Analysis of Imprecise Perception in Route Choice Considering Fuzzy Costs

In this work we describe a path choice model in which costs are represented by fuzzy numbers in order to consider uncertainty of users and trying to overcome some limits of well know logit based choice models. Users’ estimation costs in order to choice a route over a road network is made in a real uncertain, imprecise and ambiguous environment. As suggested by research in this field, fuzzy numbers is a suitable framework to model such choice context. In this paper, we analyse path costs represented by Fuzzy Numbers. For the fuzzification of the crisp value of the cost we introduce a parameter, that aims at representing the imprecision of users in path cost perception. We assume that users associate a preference index to the paths according to the estimated costs and that the probability of choice of a path is proportional to the preference index. Moreover, we introduce an index for evaluating the overlapping degree of each path with the others. In this way, we overcome the problem due to the Independence from Irrelevant Alternatives (IIA) of Logit based models, which rises for overlapping paths. The method allows to reproduce user choices as compared to other well established ones.