DOT HS 810 857 November 2007

Characteristics of Crash 

Injuries Among Young, 

Middle-Aged, and Older 

Drivers

Technical Report 

This document is available to the public from the National Technical Information Service, Springfield, Virginia 22161
[This Page Intentionally Left Blank]
 Technical Report Documentation Page 

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

DOT HS 810 857 

5. Report Date 

November 2007 

4. Title and Subtitle 

Characteristics of Crash Injuries 

Among Young, Middle-Aged, and Older Drivers 6. Performing Organization Code 

NVS-421 

7. Author(s) 8. Performing Organization Report No.

Cejun Liu,* Dennis Utter,† and Chou-Lin Chen†

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

* Program analyst, employed by URC, Inc., works with the Mathematical Analysis Division, National 

Center for Statistics and Analysis, NHTSA.

†

 Mathematical statisticians, Mathematical Analysis Division, National Center for Statistics and 11. Contract of Grant No. 

Analysis, NHTSA.

13. Type of Report and Period Covered

NHTSA Technical Report 

12. Sponsoring Agency Name and Address

Mathematical Analysis Division, National Center for Statistics and Analysis 

National Highway Traffic Safety Administration 

U.S. Department of Transportation 14. Sponsoring Agency Code

1200 New Jersey Avenue SE., Washington, DC 20590 

15.Supplementary Notes 

The authors wish to thank Rajesh Subramanian, Joseph Tessmer, Seymour Stern, Mark Mynatt, Eric Ferguson, Kirk Allen, John Kindelberger, 

and Xuemei Pan for helpful comments and Cecily Williams and Richard Maurey for proofreading this report. 

16. Abstract 

One of the most important factors that affects a person’s risk of injury in a motor vehicle crash is the age of the person. This study investigates 

patterns of injury severity, location of injuries, and contact sources for the driver injuries by driver age. 

Based on the data from NHTSA’s National Automotive Sampling System — Crashworthiness Data System (NASS-CDS) from 1993 through 

2004, this study examines in great detail the driver injury severity, injured body regions, and injury contact sources by driver age in rollover and 

non-rollover real-world traffic crashes. The effect of seat belt use on injury patterns is also investigated.

Studies show that among older drivers, females are more likely to sustain severe injuries, as measured by the Maximum Abbreviated Injury Scale 

(MAIS) of 4 or above, as compared to males. This pattern is reversed for drivers under age 65. 

The pattern of severe injuries to those in rollovers was independent of age. However, in non-rollover crashes, the older drivers are more likely to 

sustain severe injuries, especially in left-side impact crashes. There is a statistically significant reduction in injury severity in both rollover and 

non-rollover crashes to the drivers when seat belts were used. 

This study by analyzing the injury locations, source, and severity, enables the identification of features associated with crash protection of drivers 

from aspects such as engineering, human factors, and clinical research. Studies also call attention to the need for vehicle improved 

crashworthiness and design to make vehicles more protective for older drivers. 

17. Key Words 18. Distribution Statement

Driver, age, gender, older drivers, rollover, non-rollover, frontal, right- Document is available to the public through the National Technical 

side, rear, left-side, MAIS, AIS, seat belt, injury severity, NASS-CDS Information Service, Springfield, VA 22161 

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No of Pages 22. Price

 Unclassified Unclassified 48 

Form DOT F1700.7 (8-72) Reproduction of completed page authorized 
Table of Contents 

1. Executive Summary......................................................................................................................... 2

2. Introduction ...................................................................................................................................... 4

 2.1 Background .................................................................................................................................. 4

 2.2 Object of the Study ...................................................................................................................... 6

3. Data and Methods ............................................................................................................................ 7

4. Driver Overall Injury Severity.......................................................................................................... 8

 4.1 Driver Overall Injury Severity...................................................................................................... 8

 4.2 Driver Overall Injury Severity by Gender................................................................................... 9

5. Driver Injury Severity by Crash Modes........................................................................................ 10

 5.1 Driver Injury Severity in Rollover Crashes.............................................................................. 10

 5.2 Driver Injury Severity in Non-Rollover Crashes...................................................................... 11

 5.3 Driver Injury Severity by Seat Belt Use.................................................................................... 12

 5.4 Logistic Regression Modeling on Driver Injury Severity....................................................... 14

6. Driver Injured Body Region .......................................................................................................... 15

 6.1 Rollover Crashes........................................................................................................................ 15

 6.2 Non-Rollover Crashes ............................................................................................................... 17

7. Driver Injury Contact Sources ...................................................................................................... 25

 7.1 Rollover Crashes........................................................................................................................ 25

 7.2 Non-Rollover Crashes ............................................................................................................... 27

8. Discussions .................................................................................................................................... 35

9. Conclusions.................................................................................................................................... 36

10. References.................................................................................................................................... 38

11. Appendix....................................................................................................................................... 41

 11.1 Driver Overall Injury Severity.................................................................................................. 41

 11.2 Driver Overall Injury Severity by Gender............................................................................... 41

 11.3 Driver Injury Severity by Crash Modes.................................................................................. 42

 11.4 Driver Injury Severity by Seat Belt Use.................................................................................. 43

 11.5 Driver Injured Body Region .................................................................................................... 44

 11.6 Driver Injury Contact Sources ................................................................................................ 47
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1. Executive Summary 

One of the most important factors that affects a person’s risk of injury in a motor vehicle 

crash is the age of the person. This study investigates patterns of injury severity, location 

of injuries, and contact sources for the injuries by age. Data pertaining only to drivers 

involved in real-world crashes as sampled by NHTSA’s National Automotive Sampling 

System’s Crashworthiness Data System (NASS-CDS) were used in this study. 

Of particular interest is the difference in the characteristics of injuries and their contact 

sources among drivers categorized into four age groups: young (16 to 24), two middleaged groups (25 to 44 and 45 to 64), and older drivers (65 and older). These patterns are 

presented for drivers in vehicles that rolled over and those involved in non-rollover 

crashes, as these differ significantly from each other in terms of occupant kinematics, 

nature of injuries, and their outcomes. The effect of seat belt use on injury patterns was 

also investigated. 

Twelve years of CDS data were included in the analysis (1993 to 2004). Injury severity 

was categorized into 2 levels (no injury to major injury or severe injury) using the 

Maximum Abbreviated Injury Scale (MAIS). Our results indicate that in the three 

youngest age groups, males sustained more severe injuries than females, whereas this 

pattern was reversed for the oldest age group. 

The pattern of severe injuries to those in rollovers was independent of age. However, in 

non-rollover crashes, the older drivers are more likely to sustain severe injuries, 

especially in left-side impact crashes. 

There is a statistically significant reduction in injury severity in both rollover and nonrollover crashes to the driver when seat belts were used. Non-belted drivers were eight 

times more likely than belted drivers to sustain serious injury. The driver serious injury 

risk (odds) in vehicle rollover crashes is three times higher than that in vehicle nonrollover crashes. 

About 80 percent of the severe injuries were either to the head or the chest. The less 

severe injuries occurred to the face and upper and lower limbs. 

The major injury contact sources in rollovers are the vehicle roof and top. The pattern of 

the body region injured in rollovers is similar across the age groups with large 

proportions of the severe injuries occurring to the head and the chest, followed by the 

neck and spine. 

In frontal crashes, the major injury contact sources for the drivers for all ages were the 

belt webbing/buckles, air bags, steering wheel rim, left instrument panel, and windshield. 

The two highest proportions for the severe injuries were to the head and the chest. The 
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NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

3

abdomen is another frequently injured portion in such crashes across all age groups. The 

less severe injuries occur mainly to the upper/lower limbs, face, and head, and this was 

true across all age groups. 

In left-side impact crashes, the major injury contact sources were left-side interior, leftside hardware, and belt webbing and buckles; this was true for all ages. The severe 

injuries in such crashes were similar across all ages with the head and the chest being the 

most injured body regions. The less severe injuries occurred to the lower/upper limbs, 

neck/spine and the face. The percentage of chest injuries increases as driver age 

increases. 

In right-side impact crashes, the major contact source of injuries showed some 

differences by age group. Belt webbing was a major injury contact sources among all age 

groups; other injury contact sources such as the windshield, air bags, and other noncontact sources did not show a pattern among the age groups. A reason for this finding 

may be differences in travel speed or other age-related factors. An analysis of such 

factors is outside the scope of this study. Also injury severity to drivers in right-side 

impact crashes could be confounded by the presence of a front right passenger. The most 

severe injuries in such crashes occurred to the head and the chest, and this was true for all 

age groups. While the relative percentage of head injuries decreases as driver age 

increases, the percentage of chest injuries increases with age. The abdomen and the 

neck/throat were other body regions injured in such crashes. 

In rear-impact crashes, the major sources of injury contact to the driver were a bit 

different among the four age groups. The most common source was the head restraint 

system. Evolution of head restraint systems might reduce whiplash injuries suffered by 

drivers in rear-impact crashes. Severe injuries in such crashes occurred predominantly to 

the head. The neck and the spine had the highest proportion of less severe injuries. 

In summary, this study – by analyzing the injury locations, source, and severity – enables 

the identification of features associated with crash protection of drivers from aspects such 

as engineering, human factors, and clinical research. It is also imperative to monitor the 

effectiveness of safety systems such as door, frontal, and side air bags, and electronic 

stability control (ESC) systems. 
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2. Introduction 

2.1 Background 

One of the most important variables related to crash risk is driver age. Numerous studies 

have confirmed that the crash risk, as a function of age, conforms to a U-shaped 

relationship – crash rates, when based on vehicle miles traveled (VMT), are high among 

teenagers, are lower among middle-aged drivers, and increase again among older drivers. 

