The trans-European transport network has different effects at inter-regional, macro-regional and mezzo-regional level, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. In that respect the brief review of surveys, strategic framework and policies in the European Union has been given. The importance of increased accessibility and mobility for regional expansion and for a more balanced and polycentric system of city networks has been underlined. The question is how the new major transport infrastructure affects the development of functional complementarity between cities and regions. The new trans-European or major transport infrastructure does not per se create regional and urban system network development, although it can affect the conditions for the processes that create growth and development. The effects can be reinforced by co-ordination of measures of regional and urban policy, land use, transport and other policies. The necessary measure is the introduction of spatial impact assessment as an instrument for spatial assessment of large transport infrastructure projects.