A methodology for the assessment of the environmental effects of traffic in district shopping centres

Abstract

This thesis has its origins in an applied research problem identified by the West Midlands Transportation Study Group, a team of local authority officers responsible for the development of transportation policy in the West Midlands Conurbation. The Study Group were aware of environmental problems arising in district shopping centres located on heavily trafficked links in the strategic highway network. The need to evaluate the environmental implications of alternative policies for these important shopping links was recognised. The research work carried out by the author was directed to the development of an environmental evaluation methodology applicable to this particular type of environmentally sensitive location. The general, disciplinary and operational contexts of the project are discussed. Alternative methodologies for environmental evaluation are examined. An environmental impact statement approach is postulated as the feasible methodology responding to the research problem identified by the Study Group. Existing evidence regarding the nature of subjective responses to traffic environments is examined to determine environmental variables for inclusion in the impact statement. Techniques for the prediction of these environmental variables are presented and discussed. The key issue of pedestrian exposure to traffic effects is reviewed and the thesis seeks to make an original contribution to this area through the development of a disaggregated technique of exposure accounting. The components of the methodology are presented in the form of a manual. A range of policy options for shopping links based on various levels of vehicle access restriction are defined for test purposes. The proposed manual is then tested, using these policy options, in a sample of district shopping centres drawn from the West Midlands Transportation Study Area. Conclusions relating to the applicability and effectiveness of the methodology are presented.