Comparing the effects of age,BMI and gender on severe injury (AIS 3+) in motor-vehicle crashes

Background

The effects of age, body mass index (BMI) and gender on motor vehicle crash (MVC) injuries are not well understood and current prevention efforts do not effectively address variability in occupant characteristics.

Objectives

(1) Characterize the effects of age, BMI and gender on serious-to-fatal MVC injury. (2) Identify the crash modes and body regions where the effects of occupant characteristics on the numbers of occupants with injury is largest, and thereby aid in prioritizing the need for human surrogates that represent different types of occupant characteristics and adaptive restraint systems that consider these characteristics.

Methods

Multivariate logistic regression was used to model the effects of occupant characteristics (age, BMI, gender), vehicle and crash characteristics on serious-to-fatal injuries (AIS 3+) by body region and crash mode using the 2000–2010 National Automotive Sampling System (NASS-CDS) dataset. Logistic regression models were applied to weighted crash data to estimate the change in the number of annual injured occupants with AIS 3+ injury that would occur if occupant characteristics were limited to their 5th percentiles (age ≤ 17 years old, BMI ≤ 19 kg/m²) or male gender.

Results

Limiting age was associated with a decrease in the total number of occupants with head [8396, 95% CI 6871–9070] and thorax injuries [17,961, 95% CI 15,960–18,859] across all crash modes, decreased occupants with spine [3843, 95% CI 3065–4242] and upper extremity [3578, 95% CI 1402–4439] injuries in frontal and rollover crashes and decreased abdominal [1368, 95% CI 1062–1417] and lower extremity [4584, 95% CI 4012–4995] injuries in frontal impacts. The age effect was modulated by gender with older females more likely to have thorax and upper extremity injuries than older males. Limiting BMI was associated with 2069 [95% CI 1107–2775] fewer thorax injuries in nearside crashes, and 5304 [95% CI 4279–5688] fewer lower extremity injuries in frontal crashes. Setting gender to male resulted in fewer occupants with head injuries in farside crashes [1999, 95% CI 844–2685] and fewer thorax [5618, 95% CI 4212–6272], upper [3804, 95% CI 1781–4803] and lower extremity [2791, 95% CI 2216–3256] injuries in frontal crashes. Results indicate that age provides the greater relative contribution to injury when compared to gender and BMI, especially for thorax and head injuries.

Conclusions

Restraint systems that account for the differential injury risks associated with age, BMI and gender could have a meaningful effect on injury in motor-vehicle crashes. Computational models of humans that represent older, high BMI, and female occupants are needed for use in simulations of particular types of crashes to develop these restraint systems.     

Seat position and the risk of serious thoracoabdominal injury in lateral motor vehicle crashes

CONTEXT: Previous studies have suggested that motor vehicle occupants seated on the near-side of a lateral impact have a higher proportion of thoracoabdominal injuries. However, due to limitations in previous studies, the true association between seat position, side of lateral impact, and thoracoabdominal injury is unclear. OBJECTIVE: To assess the relationship between seat position (i.e., near-side, middle-seat, and far-side, regardless of row), side of lateral motor vehicle crash (MVC), and serious thoracoabdominal injury after adjusting for important crash factors. DESIGN: National population-based cohort of adult subjects involved in MVCs and included in the National Automotive Sampling System Crashworthiness Data System database (NASS CDS) from 1995 to 2003. PATIENTS: Occupants aged > or =16 years involved in MVCs where the highest external deformation of the vehicle was located on the right or left side (i.e., lateral). MAIN OUTCOME MEASURE: Serious thoracic or abdominal injury, defined as an Abbreviated Injury Scale (AIS) > or =3 in the thoracic or abdominal body region. RESULTS: Fifteen thousand, one hundred and sixty persons involved in primary lateral MVCs were represented in the NASS CDS database during the 9-year period. There were 1867 (2%) persons with serious thoracic injuries and 507 persons (0.5%) with serious abdominal injuries. In multivariable logistic regression models that adjusted for important crash factors and the NASS CDS sampling design, seat position was a strong effect modifier of the association between side of lateral impact and serious thoracic (p<0.0001) and abdominal (p=0.0009) injury, with the risk of serious thoracic and abdominal injury highest for occupants seated on the near-side of the crash. The mean probability of injury was higher for near-side and middle-seat occupants compared to far-side occupants, and the probability of thoracic injury was approximately four times higher than that of abdominal injury for all seat positions. CONCLUSIONS: There is a strong, synergistic relationship between seat position and side of lateral MVC in assessing risk of serious thoracic and abdominal injury among adult occupants. The probability of serious thoracoabdominal injury increases with increasing proximity of seat position to side of the crash and the risk of thoracic injury is higher than abdominal injury for all seat positions.     