Young drivers are over-involved in head-on crashes and crashes related to speeding and 

rollover. Drivers of middle age were found to have a higher percentage of crashes while 

under the influence of alcohol. Whether at intersections or at other locations, older 

drivers were found to be over-involved in right- and left-turn crashes.1 2 3 4 

Results from highway crashes generally have been and continue to be major problems, 

and they have been attracting increased attention from researchers in engineering, human 

factors, and clinical science.5 6 7 8 9 The difference in characteristics of crashes between 

young, middle-aged, and older drivers has already resulted in the difference of crash 

injuries to young, middle-aged, and older drivers. For instance, a study conducted by the 

Trauma Center of the University of Michigan shows that older drivers are at higher risk 

of chest injuries.10 This finding can be partially explained from the following two 

perspectives: Older drivers are more likely to be involved in left-turn (driver-side-impact) 

crashes, which lead to a higher percentage of driver chest injuries; and older drivers have 

higher percentages of restraint use,11 and the chest is the major load-bearing area for 

restraint systems. † ‡ 

For driver injury severity by age, it is generally acknowledged that the energy required to 

cause an injury decreases with age, given assumed similar crash conditions, and therefore 

older drivers are more vulnerable to injury in a crash. Their skeletal structures are more 

easily damaged, and the consequences of any assault are likely to be more serious 

compared with younger drivers.14 15 16 17 18 19 

Older drivers have become a larger part of the driving population and will continue to do 

so as baby boomers reach retirement age. In Figure 1, the data of licensed drivers per 100 

population by age groups for the period 1992-2005 are displayed.20 21 An overall upward 

trend of licensed drivers age 65 and older per 100 population is shown in the past in the 

United States, which is a completely different trend from the other three driver age 

groups. 

† It is noted that restraint systems generally helps to reduce the level of injuries in a crash. 

‡

 Studies show that the older population group could withstand a chest load of 5,000 N while the younger 

population groups could withstand a chest load of 8,000 N. 12 13
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NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

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Figure 1: Licensed drivers per 100 population in the United States, 1992-2005. 

Lisenced drivers per 100 population in U.S.

1992-2005 

60

70

80

90

100

1991 1993 1995 1997 1999 2001 2003 2005 2007

Year

Number

16-24 25-44 45-64 65 +
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2.2 Object of the Study 

One fundamental area of traffic safety study, either by means of experiment or sources of 

real-world crash data, is to understand injury severity, injured body regions, and injury 

mechanisms (i.e., the injury contact sources), and hence to understand how to minimize 

driver injuries when vehicle crashes inevitably occur. These analyses have provided 

helpful information for vehicle design and crashworthiness standards development and 

evaluation programs to effectively protect occupants.7 8 14 22 23 

The severity of injuries sustained by drivers involved in crashes is of considerable 

interest to policy makers and safety specialists.†

 In this study, the driver injury severity, 

injured body regions, and injury contact sources by driver age in real-world traffic 

crashes are examined in great detail. Specifically, since the injury pattern and injury 

mechanism of drivers in rollover vehicles are completely different from those in nonrollover vehicles in crashes, driver injuries were extensively studied by vehicle crash 

modes: rollover crashes versus non-rollover crashes. Furthermore, non-rollover crash 

vehicles were divided into four types by vehicle highest impact damage area (frontal, 

right-side, rear, and left-side). Difference in driver injury pattern by seat belt use and 

crash modes is also investigated in the study. 

Driver age was partitioned into four age groups: 16 to 24, 25 to 44, 45 to 64, and 65 and 

older (i.e., four groups of drivers including one younger group, two middle-aged groups, 

and one older driver group).24 Although different age groups of drivers are used in 

existing studies, “older driver” typically refers to drivers 65 and older.3 24 

This analysis could better enable the identification of features associated with crash 

protection of drivers from such aspects as engineering, human factors, and clinical 

science. 

 

† Kockelman, K.M., and Kweon, Y.-J. (2002). Driver injury severity: an application of ordered probit 

models. Accident Analysis and Prevention, 34, 313.
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3. Data and Methods 

The primary database used in this study is the National Automotive Sampling System—

Crashworthiness Data System (NASS-CDS), 1993-2004. NASS-CDS contains data on 

passenger vehicle crashes in which at least one vehicle was towed due to damage. 

In this study a vehicle had a rollover crash if the vehicle experienced a rollover event in a 

crash, regardless of the event sequence number. Otherwise, the vehicle had a non-rollover 

(planar) crash. Vehicle rollover could be further coded with the number of quarter-turns, 

end-over-end rollover, or rollover with details unknown in the NASS-CDS dataset. † ‡ 

The rollover crash is complicated by a lot of confounding factors. The injury pattern and 

injury mechanism of drivers in rollover crashes are completely different from the ones in 

non-rollover crashes. In this study, driver injuries by crash modes were extensively 

studied as follows: rollover crashes, and non-rollover crashes by vehicle highest impact 

damage area in crashes (frontal, right-side, rear, and left-side). Differences in driver 

injury pattern by seat belt use are also investigated in this study. Crashes with missing or 

unknown variables (e.g., crash modes, occupant type, and unknown vehicle damage area) 

were excluded from the study. 

Driver injury severity in the crash was measured by the Maximum Abbreviated Injury 

Severity Score (MAIS)††: 0-not injured, 1-minor, 2-moderate, 3-serious, 4-severe, 5-

critical, and 6-maximum (fatal). In this analysis, driver injury severity was separated into 

two groups: no injury to serious injury (MAIS ≤ 3) versus severe injury to fatal (MAIS ≥

4).8 * 

Frequency (percentage) tables in the following sections are all based on weighted 

estimates. Due to the complex nature of the NASS-CDS sample design, the standard 

errors, and the statistical methods used in this study, chi-square statistics (for assessing 

the difference in percentage distributions among groups) and logistic regression were 

implemented by the professional software for survey data analysis for multistage sample 

designs, SUDAAN, 8.0.1, developed by Research Triangle Institute (RTI). **

†

 In FARS and NASS-GES database, rollover is defined as any vehicle rotation of 90 degrees or more, 

about any true longitudinal or lateral axis, regardless of the event sequence (first or subsequent event) and 

whether tripped rollover (by curb, guardrail, ditch, soft soil, other and unknown mechanism) or untripped 

rollover. 

‡

 For a discussion of rollover crash and its severity measurements in NASS-CDS, one may see Digges, K., 

and Eigen, A. (2005). Severity Measurements for Rollover Crashes. Prague: IRCOBI, and references 

therein. 

†† 2000 NASS Injury Codeing Manual, NHTSA, U.S. DOT. *

Another reason is that there exist two significantly different distributions of driver injured body regions 

between two groups of AIS (AIS ≤ 3 versus AIS ≥ 4, see Section 6). ** Sudaan User’s Manual, Research Triangle Institute, NC, 1997. 
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4.1 Driver Overall Injury Severity 

Driver overall injury severity was evaluated in the NASS-CDS dataset (Figure 2 and 

Appendix 11.1). NASS-CDS data indicate that the older the drivers the higher the 

percentage of drivers to sustain severe injuries (MAIS ≥ 4) in motor vehicle crashes. 

This difference of driver injury severity (MAIS 0-3 versus MAIS 4-6) among drivers’ age 

groups is statistically significant (χ

2

=28.5, p-value=0.0009; see Appendix 11.1). Data also 

show that severe injuries are a relatively low percentage of overall injuries. 

This result is consistent with the fact that older drivers are more vulnerable to injury in a 

crash given assumed similar crash conditions. Their skeletal structures are more easily 

damaged and the consequences of any assault are likely to be more serious compared 

with younger drivers. 

Figure 2: Relative percentage of driver overall injury severity 

Source: NASS-CDS 1993-2004 

4. Driver Overall Injury Severity 

Relative Percentage of Driver Overall Injury Severity

98

99

100

16-24 25-44 45-64 65 +

Driver Age

Percentage

MAIS 0 - MAIS 3 MAIS 4 - MAIS 6
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4.2 Driver Overall Injury Severity by Gender 

Studies based on Alabama2 and Michigan25 police-reported traffic crash data show that 

among younger drivers, the relative crash proneness is higher for male drivers, but the 

pattern is reversed among older drivers. These studies did not consider the severity of 

injuries. We examine the driver overall injury severity by driver gender in NASS-CDS 

dataset in this section. 

CDS data indicates that male drivers 64 and younger are more likely to sustain severe 

injuries (MAIS ≥ 4) than female drivers, but this pattern is reversed among drivers 65 and 

older (Figure 3 and Appendix 11.2). 

It is noticed, however, that the difference of driver injury severity (MAIS 0-3 versus 

MAIS 4-6) between drivers’ gender is statistically significant for young drivers ages 16 

to 24 (χ

2

=6.94, p-value=0.0187) and middle-aged drivers 25 to 44 (χ

2

=7.32, pvalue=0.0163), but not statistically significant for middle-aged drivers 45 to 64 (χ

2

=2.98, 

p-value=0.1048) and older drivers (χ

2

=1.43, p-value=0.2502). This feature is due to the 

differences in standard errors among the four age groups (see Appendix 11.1). 

Figure 3: Percentage of driver overall severe injury severity (MAIS 4 – 6) by gender 

Source: NASS-CDS 1993-2004 

Percentage of Driver Overall Severe Injury Severity (MAIS 4 - MAIS 6) 

0

1

2

3

16-24 25-44 45-64 65 +

Driver Age

Percent

Male Female
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5. Driver Injury Severity by Crash Modes 

Injury pattern and injury mechanism of drivers in rollover crashes are completely 

different from those in non-rollover crashes; driver injuries by crash modes are 

extensively examined. Difference in driver injury pattern by seat belt use is also 

investigated in the study. 

5.1 Driver Injury Severity in Rollover Crashes 

Data show that drivers 65 and older are more likely to sustain severe injuries in rollover 

crashes compared with other age groups of drivers (Figure 4 and Appendix 11.3). 

