Analysis of Roadside Safety Devices for Use on Very High-Speed Roadways

摘要

The Texas Department of Transportation (TxDOT) is embarking on a multi-decade effort to expand the states transportation system. TxDOT has expressed an interest in using very high design speeds (above 80 mph) for some of these facilities to promote faster and more efficient travel within the state. Currently, roadside safety hardware is tested at a speed of 62 mph. This impact speed was derived from crash data collected on roads with design speeds up to 70 mph. The ability of existing roadside safety features to accommodate more severe, higher energy impacts is not known. The objective of this research is to develop roadside safety hardware suitable for use on very highspeed highways. Finite element simulations are used to evaluate the impact performance of selected roadside safety devices subjected to very high-speed impacts. Systems analyzed include single slope concrete barrier, modified thrie-beam guardrail, box beam guardrail, and slip-base sign supports. Design modifications to some of these systems are recommended for further consideration.