Appropriate analysis of CIREN data: Using NASS-CDS to reduce bias in estimation of injury risk factors in passenger vehicle crashes

The Crash Injury Research Engineering Network (CIREN) database contains detailed medical and crash information on a large number of severely injured occupants in motor vehicle crashes. CIREN's major limitation for stand-alone analyses to explore injury risk factors is that control subjects without a given injury type must have another severe injury to be included in the database. This leads to bias toward the null in the estimation of risk associations. One method to cope with this limitation is to obtain information about occupants without a given injury type from the National Automotive Sampling System's Crashworthiness Data System (NASS-CDS), which is a probability sample of towaway crashes, containing similar crash information, but less medical detail. Combining CIREN and NASS-CDS in this manner takes advantage of the increased sample size when outcomes are available in both datasets; otherwise NASS-CDS can serve as a sample of controls to be combined with CIREN cases, possibly under a sensitivity analysis that includes and excludes NASS-CDS subjects whose status as a control is uncertain. Because CIREN is not a probability sample of crashes that meet its inclusion criteria, we develop a method to estimate the probability of selection for the CIREN cases using data from NASS-CDS. These estimated probabilities are then used to compute “pseudo-weights” for the CIREN cases. These pseudo-weights not only allow for reduced bias in the estimation of risk associations, they allow direct prevalence estimates to be made using medical outcome data available only in CIREN. We illustrate the use of these methods with both simulation studies and application to estimation of prevalence and predictors of AIS 3+ injury risk to head, thorax, and lower extremity regions, as well as prevalence and predictors of acetabular pelvic fractures. Results of these analyses demonstrate combining NASS and CIREN data can yield improvements in mean square error and nominal confidence interval coverage over analyses that use either the NASS-CDS or the CIREN sample alone.     

Headrest position during normal driving: Implication to neck injury risk in rear crashes

The gap and relative height of headrest behind drivers were determined for 1915 vehicles approaching an intersection on a two lane road. Vehicle type and headrest adjustment were also evaluated using film of normal driving taken by the Insurance Institute for Highway Safety. Only 10% of drivers had headrests in the most favorable position to prevent neck extension during a rearend crash. 73% of cars had adjustable headrests, but only a quarter were placed in the up position. 83% of the adjustable headrests could have been raised to better protect the driver. Hyge sled tests were run to determine biomechanical responses for the various conditions observed in normal driving. This included three headrest heights and three gaps behind the head. Neck extension from the Hybrid III dummy was normalized to the response for a high, close headrest, and injury risk was assumed to be proportional to neck extension. The current driving situation has a relative injury risk of 3.4 in rearend crashes, compared to 1.0 for the favorable condition. If all adjustable headrests were placed in the up position, the relative risk would be lowered to 2.4, a 28.3% reduction in whiplash injury risk. Public education and vehicle design should address the importance of proper headrest placement for driving safety.     

Age of drinking onset, driving after drinking, and involvement in alcohol related motor-vehicle crashes.

