The present report results from the study of 278 computer selected among 350 in-the-field frontal crashes investigated by a bidisciplinary team.The study has 2 aspects: I . Computer analysis, to determine the main injury-causing agents . Injury-causing factors, to determine the influence of various inner parts of the vehicle (i.e. instrument panel, windscreen, steering assembly, restraint system) II . Case-by-case analysis of injury-causing mechanisms stressing towards the precise determination of the injury-causing mechanisms induced by the injury/impact relationship. Our purpose is to lead to a better understanding of the injury-causing agents and mechanisms going with traffic accidents.