10 years in the making: New I-5/SR 529 interchange now open

Snohomish County drivers rejoice!

The new on/off ramps from I-5 at State Route 529 (SR 529) in Marysville opened Friday. This project has been in the works for a decade and promises game-changing congestion relief.

The drive between Everett and Marysville is one of the most congested in the state. You can expect bumper-to-bumper traffic there at any time of day or night. This new interchange allows northbound I-5 drivers to access the east side of Marysville directly, eliminating the possibility of being stuck behind a train.

Huge news for @snocounty The new I5/529 ramps are open in Marysville!!! Here’s a look at the new NB 5 off ramp to State St. Hopefully this will give us some congestion relief. @wsdot @wsdot_traffic @WA_Marysville @KIRONewsradio @Mynorthwest pic.twitter.com/oYEJ6gJhT0

— Chris Sullivan (@NEWSGUYSULLY) October 3, 2025

Major traffic relief arrives for Snohomish County commuters

The current Marysville exit at SR 528 routinely gets backed up by trains that run across 4th Street. Washington Department of Transportation (WSDOT) spokesperson Tom Pearce described the issue during an interview earlier this year.

“About a thousand feet off the off-ramp, there’s a railroad crossing, and it’s fairly heavily used,” he said. “Any time a train goes through there, the road is stopped, and we get backed up onto I-5. With the new ramp, people are going to be able to get into downtown Marysville and avoid that rail crossing.”

You can access north and southbound SR 529 from the new off-ramp. Traffic is controlled by a new roundabout, which has been in use for several months. WSDOT also opened a new northbound HOV lane earlier this year to help with the congestion. These new ramps will complete the job.

“The work has been a real pain for all the people that commute up there,” Pearce said. “We do appreciate that. We’re going to have a real improvement for them once we get these ramps open.”

Construction has been underway since 2023. The price tag for this project is listed at $123 million.

Chris Sullivan is a traffic reporter for KIRO Newsradio. Read more of his stories here. Follow KIRO Newsradio traffic on X.

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