This study assessed whether persons who begin drinking at younger ages are more likely to report drunk driving and alcohol-related crash involvement over the life course, even after controlling analytically for diagnosis of alcohol dependence, years of drinking alcohol, and other personal characteristics associated with the age respondents started drinking. A national survey asked 42,862 respondents the age that they started drinking, whether they drove after drinking too much, and whether they were in motor-vehicle crashes because of their drinking. This analysis focused on 27,081 (65%), who reported ever drinking in their lifetime. The earlier the age respondents started drinking, the more likely they were to report driving after drinking too much and being in a motor-vehicle crash because of their drinking even after adjusting for current/ever diagnosis of alcohol dependence, number of years respondents had been drinking, and other characteristics and behaviors associated with the age respondents started drinking. Particularly, among persons who were never alcohol-dependent, those who began drinking in each age group under 21, relative to those starting at age 21 or older, were more likely to report "ever" and "in the past year" being in a crash after drinking too much. The traffic safety benefits of delaying drinking may extend well beyond the legal drinking age of 21.     

Investigating driver injury severity patterns in rollover crashes using support vector machine models

Rollover crash is one of the major types of traffic crashes that induce fatal injuries. It is important to investigate the factors that affect rollover crashes and their influence on driver injury severity outcomes. This study employs support vector machine (SVM) models to investigate driver injury severity patterns in rollover crashes based on two-year crash data gathered in New Mexico. The impacts of various explanatory variables are examined in terms of crash and environmental information, vehicle features, and driver demographics and behavior characteristics. A classification and regression tree (CART) model is utilized to identify significant variables and SVM models with polynomial and Gaussian radius basis function (RBF) kernels are used for model performance evaluation. It is shown that the SVM models produce reasonable prediction performance and the polynomial kernel outperforms the Gaussian RBF kernel. Variable impact analysis reveals that factors including comfortable driving environment conditions, driver alcohol or drug involvement, seatbelt use, number of travel lanes, driver demographic features, maximum vehicle damages in crashes, crash time, and crash location are significantly associated with driver incapacitating injuries and fatalities. These findings provide insights for better understanding rollover crash causes and the impacts of various explanatory factors on driver injury severity patterns.     

Predicting severe head injury after light motor vehicle crashes: implications for automatic crash notification systems

Motor vehicle crashes (MVC) are a leading public health problem. Improving notification times and the ability to predict which crashes will involve severe injuries may improve trauma system utilization. This study was undertaken to develop and validate a model to predict severe head injury following MVC using information readily incorporated into an automatic crash notification system. A cross-sectional study with derivation and validation sets was performed. The cohort was drawn from drivers of vehicles involved in MVC obtained from the National Automotive Sampling System (NASS). Independent multivariable predictors of severe head injury were identified. The model was able to stratify drivers according to their risk of severe head injury indicating its validity. The areas under the receiver-operating characteristic (ROC) curves were 0.7928 in the derivation set and 0.7940 in the validation set. We have developed a prediction model for head injury in MVC. As the development of automatic crash notification systems improves, models such as this one will be necessary to permit triage of what would be an overwhelming increase in crash notifications to pre-hospital responders.     

Development of a robust mapping between AIS 2+ and ICD-9 injury codes

Motor vehicle crashes result in millions of injuries and thousands of deaths each year in the United States. While most crash research datasets use Abbreviated Injury Scale (AIS) codes to identify injuries, most hospital datasets use the International Classification of Diseases, version 9 (ICD-9) codes. The objective of this research was to establish a one-to-one mapping between AIS and ICD-9 codes for use with motor vehicle crash injury research. This paper presents results from investigating different mapping approaches using the most common AIS 2+ injuries from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS). The mapping approaches were generated from the National Trauma Data Bank (NTDB) (428,637 code pairs), ICDMAP (2500 code pairs), and the Crash Injury Research and Engineering Network (CIREN) (4125 code pairs). Each approach may pair given AIS code with more than one ICD-9 code (mean number of pairs per AIS code: NTDB = 211, ICDMAP = 7, CIREN = 5), and some of the potential pairs are unrelated. The mappings were evaluated using two comparative metrics coupled with qualitative inspection by an expert physician. Based on the number of false mappings and correct pairs, the best mapping was derived from CIREN. AIS and ICD-9 codes in CIREN are both manually coded, leading to more proper mappings between the two. Using the mapping presented herein, data from crash and hospital datasets can be used together to better understand and prevent motor vehicle crash injuries in the future.     

