Thank you.
From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of
Elaine.Murakami(a)dot.gov
Sent: Wednesday, January 19, 2011 5:33 PM
To: ctpp-news(a)chrispy.net
Cc: jonathan.ehrlich(a)metc.state.mn.us; geo.taz.list(a)census.gov;
Faella.tom(a)co.la-crosse.wi.us; mark.filipi(a)metc.state.mn.us
Subject: RE: [CTPP] RE: TAZ software training vs. not using the TAZ software
Hi Mark -
1. The Census Bureau Geography Division will need a block equivalency file.
Perhaps the CB geo staff can answer the question of whether the TAZ Instruction will
include a FILE LAYOUT for the output files. If so, then it seems to me that you SHOULD be
able to do the TAZ delineation OUTSIDE of the MTPS TAZ module software, but it would NOT
be the PREFERRED method. The software has checking features, e.g. completeness,
contiguity, etc, such that if you make your own file using the new TIGER files, it will
not have the same quality control features.
2. What other purposes of "Census TAZs and TADs". The current CTPP is
funded to include the 3-year (2006-2008) tabulation and the 5-year (2006-2010) tabulation,
but depending on how things go, future 3-year and/or 5-year CTPP tabulations are possible
if someone wants to pay for them. We think that the Census Bureau should have made a
consistent geographic tabulation unit for the 20,000 population threshold (for the 3-year
ACS), so that there could be complete coverage, instead of the "swiss cheese"
coverage using counties and places, but they didn't and haven't. So, this is OUR
opportunity to do something about it, and maybe we can convince the CB that these units
could be an ACS 3-year tabulation geography in the future. The PUMAs (100,000 population
threshold) provide a consistent geographic tabulation unit for the 1-year ACS, but how
they have been defined has not always been useful to transportation planners. As you
know, PUMAs were not designed to be tabulation units, but have become tabulation
geographic units in the ACS.
3. No one is required to define Census TAZs. If you think that defining Census TAZs
is too much work for the value you will get from CTPP, you can just say to use census
tracts, or block groups for CTPP. However, we still would recommend that you define TADs,
by combining tracts, for the reason listed above.
Elaine
From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of
Flinner, Mark (DOT)
Sent: Wednesday, January 19, 2011 2:46 PM
To: ctpp-news(a)chrispy.net
Cc: jonathan ehrlich; Tom Faella; mark.filipi(a)metc.state.mn.us
Subject: [CTPP] RE: TAZ software training vs. not using the TAZ software
Is there anything to prevent an MPO from creating their own shape files for Census TAZ or
Census TAD boundary/ Block Equivalencies assuming they have already obtained 2010 TIGER
boundary sets?
Also, we am planning a Census TAZ delineation workshop on February 7th to discuss issues
associated with nesting model TAZs within Census TAZs given the relatively low populations
of most of our MPO model TAZs. I had hoped to acquaint people with the software
environment prior to the training sessions at the end of the month but understand that we
are not a testing state. I also expect a discussion of the complexities of obtaining
CTPP special tabulation data then needing to reallocate the data to model TAZ geographies.
Is there anything you can share with us to assist in these areas? I have also received a
question of what other uses (besides the one-time use of obtaining CTPP data) the census
TAZ and TAD geographies have beyond the census year. LEHD On the Map comes to mind...
other uses?
Thank you.
From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of
Elaine.Murakami(a)dot.gov
Sent: Thursday, January 13, 2011 5:25 PM
To: ctpp-news(a)chrispy.net
Subject: [CTPP] TAZ software training: WEB ONLY scheduled for Friday, Feb 25 and Monday,
Feb 28
As you know, TAZ delineation by State DOTs and MPOs will occur very soon, with software
distribution in March/early April and files returned to the CB by mid-July. The software
is being tested by volunteer State DOTs and MPOs starting from Friday, Jan 14 thru Feb 2.
Thank you to all the volunteers! We do not need any additional software testers.
We have two web training events scheduled. REGISTRATION IS REQUIRED. Please make sure
that you capture the full http:// address, in case the listserv breaks it up. You need
the address including webconfid=22433, or webconfid=21975
I have reserved 300 spaces for each day, so there should be enough room for everyone. If
you are unavailable on those days, the sessions will be recorded and available for later
viewing. The same training will occur on each day, so please sign up for only one.
The web meeting software has been upgraded, therefore, the email with the confirmation of
your registration will have a link to check the functionality on your computer.
Friday, 2/25/2011, from 10 a.m. - noon EASTERN:
Registration URL:
https://www.nhi.fhwa.dot.gov/resources/webconference/web_conf_learner_reg.a…
Monday, 2/28/2011, from 2 - 4 p.m. EASTERN:
Registration URL:
https://www.nhi.fhwa.dot.gov/resources/webconference/web_conf_learner_reg.a…
Question: why is the time to do this only 3 months?
Answer: For the TAZ and TAD delineation, it is important to be able to use the TIGER
files with the 2010 geography and 2010 population counts. The 2010 population counts will
be released to the public on a flow basis starting in March 2011, so we have to wait until
these data are available to begin TAZ and TAD delineation. If the 5-year CTPP using
2006-2010 ACS records will be tabulated for TAZs and TADs, the TAZ and TAD delineations
need to be completed quickly and returned to the CB Geography Division (GEO) 3 months
after the agencies receive their files (no later than July 2011).
This provides GEO with sufficient time to QC the submissions, produce the necessary files
so that ACS records will get TAZ/TAD identifiers, and create TIGER/Line shapefiles for
TAZ/TAD geography. If the TAZs and TADs
are not delineated within this time frame, the CTPP tabulation could be delayed for
another year, that is, Fall 2013.
Question: are there strict thresholds on either residential population or workplace
population?
Answer: No. The software will give a warning message, but will still allow you to define
TAZs below the recommended "threshold." (The FAQ will include more discussion
about this topic.)
We are working on an FAQ document on TAZs and will post it on the AASHTO CTPP page.
http://ctpp.transportation.org/Pages/taz.aspx
Elaine Murakami
FHWA Office of Planning
206-220-4460