Container movement by trucks in metropolitan networks: modeling and optimization

Container movement by trucks with time constraints at origins and destinations is modeled as an asymmetric ‘‘multi-Traveling Salesmen Problem with Time Windows’’ (m-TSPTW) with social constraints. A two-phase exact algorithm based on dynamic programming (DP) is proposed that finds the best routes for a fleet of trucks. Since the m-TSPTW problem is NP-hard, the computational time for optimally solving large size problems becomes prohibitive. For large size problems, we develop a hybrid methodology consisting of DP in conjunction with genetic algorithms. The developed algorithms are compared with an insertion heuristic method. Computational results demonstrate the efficiency of the developed algorithms. 2004 Elsevier Ltd. All rights reserved.