Roadside safety improvment programs must compete with other highway construction and maintenance programs for limited funds. As emphasis on roadside safety increases, the need for methods by which administrators may evaluate alternative safety improvements becomes apparent. This paper concerns the develpment of an implementable procedure for evaluating safety improvements for hazards along controlled- and non-controlled-access rural highways by using a general computerized analysis model to accommodate both. A cost-effectiveness conceptual model developed in a recently completed NCHRP research study provides the basic technique for comparing recommended safety improvements. The conceptual model, developed specifically for freeway evaluation, was extended to accommodate non-controllled- access roadways, and the implementation procedure was developed to fit the particular needs of the Texas Highway Department. The implementation procedure comprises three functions: conducting a detailed inventory of a highway to locate and define each roadside hazard, recommending feasible safety improvement alternative for each hazard or group of hazards, and evaluating the recommended alternatives by using the computer model. A hazard inventory form on which to record information regarding the existing hazard and a hazard improvement form on which to record suggested improvements were developed. The data from these forms are transferred to computer cards to provide the necessary input information for cost- effectiveness analysis of the safety alternatives. Each phase of the procedure is discussed including composition of inventory team, methods to locate existing hazards, details of the two data forms, operation of the computer analysis model, and interpretation of the analysis results. Also included are case examples illustrating typical analysis results.
Samenvatting