[CTPP] ZIP code tabulation areas

****** C E N S U S 2 0 0 0 B U L L E T I N ****** Vol. 3 - No. 18 Sept. 27, 1999 One of the lesser known new features of Census 2000 data tabulation is the planned use, for the first time, of ZIP Code Tabulation Areas (TM) (ZCTAs), a statistical entity developed by the Census Bureau as an approximation of the U. S. Postal Service's ZIP (R) Codes. ZIP Codes do not represent areas, but rather a network for the delivery of mail. The Census Bureau has released prototype ZCTAs for the three Census 2000 Dress Rehearsal sites (Columbia, S.C., and 11 surrounding counties; Menominee County, Wis.; and Sacramento, Calif.). Thus, the ZCTA will take its place alongside standard statistical tabulation areas, such as regions, divisions, metropolitan areas, urbanized areas, tribal statistical areas, county subdivisions, census designated places, census tracts, block groups and census blocks, as well as the legal and administrative areas for which the Census Bureau traditionally publishes summary data. The ZCTAs will be assigned in a computer-delineated process based on the Census Bureau's address list at the time of the census. The Census Bureau's address list itself is confidential under Title 13, U.S. Code, and therefore is not available to the public. ZCTAs follow census block boundaries, with the ZCTA code for each census block being the majority ZIP Code for addresses within that census block. Automated processes will extend ZCTA codes to blocks that have no addresses or no addresses with ZIP Codes. This means that the Census Bureau will be able to display the ZCTAs as polygons on maps. For the Census 2000 Dress Rehearsal sites, ZCTA codes are assigned to all land -- even that which is uninhabited -- and water areas, which will be displayed with three-digit instead of five-digit codes. A three-digit code indicates that the Census Bureau was not confident with the assignment of a five-digit code based on information available in its files. The Census Bureau hopes data users will look at its implementation of ZCTAs for the Census 2000 Dress Rehearsal sites and provide comments on the resulting product. More information is available on the Internet at http://www.census.gov/geo/ZCTA/zcta.html. ZCTAs exclude unique, single-delivery-point ZIP codes for firms and organizations, but do include dedicated Post Office Box ZIP Codes where a main post office has only Post Office Box deliveries. ZCTAs will be summary levels in both the 100 percent and sample data files and should be available at the same time as the data for the other summary levels, between June of 2001 and December of 2002. The Census Bureau's new American Community Survey plans to tabulate data for ZIP code tabulation areas once the 2000 ZCTAs become available. (ZCTA is a trademark of the U. S. Bureau of the Census. ZIP is a registered trademark of the U. S. Postal Service.)