Substantial investment has been made at national and European level in transport infrastructure over the last fifty years and is likely to continue in the future. The need to appraise transport projects in economic and social terms has developed alongside this in both scope and complexity. The state of the art of the economic appraisal of transport projects, progress and future challenges are reviewed. National practice in Western European countries varies substantially reflecting a range of cultural and economic differences. Some points of commonality exist and the principle of monetising direct transport impacts is generally accepted. Progress has been made towards the measurement of environmental impacts, but the assessment of the wider impacts remains underdeveloped. Increased sophistication and complexity has brought increasing data and presentation requirements, where computerised decision support methods have potential. Many challenges exist for the future of appraisal and some key issues are discussed. At the heart of these is the continuing debate between the relative roles of national and European government in decision making and resource allocation. (A)
Abstract