Multimodal transportation network for bio-waste collection: the case of Normandy

In this paper, we introduce a new topology, connected-hubs, to the multimodal transportation literature. As strategic planning, the multimodal transportation network design decides the locations of consolidation centers and the routes between the origins and the destinations with the minimum of total cost. Most existing papers formulate the problem based on the hub-and-spoke topology, while our work is the first attempt to apply the connected-hub topology, which considers local consolidation by vehicle routing and extends some widely-used assumptions in the hub-and-spoke topology. A mathematical model is developed to formulate and solve the problem to optimality. Further, considering the problem complexity, a particle swarm optimization (PSO) algorithm is also proposed to generate efficient solutions for large-scale cases. The results of a case study in Normandy, France illustrate the efficiency and practicability of the proposed PSO in terms of economic and environmental sustainability objectives.