Wednesday, January 18, 2006

New Study: Put Housing Near Transit

The D.C. Examiner writes today about results of an ongoing study on how the Washington, D.C. region should plan its land use and transportation.
'The study found that plans based around jobs and transit would decrease travel time in the region by 10 percent due to shorter trips and more transit use, said Ron Kirby, a regional transportation planner.If the additional people follow current trends, traffic and housing situations would get worse, Kirby said.'
The Metropolitan Washington Council of Governments is the group responsible for the study; here's a link to the study's web page.


At 3:45 PM, Blogger Ray Hyde said...

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At 3:51 PM, Blogger Ray Hyde said...

"The study found that plans based around jobs and transit would decrease travel time in the region by 10 percent due to shorter trips and more transit use, said Ron Kirby, a regional transportation planner."

How wrong and mis-stated does this sort of thing need to be to put the entire study in doubt? No one can possibly believe that new development will decrease travel time in the region by 10%. The study made no such finding.

The study did not find developments based around jobs and transit decrease travel time in the region by 10 percent.

What the study did was make the unproven prediction that if such development ever occurs, then it would result in 10% reduction travel that would otherwise occur with respect to those developments. That is still an increase in total traffic and a lot different from a regionwide 10% reduction.

We will need to build those developments and measure the results before we can make such "findings".

Taken together, the possibility that the developments might get built, and that they might result in some reduction in the increase of traffic is an enormous difference from what is stated in the quote.

At 4:52 PM, Blogger Jim Wamsley said...

What did the study find?

That if we keep going as we are going, Daily Vehicle Miles Traveled will go from 109 Million in 2000 to 150 Million in 2030. That’s a 37% increase.

Meanwhile Freeway and Arterial Lane Miles will go from 15,300 Miles in 2000 to 17,600 lane miles in 2030. That’s a 16% increase.

The rest of the study compared Scenario’s to the 2030 base line. That means savings in Daily Vehicle Miles Traveled by Scenario is (in 2030):
More Households – 1.95 Million miles saving
Households in – 1.35 Million miles saving
Jobs out – 0.17 Million Miles saving
Region Undivided – 1.2 Million Miles saving
Transit Oriented Development – 1.5Million Miles saving.

The study was conducted because everyone saw the 150 Million Daily Vehicle Miles Traveled looming in the future and Operations and Preservation getting 77% of the transportation dollar. The next question is what changes have the highest payoffs?

At 6:11 PM, Blogger Ray Hyde said...

They didn't "find" that either. Those are predictions that may well not happen, for reasons previously discussed by Bacon and others. They are based on past "if current trends continue" explosive growth trends in travel which are unlikey to continue. Then those projections are used to justify the predicted results.

On the study results page I find the headlines, "Short Term Results are Modest" and "Scenario impacts may be large locally but small regionally"

And no numbers anywhere.

Under the scenarios tab I find "The region is growing jobs much faster than housing can be built." Faster than housing is allowed to be built, maybe, but again, no evidence.

and statements such as

"The land around public transit is underutilized." as part of their justification for land use scenarios chosen.

These sound more like conclusions that inputs and raise the question of whether this isn't an elaborte exercise to justify a pre-conceived position.

Finally, the four step model they use is a tgraffic generation model. The land use portion of it is entirely exterior, and can be handled only by guesses or "Scesnarios as to wht might happen. This four step model is widely recognized as inadequate.

The section where they talk about validation is vague in the extreme. Validation is the hardest part of any model, but without it the model is worse than useless.

The letters page is full of comments concerning the accuracy of the model.

Finally, I would feel a lot better if the thing was run by an organization not related to the government, but t=it is so politically charged, I'm not sure we can ever get anything useful out of it.

At 9:51 PM, Blogger Ray Hyde said...

Calgary has often been cited for its forward looking Go! Plan which featured many of the theories frequently mentioned here.

To see how people think they worked out and what recent changes resulted, see:

At 10:09 PM, Blogger Ray Hyde said...

Get this: The Association of Train Operating Companies (Atoc) proposed "rail peak pricing" to combat a forecast rise in travellers of at least 28% in 10 years.

This, I suppose, is a reflection of the greater demand on the transit system caused by congestion pricing for cars.

At 10:13 PM, Blogger Ray Hyde said...

There are other studies:

"According to Technology Research News (TRN), researchers from Oxford University, U.K., have designed a model which maps traffic congestion. This model combines roads going through the center of a city and other ones avoiding it.

And they found that, from a cost point of view, it would be sometimes better to close roads going through cities than adding more."


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