Comparison and evaluation of contemporary restraint systems in the driver and front-passenger environments

Abstract

Restrained driver and passenger kinematics and injury outcome in frontal collisions are compared using US fatality field data and post-mortem human surrogate sled tests. The fatality data indicate that a frontal airbag may provide greater benefit for a passenger than for a driver. The thoracic injuries sustained by passenger-side surrogates restrained by a force-limited, pre-tensioned belt and airbag are evaluated, and kinematics are compared with driver-side subjects exposed to a similar impact. Driver and passenger kinematic differences are identified and the implications are discussed with respect to the injury-predictive ability of existing thoracic injury criteria. The chest acceleration of the passenger-side subjects exhibited a bimodal profile with an initial (and global) maximum before the subject loaded the airbag. A second acceleration peak occurred as the subject loaded both the belt and the airbag. A similarly restrained driver-side subject loaded the belt and airbag concurrently at the time of peak chest acceleration and therefore did not exhibit this biomodal chest acceleration. While the injury-causing or injury-mitigating significance of this bimodal response is not known, its significance with respect to thoracic injury prediction is discussed.