 0.4% 2.1% 

 Top or Under 0 0 8,483 12,747 

-- -- 66.5% 0.1% 

Total 2,690,654 790,100 725,991 11,233,389 

24.0% 7.0% 6.5% 100.0% 

*For each crash mode, the first data row shows the number of occupants ejected or entrapped and

the second row shows the percentage of the row total.
National Automotive Sampling System/Crashworthiness Data System 1993-1995 49

Appendix A. Glossary

AIS (Abbreviated Injury Scale)

An integer scale developed by the Association for the Advancement of

Automotive Medicine to rate the severity of individual injuries. The AIS

includes: 1=minor, 2=moderate, 3=serious, 4=severe, 5=critical, and

6=maximum (virtually untreatable). The scale does not explicitly denote a fatal

injury. An AIS rating of 7 (injured, severity unknown) is used when sufficient

information about an injury is not available.

Body Type

Refers to the individual classifications of motor vehicles by their design

structure based on definitions developed by the Society of Automotive

Engineers.

Crash

An event that produces injury and/or damage, involves a motor vehicle in

transport, and occurs on a trafficway or while the vehicle is still in motion after

running off the trafficway. In this report, crash and motor vehicle crash are

synonymous. To qualify for the CDS, all crashes must be reported by the

police to the state and involve a towed CDS applicable vehicle.

Crash Severity (delta-v is used as a measure of crash severity)

CRASHPC and OLDMISSPC are computer models that provide a measure of

crash severity in terms of delta-v (see Appendix E). In vehicle-to-vehicle

crashes, the models assume that the two vehicles approach each other at an

impact velocity, reach a common velocity, and then separate. Delta-v is equal

to the impact velocity minus the separation velocity. Other factors being equal,

the greater the delta-v during a collision, the greater the potential for occupant

injury.

Crashworthiness Data System Applicable Motor Vehicle

Refers to those motor vehicles classified as automobiles, automobile

derivatives and short utility vehicles, van-based light trucks, and light

conventional trucks where the qualifying trucks must have a gross vehicle

weight rating (GVWR) of less than or equal to 10,000 pounds.

Ejection

Refers to persons being completely or partially thrown from the vehicle as a

result of an impact or rollover. Partial ejection refers to a situation where part

of the occupant's body remains in the vehicle. This does not apply to

occupants who are not initially in the seating compartment of the vehicle (e.g.,

persons riding in pickup beds, boots of convertibles, or open tailgates), since

any ejection for them is coded as complete ejection.
Glossary

50 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Entrapment

Refers to persons being partially or completely in the vehicle and mechanically

restrained by a damaged vehicle component. Jammed doors and immobilizing

injuries, by themselves, do not constitute entrapment. Occupants pinned by

cargo shift are not considered to be entrapped. Occupants who are completely

or partially ejected and subsequently become pinned by their own vehicle and

any surface other than their own vehicle are not considered entrapped. An

occupant whose seat belt buckle release mechanism is jammed as a result of

a crash is not considered entrapped.

Fatally Injured Occupant

A death caused by injuries sustained by an occupant within 30 days of a CDS

applicable motor vehicle crash.

Fatal Motor Vehicle Traffic Crash

A crash in which at least one occupant of a CDS applicable motor vehicle dies

within 30 days of the crash as a result of injuries sustained in the crash.

Fixed Object

An object attached to the terrain (trees, abutments) or stationary objects

intentionally placed for a particular purpose (e.g., poles, barriers).

Gross Vehicle Weight Rating (GVWR)

The maximum capacity of a vehicle, including the weight of the base vehicle,

all added equipment, driver and passengers, and all cargo loaded into or onto

the vehicle. Actual weight may be less than or greater than GVWR.

Injured Occupant

Occupant of a CDS applicable motor vehicle sustaining any type of injury as a

result of a crash, including injuries from non-impact forces.

Light Trucks

Includes utility vehicles, pickups, vans, and truck-based station wagons, with a

GVWR less than 10,000 pounds.

Maximum AIS

Represents the highest AIS level sustained by an injured occupant of a CDS

applicable motor vehicle.

Motor Vehicle in Transport

A CDS applicable motor vehicle on a roadway or in motion within a trafficway.

Non-Fixed Objects

Objects that are movable or moving but are not motor vehicles, pedestrians,

pedalcyclists, animals, or trains.

Occupant

Any person who is in a CDS applicable motor vehicle in transport.
Glossary

National Automotive Sampling System/Crashworthiness Data System 1993-1995 51

Passenger Car

Any motor vehicle that is an automobile, auto-based pickup, large limousine,

or three-wheel automobile or automobile derivative.