However, it is noticed that the difference of driver injury severity (MAIS 0-3 versus 

MAIS 4-6) among drivers’ age is not statistically significant (χ

2

=7.26, p-value=0.1065, 

see Appendix 11.3). This result indicates that the rollover crashes resulted in severe 

injuries to vehicle drivers regardless of driver’s age. Actually, as a percentage, the MAIS 

scores for rollover drivers tended to be greater than those for non-rollover crash drivers 

(see Appendix 11.3, Figure 5, ref. [26] and Section 5.4). Rollover crashes are one of the 

most significant safety problems for all classes of vehicles and all age groups of drivers. 

Figure 4: Percentage of driver severe injury severity (MAIS 4 – 6) in rollover crashes 

Source: NASS-CDS 1993-2004 

Percentage of Driver Severe Injury (MAIS 4 - MAIS 6) in Rollover Crashes 

0

2.5

5

Driver Age 16-24 25-44 45-64 65 + Percent
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5.2 Driver Injury Severity in Non-Rollover Crashes 

In this section, the driver injury severity in non-rollover (planar) crash by vehicle highest 

impact damage area (frontal, right-side, rear, and left-side) is studied (Figure 5 and 

Appendix 11.3). 

The older the drivers the higher the percentage of drivers to sustain severe injuries (MAIS 

≥ 4) in frontal impact crashes. This difference of driver injury severity (MAIS 0-3 versus 

MAIS 4-6) among drivers’ age groups is statistically significant (χ

2

=15.9, pvalue=0.0108, see Appendix 11.3) in frontal impact crashes. 

Drivers 65 and older are more likely to sustain severe injuries (MAIS ≥ 4) in right-side 

impact crashes. However, the difference of driver injury severity (MAIS 0-3 versus 

MAIS 4-6) among drivers’ age groups is not statistically significant (χ

2

=2.81, pvalue=0.4476, see Appendix 11.3) in right-side impact crashes. This result may be due to 

the relatively wide space between the driver and the right-side impact area, which may 

help reduce impact injuries for all driver age groups. 

Older drivers are more likely to sustain severe injuries (MAIS ≥ 4) in rear-impact 

crashes. The difference of driver injury severity (MAIS 0-3 versus MAIS 4-6) among 

drivers’ age groups is not statistically significant at 0.05 significance level but is 

significant at 0.1 significance level (χ

2

=8.45, p-value=0.0748, see Appendix 11.3) in rearimpact crashes. 

The older the drivers the higher the percentage of drivers to sustain severe injuries (MAIS 

≥ 4) in left-side impact crashes. This difference of driver injury severity (MAIS 0-3 

versus MAIS 4-6) among drivers’ age groups is statistically significant (χ

2

=18.6, pvalue=0.0060, see Appendix 11.3) in left-side impact crashes. There is a high percentage 

of drivers 65 and older to sustain severe injuries compared with other age groups of 

drivers in left-side impact crashes. 
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Figure 5: Percentage of driver severe injury severity (MAIS 4 – 6) 

in non-rollover crashes by vehicle damage area 

Source: NASS-CDS 1993-2004 

Percentage of Driver Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes: Frontal Damage Area 

0

2

4

Driver Age 16-24 25-44 45-64 65 + Percent

Percentage of Driver Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes: Right-Side Damage Area 

0

2

4

Driver Age 16-24 25-44 45-64 65 + Percent

Percentage of Driver Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes: Rear Damage Area 

0

2

4

Driver Age 16-24 25-44 45-64 65 + Percent

Percentage of Driver Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes: Left-Side Damage Area 

0

2

4

Driver Age 16-24 25-44 45-64 65 + Percent

5.3 Driver Injury Severity by Seat Belt Use 

Seat belt use has a positive effect on reducing crash injuries for four age groups of drivers 

in both rollover and non-rollover crashes (see Figure 6 and Appendix 11.4). 

It is noticed (see Appendix 11.4 for χ

2 test results) that the safety effect of driver seat belt 

use is significant in rollover crashes for all age groups of drivers at α = 0.05 significance 

level. In non-rollover crashes, the safety effect of driver seat belt use is significant or 

marginally significant at α = 0.05 significance level or at α = 0.1 significance level for 

each of four age groups of drivers in frontal, right-side, and left-side impact crashes, but 

not significant at α = 0.05 significance level for each of four age groups of drivers in rear 

impact crashes. † 

† The designs of seats and head restraints in 21 current SUV, pickup, and minivan models are rated good 

for protecting people in rear impacts, but those in 54 other models are rated marginal or poor. The latest 

evaluations of occupant protection in rear-end collisions found that the seat/head restraints in more than 

half of light-truck and minivan models fall short of state-of-the-art protection from neck injury or whiplash. 

See Insurance Institute for Highway Safety (IIHS): Rear crash protection in SUVs, pickup trucks, & 

minivans: most of their seat/head restraints are marginal or poor. News Releases, July 3, 2007. 
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NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

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Figure 6: Percentage of driver severe injury severity (MAIS 4 – 6) by seat belt use 

Source: NASS-CDS 1993-2004 

That is, the safety effect of driver seat belt use is significant in rollover, non-rollover 

frontal, right-side, and left-side impact crashes. These results are easily understood from 

the structure of the seat belt and the direction of impact force in rollover and non-rollover 

crashes. 

Percentage of Drivers Severe Injury 

(MAIS 4 - MAIS 6) in Rollover Crashes 

by Seat Belt Use 

0

4

8

12

16

Driver Age 16-24 25-44 45-64 65 + Percent

Used

Not Used

Percentage of Drivers Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes by Seat Belt Use

Frontal Damage Area 

0

4

8

12

16

Driver Age 16-24 25-44 45-64 65 + Percent

Used

Not Used

Percentage of Drivers Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes by Seat Belt Use

Right-Side Damage Area 

0

4

8

12

16

Driver Age 16-24 25-44 45-64 65 + Percent

Used

Not Used

Percentage of Drivers Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes by Seat Belt Use

Rear Damage Area 

0

4

8

12

16

Driver Age 16-24 25-44 45-64 65 + Percent

Used

Not Used

Percentage of Drivers Severe Injury 

(MAIS 4 - MAIS 6) in Non-Rollover 

Crashes by Seat Belt Use

Left-Side Damage Area 

0

4

8

12

16

Driver Age 16-24 25-44 45-64 65 + Percent

Used

Not Used
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As shown in the previous sections the crash mode (rollover versus non-rollover), driver 

age, gender, and seat belt use were all associated with the driver’s injury severity in 

crashes. In this section, the impacts of these factors are assessed by jointly estimating the 

effect they have on the likelihood of driver injury severity. 

A logistic regression modeling is estimated with the likelihood (odds) of driver receiving 

serious injury (MAIS ≥ 4) to crash modes, driver’s age, gender, and seat belt use in 

crashes. The odds indicate the relative chance for a group of drivers to sustain serious 

injury (MAIS ≥ 4) compared to a base group (odds=1.00). The p-value (listed in Table 1) 

measures how strong the evidence is against the null hypothesis for the coefficients in 

logistic regression modeling. Statistically significant difference of the odds for a group of 

drivers from the base group (odds=1.00) is indicated in the table (α = 0.05). 

 

Three factors have shown statistically significant difference at α = 0.05 significance level 

(see Table 1): driver age, seat belt use, and crash modes. Note that there is no significant 

difference in crash severity (MAIS ≤ 3 versus MAIS ≥ 4) between male and female 

drivers, after correcting for other factors (seat belt use, age, and crash modes). 

The older the drivers, the higher the odds to receive serious injuries (4.31:1.85:1.37:1.00 

for four age group driver). Drivers 65 and older have four times the odds of sustaining 

serious injuries compared to young drivers under 24 years old, after correcting for other 

factors (seat belt use, gender, and crash modes). 

The odds of a non-belted driver sustaining serious injuries compared to belted drivers are 

more than eight. The driver serious injury risk (odds) after correcting for other factors 

(gender, age, and seat belt use) in vehicle rollover crashes is three times higher than that 

in non-rollover crashes. 

5.4 Logistic Regression Modeling on Driver Injury Severity 

by

Table 1: The likelihood (odds) of driver receiving serious injuries (MAIS ≥ 4) 

crash modes, driver’s age, gender, and seat belt use in crashes (Source: NASS-CDS 1993-2004) 

Factors Odds p-value for the coefficient 

Male 1.00 ---

Gender Female 0.91 0.3866

16-24 1.00 ---

25-44 1.37 † 0.0141 

Age 45-64 1.85 †

 0.0087 

65 + 4.31 † 0.0000 

Used 1.00 ---

Seat Belt Not Used 8.26 †

 0.0000 

Non-Rollover 1.00 ---

Crash Mode Rollover 3.31 †

 0.0000 

p-value for entire model: 0.0000. † Statistically significant difference (α = 0.05) from the base group (odds=1.00). 
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

15

The driver injured body regions and the driver major injury contact sources will be 

examined in this section and the next. In a crash, an injured driver might sustain multiple 

injuries in different body regions, and an AIS injury scale was recoded for each injured 

body region. All recorded body regions were included in the following analysis. † 

6.1 Rollover Crashes 

In rollover crashes, for minor to serious injuries (AIS ≤ 3), the pattern of driver injured 

body region is similar for the four age groups of drivers. The four highest percentages of 

injured body regions related to upper limbs (UL), lower limbs (LL), face (F), and head 

for all age groups of drivers. Upper limbs are the most-injured body regions in rollover 

crashes (Figure 7 and Appendix 11.5 (a)). 

