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@census.gov).