I would assume that TAZs would need to meet the minimum size criteria for block-groups to avoid significant suppressions.  Looking those up now . . . 240 households or 600 persons.

Frank Lenk

Director of Research Services

Mid-America Regional Council

From: ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Paddock, Bob
Sent: Tuesday, August 04, 2009 3:33 PM
To: 'ctpp-news@chrispy.net'
Subject: [CTPP] TAZ Development

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.

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.

Bob Paddock

Transportation Planning

Metropolitan Council

Bob.paddock@metc.state.mn.us

651 / 602-1340