WHEN
WAS THE DATA AVAILABLE?
INTRODUCTION
TO CTPP 2000
CTPP2000 is a special tabulation of responses from households
completing the Census long form. The special tabulation is intended to
provide data to support a wide range of transportation planning activities.
It is the only Census product that summarizes data by place of work and
tabulates the flow of workers between home and work. And it is the only
source of information with summary tabulations available for traffic analysis
zones (TAZ’s) that have been defined by State and regional transportation
agencies.
A CTPP technical working group of staff from the Federal Highway
Administration, the Bureau of Transportation Statistics, the Federal Transit
Administration, AASHTO and the Census Bureau met on a regular basis over
several years to develop the content for CTPP2000. The working group used
the contents of special tabulations from previous Censuses and inputs from
staff of several state and local transportation agencies to develop a draft
of the standard tabulations. Identification of the CTPP2000 tables was
based on the following:
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Data to describe the characteristics of households and their travel to
work;
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Comparability with 1990 CTPP standard tabulations;
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Comments received in the June 25, 1999 meeting of CTPP users;
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Data to support travel forecasting;
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Data to support the FTA New Starts Program;
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Data to support emerging transportation planning issues such as access
to jobs and environmental justice.
OVERVIEW OF TABLES
The Working Group maintained three sets of tables as the structure
for CTPP2000:
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Part 1: At Residence (Home End)
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Part 2: At Workplace (Work End)
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Part 3: Worker Flows
The Working Group rationalized the organization of the tables so that users
know what is being reported in the table and that the information in Part
1: "at residence" tables, could be paired with the information in Part
2: "at workplace" tables, to facilitate and support broader analysis of
the travel behavior of workers.
To accomplish these ends, each set of tables were organized by its content,
i.e., by what is being counted. For Parts 1 and 2, this was the number
of persons, number of households, number of workers, number of housing
units; for Part 3, this was the number of workers traveling from residence
to workplace. Each table was categorized by its universe where the universes
are all persons, all households, all workers, workers in households, workers
in group quarters and all housing units. Cross-tabulations of household
and worker characteristics by travel characteristics were reported for
the same universes in the "at residence" tables and the "at workplace"
tables.
PART 1: AT RESIDENCE TABULATIONS
The "at residence" tables are organized into six distinct groups, reflecting
the content:
-
Characteristics of Persons
-
Characteristics of All Households
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Characteristics of All Workers
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Characteristics of Workers by Residence Type
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Characteristics of Housing Units
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Computed Tables
PART 2: AT WORKPLACE TABULATIONS
The "at workplace" tables are organized into three distinct groups,
reflecting the content:
-
Characteristics of All Workers
-
Characteristics of Workers in Households
-
Computed Tables
PART 3: WORKER FLOWS
The "worker flow" tables provide information on the number of workers
from the residence to the workplace, their household characteristics and
their work travel behavior. This information is organized into two distinct
groups, reflecting the content:
-
Flows and Times
-
Computed Tables
CTPP2000
Documentation
A comprehensive set of documentation for the CTPP can be found on the
MTC (The MPO for the San Francisco Bay Area) website at
http://www.mtc.ca.gov/maps_and_data/datamart/census/ctpp2000/index.htm
CTPP2000 Frequently
Asked Questions
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Who do I call for more information? Call the CTPP Hotline at 202-366-5000.
-
Who got the CTPP2000? The CTPP was initially distributed by the
Census Bureau and USDOT to all State Departments of Transportation and
Metropolitan Planning Organizations. Subsequent distribution is managed
by the Bureau of Transportation Statistics.
-
Is the Data be Available on CDs or DVDs? The CTPP was produced
on CDs with extraction software. It is also available on the Bureau
of Transportation Statistics TranStats website.
-
Is the CTPP2000 Data available on American FactFinder? No, there
are no plans to put CTPP data on American FactFinder.
-
How much does CTPP2000 cost? The CTPP is a pooled-fund product sponsored
by the State Departments of Transportation through the American Association
of State Highway and Transportation Officials (AASHTO). It is already
paid for. Subsequent costs for reproducing CDs to distribute to data
users will be borne by the US Department of Transportation.
