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UTC @ UIC October 28, 2010. Where are we with Census Data as it relates to transportation planning?. Topics Background 3-year CTPP/ACS 5-year CTPP TAZs/TADs PUMS/PUMAS. Ed Christopher Resource Center Planning Team Federal Highway Administration 4749 Lincoln Mall Dr. Rm 600
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UTC @ UIC October 28, 2010 Where are we with Census Data as it relates to transportation planning? • Topics • Background • 3-year CTPP/ACS • 5-year CTPP • TAZs/TADs • PUMS/PUMAS Ed Christopher Resource CenterPlanning Team Federal Highway Administration 4749 Lincoln Mall Dr. Rm 600 Matteson, IL 60443 708-283-3534 edc@EdtheFed.com
Some Background What happens every 10 years and is the single most important undertaking of every person living in the US? 2
They Get Counted Every 10 years the Census Bureau Counts the population (Short Form) Samples our characteristics (Long Form) Now just called The Census Form 3
Census (Short) Form 100% Population count First Census 1790 Constitutionally Mandated Sets Congressional Seats Mandatory Participation $100 fine failing to respond $500 fine for lying 2010 is the 23rd Headcount Census Day became April 1st in 1930 10 Questions Name Sex Age Relationship Hispanic Origin Race Owner/Renter Telephone Number Part Time Residency April Residents 4
Census (Long) Form Now the ACS American Community Survey • Nationwide mail survey • Sent to a sample of households • Continuous Survey Methodology • Replaces “long form” of decennial census • Covers the same major topics as “long form” • Provides annual data http://www.census.gov/acs/www/
How does the ACS work? Three Methods of Data Collection 1. MailSelf-administered mail-out/mail-back 2. TelephoneComputer Assisted Telephone Interviewing (CATI) 3. Personal VisitsComputer Assisted Personal Interviewing (CAPI) 1:3
Data Type Population Size of Area Data for the Previous Year Released in: 2006 2007 2008 2009 2010 2011 2012+ Annual 65,000+ 3-year Period 20,000+ 5-year Period Tract and Block Group ACS Data Releases
And then the CTPP Census Transportation Planning Products (CTPP) Program The CTPP is an umbrella program of Census related data products, custom tabulations, training, technical assistance, and research for the transportation community
CTPP History http://www.trbcensus.com/articles/ctpphistory.pdf
CTPP then and Now CTPPackage Prior to ACS CTPProducts Program Post ACS • The CTPP program now includes • Many more Data products • Training and technical assistance • On-call user support • Training classes and web seminars • Research Federal Technical Advisory Group TRB Subcommittee -- List Serve (800 strong) Quarterly Newsletter -- Outreach -- Several Websites 10
3-year CTPP Data Product CTPP 3-Year September 2010 Oct/Nov 2010 2006, 2007, 2008 20,000 Pop. Areas (County, Place, PUMAs) Actual Flows _______________ XXVXX http://trbcensus.com/products
2008 Geography Product Structure 3-Parts Part 1-Place of Residence Part 2-Place of Work Part 3-Flows between Home and Work with On-Line Extraction Software Nation (US Total) State State-County State-County-MCD State-Place State-PUMA(red = 2000 geo.) State-POW PUMA Metropolitan Statistical Area MSA – EACH Principal City The 3-year Product Design http://ctpp.transportation.org/Documents/CTPP_custom_tabulations_based_on_3yracs2006_2008.xls
Some Issues to be aware of 3-year ACS (2006, 2007, 2008) What year is the data? Period Estimate brought forward to year of release What Data to use? Reliability vs. Currency
Significance Testing--Why do it? MOE, MOE, MOE Source: CTPP Data Profiles http://ctpp.transportation.org/Pages/overview.aspx http://www.edthefed.com/presentations/significance%20testing.ppt
Working with ACS A Compass for Understanding And Using ACS Data l Set of user-specific handbooks l Train-the trainer materials l E-learning ACS Tutorial l Annotated Presentations http://www.census.gov/acs/www/UseData/Compass/compass_series.html
What data should I use? Travel Times for the 6-counties in NE Illinois 1. To compare with 1970, ‘80, ‘90 and 2000 Travel Times? 2. To compare with my town of 52,000 people? 3. To validate my 2008 vintage travel demand model?