Cervical and thoracic spine injury from interactions with vehicle roofs in pure rollover crashes

Around one third of serious injuries sustained by belted, non-ejected occupants in pure rollover crashes occur to the spine. Dynamic rollover crash test methodologies have been established in Australia and the United States, with the aims of understanding injury potential in rollovers and establishing the basis of an occupant rollover protection crashworthiness test protocol that could be adopted by consumer new car assessment programmes and government regulators internationally. However, for any proposed test protocol to be effective in reducing the high trauma burden resulting from rollover crashes, appropriate anthropomorphic devices that replicate real-world injury mechanisms and biomechanical loads are required. To date, consensus regarding the combination of anthropomorphic device and neck injury criteria for rollover crash tests has not been reached. The aim of the present study is to provide new information pertaining to the nature and mechanisms of spine injury in pure rollover crashes, and to assist in the assessment of spine injury potential in rollover crash tests. Real-world spine injury cases that resulted from pure rollover crashes in the United States between 2000 and 2009 are identified, and compared with cadaver experiments under vertical load by other authors. The analysis is restricted to contained, restrained occupants that were injured from contact with the vehicle roof structure during a pure rollover, and the role of roof intrusion in creating potential for spine injury is assessed. Recommendations for assessing the potential for spine injury in rollover occupant protection crash test protocols are made.     

The relationship between body weight and risk of death and serious injury in motor vehicle crashes

We sought to investigate the effect of increased body weight on the risk of death and serious injury to occupants in motor vehicle crashes. We employed a retrospective cohort study design utilizing data from the National Automotive Sampling System, Crashworthiness Data System (CDS), 1993-1996. Subjects in the study included occupants involved in tow-away crashes of passenger cars, light trucks, vans and sport utility vehicles. Two outcomes were analyzed: death within 30 days of the crash and injury severity score (ISS). Two exposures were considered: occupant body weight and body mass index (BMI; kg/m2). Occupant weight was available on 27263 subjects (76%) in the CDS database. Mortality was 0.67%. Increased body weight was associated with increased risk of mortality and increased risk of severe injury. The odds ratio for death was 1.013 (95% CI: 1.007, 1.018) for each kilogram increase in body weight. The odds ratio for sustaining an injury with ISS > or = 9 was 1.008 (95% CI: 1.004, 1.011) for each kilogram increase in body weight. After adjustment for potentially confounding variables (age, gender, seatbelt use, seat position and vehicle curbweight), the significant relationship between occupant weight and mortality persisted. After adjustment, the relationship between occupant weight and ISS was present, although less marked. Similar trends were found when BMI was analyzed as the exposure. In conclusion, increased occupant body weight is associated with increased mortality in automobile crashes. This is probably due in part to increased co-morbid factors in the more overweight occupants. However, it is possibly also due to an increased severity of injury in these occupants. These findings may have implications for vehicle safety design, as well as for transport safety policy.     

