A Decision Support System based on Electre III for safety analysis in a suburban road network

The aim of this paper is to develop a methodological procedure for supporting decision makers in transport planning. The methodology is adopted for evaluating safety conditions in a road infrastructure. Public administrations need to reduce road accidents and injuries, so as to reduce the social costs of transport. However dwindling financial resources for road maintenance call for targeted interventions to achieve the best results, optimizing resources for the most critical sections. In this analysis, the multicriteria method Electre III is used, a ranking procedure applied in the specific case to a suburban road system. The analysis provides some indications for choosing and ranking the most critical sections of the network. The safety conditions of an infrastructure of roads can be determined as a function of accidents, injuries, fatalities and exposure to risk and depend on road and traffic characteristics. In this analysis safety conditions for each road section are measured on the basis of several criteria including number of accidents, state of road maintenance, curvature, grade, access-point density. Values of the criteria are obtained from on-site measurements. This analysis is based on a comparison of criteria and alternatives. It identifies priorities for safety interventions. The road sections have been hierarchically ranked, according to the priority of interventions for improving safety conditions.