Census Geographic Area Programsand Geographic Products Update

Michael Ratcliffe

Geography Division

US Census Bureau

Let’s Focus on Census Geography Workshop

GIS-T

April 11, 2010

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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

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PUMAs follow county boundaries where possible.

May cover large land areas due to minimum population requirement.

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Counties with populations greater than 200,000 may contain multiple PUMAs.

Census tracts may be aggregated to form PUMAs.

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Traffic Analysis Zones

Two types of areas:• Traffic Analysis Zones

– Defined based on 2010 census blocks

• Traffic Analysis Districts– Aggregations of TAZs

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Traffic Analysis ZonesDraft Program Schedule

Task Start FinishAASHTO/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 2010 February 2011

Spatial Files, MTPS, Delineation Guidelines and Documentation Distributed to MPOs

April 2011 April 2011

State DOTs and MPOs delineateTAZs and TADs

April 2011 August 2011

Census Bureau reviews and inserts TAZs into MAF/TIGER database

August 2011 November 2011

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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

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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

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Census Tracts and Block Group Thresholds

Census Tract Thresholds

  Census 2000 2010 Census

   Population Population Housing Unit

Optimum 4,000 4,000 1,600

Minimum 1,500 1,200 480

Maximum 8,000 8,000 3,200

Block Group Thresholds

  Census 2000 2010 Census

   Population Population Housing Unit

Optimum 1,500 --- ---

Minimum 600 600 480

Maximum 3,000 3,000 1,200

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

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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?

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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

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Questions? Comments?

Michael RatcliffeGeography DivisionU.S. Census Bureau

michael.r.ratcliffe@census.gov301-763-8977

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