[en] In its White Paper on Transport, the European Commission recognizes intermodal transport as an alternative solution to road transport. In practice, intermodal transport can be constituted by any combination of modes, while in the literature, intermodal transport is often modeled as a combination of modes in the order “road-rail/inland waterway-road”. This work develops a new intermodal allocation model which allows choosing between any direct (road, rail and inland waterways) transport and any intermodal transport chain constituted by up to three modes of transport. Intermodal solutions can pass through one or two intermodal terminals. Applied on experimental data at the European level, the model gives insight on the optimal flow distribution for economic objectives (optimization of transport operational costs) and environmental objectives (optimization of transport CO2 emissions and air pollution external costs). Results highlight that the traditional modeling of intermodal transport as a “road-rail/inland waterway-road” combination better fits economic than environmental objectives.