Census Geographic Area Programs and Geographic Products Update Michael Ratcliffe Geography Division US Census Bureau Let’s Focus on Census Geography Workshop GIS-T April 11, 2010

Public Use Microdata Areas Minimum population: 100,000 Super-PUMAs will not be defined. Anticipate publication of proposed criteria in Federal Register, Summer 2010. Delineation program expected start: Spring 2011. SDCs will delineate PUMAs.

Public Use Microdata Areas PUMAs will be used to tabulate and present data for: 2010 Census Public Use Microdata Sample (PUMS) Files American Community Survey PUMS Files American Community Survey 1-year data

PUMAs follow county boundaries where possible PUMAs follow county boundaries where possible. May cover large land areas due to minimum population requirement.

Counties with populations greater than 200,000 may contain multiple PUMAs. Census tracts may be aggregated to form PUMAs.

Traffic Analysis Zones Two types of areas: Traffic Analysis Zones Defined based on 2010 census blocks Traffic Analysis Districts Aggregations of TAZs

Traffic Analysis Zones Draft Program Schedule Task Start Finish AASHTO/FHWA submits short version of requirements to Census Bureau November 2009 AASHTO/FHWA submits formal version of requirements to Census Bureau February 2010 MAF/TIGER Partnership Software Development February 2011 Spatial Files, MTPS, Delineation Guidelines and Documentation Distributed to MPOs April 2011 State DOTs and MPOs delineateTAZs and TADs August 2011 Census Bureau reviews and inserts TAZs into MAF/TIGER database November 2011

Traffic Analysis Zones TAZ Delineation Software: MAF/TIGER Partnership Software will be utilized Block Equivalency Files Caliper Corporation has reviewed and commented on software requirements Census Bureau will need a list of counties (towns in New England) associated with each MPO

Statistical Areas Program Census tracts Block groups Census county divisions Census designated places Delineated areas were entered into the MAF/TIGER data base December 2009 Currently verifying final boundaries

Statistical Areas No longer just for the decennial census! ACS will tabulate data for all statistical areas Economic Census data tabulated for CDPs: 5,000 or more people 5,000 or more workers

Census Tracts and Block Group Thresholds Census Tract Thresholds   Census 2000 2010 Census  Population Population Housing Unit Optimum 4,000 1,600 Minimum 1,500 1,200 480 Maximum 8,000 3,200 Block Group Thresholds   Census 2000 2010 Census  Population Population Housing Unit Optimum 1,500 --- Minimum 600 480 Maximum 3,000 1,200 2.5 persons per Household. We have had a number of comments asking us to switch to HU counts, because of ease of validation, although data disclosure issues primarily involve population and not HUs. Thus we will allow locals to use either threshold. In addition, the HU counts allow a better definition of seasonal communities that may receive ACS data.

TIGER/Line and Map Products Public TIGER/Line Shapefiles Reference Maps Congressional District maps P.L.94-171 County Block Maps Census Tract Outline Maps Census 2010 Block Maps Thematic Maps Loss and Gain of Seats in Congress by State Population Distribution (“Nighttime”) Map

Geographic Relationship Files 2000 Tabulation Block to 2010 Collection Block 2000 Tabulation Block to 2010 Tabulation Block 2010 Current (ACS) Block to 2010 Tabulation Block 2010 Collection Block to 2010 Tabulation Block 2000 Census Tract to 2010 Census Tract Other Potential Relationship Files?

Geographic Reference Products Gazetteer Files Counties County subdivisions Places Geographic Area Inventory Lists (with population, housing units, and land area) Geographic Change Notes Geographic Terms and Concepts

Questions? Comments? Michael Ratcliffe Geography Division U.S. Census Bureau michael.r.ratcliffe@census.gov 301-763-8977