On the nature of urban dependencies: How Manhattan and Barcelona reinforced a natural organisation despite planning intentionality

Abstract

Cities appear to display similar features and mechanisms across different geographies. This phenomenon seems to hold despite planning intentionality. In questioning the nature of this behaviour, an attempt is made in this paper to examine how cities retrieve their relational dependencies between street structures and other form-function attributes after the imposition of large-scale planning interventions. For the purpose of this investigation, indices of accessibility and form-function data are binned in a grid layer to enable mapping dependencies between these variables in Manhattan and Barcelona. Ordinal Regression models are fitted to empirical data in order to identify the effect of planning on urban dependencies. To reveal how these dependencies build up in time, we model and visualise a dependency network that captures the spatiotemporal relationships between accessibility and form-function variables in Manhattan (1880–2010). The hypothesis is that where planning interventions are more dominant, the natural organisation that couples urban dependencies will be destabilized. The results confirm the hypothesis true for some form-function variables and within certain grid resolutions. The dependency network representing urban transformations in Manhattan explained some aspects of temporality in the relationships between the network structure of streets, street width, building height, land values and retail land uses. The models presented in this paper are thought to highlight regularities in the growth and change of Manhattan and Barcelona. An explanatory theory on how cities display this convergent behaviour is thought to be vital for urban design and planning policies.