Review on the comparison of external costs of intermodal transport and unimodal road transport

Abstract

Due to the continuous growth of freight transport, external costs caused by transport are rising. Road transport is the main contributor to these external costs. Alternative, more environmentally friendly transport modes, like barge and rail transport, often lack the opportunity to offer door-to-door transport services. Through the combination of several modes of transport, intermodal transport could provide a solution to overcome these issues. Combining barge or rail transport with road transport assures the flexibility which is needed to offer door-to-door services. Besides, intermodal transport is often assumed to be more environmentally friendly than unimodal road transport. Comparing the external costs from intermodal transport with those of unimodal road transport is however not straightforward. Intermodal transport involves several activities, which all have to be accounted for. Furthermore, external costs are very dependent on the situation in which they are caused and calculations are subject to large uncertainties. This paper offers an overview on how external costs of intermodal transport and unimodal road transport may be compared. First, a brief review on the calculation and comparison of external costs of transport is given. Next, two key models for the comparison of intermodal transport and unimodal road transport are discussed. Finally, a sensitivity analysis is performed on the second model. Key parameters for increasing the competitiveness of intermodal transport regarding external costs, are determined.