Subcommittee on Census Data for Transportation Planning
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C T P P  2 0 0 0  Status Report
September 1999
a product of the CTPP Planning Group  
Special TAZ-UP Caution
TAZs  Due
October 1, 1999
LREF Now Called Workplace Update
Data Collection Programs for MPOs and State DOTs: Beyond CTPP
Meet the CTPP Working Group 

1990 CTPP Used in Economic Study
of  Large U.S. Cities
We Want Our Cake
We Want to Eat it Too!!
TRB Subcommittee
Message from the
CTPP Contacts
Web Sites to Remember
Bureau Regional 
Office Contacts

TAZs are Due on October 1, 1999

Most of you are working hard to complete your TAZ definitions to be submitted to the Census Bureau Geography Division.

Why are they due on October 1, 1999?
One of the goals of the CTPP Working Group is to get the CTPP 2000 data delivered earlier than in previous decades.   Defining TAZs now will improve our chances of getting the CTPP data  delivered to us by late 2002 or early 2003.  TAZs will be added to the tabulation geography of the individual records rather than in a post-processing step using equivalencies  between census blocks and TAZs, as was done in 1990.

The Census Bureau will enter the TAZ geography  into the central TIGER database between October ‘99 and Jan ‘00.  They will issue TIGER/Line 99 in early 2000 for the TAZ verification phase.  TIGER/Line 99 will include TAZs that you have submitted as well as (near final)  2000 Census tract boundaries.  You will have an short window (about one month) of opportunity to review your TAZs and make corrections to submit to the Census Bureau.

Is October 1 the real deadline?
No, October 1 is the “official” deadline.  However, the Census Bureau Geography Division recognizes that errors in some of the TIGER files caused delays in delivering some of the TIGER/Line 98 files to you for the TAZ-UP program.  However, if you cannot meet the October 1 deadline, you MUST send an email to on or before October 1, and let us know that you still plan to submit TAZs but will be late. You must submit your TAZs by October 29, 1999.

How do I submit my TAZs?
The instructions for submittal are on page 9 of the “Reference” section of the TAZ-UP manual.  If you are not using TAZ-UP, you should have received paper instructions on the file format and submittal instructions.  If you have questions, please send an email to, or call 1-202-366-5021, to ask Nanda Srinivasan for assistance.  If you have difficulty with the electronic file submission to the Census Bureau, please call Valerie Murdock at 301-457-1099.


Special Cautions on Using Municipal Boundaries or MCD Boundaries 
An email notice was sent on July 23, and a letter was mailed on August 6, notifying all CTPP participants of an error in TAZ-UP.  This reiterates those messages.  The TAZ-UP software inadvertently reads in the 1990 Municipal and MCD boundaries rather than the 1998 boundaries.  If you want to use Municipal or MCD boundaries which are (acceptable) non-visable features as part of defining your TAZs, you should email Kim Brace of EDS at and let him know for which counties you need the correct 1998 boundaries.
Troubles with Your TAZ-UP Process?

Visit our Frequently Ask Questions at
Call our CTPP HotLine at 202-366-2000 
Email us



LREF Now Called Workplace Update (Work-UP)

The Local Review of Employer Files (LREF) program that described in previous CTPP Status Reports has undergone a name change.  This project is now being called the Workplace Update (Work-UP).  The new name still relays the overall nature of the project and highlights the similarities with the TAZ update project that is currently underway. Both programs involve the use of an extension to ArcView GIS with the TIGER/Line 98 files and local updating.

Under the Work-UP project, MPOs will use an extension to ArcView GIS to evaluate the commercial employer database Census licensed for their area.  The extension will include the following capabilities:

1) Sort the file by ZIP code, street name, type of business, number of employees, or census geography (such as tracts or block groups). 
Address Match
Own Employer
File to TIGER'98
2) Select and work on only those records the Census Bureau was not able to geocode. 
Add New
3) Add employer names and addresses to the file.
Names and 
Addresses and 
4) Correct the names and addresses of employers, re-geocoding the address 
against the TIGER/Line 98 file and placing a new point on the map.  If the new address cannot be geocoded, the user will be able to assign the employer record to a point by clicking on the employer's location on the map.

Any changes or deletions made by the MPO will be written to a transaction file which will be returned to Population Division at Census.  The verified employer list will be used in place-of-work block coding after the 2000 Census.  The automated phase of the coding will use both the address and the employer name information provided by the respondents and choose the best match.  For responses that fail automated (machine) coding, Census Bureau clerks will attempt to geocode them using both the address and employer name information. Thus the quality and completeness of the employer database will directly affect the quality of the place-of-work data released in the CTPP 2000.

