The article looks at some elements of economic theory and state intervention in the field of infrastructures and transport, showing the importance of the political dimension in decisions which are generally considered to be technical. Some critical considerations are made, on the transport sector in particular, on competitive potential and practical effectiveness. More specifically, the regulatory problems posed by the liberalisation of some sectors are evident in the Italian experiences examined. The discussion on the choice of different governance instruments highlights the technical and political importance of direct public intervention in the regulation and delivery of incentives and disincentives