The city as a socio-technical system a spatial reformulation

On the face of it, cities as complex systems are made of (at least) two sub-systems: a physical sub-system, made up of buildings linked by streets, roads and infrastructure; and a human sub-system made up of movement, interaction and activity. As such, cities can be thought of as socio-technical systems. Any reasonable theory of urban complexity would need to link the social and technical sub-systems to each other. Historically, most urban models have sought to make the link through the concept of distance in the physical system as a cost in the social system, defining the physical sub-system as a set of discrete zones. Such models have proved practical tools, but over the years have contributed relatively little to the development of a more general theory of the city. Here we propose a more complex and, we believe, true-to-life model based on the definition of the physical sub-system of the city as a network of spaces – streets and roads - linking buildings, rather than as a system of discrete zones. This allows us to approach urban complexity in a new way.