Network externalities are the unpaid advantages that users of an interactive network benefit from when the number of network subscribers increases. Hitherto, as far as economic theory is concerned, this concept has mostly been applied to demand model aiming to account for the increasingly widespread phenomenon of new interactive telecommunications technologies. Drawing inspiration from the current literature in telecommunications networks, this article investigates the hypothesis of forming network externalities in the field of combined transport. Indeed, applying demand models with network externalities to combined transport would probably allow a better theoretical interpretation of this market, and lead to a number of practical suggestions. The widespread occurrence of network externalities, which would be achieved through state policies aiming to strength network connectivity, could be a precondition for a significant expansion of this new sector, which will augurably reconcile freight transport and environmental protection.