-
What software is bundled with CTPP2000? The CTPP2000 data comes
with an access tool. This software is a product that combines Beyond
20/20 and ESRI’s MapObjects. It allows for data extraction, browsing,
exporting, and simple mapping. The mapping component does not
require you to have another GIS package, and it will be able to print maps
and export .shp files. For more complex data analysis and for complex
mapping, you will need to export data files and process them in a spreadsheet,
database, statistical, or GIS package.
-
How will I be able to get CTPP2000 data into my GIS? You can extract
the tables you want for the geography you want with the CTPP2000 Access
Tool (see Question 6 above), and export files in SHAPEFILE format.
Since shapefiles are generic GIS formats, you should be able to open these
files in any standard GIS product.
-
What data format will the CTPP2000 be produced in? The data
on the CDs is in a proprietary Beyond 20/20 format. The CTPP2000 Access
Tool software allows users to export selected data in a number of other
formats, including ASCII, xls, csv, dbf, html, and shp. Complete ASCII
data sets may be obtained directly from the Journey to Work and Migration
Branch of the Census Bureau, along with documentation describing the ASCII
file layouts.
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Where can I find the description of the detailed tables? The table
definitions are at: www.fhwa.dot.gov/ctpp/content.htm
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Is training available for CTPP2000? Because it has become difficult
for many people to travel for multi-day training, or out-of-state training,
FHWA developed an “electronic guidebook” to help data users understand
both general Census data concepts and specific CTPP2000 data concepts.
This is a self-instruction CD-based guidebook that will run on a PC.
It takes approximately 5 hours of time to cover the 11 modules. Copies
are available by contacting Ed Christopher at edc@berwyned.com.
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Where can I get the 1990 CTPP for my area? The 1990 CTPP is
available on CD (12 CDs for the statewide element, and 33 CDs for the urban
elements). These CDs are being distributed FREE of cost by the USDOT Bureau
of Transportation Statistics. You can order the CD-ROMs online at
http://products.bts.gov/.
You can also order by calling 202-366-DATA(3282). The 1990 CTPP came
with TransVu software for easy data access, however, it does NOT work under
Windows 2000 or later versions. TransVu will work under Windows NT,
using a patch available at:
http://www.bts.gov/btsprod/setupnt.exe.
BTS also has the 1990 CTPP data available through it’s online data access
tool called TranStats. These files are in a csv.ascii format and
are downloadable. A data dictionary is available on the CD.
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Where do I get 1990 TAZs to use in my GIS?
There are 3 ways to get TAZ geography that goes with the 1990 CTPP.
a. Get the layer from the ESRI website. The ESRI website has all the
1995 TIGER/Line files converted to shape files available for free. For
more information, please visit http://www.esri.com/data/online/tiger/index.html
ESRI is also supplying enhanced version of TIGER/Line, and tips on using
TIGER/Line along with other spatial databases.
b. Read in TIGER/Line files. Download/order any version of TIGER/Line
from 1994-1998 that contains a TAZ layer from the Census Bureau website
(http://www.census.gov/geo/www/tiger/)
You can either write a program to convert TIGER/Line file to your GIS or
buy any commercial software that can convert TIGER/Line to a GIS Format.
For example, GIS Tools contains a commercial software to convert TIGER/Line
to GIS formats. The website is www.gistools.com.
c. Use Caliper software to read files from TransVu and use in Caliper
software, or use Caliper software to convert proprietary format into shapefiles.
The boundary files are available in CALIPER (.mdx) format on the 1990 CDROM
supplied by BTS. However, these files are in CALIPER proprietary
format. You can open these files in Maptitude or Transcad and convert
the files into shapefile format.
For users of ESRI software who do not have access to a CALIPER product,
a procedure to get 1990 TAZs and attach 1990 CTPP data is posted at http://www.fhwa.dot.gov/ctpp/articles.htm
Page last updated: April 8, 2008
http://www.trbcensus.com/ctpp.html
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