THE GENERAL EFFECTIVENESS OF COUNTERMEASURES FOR CRASHES INTO FIXED ROADSIDE OBJECTS

This study aimed to evaluate treatments implemented to address the problem of crashes into fixed roadside objects, in terms of casualty crash occurrence, costs, and economic worth. The results may help set priorities to further improve the return on future road safety investments. Over 250 countermeasures for crashes into fixed roadside objects, undertaken in Victoria since 1989, were evaluated. Analyses were divided into several distinct levels to provide a comprehensive evaluation of various treatment types, both individually and when aggregated. For the sample of treatments evaluated, casualty crashes and costs were reduced by nine percent and 16 percent, respectively, and a benefit/cost ratio of 4.1 was achieved. Changes to horizontal road geometry reduced casualty crashes by 44 percent, while large-scale shoulder sealing reduced casualty crashes and costs by 32 percent and 37 percent, respectively. Several other results approached statistical reliability and should therefore be considered indicative only at this stage. These results have both immediate and medium-term implications for existing strategies for roadside safety. They suggest existing strategies should give increased emphasis to the highly effective treatments, such as shoulder sealing, improved horizontal road alignment and skid resistant pavements. Further critical assessment of selected other treatments is recommended before they form a significant part of future roadside safety strategies. A number of opportunities for further strategic improvements are also recommended. (a)