For severe injuries to drivers (MAIS ≥ 4), the pattern of driver injured body region is also 

similar for the four age groups of drivers. The two highest percentages of injured body 

regions related to the head and chest (C), which are much higher than other injured body 

regions. Older drivers receive a large percentage of chest injuries in rollover crashes. For 

all age groups of drivers in rollover crashes, neck and throat (NT) is another injured body 

region (Figure 7 and Appendix 11.5 (a)). 

 

†

 In this section and the next, the standard error of the estimate and the χ

2 test are not provided in the 

calculations as the sample size is very small for some cells. 

6. Driver Injured Body Region 
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

16

Figure 7: Relative percentage of driver injured body region in rollover crashes 

(Head-H, Face-F, Neck/Throat-NT, Chest-C, Abdomen-A, Neck/Spine-NS, 

Upper Limbs-UL, Lower Limbs-LL, Other/Unknown -OU) 

Source: NASS-CDS 1993-2004 

Relative Percentage of Driver Injured Body Region in Rollver Crashes

AIS 1 - AIS 3

0

7

14

21

28

35

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+

Relative Percentage of Driver Injured Body Region in Rollver Crashes

AIS 4 - AIS 6

0

10

20

30

40

50

60

70

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

17

6.2 Non-Rollover Crashes 

Frontal Impact Crashes 

In frontal impact crashes, for minor to serious injuries (MAIS ≤ 3) the patterns of driver 

injured body region is similar for the four age groups of drivers. The four highest 

percentages of injured body regions related to the upper limbs, lower limbs, face, and 

head for all age groups of drivers in non-rollover frontal impact crashes (Figure 8 and 

Appendix 11.5 (b)). 

For severe injuries to drivers (MAIS ≥ 4), the pattern of driver injured body region is also 

similar for the four age groups of drivers. The two highest percentages of injured body 

regions related to head and the chest, which are much higher than other injured body 

regions. It also shows that the abdomen (A) is another frequently injured body region to 

all age groups of drivers in non-rollover frontal impact crashes (Figure 8 and Appendix 

11.5 (b)).
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

18

Figure 8: Relative percentage of driver injured body region in frontal impact crashes 

(Head-H, Face-F, Neck/Throat-NT, Chest-C, Abdomen-A, Neck/Spine-NS, 

Upper Limbs-UL, Lower Limbs-LL, Other/Unknown -OU) 

Source: NASS-CDS 1993-2004 

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Frontal Damage Area / AIS 1 - AIS 3

0

7

14

21

28

35

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Frontal Damage Area / AIS 4 - AIS 6

0

20

40

60

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

19

Right-Side Impact Crashes 

In right-side impact crashes, for minor to serious injuries (MAIS ≤ 3), the pattern of 

driver injured body region is similar for the four age groups of drivers. The three highest 

percentages of injured body regions related to the upper limbs, lower limbs, and face for 

all age groups of drivers in non-rollover right-side impact crashes (Figure 9 and 

Appendix 11.5 (c)). 

For severe injuries to drivers (MAIS ≥ 4), the pattern of driver injured body region is also 

similar for the four age groups of drivers. The two highest percentages of injured body 

regions related to head and the chest, which are much higher than other injured body 

regions. It also shows that the relative percentage of head injuries deceases as the driver 

age increases, but the chest injuries increases as the driver age increases in right-side 

impact crashes. For all age groups of drivers in non-rollover right-side impact crashes, 

abdomen and neck and spine are the other two injured body regions (Figure 9 and 

Appendix 11.5 (c)). 
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

20

Figure 9: Relative percentage of driver injured body region in right-side impact crashes 

(Head-H, Face-F, Neck/Throat-NT, Chest-C, Abdomen-A, Neck/Spine-NS, 

Upper Limbs-UL, Lower Limbs-LL, Other/Unknown -OU) 

Source: NASS-CDS 1993-2004

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Right-Side Damage Area / AIS 1 - AIS 3

0

7

14

21

28

35

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Right-Side Damage Area / AIS 4 - AIS 6

0

20

40

60

80

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

21

Rear-Impact Crashes 

In rear-impact crashes, for minor to serious injuries (MAIS ≤ 3), the pattern of driver 

injured body region are similar for the young and two middle-aged groups of drivers. The 

body region with the highest percentage of injury is the neck and spine. However, for 

older drivers, the body region with the highest percentage of injury is the lower limbs, 

followed by the upper limbs, and neck and spine in non-rollover rear-impact crashes 

(Figure 10 and Appendix 11.5 (d)). A high percentage of neck and spine injuries to all 

age groups of drivers related to the impact force the seat back support applied to the 

drivers. Whiplash injuries to drivers often occurred in rear-end impact crashes. 

For severe injuries to drivers (MAIS ≥ 4), the pattern of driver injured body region is a 

little different among the four age groups of drivers (Figure 10 and Appendix 11.5 (d)). 

This could be due to the relatively small sample size in this type of crash (for MAIS ≥ 4) 

in the CDS dataset. One significant feature is that drivers sustained a high percentage of 

head injuries in rear-impact crashes. Improving head restraints could reduce these 

whiplash injuries of drivers in rear-impact crashes.27
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

22

Figure 10: Relative percentage of driver injured body region in rear impact crashes 

(Head-H, Face-F, Neck/Throat-NT, Chest-C, Abdomen-A, Neck/Spine-NS, 

Upper Limbs-UL, Lower Limbs-LL, Other/Unknown -OU) 

Source: NASS-CDS 1993-2004

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Rear Damage Area / AIS 1 - AIS 3

0

10

20

30

40

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Rear Damage Area / AIS 4 - AIS 6

0

20

40

60

80

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

23

Left-Side-Impact Crashes 

In left-side-impact crashes, for minor to serious injuries (MAIS ≤ 3) the pattern of driver 

injured body region is similar between all age groups of drivers. The lower limbs, upper 

limbs, neck and spine, face, and head are frequently injured regions. The percentage of 

chest injuries increases as driver age increases (Figure 11 and Appendix 11.5 (e)). 

For severe injuries to drivers (MAIS ≥ 4), the pattern of driver injured body region is also 

similar for the four age groups of drivers. The two highest percentages of injured body 

regions related to the head and chest, which are much higher than other injured body 

regions. It also shows that the percentage of head injuries is higher for drivers ages 16 to 

24, and the percentage of chest injuries is higher for the two middle-aged groups and the 

older drivers. The abdomen is another injured body region for all age groups of drivers in 

non-rollover left-side-impact crashes (Figure 11 and Appendix 11.5 (e)). 
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

24

Figure 11: Relative percentage of driver injured body region in left-side impact crashes 

(Head-H, Face-F, Neck/Throat-NT, Chest-C, Abdomen-A, Neck/Spine-NS, 

Upper Limbs-UL, Lower Limbs-LL, Other/Unknown -OU) 

Source: NASS-CDS 1993-2004

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Left-Side Damage Area / AIS 1 - AIS 3

0

7

14

21

28

35

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+

Relative Percentage of Driver Injured Body Region in Non-Rollver Crashes

Left-Side Damage Area / AIS 4 - AIS 6

0

20

40

60

H F NT C A NS UL LL OU

Injured Body Region

Relative Percentage

16-24

25-44

45-64

65+
________________________________________________________________________

NHTSA’s National Center for Statistics and Analysis 1200 New Jersey Avenue SE., Washington, DC 20590 

 

25

7. Driver Injury Contact Sources 

In this section, we examine the major suspected injury contact sources to injured drivers 

across the four age groups and two crash modes (rollover and non-rollover frontal, rightside, rear- and left-side impact crashes), regardless of injured body regions and injury 

severity.†

 This analysis could enable the identification of the most frequent injury contact 

sources of the drivers’ injuries resulting from motor vehicle crashes. 

7.1 Rollover Crashes 

In rollover crashes, the driver major injury contact sources were similar for the four age 

groups of drivers. A detailed examination of the injury contact sources in this type of 

crash is found in Figure 12 and Appendix 11.6 (a). 

Vehicle “roof/top” is one of the major injury contact sources to vehicle drivers in rollover 

crashes. NHTSA proposed new “Roof Crush Resistance Standard” that would extend 

roof strength requirements to all vehicles weighing up to 10,000 pounds.28 Improved roof 

strength is one aspect of a comprehensive NHTSA plan to reduce deaths and injuries of 

vehicle drivers and passengers in rollover crashes. 

The ground was a frequent contact source for the three younger groups. This feature is 

related to younger drivers’ over-involvement in speed-related crashes4 in which drivers 

are likely to be partially or totally ejected from their vehicles.29

Injuries to drivers from seat belts, belt webbing, and buckles occurred because of the 

deceleration pulse that seat belts apply in rollover crashes. However, seat belts can help 

to reduce the level of driver injuries in rollover crashes, such as protecting the drivers 

from ejection. 29

“Left-side interior” (driver side) and “flying glass” were also frequently injury contact 

sources to vehicle drivers in rollover crashes. 

† Data show that there is no significant difference in the distribution of the driver major injury contact 

sources between minor to serious injuries (MAIS ≤ 3) and severe injuries (MAIS ≥ 4) by crash modes. 
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

26

Figure 12: The highest percentage of driver injury contact sources in rollover crashes 

Source: NASS-CDS 1995-2004

Highest Percentages of Injury Contact Sources to Injured Driver

 in Rollover Crashes 

0

5

10

15

Roof/Top

Ground

Flying Glass

Belt Webbing&Buckles

Left-Side Interior

Injury Contact Sources

Percentage

Age 16-24

Highest Percentages of Injury Contact Sources to Injured Driver

 in Rollover Crashes 

0

5

10

15

Roof/Top

Ground

Belt Webbing&Buckles

Flying Glass

Left Instrument Panel

Injury Contact Sources

Percentage

Age 25-44

Highest Percentages of Injury Contact Sources to Injured Driver

 in Rollover Crashes 

0

5

10

15

Belt Webbing&Buckles

Roof/Top

Flying Glass

Steering Wheel Rim

Ground

Injury Contact Sources

Percentage

Age 45-64

Highest Percentages of Injury Contact Sources to Injured Driver

 in Rollover Crashes 

0

5

10

15

Left-Side Interior

Flying Glass

Roof/Top

Belt Webbing&Buckles

Steering Wheel Rim

Injury Contact Sources

Percentage

Age 65 +
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

27

7.2 Non-Rollover Crashes 

Frontal Impact Crashes 

In non-rollover frontal impact crashes, the distribution of major injury contact sources 

was similar across the four age groups of drivers: belt webbing and buckles, air bag, 

steering wheel rim, left instrument panel, and windshield (Figure 13 and Appendix 11.6 

(b)). 

