Guardrail End-Types, Vehicle Weights, and Accident Severities

Abstract

A study of guardrail end accidents on the Oklahoma State Highway System (1988–91) examined the severity of exposed and turned-down guardrail end accidents in relation to the type of end, vehicle weight, and vehicle rolling and/or vaulting. The data showed that lightweight vehicles and turned-down ends were associated with increased rolling and/or vaulting. Rolling and/or vaulting was associated with increased accident severity. A direct interaction among end-type, vehicle weight, and accident severity was not present; however, the interaction among end-type, vehicle weight, and rolling/vaulting was statistically significant. In terms of the resulting injury and death, the overall performance of the turned-down ends was no better than the exposed ends that they had replaced.