Influencing factors on the injury severity of restrained front seat occupants in car-to-car head-on collisions

Abstract

The results of 319 cases of belt-restrained front seat car occupants (234 drivers and 85 passengers) from 241 vehicles in car-to-car head-on collisions were examined. Ninety-five occupants were uninjured, 195 sustained a total injury severity of Maximum Abbreviated Injury Score (MAIS) 1–3 and 29, MAIS 4–6. There were 27 fatalities, and the main causes of death were polytrauma and hemorrhage. The main factors influencing occupant injury severity were: the energy equivalent speed (EES); the change of velocity (delta v); the maximum deformation depth; and the collision angle. With an EES > 50 km/h fatal injuries can be expected, and above 60 km/h no occupant remained uninjured. The results of a multivariate analysis were: EES influenced the injury severity at all body locations except the spinal cord; occupant position effected only head injury severity, with drivers being more severely injured; occupant age influenced the injury severity at the thorax, abdomen, and extremities and MAIS as well. Age was a further factor influencing injury severity, e.g. with an EES of 50 km/h the probability of being fatally injured was 30%–45% higher for occupants over 59 years than those under 20.