Increased risk of driver fatality due to unrestrained rear-seat passengers in severe frontal crashes

While belt usage among rear-seat passengers is disproportionately lower than their front-seat counterpart, this may have serious consequences in the event of a crash not only for the unbelted rear-seat passenger but also for the front-seat passengers as well. To quantify that effect, the objective of the study is to evaluate the increased likelihood of driver fatality in the presence of unrestrained rear-seat passengers in a severe frontal collision. U.S.-based census data from 2001 to 2009 fatal motor vehicle crashes was used to enroll frontal crashes which involved 1998 or later year vehicle models with belted drivers and at least one adult passenger in the rear left seat behind the driver. Results using multivariate logistic regression analysis indicated that the odds of a belt restrained driver sustaining a fatal injury was 137% (95% CI = 95%, 189%) higher when the passenger behind the driver was unbelted in comparison to a belted case while the effects of driver age, sex, speed limit, vehicle body type, airbag deployment and driver ejection were controlled in the model. The likelihood of driver fatality due to an unrestrained rear left passenger increased further (119–197%) in the presence of additional unrestrained rear seat passengers in the rear middle or right seats. The results from the study highlight the fact that future advances to front row passive safety systems (e.g. multi-stage airbag deployment) must be adapted to take into account the effect of unrestrained rear-seat passengers.     

Driver injury severity outcome analysis in rural interstate highway crashes: a two-level Bayesian logistic regression interpretation

There is a high potential of severe injury outcomes in traffic crashes on rural interstate highways due to the significant amount of high speed traffic on these corridors. Hierarchical Bayesian models are capable of incorporating between-crash variance and within-crash correlations into traffic crash data analysis and are increasingly utilized in traffic crash severity analysis. This paper applies a hierarchical Bayesian logistic model to examine the significant factors at crash and vehicle/driver levels and their heterogeneous impacts on driver injury severity in rural interstate highway crashes. Analysis results indicate that the majority of the total variance is induced by the between-crash variance, showing the appropriateness of the utilized hierarchical modeling approach. Three crash-level variables and six vehicle/driver-level variables are found significant in predicting driver injury severities: road curve, maximum vehicle damage in a crash, number of vehicles in a crash, wet road surface, vehicle type, driver age, driver gender, driver seatbelt use and driver alcohol or drug involvement. Among these variables, road curve, functional and disabled vehicle damage in crash, single-vehicle crashes, female drivers, senior drivers, motorcycles and driver alcohol or drug involvement tend to increase the odds of drivers being incapably injured or killed in rural interstate crashes, while wet road surface, male drivers and driver seatbelt use are more likely to decrease the probability of severe driver injuries. The developed methodology and estimation results provide insightful understanding of the internal mechanism of rural interstate crashes and beneficial references for developing effective countermeasures for rural interstate crash prevention.     

Vehicle mass and injury risk in two-car crashes: A novel methodology

This paper introduces a novel methodology based on disaggregate analysis of two-car crash data to estimate the partial effects of mass, through the velocity change, on absolute driver injury risk in each of the vehicles involved in the crash when absolute injury risk is defined as the probability of injury when the vehicle is involved in a two-car crash. The novel aspect of the introduced methodology is in providing a solution to the issue of lack of data on the speed of vehicles prior to the crash, which is required to calculate the velocity change, as well as a solution to the issue of lack of information on non-injury two-car crashes in national accident data. These issues have often led to focussing on relative measures of injury risk that are not independent of risk in the colliding cars. Furthermore, the introduced methodology is used to investigate whether there is any effect of vehicle size above and beyond that of mass ratio, and whether there are any effects associated with the gender and age of the drivers. The methodology was used to analyse two-car crashes to investigate the partial effects of vehicle mass and size on absolute driver injury risk. The results confirmed that in a two-car collision, vehicle mass has a protective effect on its own driver injury risk and an aggressive effect on the driver injury risk of the colliding vehicle. The results also confirmed that there is a protective effect of vehicle size above and beyond that of vehicle mass for frontal and front to side collisions.     

