Multi-Echelon Distribution Systems in City Logistics

In the last decades, the increasing quality of services requested by the customer, yields to the necessity of optimizing the whole distribution process. This goal may be achieved through a smart exploitation of existing resources other than a clever planning of the whole distribution process. For doing that, it is necessary to enhance goods consolidation. One of the most efficient way to implement it is to adopt Multi-Echelon distribution systems which are very common in City Logistic context, in which they allow to keep large trucks from the city center, with strong environmental advantages. The aim of the paper is to review routing problems arising in City Logistics, in which multi-echelon distribution systems are involved: the Two Echelon Location Routing Problem (2E-LRP), the Two Echelon Vehicle Routing Problem (2E-VRP) and Truck and Trailer Routing Problem (TTRP), and to discuss literature on optimization methods, both exact and heuristic, developed to address these problems.