Its my understanding that "Tracts" are based on population criteria
(minimum, optimal, and maximum number of persons). TAZs may be too small in
some cases to fit the "tract" definition, or may not have any population at
. . Jamsheed Mehta, AICP
Chief Planner, Transportation Division
Metropolitan Area Planning Department
Tel: (316) 268-4457
Fax: (316) 268-4390
From: ed christopher [mailto:firstname.lastname@example.org]
Sent: Thursday, November 08, 2001 3:37 PM
To: 'ctpp-news maillist'
Subject: Re: [CTPP] Re: Geographic coverage, C2SS & ACS
since patty raised the issue of tracts, i have often wondered why do we have
tracts? why don't we
have a zonal system in urban areas that is created by the public data
users--something like TAZs. in
many areas the TAZs are developed by a collection agencies with planning and
if memory serves me tracts were historically a creation of the census bureau
which is a data
collector. TAZs are a product of regional planning organizations (which
happen to have
transportation responsibilities) which are data users.
Patty Becker wrote:
Again, please feel free to post this to the list serve
if you wish.
My clear understanding is that "small area" means tract. I don't think
anyone thinks the 60 month data will be good enough for block groups.
If TAZs are tract equivalent, then the data should be as good as for
tracts. For heavy attractor TAZs which are split below tract level, the
transportation community has to negotiate with the bureau for a special
to deliver all TAZs. The data should support the tab
adequately, Meanwhile, of course, someone is going to have to be
responsible (MPO by MPO and state by state) for keeping the geocoding file
up to date!
No one knows whether these 60 month data are going to "feel right." Only
time will tell. But in any event the CTPP users will have data equivalent
to that for all users who use tracts. Meanwhile, we still have all these
hurdles in Congress, etc. etc.
Midwest Resource Center
Federal Highway Administration
19900 Governors Drive
Olympia Fields, Illinois 60461