A Bi-Objective Vehicle Routing Problem with Time Windows Considering Fuel Consumption and Co2 Emission

In this research, a new bi-objective routing problem is developed in which a conventional vehicle routing problem with time windows (vrptw) along with its environmental impacts and heterogeneousvehicles is considered. in this problem, minimization of fuel consumption(liter) as well as reduction of the length of the routes (meter) are themain objectives of this study. therefore, a mathematical bi-objectivemodel is solved to create pareto's solutions. the objectives of theproposed mathematical model are to minimize the sum of distance costsas well as fuel consumption and co2 emission. then, the proposedmixed-integer linear program (milp) is solved using the ε-constraintapproach. furthermore, numerical tests are performed to quantify thebenefits of using a comprehensive goal function with two differentobjectives. managerial insights and sensitivity analysis are alsoperformed to show how different parameters of the problem affect thecomputational speed and the solutions’ quality.