The authors encapsulate four theories that were presented in the preceding chapters:

1) Large Technical System: The city is viewed as a dynamic, complex machine constructed by politics, society, institutions, and entrepreneurs. Strong, interconnected infrastructure is the key to the arrangement; constant innovation for support and maintenance activities help prevent a stagnant system. Because the system is a complex, interactive web, issues naturally arise when these nodes are separated.

2) Actor Network Theory : This theory emphasizes the combination of technology and capital across space and time. Human interaction is seen as the crucial component that links society and technology, thus creating a blended system of technical and social networks.

3) Changes in the political economy of capitalist urban infrastructure: These changes can be observed in several groupings of interactions. The first regards the diverse nature of connections between space, as different infrastructure systems have differing abilities to move across space and time. The intensity of the connection between individual systems becomes more important than the overall size; more intense connection makes a city a more strategic system. The second change is the effect of globalization, which links cities in a dynamic continuum of global-local interaction. Advances in information technology have allowed a complex reshaping of the way that infrastructure is managed, creating increasing global inter-connectedness. Third, as cities become increasingly technologically advanced and globally integrated, the natural monopolies of many infrastructure systems will be eroded as the public goods and services can be traded in private market. Fourth, the homogeny and vertical integration within a city will lead to a glocal interaction. These unbundled systems create a tunnel effect, where intense links between nodes exclude and bypass the intervening spaces.

4) Relational urban and social theories: Space changes through social action in a continually evolving way. There are three main challenges to these dynamic changes: space that resists easy generalization, relational links between cities that tend to be multiple and complex, and the time and space fundamentals that exists within cities.

According to the first theory, the unbundling of infrastructure is a long term historical trend; a process where infrastructure systems are continually reconfigured at the social and institutional level. Our authors suggest that the Actor Network perspective adds a distinction between technology and society, emphasizing the continuous effort by actors that is needed to ensure all elements operate to remake spaces in a preferred and rational manner. Further, the spatial political economy approach advances that technology and infrastructure emerge from - rather than are embedded in - social control. It paints a distinction between local and global, emphasizing the tunnel effect that results from linking infrastructure and territories across spatial scales. Finally, the relational urban theories add the ambivalent social tension that surrounds the configuration of networks, and the ways in which the world is intensely interconnected.