Multi-depot vehicle routing problem with split delivery and traffic restriction: Variable neighborhood search algorithm

The purpose of solving the problem of vehicle routing is to find a suitable route taking into account the existing conditions in the transportation problem. In this case, considering the routing conditions with several depots along with imposing traffic restrictions on some vehicles on some routes, will create quite real and complex conditions. Furthermore, in some cases, it is necessary to deliver the customer demand by visiting several times. For this purpose, in this research, by simultaneous considering of multiple depots, split delivery and traffic restrictions, it has been tried to bring the conditions of the routing problem very close to real-world problems. In this paper, after presenting a mathematical model, the problem is solved in small-size instances using CPLEX solver. Then, due to NP-Hardness of considered problem, to solve it on a larger size instance, a variable neighborhood search algorithm is proposed. Finally, the simulated annealing algorithm is used to validate and evaluate the quality of the proposed algorithm. The computational results show that the proposed algorithm has good performance in terms of runtime and solution quality.