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Public Transportation Data in the American Community Survey

(ACS) and Census Transportation Planning Products (CTPP)

Dec 3, 2009AASHTO Standing Committee on Public Transportation

and Multi-State Technical Assistance Program Winter Meeting

Melissa Chiu, CTPP Coordinator Journey-to-Work and Migration Statistics Branch

Housing and Household Economic Statistics DivisionU.S. Census Bureau

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Transition to the American Community Survey

The 2010 Census will not ask journey-to-work information

Census “long form” information is now asked on the American Community Survey (ACS)Large, continuous demographic surveyProduces characteristics, not a population countProduces annually updated single-year and multi-year

estimates of the characteristics of the population and housing

Produces information for small areas including tracts, block groups and population subgroups - updated every year

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How Does the Sample Compare?Timing

ACS samples every year and spreads sample over 12 months

Census samples once a decade and uses the entire sample at the same time

Follow-upACS subsamples for personal visit follow-upCourt ruled against census subsampling

Sample sizeACS 5-year estimates based on about 11 million

housing units Census sample estimates based on about 18 million

housing units

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ACS Data Release Schedule

Data products are released in the year following the single year or multiyear period in which data are collected.

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Information about the American Community Survey

www.census.gov/acs/Subscribe to the

ACS Alert

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Means of Transportationon the ACS Questionnaire

Same as on Census 2000 long form

Q: How did this person usually get to work last week? Car, truck, or van Motorcycle

Bus or trolley bus Bicycle

Streetcar or trolley car Walked

Subway or elevated Worked at home

Railroad Other method

Ferryboat

Taxicab

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Other Commuting Informationon the ACS Questionnaire

Ridership for car, truck or van Report up to 99 peopleCensus 2000: reporting topcoded at 7 or more

Time left home to go to workHour and minute, time of day

Usual travel time to commute Report up to 999 minutes

Place of work Report street address, zip code Geocoded to block, if possible

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Journey-to-Work ACS Data Products

Data products and prefixes B Base Detailed Table

C Collapsed Detailed Table

S Subject Table

R Ranking Table (single-year only)

GCT Geographic Comparison Table

M Thematic Map

Commuting products are numbered “08” Example: B08xxx is a Base Table on commuting

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Journey-to-Work ACS Data Products

Detailed tables show univariate and crosstab frequencies and some summary statistics

Detailed table examples (B08xxx / C08xxx):Means of transportation by worker characteristicsTravel time by time leaving home Place of work for metropolitan, micropolitan, and non-

metro/micro levelsVehicles available in household

Majority of tables available at both residence geography (B081xx, B082xx, B083xx) & workplace geography (B084xx, B085xx, B086xx)

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Journey-to-Work ACS Data Products

Detail in means of transportation varies by table All 5 public transportation categories shown

on univariate table and sex crosstab3 categories (bus, streetcar and subway,

railroad and ferry) shown on travel time crosstab

A single public transportation category shown on all other crosstabs of means of transportation

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Journey-to-Work ACS Data Products

Subject Tables based on same information as Detailed Tables but more user friendly format

Tables show distribution and summary of characteristics

Examples (S08xx):Commuting characteristics by sex (S0801)

Characteristics by means of transportation to work (Public transportation grouped together)

- at residence geography (S0802)

- at workplace geography (S0804)

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Journey-to-Work ACS Data ProductsRanking Tables, Geographic Comparison Tables,

and Thematic Maps all show data on five measures of commuting: Mean travel time to work (#01) Percent of workers who traveled to work …

by car, truck, or van alone (#02)by carpool (#03) by public transportation (#04)

Percent of workers who worked outside county of residence (#05)

Residence geography only Ranking Tables rank states (R08xx)

(single year data only)

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Journey-to-Work ACS Data Products

Geographic Comparison Tables allow comparison of more geographies on the same measures

Examples (GCT08xx): Mean travel time to work for all countiesPercent of workers who traveled to work by

public transportation for all places (cities)Percent of workers who worked outside

county of residence by urban / rural, metropolitan and micropolitan area status

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Journey-to-Work ACS Data ProductsThematic Maps allow users to design maps on

the same measures (M08xx) Levels of geography available:

StateCounty Metropolitan/ micropolitan statistical areaCongressional district Public Use Microdata Area (PUMA)Combined Statistical Area

