SR 520 - Rest of the West

Review Status

We have completed our 2016 consultation with WSDOT, where we were asked to provide our input and advice on urban design options for the Montlake Lid and related investments. WSDOT asked us to provide them with advice on how urban design concepts (pedestrian connections, open spaces, landscaping, bicycle improvements, transit connections, etc.) could be further enhanced for the Montlake Lid and related infrastructure, following our work with WSDOT in 2014. The summary of this most recent work, and the key issues of greatest concern to us, will be included in the Request for Proposal documents under development by WSDOT for the award of a design build contract for construction of phase I of the SR 520 Rest of the West project. You can see a copy of this report here.

In 2019, continued to review and comment on WSDOT's 'Rest of the West' proposal.  Following their award of a design build contract to a consortium headed by Graham Construction, continued to review design concept updates for the Montlake Lid & Pedestrian Land Bridge. We held three meetings to evaluate how the proposal aligns with the proposal that we supported in our December 2016 letter to WSDOT.

We also completed the initial review of the proposed design concepts for the Roanoke Lid & Portage Bay Bridge in 2019.  In April 2020, we provided an endorsement letter documenting our support for Washington State Department of Transportation (WSDOT) proposals that integrate urban design solutions into the Portage Bay Bridge and Roanoke Lid Phase of the State Route (SR) 520 project.

Project Description

The Washington State Department of Transportation (WSDOT) is redeveloping the Seattle segment of the State Route (SR) 520 corridor between I-5 and Lake Washington. The redevelopment will include new bridges that meet current seismic standards, HOV capacity, updated roadways, new pedestrian and bicycle facilities, improved transit connections, open spaces, and enhanced non-motorized connections. Although the entire project is fully funded, funding for design and construction is spread across several biennia, and construction is anticipated to occur in three phases:

  • Phase I – Includes the corridor spanning from Lake Washington to Montlake Blvd. This phase will include the design and construction of the Montlake lid, land bridge, and West Approach Bridge South (WABS).
  • Phase II – Includes the planning, design, and construction of the Portage Bay Bridge, 10th and Roanoke lid, and I-5 interchange.
  • Phase III – Includes a second bascule bridge over the Montlake Cut.

We are providing advice to WSDOT on final design concepts related to Phase I of the corridor. This final design work will assist WSDOT in developing the Request for Proposals (RFP) for construction of Phase 1.

We are reviewing the SR 520 'Rest of the West project' in several phases.  Listed below are the review phases. Please click on each project to access the project materials.

June 2, 2016

April 7, 2016

February 4, 2016

November 7, 2019 Meeting

September 5, 2019 Meeting

June 6, 2019 Meeting

Other Documents

Seattle Design Commission

Address: 600 4th Avenue, 5th Floor, Seattle, WA, 98124
Mailing Address: P.O. Box 94788, Seattle, WA, 98124-7088
Phone: (206) 684-0435

The Seattle Design Commission advises the Mayor, City Council, and City departments on the design of capital improvements and other projects and policies that shape Seattle's public realm.