I’ll
just jump in. I am on the CTPP Oversight Committee that prepared the
“Business Rules” for delineating the TAZs for which Census will report the
data.
Census
has been collecting journey to work data through the American Community Survey
nationwide since 2006 that will go into the CTPP 2006-2010 tabulation.
They need all of us FIRST to delineate our TAZs for them to create the
tabulation. So you won’t be able to wait to see the data first in order to
determine how best to delineate your TAZs.
Sometime
around December of this year, the 2005-2009 5-year dataset will come out,
providing data down to the block group level (2000 census block group
geography), and you may find that useful in determining how you want to
delineate your TAZs. It won’t be exactly what you are looking for
geographically, the standard tables will not be as specifically tailored to
transportation modelers, and the data won’t be benchmarked to this year’s
decennial census like the 2006-2010 dataset will. But it may give you some
useful data.
Pete
Swensson, Senior Planner
Thurston
Regional Planning Council
2424
Heritage Ct. SW
Olympia,
WA 98502
(360)
741-2530 (direct line)
(360)
956-7575 (main desk)
(360) 956-7815
(fax)
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From:
ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On
Behalf Of Curt Hutchings
Sent: Friday, October 08, 2010 12:20
PM
To: ctpp-news@chrispy.net
Subject: [CTPP] RE: TAZ
delineation for CTPP (2006-2010) tabulation
SCHEDULE
Elaine,
Please excuse my
ignorance. I have had questions about how the Census Dept. would collect
TAZ data for the Census. I have been waiting for information like you have
provided below. Can you give me any additional information? We are
in the process of modifying our TAZ structure now and want, If possible to use
the new information in this count. Any thoughts?
Thanks,
From:
ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On
Behalf Of Elaine.Murakami@dot.gov
Sent: Wednesday, October 06,
2010 10:32 AM
To: ctpp-news@chrispy.net
Subject: [CTPP] TAZ
delineation for CTPP (2006-2010) tabulation SCHEDULE
At our monthly CTPP Technical meeting last week, April
Avnayim of the Census Bureau Geography Division, gave us an update on the TAZ
delineation software schedule.
November 2010: agencies verify contact names by
reviewing file at Cambridge Systematics ftp site, and report any changes to
Liang Long.
December 2010: final delivery of software by Caliper to
CB
February 2011: web-based training coordinated with FHWA
January thru March 2011: delivery of software and
Census 2010 data and geographic files on a rolling basis.
Each state will get 3 – 4 months to delineate their TAZ and
TADs and return the files to the Census Bureau.
July 2011: all files MUST be returned to CB Geography
Division.
Please note: TAZs for CTPP tabulation do not
necessarily match the TAZs for your travel demand model. Because the ACS
sample is small, some agencies are planning to make the TAZs for CTPP LARGER
than their model TAZs, e.g. combining their model TAZs together. Also, TAZs for
CTPP are census block equivalencies. You will NOT be able to modify the
TIGER segments (which was possible in the CTPP2000). Finally,
agencies are NOT required to define TAZs or TADs. If you do not define
TAZs, then census tracts will be used as the default geography for CTPP
(2006-2010) tabulation. However, even if you do not define TAZs, we
recommend that you create TADs (population threshold of 20,000) by combining
census tracts together.
The TAZ business rules are posted on the FHWA webpage: http://www.fhwa.dot.gov/ctpp/tazddbrules.htm