The American Planning Association is the professional organization for urban and regional planners. Planners work in cities, suburbs, and towns, specialize in transportation, housing, design, and the environment.

The CDC has a number of resources on urban sprawl as they relate to health. Do a search on their site to locate relevant pages.

The Congress for the New Urbanism (CNU) is an organization that promotes walkable, neighborhood-based development as an alternative to sprawl.

Provides government statistics provided by the U.S. Department of Housing and Urban Development. Performing a site search for ‘urban sprawl’ produces links to reports.