A New Estimation of Road Safety Index in Transportation Systems with Fuzzy-DEA Method: A Case Study on Roads of East Azarbaijan Province in Iran

Road safety problem is an important issue which is always considered as one of the main benchmarks to assess growth and development in many countries. Many factors influence in calculating the road safety index. In the past, for calculating the road safety index, all factors affecting road safety were considered as desirable indicators. In this paper, the road safety factors are considered in two categories: desirable and undesirable indicators. Moreover, the observed values of the factors affecting the road safety index in practice are sometimes uncertain. In this study, fuzzy data envelopment analysis method is applied to calculate and evaluate road safety index. A generalised fuzzy index-maximising model is proposed to obtain an optimal road safety index, in which the optimal index is obtained as the maximum value of sum of weighted desirable–undesirable factors. In addition, the problem of ranking of the roads is investigated with regard to the optimal composite index. In order to rank the roads, a new index is suggested that discriminates the efficient roads. Finally, the proposed method is applied to evaluate the safety problem for a case study on the roads of East Azarbaijan Province in Iran.