Earlier this year Reid Ewing and Shima Hamidi released the latest version of their urban sprawl index. The first version came out a decade or so ago and the latest version uses current data and has an improved methodology.
The index came out of the fact that commentators, scholars, policymakers, and journalists would constantly talk about “sprawl” without there being an authoritative definition of the phenomenon. Ewing and his colleagues set out to change this in 2002 by developing an index of sprawl that draws on objective data relating to population and employment density, the mixture of uses and destinations apparent, the presence of urban centers, and the connectivity of street systems.
The 2002 study defined its index at the level of county and metropolitan areas. The current effort added sprawl scores at the census tract level for the largest urbanized areas in the United States allowing for greater detail in analyzing patterns of sprawl and metropolitan development.
The map below reflects the sprawl indices for metropolitan census tracts in Illinois. Higher scores indicate more density and less sprawl.
There are obvious patterns of density around transit lines, however it is interesting to see the north/south differences within the City of Chicago which probably reflect disparities in mix of jobs and destinations. Also notable are the numerous suburban centers which score high on the index. This could be promising for thinking about the viability of sprawl mitigation policies. Such efforts as higher-density and mixed-use development in the Chicago suburbs could take advantage of an existing social, economic and physical infrastructure to help slow sprawl regionally.