Traffic Modeling and Studies Ignoring Climate: At the MPO

The Policy Committee for our Metropolitan Planning Organization meets on Tuesday the 26th and they'll hear an information report on the Keizer Growth Transportation Impacts Study.

Nothing about climate and emissions here

We haven't followed the City of Keizer much here. A couple of items here and there, but it has also been clear that even with an immediate next door neighbor, there was a body of hyperlocal knowledge, history, and politics that made it difficult to follow things meaningfully without a full commitment to follow things closely. Dipping in and out necessarily meant shallow. Hence, little discussion of Keizer here, and the development of this plan has not been remarked on.

But as the City of Salem finally begins to grapple with a Climate Action Plan, and the State also begins to work out climate policy, there are these local initiatives proceeding blithely and seemingly unawares of the need to reduce emissions and reduce driving.

On the agenda at SKATS is an informational presentation on the Keizer study. The summary describes it as evaluating "the expected magnitude of added vehicular traffic" associated with the "planned expansion of the City's Urban Growth Boundary." (See the Oct 2020 Keizer Planning Commission packet.)

Always projecting more traffic

That is a Climate Fail right there.

It's always Widening

On a separate agenda item is the the draft of the 2021 formal Work Plan, and in the summary of the Cordon Kuebler Corridor Study we see the same assumptions ignoring climate.

Summary of Cordon Kuebler Study
in draft Work Plan

All of these studies model out 2043 traffic volumes without any consideration that our Climate Goals require less driving, not "added vehicular traffic."

Of course, planners and electeds have heard of climate and emissions, so it's not just blithely unaware; instead, it really is that our planning and governance continue to marginalize them by design. The initiatives deliberately sideline climate.

But all of our studies need to be reoriented to climate action and to urban mobility with much less driving. We should be managing and planning to driving targets rather than letting the modeling drive our planning. We've got it bass-ackwards

Salem on individual choice
(January 2021 Climate Action Plan Task Force)

And as long as we continue to plan for "added vehicular traffic" and induce that same traffic with road widening, the network effects of our total driving system subsidy will swamp the puny efforts of individuals to swim against the tide and try to "replace car trips" with different kinds of trips or even with no trips. By design we make it difficult to do the right thing!

We have to quit this disconnect and better align our large-scale planning, policy, and budgeting with our messaging to individuals.

Additionally, as the MPO continues to write the work plan, the ongoing traffic modeling refinement should include statements of uncertainty and probability in traffic forecasts. In the two studies referenced here, the modeling goes out 20 years to 2043 with a single number. But even on a five-year budget forecast for the City of Salem budget there is a statement of uncertainty, expressed as three scenarios. (It could be improved with more discussion of probability: How probable are the +1% and -1% scenarios? Is that an actually useful bracket, or should the bracketing use different values? And why is the yellow policy line more closely associated with the +1% scenario rather than the probable one?)

Uncertainty at City's Budget Committee

It's time for traffic modeling to be more intellectually honest and to embrace and underscore explicit statements of uncertainty and error.

The MPO zooms at noon on Tuesday the 26th. See the agenda and meeting packet for details.