This paper develops a model for analyzing the potential of longer and heavier vehicles (LHVs) related to pre- and post-haulage in the intermodal rail-road transport chain (IRT). The paper considers the combined economic and emission costs among three different transport networks including intermodal rail-road transport with current Swedish regulatory framework for trucks, intermodal rail-road transport with LHVs, and direct-road transport. The objective is to analyse the potential of high-capacity transport associated with pre- and post-haulage for enhancing the competitiveness of intermodal transport from a full-costs perspective. The model developed is applied to a Swedish context and case study. Research findings reveal that the break-even of the IRT compared to the direct road transport could be significantly lowered, which suggests the LHVs contribute to exploring the market of IRT over smaller flows.