Roadside Safety Analysis Program as a Tool for Economic Evaluation of Roadside Safety Projects

Abstract

Highway agencies are continually called upon to make decisions about roadside safety projects by considering their relative benefits and costs. ROADSIDE software is a tool developed in the late 1980s for costeffectiveness analysis of safety features and has been used by different highway agencies. As a part of the continuing effort to improve such costeffectiveness procedures, the Roadside Safety Analysis Program (RSAP) has recently been developed at the Texas Transportation Institute. RSAP uses a simulation technique to replicate single-vehicle accidents on a highway facility and can test the effectiveness of the various countermeasures that are used to reduce the severities of these accidents. The application of RSAP to actual case study sites and the outcome of a study recently conducted at Wayne State University are described. Various median treatments on freeways were tested, and their respective benefit-cost ratios, as estimated by RSAP output, were examined. A set of sensitivity analyses of the RSAP output to various input parameters was also conducted. It is found that RSAP is user-friendly software and is fully operational on a personal computer with a Pentium processor in the Windows 95 environment. RSAP provides a summary of the accidents predicted for each scenario tested, and those are segregated by each feature coded along with its respective severity and cost. The economic analysis procedure is based on strong analytic principles, and the results are sensitive to accident cost, cost of construction, and interest rate. The software output is generally sensitive to the input parameters, and the trends appear to be logical. Additional research to calibrate the accident prediction model with historic accident data at the project site will be highly desirable.