Injuries from vehicle restraint systems (belt webbing and buckles and air bags) occurred 

because of the deceleration pulse the restraint systems apply in frontal impact crashes 

(restraint systems generally help to reduce the level of injuries in a crash). For these 

injuries, the injured body regions were frequently the chest, face, and upper limbs. 

The steering wheel rim, left instrument panel (driver side), and windshield were 

frequently injury contact sources to vehicle drivers. These sources of injury are linked 

with the direction of impact force and principle of dynamics in non-rollover frontal 

impact crashes. 
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

28

Figure 13: The highest percentage of driver injury contact sources 

in non-rollover frontal impact crashes 

Source: NASS-CDS 1995-2004

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Frontal Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Air Bag

Steering Wheel Rim

Left Instrument Panel

Windshield

Injury Contact Sources

Percentage

Age 16-24

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Frontal Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Air Bag

Steering Wheel Rim

Left Instrument Panel

Windshield

Injury Contact Sources

Percentage

Age 25-44

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Frontal Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Air Bag

Left Instrument Panel

Steering Wheel Rim

Windshield

Injury Contact Sources

Percentage

Age 45-64

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Frontal Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Air Bag

Steering Wheel Rim

Left Instrument Panel

Windshield

Injury Contact Sources

Percentage

Age 65 +
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

29

Right-Side-Impact Crashes 

In non-rollover right-side-impact crashes, the driver major injury contact sources were 

slightly different among the four age groups of drivers. The most common source was the 

belt webbing and buckles (Figure 14 and Appendix 11.6 (b)). Again, although this is a 

seat belt use-related injury (because of the deceleration pulse the seat belt applies to the 

driver), seat belt use has reduced the level of driver injuries. 

Other non-contact injury sources, excluding fire in vehicle, flying glass, air bag 

exhausted gas, etc., (e.g. the flying objects inside the car), are major injury contact 

sources to the young and two middle-aged groups of drivers but not to the older drivers in 

right-side-impact crashes. The reason for this is not immediately clear but possible 

explanations include differences among the four age groups of drivers in travel speed, 

object struck, and other such factors that were not considered in detail for this particular 

study. 
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

30

Figure 14: The highest percentage of driver injury contact sources 

in non-rollover right-side impact crashes 

Source: NASS-CDS 1995-2004

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Right-Side Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Other Non-Contact

Steering Wheel Rim

Windshield

Flying Glass

Injury Contact Sources

Percentage

Age 16-24

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Right-Side Damage Area 

0

5

10

15

20

25

Air Bag

Belt Webbing&Buckles

Flying Glass

Other Non-Contact

Knee Bolster

Injury Contact Sources

Percentage

Age 25-44

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Right-Side Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Steering Wheel Rim

Other Non-Contact

Mirror

Air Bag

Injury Contact Sources

Percentage

Age 45-64

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Right-Side Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Air Bag

Left Instrument Panel

Steering Wheel Rim

Seat Back Support

Injury Contact Sources

Percentage

Age 65 +
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

31

Rear-Impact Crashes 

In non-rollover rear-impact crashes, the driver major injury contact sources were slightly 

different among the four age groups of drivers. A common source is the head restraint 

system (Figure 15 and Appendix 11.6 (b)). This is easily understood from the position of 

head restraint system and the direction of impact force in non-rollover rear-impact 

crashes. It can be seen that improved head restraints could further reduce this whiplash 

injury of drivers in rear-impact crashes.27

Other restraint-related systems (belt webbing and buckles, or air bags), and seat back 

support are also major injury contact sources for different age groups of drivers. Due to 

“other non-contact,” excluding fire in vehicle, flying glass, air bag exhausted gas, etc. 

(e.g. the flying objects inside the car), we see the possible importance of fastening down 

the free items inside the car when traveling. 
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

32

Figure 15: The highest percentage of driver injury contact sources 

in non-rollover rear impact crashes 

Source: NASS-CDS 1995-2004

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Rear Damage Area 

0

5

10

15

20

25

Other Non-Contact

Steering Wheel Rim

Belt Webbing&Buckles

Head Restraint System

Air Bag

Injury Contact Sources

Percentage

Age 16-24

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Rear Damage Area 

0

5

10

15

20

25

Other Non-Contact

Belt Webbing&Buckles

Seat Back Support

Head Restraint System

Steering Wheel Rim

Injury Contact Sources

Percentage

Age 25-44

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Rear Damage Area 

0

5

10

15

20

25

Head Restraint System

Seat Back Support

Other Non-Contact

Belt Webbing&Buckles

Left Instrument Panel

Injury Contact Sources

Percentage

Age 45-64

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Rear Damage Area 

0

5

10

15

20

25

Head Restraint System

Seat Back Support

Belt Webbing&Buckles

Floor/Toe Pan

Left Instrument Panel

Injury Contact Sources

Percentage

Age 65 +
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

33

Left-Side-Impact Crashes 

In non-rollover left-side-impact crashes, the driver major injury contact sources were 

similar for the four age groups of drivers: left-side interior, left-side hardware, and belt 

webbing and buckles are most frequently injury contact sources (Figure 16 and Appendix 

11.6 (b)). 

The likely proximity of the driver to the left-side door, and hence the very limited crash 

spaces on the left side of vehicle drivers, has resulted in the severe injuries to vehicle 

drivers in non-rollover left-side-impact crashes. Additional inflatable protection systems 

such as curtains or side air bags could mitigate the injury severity to vehicle drivers in 

left-side-impact crashes.30 31 32
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

34

Figure 16: The highest percentage of driver injury contact sources 

in non-rollover left-side impact crashes 

Source: NASS-CDS 1995-2004

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Left-Side Damage Area 

0

5

10

15

20

25

Belt Webbing&Buckles

Left-Side Interior

Other Non-Contact

Left-Side Hardware

Flying Glass

Injury Contact Sources

Percentage

Age 16-24

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Left-Side Damage Area 

0

5

10

15

20

25

Left-Side Interior

Belt Webbing&Buckles

Other Non-Contact

Left-B Pillar

Left-Side Hardware

Injury Contact Sources

Percentage

Age 25-44

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Left-Side Damage Area 

0

5

10

15

20

25

Left-Side Interior

Belt Webbing&Buckles

Other Non-Contact

Left-Side Hardware

Left Instrument Panel

Injury Contact Sources

Percentage

Age 45-64

Highest Percentages of Injury Contact Sources to Injured Driver

 in Non-Rollover Crashes: Left-Side Damage Area 

0

5

10

15

20

25

Left-Side Interior

Belt Webbing&Buckles

Other Non-Contact

Left-Side Hardware

Roof/Top

Injury Contact Sources

Percentage

Age 65 +
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

35

8. Discussions 

This study has investigated in great detail the driver injury severity, injured body regions, 

and injury contact sources by driver age in rollover and non-rollover real-world traffic 

crashes. Although the characteristics examined in the report were that only of driver 

injuries, the existence of passengers in vehicles could affect the patterns of driver injuries 

in vehicle crashes. 

With careful consideration of nonexistence of passengers in vehicles, we have examined 

the driver injury patterns with only single occupant (the driver) in vehicles in rollover and 

non-rollover frontal, right-side, rear, and left-side crashes (detailed results were not 

presented here). We found that all patterns and the measurements of quantities related to 

driver injuries with only the single drivers in vehicles are almost the same as the ones 

obtained in preceding studies in this report, except that unbelted drivers are a little more 

likely to sustain severe injuries (MAIS ≥ 4) in non-rollover right-side impact crashes. 

Also, the right-side interior or the right-side hardware becomes one of the major injury 

contact sources to drivers in right-side impact crashes. This feature could be due to the 

fact that the existence of other passengers in vehicles could prevent unbelted drivers from 

hitting the right-side interior or right-side hardware of the vehicles in right-side impact 

crashes. 
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

36

9. Conclusions 

In this study, driver injury severity, injured body regions, and injury contact sources by 

driver age in rollover and non-rollover real-world traffic crashes are examined. 

Twelve years of CDS data were included in the analysis (1993 to 2004). Injury severity 

was categorized into two levels (no injury to major injury, or severe injury) using the 

Maximum Abbreviated Injury Scale (MAIS). Our results indicate that in the three 

youngest age groups, males sustained more severe injuries than females, whereas this 

pattern was reversed for the oldest age group. 

The pattern of severe injuries to those in rollovers was independent of age. However, in 

non-rollover crashes, the older drivers are more likely to sustain severe injuries, 

especially in left-side impact crashes. 

There was a statistically significant reduction in injury severity in both rollover and nonrollover crashes to the driver when seat belts were used. Non-belted drivers were eight 

times more likely than belted drivers to sustain serious injury. The driver serious injury 

risk (odds) in vehicle rollover crashes is three times higher than that in vehicle nonrollover crashes. 

About 80 percent of the severe injuries were either to the head or chest. The less severe 

injuries occurred to the face, upper limbs, and lower limbs. 

The major injury contact sources in rollovers are the vehicle roof and top. The pattern of 

the body region injured in rollovers is similar across the age groups, with large 

proportions of the severe injuries occurring to the head and chest, followed by the neck 

and spine. 

