SR 520 - I-5 to Lake Washington - Montlake phase

The next phase of construction for the SR 520 Program is the Montlake Phase. This is the first stage of construction for the Rest of the West. The Montlake Phase will build a new Montlake interchange, a landscaped lid over SR 520, a bicycle/pedestrian "land bridge" east of the lid, and a West Approach Bridge South for eastbound traffic. This phase is currently in the contractor-procurement stage. We anticipate selecting a contractor by fall 2018 and launching construction later in the year.

map of SR 520 Montlake Phase key improvements

View a larger image (pdf 675 kb)


Learn about next phase of SR 520 construction in Seattle
More than 250 people attended our April 17 open house in Montlake to learn more about the next phase of SR 520 construction in Seattle. Miss the meeting? You'll find all of the open house's informational boards in our Resource Library.

Montlake Phase contracting opportunities
We published a Request for Proposals on Feb. 28 in preparation for selecting a design-build contractor for the upcoming Montlake Phase of SR 520 construction. Subcontractors and vendors interested in learning more about the RFP will find it on WSDOT’s Contract Ad and Award webpages. We expect construction on the Montlake Phase to start in late 2018. 

Final traffic management plan for the Montlake area
Check out the final Neighborhood Traffic Management Plan (pdf 4.3 mb) for the Montlake Phase. This plan, developed by WSDOT and the city of Seattle, includes a refined list of traffic-calming measures planned in the Montlake area, as well as a summary of public feedback and an overview of other city projects in the vicinity.

Design renderings

Conceptual image of the Montlake lid transit station.

Conceptual image of a bicycle-pedestrian land bridge over SR 520.


Montlake Phase timeline and next steps

  • 2017-18: Advance conceptual design
  • Fall 2018: Select contractor
  • Late 2018: Host preconstruction open house with contractor and begin construction
  • 2022-23: Complete Montlake Phase construction

Note: There will be additional design work for future project phases, such as the Portage Bay Phase, with additional opportunities for public comment.


Rebuilding the corridor in stages

map of SR 520 Montlake Phase traffic shifts
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How to stay involved

We know there is interest in staying informed about this upcoming work. Here are some resources you can use:

If your organization is interested in receiving a project briefing or presentation, please contact us.


A commitment to fair contracting

WSDOT is committed to meeting the governor's voluntary goal of providing 26 percent of the contract value for Connecting Washington transportation projects -- including the Montlake Phase of SR 520 construction -- to minority-owned, women-owned, veteran-owned and disadvantaged small businesses. Learn more about the SR 520 Diversity Program.