Progress implementing the Workplace Update project has been slow, and as a result the schedule has slipped.  The process to contract with a vendor to produce an ArcView extension is finally well underway at Census and should be completed this month.  Shipment of the employer files and Work-UP extension to the MPO’s will probably not occur until late November or early December.  This will constrict the amount of time MPO’s have to review the file to four months, instead of the six months we were hoping for.  Once the contract is in place for the development of the Work-UP extension, the Census will contact the MPOs by mail to find out who is interested in participating in the program.  In the meantime, questions can be referred to Clara Reschovsky or Phil Salopek in the Journey-to-Work and Migration Branch at (202) 366-5000, option #4, or (301) 457-2454.


Meet the CTPP Working Group 
Because there have been so many changes in the working group, here is a summary of the people working on the project. 
Nanda Srinivasan  Nanda is the main contact person for CTPP at USDOT.  Nanda started on August 16.  He is a contractor working for Cambridge Systematics and is physically located at FHWA in Washington, D.C.  Debbie Buchacz  Debbie is our AASHTO contact.  AASHTO sponsors the CTPP 2000 as a pooled fund project with the State DOTs, so that the work is completed under one contract with the Census Bureau.  AASHTO has sent out the invoices for the CTPP already and the funds are due by November 1. 
Elaine Murakami  Elaine works in the FHWA Office of Highway Policy Information.  She has been serving as the chair of the CTPP working group.  Ed Christopher  Ed is the chair of the TRB Subcommittee on Census Data.  Ed is on leave of absence from the Chicago Area Transportation Study (CATS) and is working at the Bureau of Transportation Statistics.
Phil Salopek  This will be the third decennial census transportation package that Phil has worked on.  Phil is chief of Journey-to-Work and Migration Statistics Branch in the Population Division of the Census Bureau.  He is the person who is responsible for the actual CTPP production.  Valerie Murdock  Valerie Murdock is a member of the Geographic Areas Branch, Geography Division.  She is the contact for questions about Census Geography and equivalency file submissions.
Clara Reschovsky  Clara started working for the Census Bureau in the last year.  She is working with Phil Salopek on CTPP. Jim Ryan   Jim is chief of the Innovation Division of the FTA Office of Planning. Jim returned to FTA in July 1999, after 13 years as a consultant in travel forecasting and project planning.
Paul Branch   Paul works for the FTA Office of Planning Operations.  Mark Sarmiento  Mark works in the FHWA Office Of Metropolitan Planning and Programs. 

We Want Our Cake, and We Want to Eat it Too!!

Invited session on CTPP tables held
On June 25th, the Bureau of Transportation Statistics hosted a working group to discuss the standard set of tabulations to be produced for the CTPP 2000.  Attendees came from different sectors of the transportation planning field including large MPOs, small MPOs, state DOTs, transit agencies, and private consultants.   The highest priority expressed by the group was the wish for custom tables on demand. Paul Reim from the Central Transportation Planning Staff (CTPS, the MPO for Boston) summed up the general sense of things as, “Keep everything and give us more!”

Standard CTPP
First, the group agreed that the traditional CTPP package of standard tabulations should be produced.  One basic requirement for the CTPP is to maintain compatibility between the 2000 and the 1990 packages. It will cover all the basic tables, especially those which have typically been used in the 4-step travel forecasting models, while adding new tables to meet the transportation planning needs associated the Americans with Disabilities Act, Environmental Justice, and Welfare-to-Work.  Some examples include the number of vehicles available in a household by race; poverty status by mode to work; and, the travel time to work by earnings.

The group also recommended that standard deviation on the means for variables such as travel time should be added to the package.  As the final tables are drafted the CTPP Planning Group will share the list with the transportation planning community for review and comment.

Tables on Demand
The attendees used many of the tables in the 1990 CTPP, but they sometimes needed tables that were not part of the package.  There were two methods to meet these demands.  First, contract with the Census Bureau for a special, individual tabulation, and second, to use another source such as the Census Public Use Microdata Sample (PUMS).  A system for tabs-on-demand could greatly reduce the need for these two alternatives.  It could provide a faster way to obtain custom defined tables and reduces the programming time and money needed to produce standard tabs.

At the Census Bureau, a tabs-on-demand program is being developed and called the American Fact Finder.  It is online at  This system will provide the Census 2000 data across a variety of subject areas summarized at their home or residential location.

A critical question concerns the role that American Fact Finder can play in fulfilling the transportation planning needs. The key difference between standard census tables and the CTPP has been the use of the workplace geography as a summary level.  The CTPP 2000 Planning Group is grappling with the practical issues of how to provide tabs-on-demand and at the same time address disclosure and geographical concerns. Another issue is whether or not the American Fact Finder can be augmented to accommodate the transportation planning needs or should a separate query system be developed.

