A new mathematical model for time window green vehicle routing problem with backhauls

Recently amounts of fuel consumptions and carbon dioxide (CO2) emissions leave quite a few of harmful marks on the environment and human mental and physical health. The experts believe that the amount of fossil fuels used in transportation systems, particularly in distribution and supply sections has a significant role in the growth of CO2 emissions and fuel consumptions rate. Hence, great deals of organizations propose to apply new approaches to reduce the amount of CO2 pollution and fuel consumptions in order to improve their systems which are able to conserve the environment and optimize their economic performance simultaneously. This paper introduces a new time window backhaul green vehicle routing problem (TWBGVRP) to attend to environmental and economical issues all at the same time. For this purpose, a mixed integer linear mathematical model (MILP) is represented that not only think over minimizing travel distance ,total travel time ,and average loads carried out, but also consider the velocity as an important factor effecting on the objective function value.