Vehicle accidents are a major worldwide health problem. One cost effective way of reducing serious injuries and fatalities due to collisions with fixed roadside hazards is to use impact attenuation devices. The difficulty is that damaged crash cushions take time to repair, and in the intervening time there is danger to the motoring public and the risk of lawsuits against the transport authority concerned. The paper describes the development of a new family of reusable, self-restorative and very low maintenance crash cushions. Kinetic energy (KE) is dissipated through the collapse of laterally loaded cylinders made of high molecular weight/high density polyethylene. The favourable properties of this material are high stiffness, abrasion resistance, chemical corrosion resistance, moisture resistance, ductility, toughness, tensile strength and impact resistance over a broad temperature range. The HMW/HDPE cylinders can therefore dissipate large amounts of KE, undergo significant deformations and strains without fracturing, and regain their original shapes and energy dissipation potential on removal of load. They are made in 70, 88.5 and 100 km/h versions. Highway safety devices are widely used and very effective, and have saved thousands of lives over the past 25 years. Their life cycle costs are however very high. These reusable crash cushions have a tremendous legal, financial and safety potential.
Abstract