Power Laws in Urban Supply Networks, Social Systems, and Dense Pedestrian Crowds

Abstract

The classical view of the spatio-temporal evolution of cities in developed countries is that urban spaces are the result of (centralized) urban planning. After the advent of complex systemsâ theory, however, people have started to interpret city structures as a result of self-organization processes. In fact, although the dynamics of urban agglomerations is a consequence of many human decisions, these are often guided by optimization goals, requirements, constraints, or boundary conditions (such as topographic ones). Therefore, it appears promising to view urban planning decisions as results of the existing structures and upcoming ones (e.g. when a new freeway will lead close by in the near future). Within such an approach, it would not be surprising anymore if urban evolution could be understood as a result of self-organization (Batty & Longley, 1994; Frankhauser, 1994; Schweitzer, 1997).