Background... I am the Principal Investigator for a new project (NCHRP 25-36), funded by the Transportation Research Board, to investigate the land use-transportation interactions in small areas and rural areas in the U.S. (A brief description of the project is available at: http://144.171.11.40/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=2987. I am working closely with Joe Huegy at North Carolina State University. The Project Officer is Nanda Srinivasan.) One of our first tasks is to develop a typology of those areas, for the specific purpose of guiding development and application of the empirical methods that we will use to quantitatively characterize those interactions. Of course, an excellent starting point for our work on the new typology is the Census Bureau's delineation of Urbanized Areas and Urban Clusters based on the 2000 Census. Question... Where may I find the codes for the 24 Urban Clusters that consist entirely or predominantly of persons living in institutional group quarters, to which the Census Bureau draws attention in its Federal Register notice about the proposed urban area criteria for the 2010 census? See 75 FR 52178. Thanks Brian J. Morton -- /Brian J. Morton, Ph.D. Senior Research Associate Center for Urban and Regional Studies University of North Carolina Campus Box 3410 Chapel Hill, NC 27599-3410 USA (919) 962-8847/