Jonathan,
Our Agency, the Pueblo Metropolitan Planning Organization, has used TELUM to develop
forecasts of population, housing and employment with moderate success. Although our
ultimate intent was to develop forecasts for the 306 individual transport analysis zones
within our jurisdiction, our initial set of TELUM forecasts were for the 40 census tracts
that comprise our region. We did not use TELUM to forecast by individual TAZ's, but
rather used the tract forecasts which TELUM developed as control totals for the more
detailed zonal forecasts.
You are certainly correct in your assessment of the amount of time and effort required to
obtain input data to calibrate and run the model successfully. We had the assistance of
several individuals with expertise in ArcGis to facilitate this process, otherwise, the
constraints to obtain the data might have been unmanageable. The TELUM documentation,
pages 4.5, 4.6, seems to imply that the larger the geographic area, the more reliable the
forecasts developed by TELUM. For this reason, our run of the TELUM model was based on
census tracts.
In the calibration phase, you may have a situation where not all of the statistical
parameters used to obtain a reality check are consistent. I would suggest that you may
wish to run the model anyway, even though one or two of the statistical tests are 'off
the wall.'
We used TELUM to forecast to 2035. In the broadest sense of the word, the TELUM forecasts
seemed reasonable, although there may be a number of zones where the results just
don't make sense. In these cases, you will have to use rerun the model. TELUM has a
useful feature allowing you to constrain growth within certain zones before you rerun it.
The single most recurring issue I had with the TELUM forecasts is that they tended to over
forecast population growth within older, developed residential areas of our metro area.
Some changes in density patterns over time in these areas can be expected, just now to the
extent that TELUM suggested.
I would reiterate that using a top-down approach may have merit. Use TELUM to develop a
set of regional (tract level) forecasts, then subsequently use the tract forecasts to
forecast to a finer geographic level. You're right. TELUM requires a lot of work.
Don R. Vest
Pueblo Area Council of Governments
Urban Transportation Planning Division
223 N. Santa Fe Ave.
Pueblo, CO 81003
Tel. (719) 553-2947 (direct)
-----Original Message-----
From: ctpp-news-bounces(a)chrispy.net
[mailto:ctpp-news-bounces@chrispy.net]On Behalf Of Jonathan Lupton
Sent: Friday, July 18, 2008 8:10 AM
To: ctpp-news(a)chrispy.net
Subject: [CTPP] TELUM
Follow members of the CTPP listserve:
Although this is not technically a CTPP issue, it is related. My
organization is trying to use the NJIT's new land use modeling software,
TELUM. We have spent a lot of time and effort putting together the data
inputs for this model, but cannot make it work reliably. So I am
querying my fellow MPO's and other transportation/land use modelers and
planners: has anybody had much luck with TELUM? For that matter, any
luck with TELUM's predecessors, DRAM and EMPAL?
I am trying to decide whether or not to continue using TELUM for our
upcoming transportation model. NJIT staff have been helpful, but they
are half a continent away and after two or three months of devoted
effort our model still crashes on calibration. I may have to scrap TELUM
and go back to conventional methods. I would appreciate any ideas, tips,
etc. Thanks!
Jonathan Lupton
Research Planner
Metroplan
Little Rock AR
501-372-3300
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