Personal mobility or community accessibility: A planning choice with social, environmental and economic consequences

The concepts of accessibility and mobility are central to urban and transport planning issues. However, although the terms are in common use, the philosophies underlying their application are not clearly understood, and they remain difficult to define in a way which enables them to be easily quantified. For example, mobility, defined as movement or distance travelled, is generally seen as a means of providing accessibility, which can be simply defined as the ease and convenience of reaching some destination. However, mobility, especially when excessive, can also have a negative connotation, whereas accessibility is always seen as making a positive contribution to a community. This thesis investigates the relationship between mobility and accessibility and describes two planning models: the first promoting personal mobility; the second promoting community accessibility. It emerges that policies which favour the one model, act against the other, and that in their application, the two models are mutually exclusive. The thesis is able to clarify the distinction between accessibility and mobility by looking at them in terms of how they relate to personal and community values. In the process, a quantitative indicator of community accessibility is derived which is intuitive and simple to use, yet robust and effective. A statistical analysis was undertaken in which the community accessibility indicator was correlated with social, environmental and economic data collected in a wide range of cities. In this way, the theoretical differences between these alternative planning approaches could be better understood. This new-found awareness makes it possible to better comprehend the implications of planning policies, and to choose those policies that will optimise community development values in cities