Spatial analysis of fatal and injury crashes in Pennsylvania

Using injury and fatal crash data for Pennsylvania for 1996-2000, full Bayes (FB) hierarchical models (with spatial and temporal effects and space-time interactions) are compared to traditional negative binomial (NB) estimates of annual county-level crash frequency. Covariates include socio-demographics, weather conditions, transportation infrastructure and amount of travel. FB hierarchical models are generally consistent with the NB estimates. Counties with a higher percentage of the population under poverty level, higher percentage of their population in age groups 0-14, 15-24, and over 64 and those with increased road mileage and road density have significantly increased crash risk. Total precipitation is significant and positive in the NB models, but not significant with FB. Spatial correlation, time trend, and space-time interactions are significant in the FB injury crash models. County-level FB models reveal the existence of spatial correlation in crash data and provide a mechanism to quantify, and reduce the effect of, this correlation. Addressing spatial correlation is likely to be even more important in road segment and intersection-level crash models, where spatial correlation is likely to be even more pronounced.     

Estimating the costs of occupational injury in the United States

This article estimates workplace injury costs in the U.S. These costs have been studied in less detail than most injury costs. Our methods, which mostly use regularly published data, produce order-of-magnitude estimates. Overall, workplace injuries cost the U.S. an estimated $140 billion annually. This estimate includes $17 billion in medical and emergency services, $60 billion in lost productivity, $5 billion in insurance costs, and $62 billion in lost quality of life. One sixth of the societal costs result from the 3% of workplace injuries in motor vehicle crashes. Motor vehicle costs per injury are almost 6 times the workplace injury average.     

Analyzing and modeling risk exposure of pedestrian children to involvement in car crashes

This paper analyzes the various variables affecting pedestrian children road crashes, placing emphasis on the effect of daily activity patterns and the built environment, including the children's residential neighborhoods and the land use of the places where they conduct their activities. Two complementary data sources from the case study of an Arab town in northern Israel were used to provide a holistic picture of child-pedestrian road crashes: police files providing detailed analyzes of the reason for each crash, its location, and the characteristics of the driver involved; and a survey of 199 households with both involved and not involved children in road crashes, including a one-day travel diary. The study found that a combination of three groups of variables affects child-pedestrian road crashes: socio-economic status, travel patterns, and land use. Most vulnerable are boys from a low socio-economic group who live in areas of high density and mixed land use near a major road and who tend to walk to and from school and additional activities after school.     

Car occupant safety in frontal crashes: a parameter study of vehicle mass, impact speed, and inherent vehicle protection

A new mathematical model was developed to estimate average injury and fatality rates in frontal car-to-car crashes for changes in vehicle fleet mass, impact speed distribution, and inherent vehicle protection. The estimates were calculated from injury/fatality risk data, delta-V distribution and collision probability of two vehicles, where delta-V depends on impact speed and mass of the colliding vehicles. The impact speed distribution was assumed to be unaffected by a change in fleet mass distribution.

The results showed that safety in frontal crashes would improve 27–35% by a 10% increase in fatality risk parameters, which reflected substantial improvement in inherent vehicle protection. A 40% safety improvement was attained by a 10% impact speed reduction. Consequences of vehicle fleet mass were not as strong, but depended on the average mass ratio of the fleet. A reduction in mass range would be the most beneficial, while a uniform mass reduction of 20% would increase the fatality rate by 5.4%. The model estimates trends in traffic safety and may help to identify priorities in active and passive safety.     

Comparison of two methods to assess the effect of age and sex on the risk of car crashes

Background

This study was designed to compare two methods (direct measurement of exposure and quasi-induced exposure) for assessing the effect of age and sex on the risk of being involved in a car crash in Spain.

Methods

Spanish crash rates (per 10,000,000 driver-km) for age and sex groups of drivers aged 18–64 years old were obtained for 2004–2007, using information from the Spanish General Traffic Office (census of reported car crashes) and the Spanish Household Survey on Alcohol and Drugs (estimate of the mean km driven for each car driver). The rate ratios estimated by direct exposure estimates were compared to those obtained with the quasi-induced exposure method, which compares the age and sex of responsible and non-responsible drivers involved in the same clean collision (in which only one of the drivers committed a driving infraction).

