Optimal Routing Problem in Dynamic Stochastic Networks

Abstract

Accidents, bad weather, traffic congestion, etc. contribute to the uncertainties of travel times in real-life transportation networks, which greatly affect the quality of individual life and the reliability of transportation system. In this paper, optimal routing problem is addressed in dynamic transportation networks with random link travel times. Taking the reliability of travel time into consideration, the robust schedule delay is used as the criterion of optimality to evaluate the paths, which is defined as minimizing the largest difference between the actual arriving time and the desired arrival time in dynamic stochastic networks. Under the stochastic consistent condition, a mathematic proof is given to simplify the problem. Then an exact modified Dijkstra's algorithm is designed for finding the optimal routing in STD networks and its computation complexity is calculated as a polynomial-time o(n2 *e). The validity of the proposed algorithm is also confirmed by conducting a test in a sampled network.