Changing intra-urban structure and spatial interaction patterns represent a major aspect of recent urban trends. A framework is outlined in this paper for the study of interaction patterns over time by taking into account changing urban forms. The paper also attempts to trace the impact of interaction costs on the overall level of population and employment change in a city. Several conditions are discussed for the development of dynamic urban models. These conditions refer to population composition, land-use conversion, residential relocation, and the evolution of the changing function of distance in urban areas
