Skip to content

It’s Happening: Washington State Revises Traffic Forecasts to Reflect Reality

The amount that the average American drives each year has been declining for nearly a decade, yet most transportation agencies are still making decisions based on the notion that a new era of ceaseless traffic growth is right around the corner.
Washington State has revised traffic projections downward, to reflect changing patterns. Image: Washington State via Sightline
The Washington State Office of Fiscal Management has revised its traffic projections downward to reflect changing patterns. Graph Washington OFM via Sightline

The amount that the average American drives each year has been declining for nearly a decade, yet most transportation agencies are still making decisions based on the notion that a new era of ceaseless traffic growth is right around the corner.

The Wisconsin Department of Transportation, for example, has overestimated traffic on its roads by an average of 73 percent, according to a recent study. And Dallas-area planners recently produced traffic projections that predicted a much larger increase in driving than the state DOT was even predicting.

That’s why a new traffic forecast from the Washington State Office of Fiscal Management is so interesting: It actually acknowledges how travel habits are changing. Seattle-based environmental think tank Sightline spotted the above traffic projection in a new government report. In its most recent financial forecast, the agency has abandoned the assumption of never-ending traffic growth that it employed as recently as last year. Instead, the agency has responded to recent trends, even projecting that total traffic will start to decline within the next ten years.

Sightline’s Clark Williams-Derry says that’s huge:

By undermining both the rationale for new roads and the belief that we’ll be able to pay for them, a forecast of flat traffic should help inject a needed dose of reality into the state’s transportation debates.

Of course, there’s no telling whether this forecast will be right. As Yogi Berra allegedly said, predictions are hard, especially about the future. But if it turns out that this forecast underestimates traffic growth, budgeters won’t find it such an unpleasant surprise, since more traffic will bring more revenue from drivers.

Update: This post has been amended to reflect that the traffic forecast was published by the Washington State Office of Financial Management, not the Washington State DOT, as originally reported. According to the OFM report, however, the projections were produced by a division of the DOT.

Photo of Angie Schmitt
Angie is a Cleveland-based writer with a background in planning and newspaper reporting. She has been writing about cities for Streetsblog for six years.

Read More:

Streetsblog has migrated to a new comment system. New commenters can register directly in the comments section of any article. Returning commenters: your previous comments and display name have been preserved, but you'll need to reclaim your account by clicking "Forgot your password?" on the sign-in form, entering your email, and following the verification link to set a new password — this is required because passwords could not be carried over during the migration. For questions, contact tips@streetsblog.org.

More from Streetsblog USA

Waymo Means Way Mo’ Cars, According To Uber Docs

April 17, 2026

Friday Video(s): Kidical Mass, Night-Biking in Tokyo, and More

April 17, 2026

Look What You Made Friday’s Headlines Do

April 17, 2026

Talking Headways Podcast: Second-Hand E-Bikes Can Be The Way Forward

April 16, 2026

Florida Town Gives New Residents Free Golf Carts to Replace Their Cars

April 16, 2026
See all posts