Given the concerns of the invited group of CTPP data users, two separate paths will be pursued.  CTPP 2000 will include many of the same tables as the 1990 CTPP for Statewide Elements Parts A, B and C and the Urban Elements Parts 1, 2, and 3.  The CTPP Planning Group will work diligently to develop a tabs-on-demand system which meets both the needs of the transportation community as well as the Census Bureau's needs regarding confidentiality.   The CTPP Planning Group is striving for the overall goals of speedier delivery, better employer geocoding, improved delivery mechanisms and high quality data.


Data Collection Programs for MPOs and State DOTs : Beyond CTPP
By Paul Branch, FTA

The CTPP 2000 data in combination with other regional surveys can be very beneficial to transportation planners. Transit operators, Metropolitan Planning Organizations (MPOs) and State Department of Transportation should be deciding what other data should be collected in conjunction with, or in close proximity to the decennial census. This will ensure supplemental data collection efforts, surveys, and studies that support the usefulness of CTPP 2000 are collected to parallel census data.

At the regional level, the CTPP is well suited to the task of estimating and validating trip distribution and modal choice models for journey-to-work. However, journey-to-work data from the CTPP may be too coarse for detailed route-level transit planning or fine-tuning an existing service.  Census data can be supplemented by on-board ridership surveys, on-off counts, and other sources to carry out finer analyses. Surveys done in conjunction with the decennial census are important because the Journey to Work question in the Census addresses only one mode, and not multiple modes. For example, if a person drives to a park and ride, and then rides a bus or a rail, it is not reflected in the data. Secondly, the issue of trip chaining is not addressed, and we know that many workers make stops on their way to work, e.g. to drop off a child.

The transit operations planners are responsible for efficiently tailoring the supply of transit service to meet anticipated or actual demand.  Primarily, the transit operations planner has two major objectives; to maximize service effectiveness and its efficiency.  Census data supplemented by other auxiliary data can help in addressing these objectives by providing information on travel characteristics and socioeconomic characteristics. CTPP provides data on residence to work flows. The data such as population, age of residents, number of physically handicapped people, income levels, vehicle ownership etc., can help in efficiently addressing transit operation issues. The CTPP can provide data to understand ridership markets. MPOs and transit operators should consider surveys independent of the decennial census to augment the CTPP data. For example, the Delaware Valley Regional Planning Commission (DVRPC) has developed a number of transportation surveys (planned over several years) to supplement CTPP 2000 data.   A few of these surveys include:

Through the metropolitan transportation planning process, the Federal Transit Administration (FTA) and Federal Highway Administration (FHWA) jointly fund transportation planning activities in urbanized areas by formula to the States. These additional surveys can be included in your Statewide and Unified Planning Work Programs.

1990 CTPP Used in Economic Study of Large U.S. Cities

Regina Armstrong of Urbanomics presented a paper entitled “Economic and Social Relevance of Central Cities in the Nation’s 12 Largest Urban Regions” as part of the TRB conference on “Transportation Issues in Large U.S. Cities” held in Detroit, Michigan in June, 1998. This article is summarized from that paper.

The original intention of the Census Transportation Planning Project was to assist transportation planners with their models.  However, its uses have expanded to include other areas of study, particularly economics and economic development. This paper examines the twelve largest metropolitan regions in the U.S., using the CTPP to look at the distribution of employment in comparison with residential population.

Armstrong points out that large urban areas are the most diverse in terms of socio-economic characteristics such as race and ethnicity, nativity, language spoken, educational attainment, household formation, household mobility, and labor force participation.  While the population of these areas looks different from the rest of the country, that population takes one third of all work trips, on just 3 percent of the land area of the U.S.  The density of these regions separates them from the rest of the country.

One single factor that makes large urban areas different from other areas is immigration.  Most immigrants to the U.S. settle in a large city, which affects languages, education, household make-up, labor force participation and demand for employment.  This is a trend that will continue to influence the conditions of large urban areas well into the next century.

Of jobs in the U.S., other than agriculture and self-employment, about 34 percent are located in the 12 largest urban regions.  However this employment represents about 45 percent of the gross domestic product (GDP).  The difference is due to higher productivity and profitability of many employers in large urban areas.  Most jobs in the major central cities are white-collar jobs that require higher educational attainment than many city residents can provide.  “Whereas the 14 central cities had a net shortfall of 2.9 million workers for their job locations, the suburbs had a surplus of 3.5 million workers.” (p. 133).  As a result, there is a significant discrepancy between city residents and city jobs.  Clearly an important result of this discrepancy is commuting between cities and suburbs and in recent years between suburbs. Often workers are not compatible with the jobs near their home.  The CTPP can help to identify these mismatches allowing planners to try and alleviate the problems.

