A simulated annealing heuristic for the truck and trailer routing problem with time windows

In this study, we consider the application of a simulated annealing (SA) heuristic to the truck and trailer routing problem with time windows (TTRPTW), an extension of the truck and trailer routing problem (TTRP). TTRP is a variant of the well-known well-studied vehicle routing problem (VRP). In TTRP, some customers can be serviced by either a complete vehicle (that is, a truck pulling a trailer) or a single truck, while others can only be serviced by a single truck for various reasons. In some TTRP applications, each customer has a predetermined time window for taking services. This problem is called the truck and trailer routing problem with time windows. It can be easily verified that the vehicle routing problem with time windows (VRPTW) is a special case of TTRPTW. Thus TTRPTW belongs to the class of NP-hard problems and it is natural to tackle this problem with heuristics approaches. Simulated annealing (SA) has seen widespread applications to various combinatorial optimization problems, including the VRP. Therefore, we developed an SA based heuristic to solve TTRPTW. To our best knowledge, there are no benchmark instances for TTRPTW in the literature. Therefore we converted 12 Solomon’s VRPTW benchmark problems into 36 TTRPTW benchmark problems and tested our SA heuristic on them. Computational study indicates that SA is capable of producing high quality solutions to TTRPTW within reasonable time.