Trade-Off between Carbon Dioxide Emissions and Logistics Costs Based on Multiobjective Optimization

This paper examines the relationship between the freight transport costs and the carbon dioxide (CO₂) emissions in given intermodal and truck-only freight networks. When the trade-off, which is represented as the relationship, is changed, the freight mode share and route choice are also modified. To show the ever changing trade-off and mode and route choice, a decision-support tool was developed. The given intermodal freight networks represent different freight combinations (i.e., a truck-only system, a rail-based intermodal system, and a short sea-based intermodal system). Because CO₂ constraints in logistics markets will need to be realized in the near future, a modal shift in freight transportation could be expected to reduce the CO₂ emissions within the reasonable cost and time constraints. The technique of multiobjective optimization is used as the core of the decision-support tool for clarifying the relationship. The tool that was developed is applied to a simplified freight transport network connecting two large European ports: the Port of Rotterdam (the Netherlands) and the Port of Gdansk (Poland). The initial solution, based on the minimization of freight costs, shows that the mode share of freight is local and regional freight transportation situations, whereas the other solutions balanced with CO₂ emissions show that the mode share is changed into an intermodal freight system, which is based on a hub-and-spoke network. In considering the changing demands and capacities of freight systems, five scenarios are tested to examine the impact of mode and route change on the trade-off. The results of scenario analyses show that the trade-off is significantly influenced by the demands and capacities of systems.