Can determine… Data classes: number and breaksBoundaries and features

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The Census Transportation Planning Products (CTPP)

Special tabulation of commuting dataUsed Decennial Censuses since 1960

Plans for using American Community Survey data (2006-2008) and (2006-2010)

Schedule 2006-2008 3-year CTPP planned for release summer

2010

TAZ Delineation program in spring/summer 2011

2006-2010 5-year CTPP currently planned for summer 2012 release

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CTPP Table StructurePart 1 Residence Geography Part 2 Workplace GeographyPart 3 Home-to-Work Flows

Tables include …characteristics of workers & householdsVehicles available in householdIncome

characteristics of tripsMeans of transportation (Public transportation mostly in 3

categories: bus, streetcar and subway, railroad and ferry)Travel timeTime leaving home

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CTPP Resources

Federal Highway Administration (FHWA)www.dot.gov/ctppUpcoming CTPP data products2000, 1990 CTPP data products

Bureau of Transportation Statistics (BTS) CTPP 2000, CTPP 1990 data downloadwww.transtats.bts.gov

Transportation Research Boardtrbcensus.com

AASHTOctpp.transportation.org

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U. S. Census Bureau

Melissa Chiu, CTPP Coordinator

Journey-to-Work & Migration Statistics Branch

Housing and Household Economic Statistics

301-763-2421, -2454

melissa.c.chiu@census.gov

www.census.gov/population/www/socdemo/journey.html

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Orientation to American Factfinder

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Organization of ACS Data in the American FactFinder (AFF)

1. Datasets (ACS, Census)

2. Data year(s)

3-year data products are the default

1-year and 3-year data products distinguished

3. Data products

4. Specific tables or maps

Assistance links highlighted

Data Products- American FactFinder factfinder.census.gov

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Select Dataset and Product Type

Organized by dataset then by

data product

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List all Tables- Select “08” Products

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Select Geography

Many ways to select geography

Geography is hierarchical: First select type of geography,then specific area.

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Subject Table- Example (S08xx)

Click “Data Sets” to change data product

Change year,

geography, subject

table

Print, download, save or load a query

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Detailed Table- Example (B08xxx/C08xxx)

Can select multiple areas for detailed tables

Select geo type, e.g. urban, rural, metro, principal city

Change to collapsed version

Can select multiple detailed tables too (scroll down)

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Detailed Tables- Geo Components (down to state only)

Click Next to see other geographies selected

Download to get all geographies and tables at once

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Download- Example

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Ranking Table- Example (single year only)

Can sort by rank or by state

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Geographic Comparison Table- Example (GCT08xx)

Geographies or geo componentswithin nation or state only

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Thematic Map- Example (M08xx)

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Thematic Map- Options

Statistical significance viewSelect a geography

Displays all areas that are statistically significantly different from the selected geography

Can save as .PDF file under “download” menu

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Other Options in American Factfinder

Can create “Custom table” from the detailed tables

Data Download Center Download selected ACS tables for all available geographies at one time

Can “Download PUMS data” file for microdata

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Data Download Center

Download large amounts of ACS dataGeographic units

Total U.S. StatesCountiesPlacesCBSAs (Metro and Micro Areas)

Congressional Districts

All areas meeting minimum population threshold

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Data Download Center

ACS Tables (Selected)Base / Detailed tables Data profilesSubject tables

Choose up to 50 tables at one timeDownload .zip file consisting of .txt files

README file Geographic identifiersData- estimate and 90% MOE for each cell, all tables

Files pipe-delimited [ | ], can load in Excel

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Data Download Center- Example

On American FactFinder …Data Sets page on upper right

…or left side bar

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Data Download Center- Example

Select Dataset

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Data Download Center- Example

Select one geographic

level

Select data product type

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Data Download Center- Example

Select up to 50 tables and ‘Add’

Click ‘Next’ to get to ‘Start Download’ then download a .zip file

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Data Download Center- Example

.Zip file includes areadme file on data values, geographic identifiers, and

data file(s) Open data file in Excel as ‘Delimited’ by pipe: |

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Supplementary Data Options

Integrated Public Use Microdata Series (IPUMS)usa.ipums.org/usaCensus microdata, historical

National Historical Geographic Information System (NHGIS) www.nhgis.orgAggregate census data, historical Boundary files, historical