Understanding the economics and the wider impact of transport infrastructure presents a major challenge to economists. The scale of investment, indivisibilities, the settling of appropriate charges and the rate of economic growth are problems which require analyses and create controversy. Further contentious issues are the need to rely on public sector finance and certain ambiguities concerning impact on productivity. This authoritative collection of previously published papers presents a selection of the developments in a field which is still attracting new ideas and challenging transport planners and governments in both the developed and developing world, and indicate something of the diversity of analysis needed and the problems which remain.