<br><font size=2 face="sans-serif">Mr. Paddock:</font>
<br>
<br><font size=2 face="sans-serif">It's safe to say that one set of TAZs
will not be able to cover both these needs for you. There's been
discussion here before about developing two or more sets of TAZs just for
different levels of disclosure problems with 2010 CTPP (ACS) data alone.
You'll need at least one more set for traffic modeling, where you
can geocode the address-based, Census block and other small area data not
subject to these disclosure problems and than from there aggregate to the
level needed for the model.</font>
<br>
<br><font size=2 face="sans-serif"><br>
Sam Granato<br>
Ohio DOT, Office of Multi-Modal Planning<br>
1980 W. Broad Street, Columbus, OH 43223<br>
Phone: 614-644-6796, Fax: 614-466-0822<br>
"It's all very well in practice, but it will never work in theory."
- French proverb</font>
<br>
<br><font size=2><tt>I must admit that, of late, I have gotten lost in
the woods while trying to see all the trees. During these past months
I have been engaged in developing a new TAZ system for the Minneapolis
- St. Paul MPO area that will both serve the needs of travel demand modeling
here at the Metropolitan Council AND provide us with the information we
want from a 2010 CTPP-like product.<br>
<br>
This new TAZ system is substantially more refined than those of the past
and should result in reasonable travel loadings on our arterial roadway
network. However, certain issues have been raising their knobby heads
regarding zone size that probably will clash with Census Disclosure Board
rules. Does anyone have a reasonable idea as to what minimum population
or household levels a TAZ will need to attain in order to circumvent large
numbers of "blank" cells? I suspect that there is not an
easy, uncomplicated answer but would like to hear one nonetheless.<br>
<br>
<br>
Bob Paddock<br>
Transportation Planning<br>
Metropolitan Council</tt></font>