ABSTRACT
In the rapid development of urban models through the 1960s and into the 1970s, the most successful products have been those models which predict population activities on a given physical infrastructure (or which incorporate some very simple assumptions about such infrastructure being determined by ‘demand’). As examples, we can cite models of transport flows, residential location and the use of service facilities, particularly shopping centres. These are partial models of the demand for the related elements of infrastructure – in the sense, at least, of being a response to supply. It has proved much more difficult to model the supply side. Such models, as they exist, still rely on the concepts of central place theory or something of that kind.
