Freight Transportation

In this presentation, I have defined the concept of the freight transportation from one of my recent studies titled "The Integrated Multi-Tier Hierarchical Hub Location and Scheduled Service Network Design Problem". This paper presents a comprehensive study of a freight transportation system that utilizes a multi-tier hierarchical hub network integrating air, rail, and highway transportation modes. The network is structured with top-level primary hubs, middle-level secondary hubs, and bottom-level service nodes, all interconnected through scheduled services designed to meet time-sensitive demands. The study aims to determine the optimal locations and capacity configurations for both primary and secondary hubs as the hierarchical hub location (HHL) problem. This paper also selects the scheduled services within this multi-tier hierarchical network as the scheduled service network design (SSND) problem. The core contribution of this research is the development of an arc-based optimization model using a mixed-integer program for the integrated multi-tier hierarchical hub location and scheduled service network design problem (HHL-SSND).