Impact of Generalized Travel Costs on Satellite Location in the Two-Echelon Vehicle Routing Problem

In this paper we address the Two-Echelon Vehicle Routing Problem (2E-VRP), the variant of VRP where freight is delivered from depots to intermediate satellites, and then it is delivered to customers while minimizing the global routing costs of the overall two-echelon network. The goal of this work is to address more realistic situations in urban freight delivery where the travel costs are not only given by distances, but also by other components, like fixed costs for using the arcs, operational costs, and environmental costs. We introduce a generalized travel cost that may combine different components, e.g., operational, environmental, congestion, etc. We then analyze how the different components of the generalized cost affect the satellite location in the 2E-VRP and whether and under which conditions the Two-Echelon approach dominates the Single-Echelon one.