Travel Time Reliability-Based Optimal Path Finding

A heuristic solution algorithm for travel time reliability-based path finding problem is proposed in this paper. Due to network uncertainties, the travel times are not deterministic and suffer from fluctuations. Under this circumstance, traditional optimal path methods based on least expected travel time can not capture the network user´s risk-taking behaviors in path finding. In reorganization of this limitation, the definition of effective travel time is introduced to take into account travel time reliability issue. Then, the optimal path defined in this paper is to find the path with minimum effective travel time. Due to the non-additive property of the effective travel time, the optimal path is difficult to find unless enumerate all the paths. To avoid path enumeration while finding the optimal path, the k-shortest paths algorithm is adopted to generate a path set by iterations. This path set is generated in an attempt to include the optimal path. Then, the optimal path can be easily found in such path set. A numerical example is carried out to show the applications and efficiency of the proposed algorithm.