SR 522 - Paradise Lake Road to Snohomish River Widening

Project news

  • Design and right-of-way acquisition funding for this project, along with the Paradise Lake Road interchange improvement project, has been advanced by the Legislature.
  • WSDOT received $12.8 million in state funds in the 2019-2021 biennium. The $10 million in Connecting Washington funding will now be available in 2021-2023.  
  • There is no construction funding to complete all widening and interchange improvement projects. The total cost of all improvements, including design, right-of-way acquisition and construction is estimated at $180 million.
  • Highway users can receive email updates about state highways in Snohomish County, including the SR 522 corridor, by signing up for Snohomish County News.

Needs and benefits

Snohomish County’s population increased 137 percent between 1980 and 2017. As the county's population grows, SR 522 has become an increasingly important north-south route connecting communities between Woodinville and Monroe.

One section, between Paradise Lake Road in Maltby and the Snohomish River, remains one lane in each direction. We plan to widen the highway to create two lanes in each direction to improve traffic flow and increase trip reliability on the roadway. The wider highway will include some type of separation between oncoming lanes of traffic to reduce the risk of head-on collisions.

Doubling the capacity will also reduce the potential for rear-end collisions during stop-and-go conditions. Additional improvements will include new detention ponds near the highway to filter dirty highway storm water runoff before it’s released into area waterways, benefiting salmon and other wildlife. Several culverts that block fish passage will also be improved.


  • 2019-2021: Design work resumes.


  • This project and the Paradise Lake Road interchange improvement project received $12.8 million in the 2019-2021 biennium. Another $10 million in Connecting Washington funds will be available in 2021.
  • This project has not yet been funded for construction. 


Kris Olsen

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