In frontal crashes, the major injury contact sources for the drivers of all ages were the belt 

webbing and buckles, air bags, steering wheel rim, left instrument panel, and the 

windshield. The two highest proportions for the severe injuries were to the head and 

chest. The abdomen is another frequently injured portion in such crashes across all age 

groups. The less-severe injuries occur mainly to the upper and lower limbs, face, and 

head, and this was true across all the age groups. 

In left-side-impact crashes, the major injury contact sources were left-side interior, leftside hardware, and belt webbing and buckles; this was true for all ages. Severe injuries in 

such crashes were similar across all ages, with the head and chest being the most-injured 

body regions. The less severe injuries occurred to the lower and upper limbs, neck and 

spine, and the face. The percentage of chest injuries increases as the driver age increases. 

In right-side-impact crashes, the major contact source of injuries showed some 

differences by age group. Belt webbing was a major injury contact source among all age 

groups. Other injury contact sources such as the windshield, air bags, and other non-
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

37

contact sources did not show a pattern among the age groups. A reason for this finding 

may be differences in travel speed or other age-related factors. The most severe injuries 

in such crashes occurred to the head and the chest, and this was true for all age groups. 

While the relative percentage of head injuries decreases as the driver age increases, the 

percentage that were chest injuries increases with age. The abdomen and the neck/throat 

were the other body regions injured in such crashes. 

In rear-impact-crashes, the major sources of injury contact to the drivers were a bit 

different among the four age groups. The most common source is the head restraint 

system. Evolution of head restraint systems might reduce the whiplash injuries suffered 

by drivers in rear-impact crashes. Severe injuries in such crashes occurred predominantly 

to the head. The neck and the spine had the highest proportion of less severe injuries. 

This study also indicates a need of intervention through vehicle design. For instance, 

there may be a requirement to further redefine seat belt systems so that biomechanical 

variation in tolerance to impact is taken into account. Methods include load limiting or 

discretionary web-lock mechanisms, which could be calibrated for specific driver 

characteristics such as age, sex, weight, and height.15 33 

 

It is also important to monitor how effectively the other safety systems such as door, 

frontal, and side air bags, and new anti-rollover technology for new vehicle (e.g., 

electronic stability control) afford protection to drivers.15 34 35 This study also calls 

attention to the need for vehicle improved crashworthiness and design to make vehicles 

more protective for older drivers. 
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

38

10. References 

1 National Highway Traffic Safety Administration. (2004). Traffic Safety Facts 2003 

(DOT HS 809 775). Washington, DC: Author. 

2

 McGwin, G., Jr., & Brown, D.B. (1999). Characteristics of Traffic Crashes among 

Young, Middle-Aged, and Older Drivers. Accident Analysis & Prevention, 31, 181. 

 

3

 Mayhew, D.R., Simpson, H.M., & Ferguson, S.A. (2006). Collisions Involving Senior 

Drivers: High-Risk Conditions and Locations. Traffic Injury Prevention, 7, 117.

4

 Liu, C., Chen, C.-L., Subramanian, R., & Utter, D. (2005). Analysis of Speeding-Related 

Fatal Motor Vehicle Traffic Crashes (NHTSA Technical Report DOT HS 809 839). 

Washington, DC: National Highway Traffic Safety Administration. 

5

 Morris, A., Hassan, A., Mackay, M., & Hill, J. (1995). Head Injuries in Lateral Impact 

Collisions. Accident Analysis & Prevention, 27(6), 749. 

6

 Atkinson, T., & Atkinson P. (2000). Knee Injuries in Motor Vehicle Collisions: A Study 

of the National Accident Sampling System Database for the Years 1979-1995, Accident 

Analysis & Prevention, 32, 779. 

7

 Lee, J.B., & Yang, K.H. (2002). Abdominal Injury Patterns in Motor Vehicle 

Accidents: A Survey of the NASS Database from 1993 to 1997. Traffic Injury 

Prevention, 3, 241.

8

 Nirula, R., Mock, C., Kaufman, R., Rivara, F.P., & Grossman, D.C. (2003). Correlation 

of Head Injury to Vehicle Contact Points Using Crash Injury Research and Engineering 

Network Data. Accident Analysis & Prevention, 35, 201. 

9

 Chipman, M.L. (2004). Side Impact Crashes – Factors Affecting Incidence and 

Severity: Review of the Literature, Traffic Injury Prevention, 5, 67.

10 Wang, S.C. (1998). An Aging Population: Fragile, Handle with Care.. Available at 

http://www-nrd.nhtsa.dot.gov/departments/nrd-50/ciren/um_fragile.html. 

Washington, DC: National Highway Traffic Safety Administration.

11 National Highway Traffic Safety Administration. (2006). Traffic Safety Facts 2005: 

Older Population (DOT HS 810 622). Washington, DC: Author. 

12 Foret-Bruno, J.Y. et al. (1978). Correlation between Thoracic Lesions and Force 

Values Measured at the Shoulder of 92 Belted Occupants Involved in Real Accidents. In 

Proceedings of 22nd Stapp Car Crashes Conference. Ann Arbor, Michigan. 
________________________________________________________________________ 

NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

39

13 Foret-Bruno, J.Y. et al. (1989). Thoracic Deflection of Hybrid III: Dummy Response 

for Simulations of Real Accidents. In Proceedings of 12th Experimental Safety Vehicle 

Conference. Gothenburg, Sweden. 

14 Morris, A., Welsh, R., Frampton, R., Charlton, J. & Fildes, B. (2002). An Overview of 

Requirements for the Crash Protection of Older Drivers. Annual Proceeding of the 

Association for the Advancement of Automotive Medicine, 46:141. 

15 Blomqvist, L.H. (1998). Older Drivers’ Accident Risk: Conceptual and Methodological 

Issues. Accident Analysis & Prevention, 30, 293. 

16 Austin, R.A., & Faigin, B.M. (2003). Effect of Vehicle and Crash Factors on Older 

Occupant Injury. Journal of Safety Research, 34, 441. 

17 Li, G., Braver, E.R., & Chen, L. (2003). Fragility versus Excessive Crash Involvement 

as Determinants of High Death Rates per Vehicle-Mile of Travel among Older Drivers. 

Accident Analysis & Prevention, 35, 227. 

18 Braver, E.R., & Trempel, R.E. (2003). Are Older Drivers at Higher Risks of 

Involvement in Collisions Resulting in Death or Nonfatal Injuries among Their 

Passengers and Other Road Users? Arlington, VA: Insurance Institute for Highway 

Safety, 2003. 

19 Lyman, S., Ferguson, S.A., Braver, E.R., & Williams, A.F. (2002). Older Driver 

Involvements in Police Reported Crashes and Fatal Crashes: Trends and Projections. 

Injury Prevention, 8, 116.

20 Federal Highway Administration, Washington, DC. 

21 U.S. Bureau of Census, Washington, DC. 

22 Research and Development (R&D) Program, NHTSA. Available at: http://wwwnrd.nhtsa.dot.gov/. Washington, DC: National Highway Traffic Safety Administration. 

23 Nirula, R. & Pintar, F.A. (2007). Identification of Vehicle Components Associated 

with Severe Thoracic Injury in Motor Vehicle Crashes: A CIREN and NASS analysis. 

Accident Analysis & Prevention, 40. 

 Hanna, R. and Hershman, L. (2007). Evaluation of Thoracic Injuries Among Older 

Motor Vehicle Occupants. Stapp Car Crash Journal,. 51. 

24 Zhang, J., Fraser, S., Lindsay, J., Clarke, K., & Mao, Y. (1998). Age-Specific Patterns 

of Factors Related to Fatal Motor Vehicle Traffic Crashes: Focus on Young and Elderly 

Drivers. Public Health, 112, 289.
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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25 Stamatiadis, N., & Deacon, J.A. (1995). Trends in Highway Safety: Effects of an 

Aging Population on Accident Propensity. Accident Analysis and Prevention, 27, 443. 

26 Eigen, A.M. (2003). Examination of Rollover Crash Mechanisms and Occupant 

Outcomes (NHTSA Research Note DOT HS 809 692). Washington, DC: National 

Highway Traffic Safety Administration. 

27 National Highway Traffic Safety Administration. (2004). NHTSA Announces 

Upgraded Rule for Head Restraints in Vehicles. Washington, DC: Author. 

28 National Highway Traffic Safety Administration. (2005). NHTSA Proposes New Roof 

Crush Standard. Washington, DC: Author. 

29 National Highway Traffic Safety Administration. (2003). Initiatives to Address the 

Mitigation of Vehicle Rollover. Washington, DC: Author. 

30 Summers, S.M., Hollowell, W.T., & Prasad, A. (2003). NHTSA’s Research Program 

for Vehicle Compatibility. In the proceedings of the 18th International Enhanced Safety 

Vehicle Conference, Paper No. 307. Nagoya, Japan. 

31 Farmer, C.M., Braver, E.R., & Mitter, E.L. (1997). Two-Vehicle Side-Impact Crashes: 

The Relationship of Vehicle and Crash Characteristics to Injury Severity. Accident 

Analysis & Prevention, 29(3), 399. 

32 Insurance Institute for Highway Safety (IIHS). (2003). In Real-World Crashes, Side 

Air Bags With Head Protection Are Saving Lives. Status Report, 38(8). 

33 Mackay, G.M., Parkin, S., & Scott, A. (1994). Intelligent Restraint Systems – What 

Characteristics Should They Have? In Advances in Occupant Restraint Technologies: 

Joint AAAM/Ircobi Special Session. Lyon, France. 

34 NHTSA Safety Standards and Regulations. Available at http://www.safercar.gov. 

Washington, DC: National Highway Traffic Safety Administration.

