Coordinated vehicle platooning on tree networks: Efficient time discretization and strengthened formulation

We consider the coordinated vehicle platooning problem on a tree network with time constraints while the routes of vehicles are given. The problem is to coordinate the departure time of each vehicle to enable platoon formation hence maximizing the total fuel saving. For this problem setting, relative time windows can be defined for all vehicles to which an efficient time discretization can be applied. This property leads to a tight mixed-integer linear program reformulation as compared to the continuous-time formulation involving big-M coefficients proposed in our previous work. It is demonstrated by systematic numerical experiments that the reformulation outperforms the continuous-time formulation for this family of problem instances. Our study hence extends upon the results of Boysen et al. (2018) from the case of a single-path network to a tree network.