Road infrastructure planning for CO₂ reduction using mathematical optimization

In this study, we address a road infrastructure planning problem by relieving traffic congestion and thereby reducing CO₂ emission. We model it as a mathematical optimization problem whose objective is to minimize the total travel time by improving road-infrastructures under the given budget. We take into account the interactions between vehicles at road intersections. By introducing an approximation technique for the interactions, the proposed model is practical in terms of both computational time and accuracy of the obtained planning. Computational results show that the obtained optimal plan for the improvement of road-infrastructures significantly reduces CO₂ emission.