35 DOT Proposes Anti-Rollover Technology for New Vehicles. Available at 

http://www.safercar.gov/Rollover/pages/NewTechESC.htm. Washington, DC: National 

Highway Traffic Safety Administration.
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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11. Appendix 

11.1 Driver Overall Injury Severity 

Relative Percentage of Driver Overall Injury Severity 

MAIS: 0-no injury, 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

(The Number in Parenthesis is the Standard Error)

MAIS

MAIS 0 – MAIS 3 MAIS 4 – MAIS 6 

Driver Age (%) (%) Total Number

16-24 99.36 (0.12) 0.64 (0.12) 10,790,000

25-44 99.24 (0.16) 0.76 (0.16) 13,410,000

45-64 99.05 (0.26) 0.95 (0.26) 5,896,639

65 + 98.15 (0.29) 1.85 (0.29) 2,486,125

χ2 test for the association between driver’s age and driver’s MAIS (MAIS 0-3 versus MAIS

4-6): χ2 =28.5 (p-value=0.0009)

Source: NASS-CDS 1993-2004

11.2 Driver Overall Injury Severity by Gender 

Percentage of Driver Serious Injury Severity (MAIS 4 – MAIS 6) by Gender 

MAIS: 0-no injury, 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

(The Number in Parenthesis is the Standard Error)

MAIS 4 – MAIS 6

Driver Age Male Female 

% Number % Number 

16-24 0.77 (0.16) 47,936 0.46 (0.08) 20,773

25-44 0.97 (0.20) 72,258 0.50 (0.12) 29,467

45-64 1.07 (0.32) 35,162 0.79 (0.19) 20,689

65 + 1.50 (0.26) 21,986 2.34 (0.61) 23,938

χ2 test for the association between driver’s gender and driver’s MAIS (MAIS 0-3 versus 

MAIS 4-6) for each age group: 

 Age 16-24: χ2 =6.94 (p-value=0.0187)

 Age 25-44: χ2 =7.32 (p-value=0.0163)

 Age 45-64: χ2 =2.98 (p-value=0.1048)

 Age 65 + : χ2 =1.43 (p-value=0.2502)

Source: NASS-CDS 1993-2004
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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11.3 Driver Injury Severity by Crash Modes 

Percentage of Driver Severe Injury Severity (MAIS 4 – MAIS 6) by Crash Modes

MAIS: 0-no injury, 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

(The Number in Parenthesis is the Standard Error)

MAIS 4 – MAIS 6 

Driver Age 16-24 25-44 45-64 65 + 

Crash 

Modes 

1 Rollover % 

2.10 

(0.25) 

3.00

(0.69) 

2.92

(0.80) 

4.39

(0.96) 

Number 18,921 28,356 9,020 3,349 

2 Non-Rollover

Vehicle 

Damage 

Area 

Frontal 

% 

0.48

(0.13) 

0.69

(0.16) 

1.07

(0.44) 

1.74

(0.53) 

Number 22,052 37,046 25,407 18,851

RightSide % 

0.66

(0.09) 

0.63

(0.08) 

0.66

(0.10) 

2.33

(1.05) 

Number 6,065 7,102 3,289 6,773 

Rear 

% 

0.17

(0.12) 

0.12

(0.03) 

0.30

(0.15) 

1.10

(0.64) 

Number 817 962 1,431 1,620 

LeftSide % 

1.12

(0.28) 

1.20

(0.31) 

1.71

(0.45) 

3.18

(0.48) 

Number 11,172 15,637 10,124 9,160 1 χ2 test for the association between driver’s age and driver’s MAIS (MAIS 0-3 versus MAIS 4-6) in Rollover

crashes: 

 χ2=7.26 (p-value=0.1065) 

2 χ2 test for the association between driver’s age and driver’s MAIS (MAIS 0-3 versus MAIS 4-6) in nonrollover crashes by vehicle damage area: 

 Frontal: χ2 =15.9 (p-value=0.0108) 

 Right-Side: χ2 =2.81 (p-value=0.4476)

 Rear: χ2 =8.45 (p-value=0.0748) 

 Left-Side: χ2 =18.6 (p-value=0.0060)

Source: NASS-CDS 1993-2004
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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11.4 Driver Injury Severity by Seat Belt Use 

Percentage of Driver Serious Crash Injury Severity (MAIS 4 – MAIS 6) by Seat Belt Use 

MAIS: 0-no injury, 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

(The Number in Parenthesis is the Standard Error)

MAIS 4 – MAIS 6 (%) 

Driver Age 16-24 25-44 45-64 65 + 

1.10 1.37 1.37 2.68

Used (0.33) (0.46) (0.44) (0.84) 1 Rollover 5.76 8.10 6.71 15.7

Not Used (0.71) (1.64) (2.34) (6.39) 

Total Number 18,886 28,188 8,747 2,993 

0.22 0.26 0.36 0.84

Used (0.05) (0.05) (0.06) (0.26) 

Frontal Not 1.45 2.66 5.43 8.77

Used (0.36) (0.50) (2.61) (3.62) Crash 

Mo Total Number 21,476 36,161 24,952 18,601 des 

0.27 0.25 0.34 0.49

Vehicle Right- Used (0.04) (0.03) (0.06) (0.14) 2 Non-Rollover Damage Side Not 2.83 3.52 3.10 14.0 Area Used (0.52) (0.37) (0.51) (7.33) 

Total Number 6,006 7,005 3,260 6,594 

0.10 0.06 0.28 0.72

Used (0.08) (0.02) (0.16) (0.38) 

Rear Not 0.55 0.33 0.59 8.58

Used (0.33) (0.17) (0.25) (7.60) 

Total Number 782 655 1,399 1,599 

0.74 0.60 1.16 2.71

Left- Used (0.17) (0.12) (0.44) (0.59) 

Side Not 2.57 5.58 5.61 6.71

Used (0.77) (2.16) (1.31) (1.67) 

Total Number 10,861 15,289 10,040 8,977 1 χ2 test for the association between driver’s seat belt use (used versus not used) and driver’s MAIS

(MAIS 0-3 versus MAIS 4-6) in Rollover crashes for each age group:

 Age 16-24: χ2 =15.2 (p-value=0.0014); Age 25-44: χ2 =7.24 (p-value=0.0168)

 Age 45-64: χ2 =6.27 (p-value=0.0243); Age 65 + : χ2 =4.65 (p-value=0.0476)

2 χ2 test for the association between driver’s seat belt use (used versus not used) and driver’s MAIS

(MAIS 0-3 versus MAIS 4-6) in non-rollover crashes by vehicle damage area for each age group (the

number in the parenthesis is the p-value): 

Driver Vehicle Damage Area 

Age Frontal Right-Side Rear Left-Side 

16-24 χ2 =6.19 (0.0251) χ2 =20.8 (0.0004) χ2 =2.10 (0.1680) χ2 =5.55 (0.0325)

25-44 χ2 =8.88 (0.0093) χ2 =32.9 (0.0000) χ2 =3.17 (0.0952) χ2 =3.73 (0.0725)

45-64 χ2 =3.13 (0.0972) χ2 =13.0 (0.0026) χ2 =0.71 (0.4120) χ2 =27.7 (0.0001)

65 + χ2 =4.35 (0.0546) χ2 =2.79 (0.1156) χ2 =1.44 (0.2486) χ2 =7.05 (0.0180)

Source: NASS-CDS 1993-2004
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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(a) Rollover Crashes 

Distribution (Column Percentage) of Driver Injured Body Region in Rollover Crashes 

MAIS: 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

Age 16-24 25-44 45-64 65 + 

Body Region AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 

Head 15.2 60.0 14.9 67.6 14.5 48.7 16.3 25.5 

Face 18.5 0.0 17.8 0.0 20.6 0.0 11.0 0.0 

Neck/Throat 1.2 0.0 1.0 1.0 1.3 0.3 0.7 0.7 

Chest 5.8 27.4 7.7 21.3 7.5 33.8 9.9 55.6

Abdomen 2.4 7.8 3.0 4.7 5.7 2.3 2.9 0.9 

Neck/Spine 10.9 3.9 11.9 4.8 9.5 6.0 5.8 5.3 

Upper Limbs 26.5 0.0 25.5 0.0 23.5 0 33.5 0.0 

Lower Limbs 16.9 0.5 17.5 0.4 16.9 1.1 19.0 3.8 

Other/Unknown 2.6 0.5 0.7 0.1 0.5 7.7 1.0 8.2 

Total Number * 1,557,682 25,042 2,180,326 44,365 858,216 15,382 175,521 4,541

*

 A driver may have more than one injured body region in the crash.

Source: NASS-CDS 1993-2004

11.5 Driver Injured Body Region 
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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(b) Non-Rollover Crashes: Frontal Damage Area of Vehicle 

Distribution (Column Percentage) of Driver Injured Body Region 

in Non-Rollover Crashes: Frontal Damage Area of Vehicle 

MAIS: 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

Body Region 

Age 16-24 25-44 45-64 65 + 

AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 

Head 7.9 55.7 7.5 43.4 7.0 47.5 7.2 40.3

Face 22.6 0.8 19.7 0.0 18.4 0.0 18.3 0.0

Neck/Throat 1.8 0.0 1.2 0.4 1.3 0.0 1.4 0.0

Chest 8.8 21.1 10.8 39.5 12.2 39.1 16.0 35.8

Abdomen 4.0 16.3 3.4 12.7 3.7 9.1 3.5 16.3

Neck/Spine 10.4 4.4 11.1 1.7 10.7 3.4 9.1 7.4

Upper Limbs 22.0 0.0 20.9 0.0 24.6 0.0 24.1 0.0

Lower Limbs 22.2 0.3 24.8 0.4 21.4 0.2 19.6 0.0

Other/Unknown 0.9 1.3 0.7 1.8 0.7 0.6 0.8 0.2

Total Number * 6,133,345 39,817 8,123,713 82,580 4,172,378 49,789 1,807,959 21,648

*

 A driver may have more than one injured body

Source: NASS-CDS 1993-2004

region in the crash.

