Abstract
This paper explores the limits of transportation planning according to the following criteria: (1) the relation between transport and spatial planning; and (2) the relation between research and policy. Firstly, the paper gives an overview of some inadequacies concerning the application of both traffic and transport research results in policy. The following five factors are important to improve both relationships: (I) integration; (II) marketing; (IIi) tuning; (IV) extending the frontiers; and (V) organization. Finally the paper discusses the desirability of the integration of transport and spatial planning.