This study presents a mathematical model for time-dependent multi-depot heterogeneous fleet green vehicles routing problem. Objective function of the proposed model includes the vehicle fixed cost, driver cost, fuel cost, and greenhouse gas emission. Fleet composition, load, vehicle speed, road slope, and traffic are considered as factors affecting the produced pollution. The presented problem is based on the use of a heterogeneous fleet and presence of multiple depots. Considering the NP-Hard complexity of this problem, a meta-heuristic algorithm based on improved adaptive large neighborhood search is proposed as the method of solution. Comparison of the results obtained for a set of problem instances by the proposed metaheuristic method and the basic adaptive large neighborhood search show the good performance of the proposed algorithm. Finally in order to investigate the effectiveness of the proposed model, A case study in Isfahan was considered; results show about 29.63% reduction in fuel consumption.
