http://tags.library.upenn.edu/tag/census+commuting PennTags Feed http://tags.library.upenn.edu/makerecord/url/7223 http://tags.library.upenn.edu/makerecord/url/7223 The Rural-Urban commuting area (RUCA) codes, a detailed and flexible scheme for delineating sub-county components of the U.S. settlement system, have been updated using data from the 2000 decennial census.