Light vehicle occupant ejections--a comprehensive investigation

Occupant ejections, about 1.5% of all crash-involved occupant events, are relatively infrequent but very harmful events in highway crashes of light vehicles, including cars, pickup trucks, vans, and multipurpose vehicles (utility vehicles, jeeps, etc.). The disparity between frequency of harm to ejectees and ejection frequency is at least one order of magnitude. Partial ejections, although less frequent, have an incidence that is comparable to that of complete ejections, except for restrained occupants, where complete ejections are very infrequent. Notwithstanding the high effectiveness of safety belts in preventing ejections, and the multifold growth of safety belt use in the last 10 years, there is no detectable reduction in the ejection rate in the same period. Ejections per se and not other pre-ejection occupant impacts are responsible for the bulk of the harm to ejectees. Furthermore, ejected occupants sustain harm much larger than that which would have occurred, had these occupants not been ejected. "Closed glazing" is the leading ejection path. "Doors" and "windshield" are distant seconds. All glazing except the windshield fail overwhelmingly by disintegration. Latch failure is the primary mode of failure in opening doors. Hinges and other modes of failure are relatively minor concerns. The sources of data in this investigation are: the National Accident Sampling System for the years 1988 to 1991, and the Fatal Accident Reporting System for 1982 to 1992.