Oregon's Vehicle Miles Traveled Estimates Face Scrutiny

Flaws in state's modeling algorithm raise concerns about transportation planning and greenhouse gas calculations

Published on Mar. 2, 2026

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A Bend Bulletin editorial examines the challenges with Oregon's use of vehicle miles traveled (VMT) estimates as the foundation for transportation planning and greenhouse gas emissions calculations. The state's modeling algorithm has acknowledged flaws, relying on surveys and assumptions that may not accurately capture actual driving patterns, including commercial traffic. This could unfairly penalize cities that have invested in transit, biking, and pedestrian infrastructure by requiring them to continue reducing VMT, while cities with higher driving rates face less pressure.

Why it matters

Accurate VMT data is crucial for state and local transportation planning, as well as efforts to reduce greenhouse gas emissions from the transportation sector. However, the editorial argues that Oregon's current VMT estimation model has significant limitations that could lead to biased and inaccurate results, with potential negative consequences for cities that have prioritized sustainable transportation.

The details

The editorial explains that Oregon requires cities to measure and set targets for reducing household-based VMT per capita as part of their transportation plans. However, the state has no direct way to track actual vehicle trips and distances, and must rely on estimates based on surveys and assumptions. The algorithm used to calculate VMT has potential for bias, and does not even include commercial traffic. This could unfairly penalize cities like 'Bikeville' that have invested in transit and active transportation, compared to 'Carville' which has higher driving rates.

  • The editorial was published on March 1, 2026.

The players

Oregon Department of Transportation

The state agency responsible for developing the algorithm and modeling used to estimate vehicle miles traveled.

City of Bend

A city in Oregon that is required to measure and set targets for reducing household-based vehicle miles traveled per capita as part of its transportation plan.

Richard Coe

The editorial page editor at The Bend Bulletin who authored the piece examining the flaws in Oregon's vehicle miles traveled estimates.

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What they’re saying

“Vehicle miles traveled aims to capture any driving trip that adds miles to a passenger car a pickup's odometer. The state has no way of tracking that. Ir has to estimate it.”

— Richard Coe, Editorial Page Editor (The Bend Bulletin)

“If you really, really want to know more about the actual algorithm the Oregon Department of Transportation developed to come up with vehicle miles traveled, as I did, there is a document more than 20 pages long that describes most of it.”

— Richard Coe, Editorial Page Editor (The Bend Bulletin)

The takeaway

This case highlights the challenges in accurately measuring and modeling transportation patterns, and the potential for flaws in state-level algorithms to unfairly impact cities that have prioritized sustainable transportation. It raises questions about the reliability of vehicle miles traveled data as the foundation for critical planning decisions around infrastructure, land use, and greenhouse gas reduction.