Finally A word about Collapsing Collapsing
And remember I noted Incomplete Coverage? NE Illinois (2009 3-year ACS) Gray = Less than 20K people and No data X “Where’s the beef Data?” “It Looks Like Swiss Cheese”
5-year CTPP Data Product New Geography Requires implementation of new disclosure avoidance (“masking”) techniques
Same Structure as 3-year CTPP Product But for Small Areas
The are DRB rules • Cell Means and aggregates require 3 unweighted records • For Pt 3 Flow Tables: 3 unweighted records for each table, each cell, with the exception of the 1-way Means of Trans. table • 3 unweighted records for the marginal's in any cross-tabulation with Means of Trans.
5-year CTPP Data Product NCHRP 08-79 ($550K) Producing Transportation Data Products from the ACS that Comply With Disclosure Rules • NCHRP is funded by State DOTs SP&R • Project schedule: Jan 2010-July 2011 • Need results to be applied to 2006-2010 ACS for the 5-year CTPP (delivery to software vendor in summer 2012) • Westat, Tom Krenzke, PI
“NEW” TAZs Traffic Analysis Zones • Defined by MPOs and State DOTS • Software Deployed (Spring 2011) • Developed in Summer 2011 • TAZs will nest with TADs • GIS equivalency process • Funded under Consolidated Purchase http://download.ctpp.transportation.org/TAZ_Rules/TAZ%20Delineation%20Business%20Rules_CTPP%20Final.pdf
What is an equivalency process? Take the map at the right and using the states boundaries make 9 contiguous regions It’s the same for TAZs Blocks cluster into TAZs
A real world example • Census Blocks will make up TAZs • TAZs will nest with TADs • TADs will nest in Counties • Nesting with Tracts is optional
TAZ Size • CB recommends • ~600 persons • corresponds to the minimum • threshold for 2010 Census • Block Groups • Threshold is guideline not a requirement • TAZs may be defined with fewer than 600 residents or workers • Data reliability and availability improves as population size increases Bigger is Better
Creating TAZs Florida Standard Urban Transportation Model Structure White Paper on Recommended Approach to Delineating TAZ http://www.fsutmsonline.net/images/uploads/reports/FDOT_TAZ_White_Paper.pdf http://www.fsutmsonline.net/images/uploads/mtf-files/PPT_12_TAZ%20White%20Paper_NOV07_FINAL_CS_Keli_Wu.ppt
PUMAs? -- What are they? Public Use Microdata Sample PUMSdata is based on individual census records and is available only at large geographic areas. Think of the PUMS dataset as the raw, disaggregate census sample data, at a large enough geographic level necessary to protect the confidentiality of the census respondent. Standard Tabs ACS Sample PUMS Records PUMAs are the zones used from PUMS data
Chicago Why are PUMAs Important? NE Illinois (2008 pop estimate) Let’s Look at Annual Data • Annual Data • 65K+ • Note the areas in gray • We call this Swiss Cheese
Why are PUMAs Important? NE Illinois (PUMAs) Tabulation Area for ACS • Represent 100K • Complete Coverage • Smaller than Counties • NO Swiss Cheese
How many PUMAs should this area have? City of Chicago 2000 PUMAs Why are PUMAs Important? - Defines areas for analysis - Tabulation Area for ACS - Custom Tabulation Who Defines Them? - The Community - Led by State Data Center When are They Defined? - Summer 2011 - Criteria out Spring 2010 2,896,016 (2000 Pop) http://www.census.gov/geo/www/maps/puma5pct.htm
PUMA Resources IPUMS maintains the PUMS data back to the 1850 census and has and online table generator Minnesota Population Center http://usa.ipums.org/usa/ CTPP Webinar on IPUMS http://ctpp.transportation.org/Pages/webinardirectory.aspx Compass Handbook by Census Bureau http://www.census.gov/acs/www/Downloads/handbooks/ACSPUMS.pdf
5 year regular ACS Fed Register Notice onACS 5-Year Data Product Plans http://edocket.access.gpo.gov/2010/pdf/2010-23373.pdf http://edocket.access.gpo.gov/2010/2010-23373.htm Data due out in December 2010 ’05, ‘06, ’07. ’08, ’09 Data Years Block Groups not on FactFinder and loaded with suppression
Census Bureau E-Tutorial and ACS http://www.census.gov/acs/www/guidance_for_data_users/e_tutorial/
By December 31st we’ll know… http://www.electiondataservices.com
Just in American FactFinder to get facelift in January Take the Advance Tour http://factfinder.census.gov/home/saff/tour.html 45
To Learn more about the CTPP http://www.dot.gov/ctpp http://www.TRBcensus.com http://ctpp.transportation.org Join the CTPP List Serve http://www.trbcensus.com/maillist.html 47