A literature review on hub location-routing models and their solution techniques

Hub location problems (HLPs), which essentially aim at optimizing the location of hubs and the allocation of spokes to satisfy a given demand, have been studied over nearly four decades. Since dedicated allocation connections between each spoke and its hub may increase the operating cost and underutilize the vehicle capacity, especially in less-than-truckload freight service applications, the last ten years have witnessed an increasing interest of researchers in hub location routing problems (HLRPs). HLRPs involve a more comprehensive approach, by considering both facility location and vehicle routing aspects simultaneously, also optimizing the assignment of customers to these hubs and finding the best routes from hubs to customers, making HLRPs more complex and practical for real-world logistics and distribution scenarios than HLPs. In this paper, we review the HLRP models proposed in the existing literature, the commonalities and differences of developed solutions techniques, particularly concerning the computation of incumbent solutions and neighborhood changes. We believe that our study contributes to the existing literature, by unifying the rather scattered publication landscape on HLRPs and proposing a set of interesting directions for future work.