A dynamical model of a central place system is described which, derived from the concepts underlying dissipative structures, takes into account the self-organizing aspects of urban evolution, and shows the importance both of chance and of determinism in such systems. A theoretical evolution is discussed together with the modified dynamics of different possible decisions showing the long-term consequences of these. A recent application of this new theory to the evolution of the Bastogne region of Belgium is briefly described, and conclusions are drawn as to the real difficulties involved in decisionmaking on the part of national, regional, and municipal authorities. -AuthorsSCOPUS: ar.jinfo:eu-repo/semantics/publishe