Transport and gross domestic product have grown at roughly a one-to-one relationship in the past. Many decision-makers consider the supply of transport infrastructure an important ingredient in fostering productivity and economic growth; some even consider it a prerequisite. This article analyses the various causal links from transport to economic growth and puts their empirical significance in perspective. The more important challenge for current transport policy, however, is found to be that concerning the reverse linkage, i.e.—given a growing economy—how can we develop a transport system that does not then erode the benefits it created in the first place? Finally, and to that end, a possible future system of sustainable access and mobility service is characterized and policy conclusions are drawn.