Design and optimisation of an innovative two-hub-and-spoke network for the Mediterranean short-sea-shipping market

Short Sea Shipping (SSS) is generally considered as a privileged transport mode in terms of reducing road congestion and related external costs. In the last two decades, SSS has attracted a lot of attention in the European Union, where it is also regarded as a key factor for economic and social cohesion between countries. In this regard, the present study proposes a new network design that aims at improving and increasing freight traffic between the north-western and the south-eastern shores of the Mediterranean Basin. The proposed model, designed for Ro-Ro (Roll-on Roll-off) freight transport, tries to overcome the limits of the existing multi-port-calling services through an innovative two-hub-based scheme of better scheduled and reliable frequencies and more competitive delivery times. The operating parameters of the new network are determined using a specially designed optimisation approach based on two separate but related mathematical models: a Mixed Integer Linear Programming Model for Service Frequency Selection and a Mixed Integer Linear Programming Model for Service Timetabling. Numerical tests, performed on real demand and supply data covering 23 ports in 8 Mediterranean countries, show the validity of the proposed approach to determine an optimal network configuration for the organisation of transport services in the area.