This paper inquires into the main characteristics of supply side public policies, and their effects on interurban rail demand. Investment in highways and motorways has solved a great deal of congestion problems on interurban roads. Moreover, it has increased their potential speed. These changes have affected the intermodal structure of travel time costs and have greatly contributed to the decrease of interurban rail demand. In this way, the transport policy has generated undesired results. Hence, the analysis shows that the absence of intermodal planning of transportation infrastructures and mass services increases the global costs of the transportation system. Therefore, it is concluded that introducing an intermodal view when planning facilities and services is needed to optimize the results of investment in infrastructures and to improve efficiency in the transportation system.

Keywords. intermodality, transportation demand, transportation infrastructure, time costs of travel.