The effects of airbags and seatbelts on occupant injury in longitudinal barrier crashes.
BACKGROUND
Longitudinal barriers, such as guardrails, are designed to prevent a vehicle that leaves the roadway from impacting a more dangerous object while minimizing the risk of injury to the vehicle occupants. Current full-scale test procedures for these devices do not consider the effect of occupant restraints such as seatbelts and airbags. The purpose of this study was to determine the extent to which restraints are used or deployed in longitudinal barrier collisions and their subsequent effect on occupant injury.


METHODS
Binary logistic regression models were generated to predict occupant injury risk using data from the National Automotive Sampling System / Crashworthiness Data System from 1997 through 2007.


RESULTS
In tow-away longitudinal barrier crashes, airbag deployment rates were 70% for airbag-equipped vehicles. Compared with unbelted occupants without an airbag available, seat belt restrained occupants with an airbag available had a dramatically decreased risk of receiving a serious (MAIS 3+) injury (odds-ratio (OR)=0.03; 95% CI: 0.004-0.24). A similar decrease was observed among those restrained by seat belts, but without an airbag available (OR=0.03; 95% CI: 0.001- 0.79). No significant differences in risk of serious injuries were observed between unbelted occupants with an airbag available compared with unbelted occupants without an airbag available (OR=0.53; 95% CI=0.10-2.68).


CONCLUSIONS
This study refutes the perception in the roadside safety community that airbags rarely deploy in frontal barrier crashes, and suggests that current longitudinal barrier occupant risk criteria may over-estimate injury potential for restrained occupants involved in a longitudinal barrier crash.
School of Biomedical Engineering and Sciences, Virginia Tech Center for Injury Biomechanics, 445 ICTAS Building, Stanger Street, MC 0238, Blacksburg, VA 24061, USA. gabauer@vt.edu
Douglas J
DJ
Gabauer
Hampton C
HC
Gabler
D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D017278:Air Bags / Q000706:statistics & numerical data*; D001334:Automobile Driving / Q000706:statistics & numerical data*; D001336:Automobiles / Q000706:statistics & numerical data*; D016001:Confidence Intervals; D016208:Databases, Factual; D004779:Environment Design; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011482:Protective Devices / Q000706:statistics & numerical data; D012372:ROC Curve; D018570:Risk Assessment; D012622:Seat Belts / Q000706:statistics & numerical data*; D014481:United States; D014947:Wounds and Injuries / Q000453:epidemiology* / Q000517:prevention & control