Branch-and-cut for the Mixed Fleet Green Vehicle Routing Problem

Several logistics companies have started introducing electric vehicles into their operating fleet to reduce the environmental impact of their operations.

However, limited driving range, high acquisition costs, and long recharging times often hinder a full substitution of an existing fleet to this green alternative. Hence, companies tend to gradually introduce electric vehicles into their existing fleet.

In our work, we consider the Mixed Fleet Green Vehicle Routing problem that concerns the planning of distribution routes for a fleet of internal combustion engine vehicles and electric vehicles with the aim of overcoming vehicle specific limitations.

To solve the problem, we propose an exact branch-and-cut algorithm and suggest several new inequalities on energy consumption and route duration to speed up resolution and ensure that no electric vehicle is left stranded with a depleted battery.