Loop-Based Maritime Transport Optimization in Swedish National Freight Transport Models

This study addresses enhancements to the Swedish national freight transport model, Samgods, focusing on improving its maritime transport modeling capabilities. The current model faces challenges in accurately representing maritime transport due to its limitations in consolidation of diverse cargo types, and modeling indirect sea routes. We propose an advanced model using a mixed integer linear programming (MILP) technique to integrate transport loops, thereby increasing the model’s efficiency and realism in depicting maritime transport scenarios. A case study on the shipping of forest products from Northern Sweden to Western Europe illustrates the method’s effectiveness. Introducing transport loops into the model results in a $10-21\%$ reduction in logistics costs and a $2-4 \%$ increase in the utilization of maritime transport. The fleet composition also changes to more resemble real world data. These findings highlight the importance of loop structures in accurately capturing the full benefits of maritime transport in freight transport modeling.