Citation

Cafiso S, Di Graziano A. Transp. Res. Rec. 2011; 2237: 20-30.

Copyright

(Copyright © 2011, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

10.3141/2237-03

PMID

unavailable

Abstract

Safety management of the local rural road network is often constrained by low budgets and a variety of external local requirements. Moreover, for the safety management of these roads, where a screening of the network based on observed crashes can be affected by a lack of quality and an insufficient quantity of collision data, alternative analyses are needed to establish those circumstances that make a particular road intervention cost-effective. Cost versus safety trade-offs must be examined for a series of alternative projects. As a result of a research project funded by the European Commission, a safety index (SI) was formulated as a surrogate measure of safety. The SI is based on the safety features of the road segment, which are assessed by two methodologies: road safety inspections and design consistency evaluations and standards checks. Given the significant correlation found between SI values and the expected number of crashes, a methodological approach that uses the SI to evaluate the safety effectiveness of the alternative proposed investments is presented. Moreover, because often the available budget was not sufficient to undertake all alternative projects evaluated as being effective, a formal method for selecting projects to be included in the budget was applied to maximize the safety benefits of the investments. The procedure implemented in the SAFOPT software (safety optimization) makes it possible to identify the intervention strategies that produce the greatest safety benefits for variations in the SI while being compatible with the available annual budget, that is, the optimum budget to obtain the maximum benefit.