An evaluation of existing travel demand estimation procedures for long term strategic urban transportation planning

Abstract

During the last few years a number of travel demand estimation techniques for long term strategic planning have been developed. These techniques have not been quantitatively evaluated on a common ?Ç£test bed?Ç¥ to see which technique would perform best under a given set of conditions. The primary objective of this research project was to select, after quantitative analysis, the most appropriate technique for application in medium and large sized cities in South Africa. The functions, data needs, appropriate level of effort and the necessary accuracy for each different level of urban transportation planning initially were identified. This effort defined the objectives and scope of long term strategic planning. Various non-conventional planning techniques (e.g., techniques that do not follow the usual four-step procedure of trip generation, trip distribution, modal split and assignment) were then qualitatively evaluated in order to select the best technique for a quantitative evaluation against the simplified conventional planning technique. Pretoria, South Africa was selected as a ?Ç£test bed?Ç¥. After evaluating the results from the application of both the simplified conventional technique and the selected non-conventional technique (the Community Aggregate Planning Model-CAPM), it was concluded that the simplified conventional four-step procedure is the recommended procedure to estimate travel demand. Finally, certain aspects were identified which would make the application of the recommended procedure more effective with particular reference to South African conditions.