Conceptual framework and environmental issue in the freight transport system

There have been fundamental changes in the roles of seaports as key nodes in the urban freight transport system, as maritime traffic grows significantly. To plan and manage the urban freight transport system effectively, it is very important to understand port decisions and interactions. Major stakeholders are shippers, carriers (i.e. ocean carriers, land carriers and port terminal operators) and Port Authorities in the freight transport system. The paper provides a conceptual framework that defines their distinctive roles and relationships in today’s global shipping market place. Then, freight network models to capture the optimal decision making process of the stakeholders are categorized by modeling methodologies and techniques with updated taxonomy. Finally, environmental issues in decision making are discussed due to increasing air pollution caused by freight shipping. A general equation for estimating port emission is proposed and modified equations of the cost functions for the carrier and shipper problems are suggested by considering the environmental cost additionally. The research provides useful insights and guidelines for future modeling directions and challenges.