Passenger Vehicles

Includes passenger cars, pickup trucks, vans, and sport/utility vehicles with a

GVWR less than 10,000 pounds. Equivalent to CDS applicable vehicles.

Police-Reported Crash

A crash investigated or reported by a police officer, documented with a

completed form which is signed by the investigating officer, and reported to

the state. Driver reports submitted only to motor vehicle officials are excluded.

Primary Sampling Unit (PSU)

A city, county, or group of contiguous counties with an aggregate population of

at least 50,000 which defines a geographic area for crash investigation. PSU

selection is the first stage in the probability sampling of crashes for the CDS.

Restraint Usage

Manually operated restraint systems include shoulder belts, lap belts, lap and

should belt combinations, or child safety seats. Automatic restraint systems

include passive belts.

Roadway

That part of a trafficway used for motor vehicle travel or, where travel by

various classes of motor vehicles is segregated, that part of a trafficway used

by a particular class. The roadway excludes shoulders, designated parking

lanes, and median areas.

Serious-Maximum Injury

Injury severity of AIS 3-6, including, for example, compound fractures and

internal organ injuries. Unless otherwise noted, summary statistics in this

report include all fatally injured persons as seriously injured, but exclude those

with unknown injury severity level (see AIS).

Towaway Crash

A crash which is noted on the police report as involving at least one CDS

applicable vehicle that was towed from the crash scene as a result of damage

from the crash. For those crashes involving injury or fatality, the injured or

killed person must be an occupant of the towed CDS applicable vehicle to

qualify for the CDS.

Towed Vehicle

A CDS applicable motor vehicle that was involved in a crash and removed

from the crash scene due to damage resulting from the crash by means other

than its own power.
Glossary

52 National Automotive Sampling System/Crashworthiness Data System 1993-1995

Trafficway

Any right-of-way open to the public as a matter of right or custom for moving

persons or property from one place to another, including the entire width

between property lines or other boundaries.

Vehicle Type

Refers to a series of CDS applicable motor vehicle body types that have been

grouped together because of design similarities. The principal vehicle types

used in this report are passenger cars, pickup trucks, vans, and sport/utility

vehicles.
National Automotive Sampling System/Crashworthiness Data System 1993-1995 53

Appendix B. NASS/CDS Sample Design

The crashes investigated in NASS/CDS are a probability sample of all police-reported

crashes in the United States. Each such crash that occurs within a CDS team's area

has a chance of being included in the sample. This design makes it possible to

compute not only national estimates but also probable errors associated with those

estimates. Many other features of the design have a significant impact on CDS data

analysis, the most important of which are highlighted in this appendix.

The selection of sample crashes for CDS is accomplished in stages. The first stage is

the selection of geographic areas called primary sample units (PSUs). Each PSU is

composed of a large city, a county, or a group of contiguous counties. The United

States was divided into 1,195 PSUs. The PSUs were then grouped into 12 categories

described by geographic region and degree of urbanization. Two PSUs were selected

from each category with probability proportional to its 1983 population. These 24 PSUs

are the first stage in the selection of CDS sample crashes.

If every crash in each of the 24 PSUs were investigated, a national estimate could be

obtained by weighting each crash in the PSU by the inverse of the probability of

selection of the PSU. For example, if a sample PSU had 1 chance in 40 of being

selected, then each crash from the PSU would be weighted by a factor of 40. This is

called the first-stage expansion factor.

It is not practical to investigate every crash in each sample PSU, so additional stages of

sampling are performed. The police agencies in a PSU are categorized by the number

and type of police crash reports they process. Sample police agencies are then

selected randomly from each category. The fraction of the agencies selected increases

as the number and severity of crashes reported by the agency increases. This is called

the second-stage expansion factor.

The final stage of sampling is the selection of crashes from all crashes reported in the

sample police agencies. A simple random selection of all reported towaway crashes

would result in a large percentage of sample crashes with property damage and few

injuries, since these constitute such a large fraction of all crashes. This type of sample

would not be effective in providing the detailed and accurate information needed for the

mitigation of crash consequences. Rather, a substantial sample of serious injury

crashes is needed for NASS/CDS.

The procedure used to obtain the desired sample by type and severity of crashes is an

unequal probability selection. This required listing police crash reports in categories

defined by most severe police-reported injury to an occupant of a towed CDS

applicable motor vehicle, disposition of the injured, and model year of the towed CDS

applicable motor vehicle. A weighting factor was assigned to crashes in each category

to increase or decrease the probability of selection. A random selection was made from

the total crashes listed in all categories. In addition to the probabilities of selection

varying by type of crash, other factors affected the selection probabilities at this stage,

such as the number of crashes listed, the date and time of the crash, and the police

agencies from which the crash was listed. The result was that each sampled crash from

a PSU has a unique selection probability.