Yes, these are the business rules agreed upon by AASHTO and the Census
Bureau Geog division.
[mailto:firstname.lastname@example.org] On Behalf Of Paul Tiley
Sent: Monday, July 12, 2010 12:30 PM
Subject: Re: [CTPP] TAZ delineation in Calendar 2011
I hadn't heard anything about the Business Rules being finalized. Are
the rules at the URL below the finalized rules?
My Email address is changing to Paul.Tiley(a)txdot.gov by early August.
>> <Elaine.Murakami(a)dot.gov> 7/8/2010 3:59
Dear Everyone -
We are awaiting the delivery of the first 3-year CTPP using 2006-2008
ACS records. This CTPP is restricted to large geography (county, places
with 20,000 population and over). Our goal was to have web-accessible
data in September 2010, but today we learned that the CB now has a delay
of 2 weeks, which MAY impact the delivery schedule from Beyond 2020 and
Citygate, the CTPP data access software vendors. We will keep you
In the meantime, you are probably putting together your annual workplans
and I want to remind everyone who plans to submit TAZ (and TADs) for the
5-year CTPP tabulation to include labor hours for Spring and Summer 2011
for this task.
For a copy of the TAZ delineation business rules:
Q. Do you have to define TAZs or TADs?
A. No, you can still get CTPP tabulations for Census tracts or
Census block groups if you do not want to delineate TAZs.
Q. What is a TAZ and what is a TAD?
A. A TAZ is a Transportation Analysis Zone and is the smallest
geographic unit for which the CTPP tabulations will be provided. A TAD
is a Transportation Analysis District, and will either be an
accumulation of TAZs, or accumulation of tracts, to total approximately
20,000 population. This will provide a geographic unit that is smaller
than a PUMA (100,000 population), and larger than a census tract (4,000
population). The TAD is larger geographic unit which has the potential
to be used in nation-wide tabulations for 3-year ACS tabulations in the
Q. What process will be used to submit TAZs?
A. some of you probably saw the Caliper announcement that they will be
developing the software for the Census Bureau's Geography Division for
this part of the CTPP. It will be a GIS-based application and will not
require you to purchase or license any additional software. It will be
a block-equivalency program. That is, you are restricted to existing
Census-defined blocks. This means that your agency's TAZ for your
forecasting model may not exactly match the TAZ submitted for the CTPP
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