Results

Both methods detected an increased risk of involvement in a crash for the youngest (18–20 years) and the oldest drivers (60–64 years), compared to middle-aged drivers (45–49 years). However, the rate ratios obtained with the quasi-induced method for the youngest group (2.0 for men, 1.6 for women) were much lower than those obtained with crash rates (13.4 for men, 5.7 for women). Both methods detected a similar increase in the risk of involvement of male drivers compared to women in the youngest age group. This excess risk for men was maintained with increasing age up to 45–49 years when the quasi-induced method was used. However, direct comparisons of crash rates revealed an increased risk of involvement in women compared to men of the same age from 25–29 years onward.

Conclusions

Both direct measurement of driving exposure and the quasi-induced exposure method detected some well-known patterns of risk associated with driver's age and sex. However, factors that could explain important differences between the two methods deserve attention, especially those related with the excess risk for the youngest drivers as well as sex-related risk.     

Relative risk of spinal cord injury in road crashes involving seriously injured occupants of light passenger vehicles

Road crashes involving occupants of light passenger vehicles are the leading cause of traumatic spinal cord injury (SCI). Confirming the results of an earlier study, this study showed that: in single vehicle car crashes in the country, the odds of SCI were nearly five times higher (4.7) for occupants of non-sedan type light passenger vehicles compared with sedans; in single vehicle rollover crashes in the country, the odds of SCI were nearly three times higher (2.8) in non-sedans compared with sedans; the odds of SCI were nearly five times higher (4.8) for sports utility vehicles (SUVs) compared with sedans. When the data from the earlier study was included in order to increase statistical power, it was found that when compared to sedans that did not roll, occupants of all types of light passenger vehicles had a statistically significant substantially higher likelihood of SCI when involved in rollover (sedans 7.5 times, SUVs 5.9 times and others 8.4 times). In addition, SUVs had a higher likelihood of SCI even when not involved in rollover (5.4 times). Vehicle designers and regulators need to give more attention to the prevention of vehicle rollover and the means to improve occupant protection in the event of rollover. This study should be extended nationally to gain a larger case series so that the SCI risk of particular vehicle configurations, considering other crash factors, can be more precisely quantified and characteristics for low occurrence of SCI identified.     

Factors affecting pelvic and thoracic forces in near-side impact crashes: a study of US-NCAP, NASS, and CIREN data

The goal of this study was to identify variables related to vehicle design which are associated with pelvic and thoracic accelerations as measured by the driver's (near side) crash dummy during new car assessment program (NCAP) testing of motor vehicles. Vehicle specific parameters were analyzed using NCAP side impact test results. Data from national automotive sampling system, crashworthiness data system (NASS-CDS) and crash injury research and engineering network (CIREN) (both National Highway Traffic Safety Administration (NHTSA) injury databases) were assessed to confirm NCAP test observations. In addition, door armrest stiffness measurements were performed using a mechanical tester on a sample of 40 vehicles. NCAP data showed that of 10 variables tested using multiple linear regression, vehicle weight and door crush correlated with pelvic acceleration of the driver's crash dummy (overall, r2=0.58, p=0.002, n=165). For thoracic trauma index (TTI) vehicle weight and peak door velocity correlated, significantly (overall, r2=0.41, p=0.03, n=165). Mean TTI was 63.7 g with no side airbag (n=108) and 55.6 g with a thoracic side airbag (n=54), p=0.01. The mean vehicle weight and door crush between airbag and no airbag groups were not significantly different. NASS-CDS data demonstrated a direct relationship between increased door crush and increased abbreviated injury score (AIS). CIREN data showed that occupants who sustained pelvic injuries had a median AIS of 3 with 24.9 cm of door crush, with abdominal injuries, a median AIS of 3 and 30 cm of crush, and with thoracic injuries, a median AIS of 4 and 34 cm of door crush. In addition, the frequency of bilateral pelvic injuries was significantly higher for subjects in CIREN crashes who were in a vehicle with a center console, but only if door intrusion was greater than 15 cm. This information may be useful in design of vehicles with greater protection in side impact crashes.