Modelling the economic impacts of transport changes: experience and emerging issues in the UK

This paper describes and illustrates the approach to land-use/transport/economic interaction modeling that the authors and colleagues have implemented as the DELTA software package and have used to forecast and appraise the economic impacts of a range of proposed or possible transport strategies and schemes under consideration in different parts of the United Kingdom. It first describes the background to the development of the approach. Secondly it outlines the models developed within this approach, focusing in particular on the two-level representation of space and on the links between transport and the economy. The workings of the model in practice are then illustrated with some example forecasts from one major study. We then outline the current approach to appraisal of wider economic impacts, and discuss the appraisal results corresponding with the example results. The final section discusses some current developments.