Road intersection ranking for road safety improvement: comparative analysis of multi-criteria decision making methods

The aim of this paper is to propose a methodology for identifying the most critical road sections in urban networks in terms of road safety. This approach is useful for the managers of the road network when they need to allocate limited financial resources to several critical sections. Since the resources are not always sufficient to solve all road safety issues, they require a methodology that is able to rank the critical sections. Road safety depends on the interaction of several factors so this methodology has to be based on a multicriteria approach. In earlier articles, the authors of this paper first adopted Electre III and later Concordance Analysis as multicriteria methods for ranking critical points in an urban road network. Both methods have some critical elements, associated with threshold choice (Electre III) and ranking procedure (Concordance Analysis). In order to improve the methodology, the authors have selected two further multicriteria methods (Vikor and Topsis), for comparison with the Concordance Analysis and for evaluating which performed best. In order to identify critical sections in a road network, a suitable set of indicators is defined, taking into account geometric and traffic volume criteria. The multicriteria methods are applied to a real case for ranking, from the worst safety conditions to the best, the most critical road intersections within the urban road network, on the basis of eight criteria. The results of all three methods considered are compared and a sensitivity analysis is performed to test the stability of the results. The results show that the Topsis method performs best in determining a complete ranking of the critical road sections, overcoming some negative aspects associated with the other methods.