Rethinking Urban Sprawl
Moving Towards Sustainable Cities
This report provides a new perspective to the nature of urban sprawl and its causes and environmental, social and economic consequences. This perspective, which is based on the multi-dimensionality of urban sprawl, sets the foundations for the construction of new indicators to measure the various facets of urban sprawl. The report uses new datasets to compute these indicators for more than 1100 urban areas in 29 OECD countries over the period 1990-2014. It then relies on cross-city, country-level and cross-country analyses of these indicators to provide insights into the current situation and evolution of urban sprawl in OECD cities. In addition, the report offers a critical assessment of the causes and consequences of urban sprawl and discusses policy options to steer urban development to more environmentally sustainable forms.
Urban sprawl as a multidimensional phenomenon
This chapter develops a conceptual framework in which the characteristics of urban sprawl are systematically categorised and disentangled from its causes and consequences. Furthermore, it provides a functional definition of urban sprawl that reflects its multidimensional nature and its main differences from other forms of urban development. Using a series of graphical illustrations, the chapter describes various features of urban development that determine urban sprawl: average population density and its variation across urban space; the share of urban footprint and population in areas where population density lies below certain thresholds; fragmentation of urban land; number of peaks of high population density; and the fraction of urban population residing outside these peaks.