The theory and practice of car ownership forecasting

Abstract

Forecast levels of car ownership play a vital role in the determination of government transportation planning and policy. Both at the urban and inter-urban level, the scale and character of transport provision for the last two decades of this century will be determined to a significant extent by the view taken now about the position of the private car in our society. In the United Kingdom, for example, the British government’s recent Transport Policy document contained a section specifically devoted to forecasting national car ownership levels. The accuracy of such forecasts has figured importantly in a number of recent controversies in the U.K. surrounding public enquiries into motorway plans. It is clear that well conceived car ownership models are an essential requirement if the uncertainty inherent in the traffic forecasts central to infrastructure investment appraisal is to be minimised.

This paper derives from work undertaken as part of a research project carried out under the auspices of a grant from the Social Science Research Council.