If you are interested in changing TAZ boundaries or adding new TAZs, Caliper has two
products that you will find very useful: Maptitude for Redistricting and TransCAD
AutoDistrict. Please take a look at our web site, http://www.caliper.com/mtredist.htm
Director, Government Services
4819 Cumberland Ave.
Chevy Chase, MD 20815
----- Original Message -----
From: Nanda Srinivasan
Sent: Thursday, June 21, 2001 12:09 PM
Subject: [CTPP] Attention: Agencies that want to define new TAZs or alterTIGER/Line 2000
Agencies have written to the CTPP Working Group asking:
If TAZs defined in TIGER/Line 2000 can be altered/changed.
Can an agency submit new TAZs in Urban areas based on TIGER/Line 2000 geography for CTPP
The CTPP Working Group met on June 14, 2001 to discuss these issues. We decided that
agencies could define new TAZs or alter TAZs in TIGER/Line 2000 and obtain CTPP 2000 data
reported for the new TAZs. However, agencies must use Census 2000 tabulation blocks to
build new TAZs or alter existing TAZs. In effect, an equivalency file between census
blocks and TAZs will be built and used, as was done in previous censuses.
However, due to processing issues and schedule considerations, agencies wishing to do
this should note the following:
1. Cost: To change TAZs or define new TAZs, agencies must separately contract with the
Census Bureau, Journey to Work Branch, and work out a process and cost for defining and
obtaining CTPP 2000 data based on the new TAZs.
2. Schedule: CTPP data will be processed for those agencies after the Standard CTPP 2000
products are released for the whole country. Currently, the expected completion date for
CTPP 2000 is June 2003.
3. Exclusion of the changes from TIGER/Line database: There are no plans or processes in
place to include new TAZs in the TIGER/Line database. Thus, the changes will not be
reflected in TIGER/Line 2000 and it is unlikely that new TAZs will be inserted into TIGER
until the next round of TAZ updating, the date of which has not been scheduled.
For more information, please contact Phillip Salopek, Census Bureau, Population Division
(Journey to Work Branch) at 301-457-2454 (e-mail: phillip.a.salopek(a)census.gov).