The nature of the study described in this report was essentially that of an exploratory exercise, intended to contribute to the Transport and Road Research Laboratory's wider understanding of the sources, scale and spread of benefits from urban road improvements. To this end, a state-of-the-art four-stage transport model of Belfast, created using 1985 data, was used. An early step in the research was to establish a cost-effective strategy for achieving adequate convergence of the SATURN road traffic assignment submodel. A serial of tests was carried out of several road network improvement schemes in order to investigate the relationship between the degree of highway network improvement and the scale of the consequent effects produced by each of the model components, for each of two levels of demand. For one scheme, a series of analyses were undertaken to display the spatial effects of the various model components. Finally, again for one scheme only, the effects of increasing demands in response to decreased travel times was investigated. This report summarises the background to the study and the methodology used, and gives the main findings and some suggestions for further research.

Want to know more about this project?