Transport studies have been undertaken in this country for over fifteen years. During that time much criticism has been levelled against them, and yet to date there has been no serious attempt to evaluate their predictive accuracy. This report describes a feasibility study to investigate whether it would be practicable to examine the predictive accuracy of early British studies by comparing forecasts made in them with current information. The study has several parts. A desk study and review of literature identifies the main weaknesses and potential sources of error in the transport planning process. The main part, a review of past studies in a sample of local authorities, reveals that in most study areas recent transport data are available which might be used for reappraising the earlier study. Discussions with the local authorities indicate that though the models appear to perform satisfactorily in the forecast situation, the studies were generally very inaccurate in their predictions of growth in population, employment and real incomes. Finally, the report discusses methods and indicators that might be used to assess the predictive accuracy of past studies and concludes that a full study is both feasible and worthwhile. (Author/publisher)
Samenvatting