1. Advisory Committee on Trunk Road Assessment (the Leitch Committee), 1978. Trunk Road Assessment, HMSO, London.
2. Department of the Environment, Transport and the Regions (DETR), 1997. National Road Traffic Forecasts (Great Britain) 1997, DETR, London.
3. DETR, 1998a. A New Deal for Transport: Better for Everyone, HMSO, London.
4. DETR, 1998b. A New Deal for Trunk Roads in England, DETR, London.
5. DETR, 1998c. A New Deal for Trunk Roads in England: Understanding the New Approach to Appraisal, DETR, London.