Minisized Automobiles and Roadside Appurtenances

Abstract

The effectiveness of roadside safety appurtenances under impact with minisized automobiles is investigated. The vast majority of existing roadside hardware have been qualified under guidelines which have not considered vehicles in this light weight range. Since the numbers of these minisized vehicles are increasing dramatically with this trend expected to continue, the potential problem areas are significant. They are shown to include excessive occupant‐vehicle interior velocities and ridedown accelerations along with vehicle dynamic instabilities. It is demonstrated that mini‐cars are much more susceptible than full‐sized automobiles to these unstable modes of behavior when subjected to eccentric impact loading. The prospects for improving existing highway appurtenances and developing new families of these devices to more effectively meet new FHWA guidelines are examined. Considerations of cost, site dimensions, variation in vehicle size, shape, and weight, and their individual effects on crash cushion performance and design are discussed.