Another part of the economic conditions of central cities, urban regions, and the rest of the country that needs to be considered by transportation planners is the proportion of expenditures by the federal government on each of those regions.  Looking at large urban regions as a whole, their proportion of federal funds is about proportionate to their populations, but not their earning capacity.  Narrowing in on central cities, that proportion is larger. However, it is in line with the cities’ portion of the GDP. The CTPP can provide data on worker characteristics at the work end to figure out the economic ramifications of worker earnings with their residential locations.

While the CTPP cannot answer all of the economic questions facing planners in large urban regions, it is a unique source of data about workers characteristics and residential choices that can help transportation planners and economic developers to increase the vitality and coordination of these regions as a whole.

The Conference Proceedings are published in Transportation Issues in Large Cities, Conference Proceedings 18" TRB.  Contact TRB at 202-334-3214, email: for a copy of the proceedings.


TRB Subcommittee:  Message from the Chair

By now everyone should be almost finished defining their TAZs and have turned them into the Census Bureau for review.  For those individuals with TAZ questions, check the "Frequently Asked Questions" posted on the subcommittee's
Website at:

Looking back on June 27th and 28th, the Data Committees of TRB met for their mid-year meeting in Washington DC.  At the meetings the Subcommittee made the record books by hosting the first ever webcasted session in TRB history.  The speakers at the session, entitled "The Reality of the American Community Survey for Transportation" raised many of the questions that are facing the transportation planning community as it looks towards the changes brought on by a continuous survey methodology.

The webcast, which was lead by Committee on Information Systems and Technology, allowed remote users to log onto the Internet and hear the presentations and see the session material without the need to travel to Washington.  Oscar Franzese, from the Center for Transportation Analysis at the Oak Ridge National Laboratory, developed the webcast.  It is currently available on-line at  To listen and view it, users will need the correct media players.  "How to" information is also available from the Oak Ridge web page.  Questions about the webcast can be directed to Oscar at or 423-576-8682.

Looking ahead, Census issues will be discussed at two different sessions during the TRB annual meetings in January.  The first discussion will be part of a larger data session that will address the overall 2000 Census.  The second session, sponsored by the subcommittee, will focus exclusively on the details of CTPP 2000.  At this session we will hear a discussion of what will happen next with regard to TAZs, see a demonstration of the Workplace Update Software (Work-UP) previously known as LREF, and discuss the table content and distribution mechanisms for the final CTPP.  The TRB annual meetings will be in Washington D.C. from January 9th through the 13, 2000.

Ed Christopher
Chair, TRB Subcommittee on Census for Transportation Planning


"Surf's Up"   Web Sites  to Remember


CTPP Hotline   202-366-5000

CTPP Contacts
TRB Committees
Ed Christopher (Census Subcommittee Chair) 
PH: 202-366-0412 
FAX: 202-366-3640 
Chuck Purvis (Urban Data Committee Chair)
PH: 510-464-7731
FAX: 510-464-7848
Ed Limoges (Census Subcommittee Secretary)
PH: 313-961-4266 
FAX: 313-961-4869
Ron Tweedie (State Data Committee Chair) 
PH: 518-457-1695 
FAX: 518-457-8317

Census Population Division (JTW questions)

Phil Salopek 
PH: 301-457-2454 
FAX: 301-457-2481
Clara Reschovsky
PH: 301-457-2454
FAX: 301-457-2481

Census Geography Division (for TAZ-UP questions)
Jamie Rosenson
PH: 301-457-1099 
FAX: 301-457-4710 
Valerie Murdock
PH: 301-457-1099 
FAX: 301-457-4710 
Bob LaMacchia 
PH: 301-457-1022 
FAX: 301-457-4710

Elaine Murakami 
PH: 202-366-6971 
FAX: 202-366-7742
Nanda Srinivasan 
PH: 202-366-5021 
FAX: 202-366-7742
Mark Sarmiento
PH: 202-366-4828
FAX: 202-366-3713

Ed Christopher
(See under TRB Committees)
Paul Branch
PH: 202-366-6694
FAX: 202-493-2478
Jim Ryan
PH: 202-366-0954
FAX: 202-493-2478
Deborah Buchacz
PH: 202-624-5839
FAX: 202-624-5806


Census Bureau Regional Office Contacts
For up-to-date Regional Census Center information go to

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