(c) Non-Rollover Crashes: Right-Side Damage Area of Vehicle 

Distribution (Column Percentage) of Driver Injured Body Region 

in Non-Rollover Crashes: Right-Side Damage Area of Vehicle 

MAIS: 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

Age 16-24 25-44 45-64 65 + 

Body Region AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 

Head 10.6 77.8 14.1 65.4 6.4 62.7 13.2 37.2

Face 18.1 0.0 15.3 0.0 16.4 0.0 13.8 0.0

Neck/Throat 0.8 0.0 0.7 0.0 2.4 0.0 0.9 0.0

Chest 11.6 16.5 7.8 20.5 13.1 29.8 16.6 51.8

Abdomen 3.9 3.9 3.0 9.3 3.1 5.8 3.2 6.8

Neck/Spine 12.9 0.9 12.2 3.4 11.8 1.5 10.0 4.3

Upper Limbs 18.7 0.0 23.7 0.0 19.6 0.0 23.1 0.0

Lower Limbs 23.2 0.3 22.6 0.0 26.9 0.0 18.7 0.0

Other/Unknown 0.2 0.6 0.7 1.4 0.2 0.1 0.6 0.0

Total Number * 871,395 7,621 1,355,359 11,358 585,108 5,723 399,242 12,824

*

 A driver may have more than one injured body region in the crash.

Source: NASS-CDS 1993-2004
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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(d) Non-Rollover Crashes: Rear Damage Area of Vehicle 

Distribution (Column Percentage) of Driver Injured Body Region 

in Non-Rollover Crashes: Rear Damage Area of Vehicle 

MAIS: 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

Age 16-24 25-44 45-64 65 + 

Body Region AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 

Head 9.7 80.7 10.1 65.7 9.7 19.3 12.0 69.6

Face 13.5 0.0 13.8 0.0 10.4 0.0 9.9 0.0

Neck/Throat 0.6 0.0 2.7 0.0 0.5 0.0 0.1 0.0

Chest 7.4 1.0 8.2 17.0 6.5 45.0 5.5 15.7

Abdomen 5.4 0.0 2.0 3.5 2.4 6.8 0.9 0.0

Neck/Spine 30.0 9.8 35.2 0.7 34.5 28.9 18.9 13.3

Upper Limbs 13.6 0.0 12.4 0.0 14.7 0.0 23.5 0.0

Lower Limbs 19.3 0.0 14.9 0.0 21.0 0.0 29.1 0.0

Other/Unknown 0.3 8.5 0.6 13.0 0.4 0.0 0.1 1.3

Total Number * 434,065 421 932,942 2,287 675,065 1,375 186,553 1,588

*

 A driver may have more than one injured body region in the crash.

Source: NASS-CDS 1993-2004

 (e) Non-Rollover Crashes: Left-Side Damage Area of Vehicle 

Distribution (Column Percentage) of Driver Injured Body Region 

in Non-Rollover Crashes: Left-Side Damage Area of Vehicle 

MAIS: 1-minor, 2-moderate, 3-serious, 4-severe, 5-critical, 6-maximum 

Age 16-24 25-44 45-64 65 + 

Body Region AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 AIS 1-3 AIS 4-6 

Head 12.6 54.5 9.3 32.2 12.5 32.6 12.0 32.0

Face 17.0 0.0 13.1 0.0 11.3 0.0 18.7 0.0

Neck/Throat 1.1 0.1 1.1 0.2 1.4 0.4 0.6 0.0

Chest 5.6 27.8 6.9 49.3 9.2 50.6 15.1 50.3

Abdomen 2.6 13.3 3.7 14.8 4.1 9.8 2.3 13.5

Neck/Spine 18.2 3.1 16.9 2.0 14.1 6.6 9.7 2.1

Upper Limbs 21.5 0.0 27.0 0.0 23.8 0.0 22.5 0.0

Lower Limbs 21.0 0.8 21.1 0.4 22.8 0.0 18.6 1.6

Other/Unknown 0.3 0.5 0.7 1.0 0.7 0.0 0.4 0.6

Total Number * 1,284,535 12,792 1,824,789 22,780 906,576 14,358 407,332 7,004

*

 A driver may have more than one injured body region in the crash.

Source: NASS-CDS 1993-2004
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

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11.6 Driver Injury Contact Sources 

(a) Rollover Crashes 

Highest (Column) Percentages of Driver Injury Contact Sources in Rollover Crashes

Driver 

Age Age 16-24 25-44 45-64 65 + 

Roof/Top Roof/Top Belt Webbing/Buckles Left-Side Interior 

Injury

Contact 

Sources 

(12.7) (14.5) (11.6) (14.2) 

Ground

(9.6) 

Ground

(9.1) 

Roof/Top

(9.9) 

Flying Glass 

(9.3) 

Flying Glass 

(9.6) 

Belt Webbing/Buckles 

(7.9) 

Flying Glass 

(8.2) 

Roof/Top

(8.6) 

Belt Webbing/Buckles Flying Glass Steering Wheel Rim Belt Webbing/Buckles 

(9.3) (6.0) (7.2) (8.3) 

Left-Side Interior Left Instrument Panel Ground Steering Wheel Rim

(6.6) (5.2) (6.5) (7.2) 

Total * 1,391,846 1,959,616 780,311 162,829 

* Total number of injury contact sources for each age group of drivers. 

Source: NASS-CDS 1995-2004
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NHTSA’s National Center for Statistics and Analysis1200 New Jersey Avenue SE., Washington, DC 20590

48

(b) Non-Rollover Crashes 

Highest (Column) Percentages of Driver Injury Contact Sources in Non-Rollover Crashes

Driver Age Age 16-24 25-44 45-64 65 + 

Belt Webbing/

Buckles (15.0) 

Belt Webbing/

Buckles (14.1) 

Belt Webbing/

Buckles (16.1) 

Belt Webbing/

Buckles (20.7) 

Air Bag 

(13.0) 

Air Bag 

(10.0) 

Air Bag 

(10.5) 

Air Bag 

(10.3) 

Steering Wheel 

Rim (9.0) 

Steering Wheel 

Rim (9.9) 

Left Instrument 

Panel (9.0) 

Steering Wheel 

Rim (10.1)

Left Instrument 

Panel (8.8) 

Left Instrument 

Panel (9.4) 

Steering Wheel 

Rim (8.1) 

Left Instrument 

Panel (9.0) 

Frontal 

Windshield

(6.7) 

Windshield

(6.0) 

Windshield

(5.8) 

Windshield

(5.1) 

Total * 5,138,968 6,965,879 3,769,431 1,601,459 

Belt Webbing/

Buckles (16.9) 

Air Bag 

(13.0) 

Belt Webbing/

Buckles (23.7) 

Belt Webbing/

Buckles (16.9) 

Other 

Non-Contact (7.7) 

Belt Webbing/

Buckles (12.8) 

Steering Wheel 

Rim (7.8) 

Air Bag 

(8.2) 

Steering Wheel 

Rim (6.9) 

Flying Glass 

(10.8) 

Other 

Non-Contact (6.0) 

Left Instrument 

Panel (6.2) 

Windshield

(6.4) 

Other 

Non-Contact (6.2) 

Mirror 

(5.2) 

Steering Wheel 

Rim (6.0) 

RightSide 

Flying Glass 

(4.9) 

Knee Bolster 

(6.2) 

Air Bag 

(4.2) 

Seat Back 

Support (5.4) 

Total * 724,345 1,228,257 520,084 356,091 

Other 

Non-Contact (14.3)

Other 

Non-Contact (13.5)

Head Restraint 

System (16.8)

Head Restraint

 System (13.5)

Steering Wheel 

Rim (10.6)

Belt Webbing/

Buckles (12.7) 

Seat Back 

Support (15.0)

Seat Back 

Support (12.3)

Belt Webbing/

Buckles (9.9) 

Seat Back 

Support (12.6)

Other 

Non-Contact (13.5)

Belt Webbing/

Buckles (11.0) 

Head Restraint 

System (9.6) 

Head Restraint 

System (10.3)

Belt Webbing/

Buckles (11.3) 

Floor/Toe Pan 

(9.5) 

Rear 

Air Bag 

(7.8) 

Steering Wheel 

Rim (7.0) 

Left Instrument 

Panel (8.8) 

Left Instrument 

Panel (8.2) 

Total * 376,429 786,175 584,888 154,877 

Belt Webbing/

Buckles (11.1) 

Left-Side 

Interior (19.0)

Left-Side 

Interior (17.5)

Left-Side 

Interior (14.7)

Left-Side 

Interior (9.5) 

Belt Webbing/

Buckles (13.9) 

Belt Webbing/

Buckles (11.3) 

Belt Webbing/

Buckles (11.4) 

Other 

Non-Contact (9.2) 

Other 

Non-Contact (8.0) 

Other 

Non-Contact (7.1) 

Other 

Non-Contact (7.3) 

Left-Side 

Hardware (7.9) 

Left-B Pillar 

(6.2) 

Left-Side 

Hardware (6.2) 

Left-Side 

Hardware (7.1) 

LeftSide 

Flying Glass 

(5.5) 

Left-Side 

Hardware (6.1) 

Left Instrument 

Panel (5.1) 

Roof/Top

(6.6) 

Vehicle 

Damage 

Area 

Total * 1,143,497 1,465,248 798,260 338,015 

Note: “non-contact injury sources” include “fire in vehicle,” “flying glass,” “air bag exhausted gas,” etc. 

* Total number of injury contact sources for each age group of drivers. 

Source: NASS-CDS 1995-2004
DOT HS 810 857

November 2007