RE: [CTPP] Re: Geographic coverage, C2SS & ACS - ctpp-news

8 Nov 2001

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
all.

. . Jamsheed Mehta, AICP
    Chief Planner, Transportation Division
    Wichita-Sedgwick County
      Metropolitan Area Planning Department
    Tel:   (316) 268-4457
    Fax: (316) 268-4390
    e-mail: mehta_j(a)ci.wichita.ks.us

-----Original Message-----
From: ed christopher [mailto:edc@berwyned.com]
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
data responsibilities.
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 tab
...
  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.

 Patty Becker 
---
Ed Christopher
Metropolitan Specialist
Midwest Resource Center
Federal Highway Administration
19900 Governors Drive
Olympia Fields, Illinois  60461
708-283-3534 (V)
708-283-3501 (F)