SR 520 Bridge Replacement and HOV Program - News and updates

Sept. 22, 2020 | News of the week

In this update:

Don’t forget to visit our Portage Bay Project online open house, open through Sept. 28

We’re hosting an online open house where you’ll have the opportunity to provide feedback on key environmental processes for the Portage Bay Bridge and Roanoke Lid Project. There you’ll find several webpages with information on three important environmental processes for the Portage Bay project, including an updated evaluation (pdf 8.4 mb) of the project's effects on nearby recreational and historical resources and parks. You’ll be able to submit comments directly to WSDOT and take a brief survey regarding potential recreational mitigation actions for WSDOT to propose in our shoreline permit application to the city. The online open house will be open through Monday, Sept. 28 – don’t miss it!

Reminder: Bridge work from SR 520 Trail begins this week

Starting this week, you may see crews making repairs to SR 520 from a specialized truck parked on the SR 520 Trail over Lake Washington. Crews will use an “under bridge inspection truck” to work from beneath the SR 520 bridge over Union Bay. The truck employs a long, articulating arm and crew bucket that extends over and under a bridge to make inspections or repairs. Here is what you should expect:

  • The work will occur between 7 a.m. and 5 p.m. on weekdays and last about 10 weeks. It is not expected to be noisy.
  • For trail users on the bridge, crews may stop people for short periods or ask cyclists to walk their bikes through the work area. Flaggers will be present at all times during this work.
  • For boaters on Lake Washington, crews will have to alternate closing one of the two western navigation channels to conduct the overhead work. One of the two channels will always remain open.

Two construction workers are in a lift basket lowered over the side of a concrete structure from a truck parked above.
WSDOT contractor crews are using an “under bridge inspection truck” like the one shown here to make repairs to the SR 520 roadway deck over Union Bay.

Registration now open for our October online meeting

During the presentation, you'll hear about the SR 520 Montlake Project's status, design updates, and upcoming construction activities. We'll also answer any of your questions related to the project.

Heads up travelers: be prepared for upcoming construction activities

A construction crews secures pieces of an old bridge onto a barge as part of a removal process.
Crews remove a large section of the old eastbound SR 520 bridge over Union Bay.

Be prepared this week for ramp and roadway closures as part of Montlake Project construction. Here’s what you can expect in the weeks to come:

  • Sept. 14-Oct. 2: Closure of right lane of eastbound on-ramp to SR 520 from Montlake Boulevard
  • Sept. 18-25: Single-lane closure with flagged through-traffic on Roanoke Street and a pedestrian detour
  • Sept. 21-Oct. 7: Early morning closure of the on-ramp to eastbound SR 520 from Lake Washington Boulevard
  • Sept. 21-Nov. 27: Short-term, temporary closures of SR 520 Trail over Lake Washington for bridge deck repairs

As always, construction schedules are dynamic and subject to change. Always check the Construction Corner map for the latest updates.


Aug. 27, 2020 | Rest of the West news

Weekend closure recap – successful traffic shift in Montlake

Looking over a highway stretching into the distance over a bay of water. Half of the highway is torn up and is dirt.
Removing SR 520 roadway surface prior to paving -  looking west toward Portage Bay.

Thank you to everyone for your patience last weekend while we closed SR 520. During the closure, crews successfully moved the east and westbound SR 520 lanes closer to the center of the roadway. These lanes are now closer to the recently constructed center pier that will support the future Montlake lid.

Shifting the lanes toward the center has opened up new work zones on the north and south edges of the roadway, where crews will construct additional lid-support piers. Read on for more information about another upcoming SR 520 closure.

A map of S R 520 in Montlake labeled before weekend closure. The highway lanes are separated by an orange area labeled work zone.

A map of S R 520 in Montlake labeled after weekend closure. The highway lanes are surrounded on either side by orange areas labeled work zones.


Aug. 19, 2020 | News of the week

We want to hear from you – Portage Bay Bridge Section 4(f) comment period

Based on public and stakeholder feedback, the  design of the SR 520 Portage Bay Bridge and Roanoke Lid Project has undergone a number of design refinements (pdf 1.29 mb) since the SR 520 Program’s environmental impact statement and federal Record of Decision were completed in 2011. WSDOT is submitting environmental and permitting updates to local, state and federal agencies to document these refinements. One of these updates is a “Section 4(f)” evaluation of the Portage Bay project’s effects on nearby parks, recreational and historic resources. You can read the report (pdf 8.4 mb) and email comments to WSDOT until Sept. 28 at:


June 29, 2020 | Rest of the West news

Paddle on, but stay out of the construction zone!

Kayakers and canoers will soon notice new barriers on Lake Washington near the Arboretum. These will keep paddlers safely out of the construction zone. Check out this new video to learn more about how to stay safe while you enjoy the lake this summer!

A map of SR 520 in Union Bay. Under 520 and south of it, west of foster island, is marked no access. North of 520, and under 520 east of foster island, is marked caution.


How to reach us and stay informed about SR 520 construction:

  • Call the 24-hour construction hotline (206-775-8885) with pressing Montlake Project questions or concerns.
  • Call the SR 520 Program information line (206-770-3554, M-F 8 a.m. - 5 p.m.) with general SR 520 inquiries.
  • Email SR 520 staff with your questions about the project or construction activities.
  • Visit the SR 520 Construction Corner for the most up-to-date information on closures and construction impacts.
  • Visit the SR 520 Program website to find general information about the project.
  • Visit the Montlake Project Information Center at 2209 E. North St., open Mondays and Wednesdays from 12 to 6 p.m., Tuesdays and Thursdays from 8 a.m. to 12 p.m., and the third Saturdays of the month from 9 a.m. to 12 p.m.
  • Follow us on Twitter @wsdot_520 to get key news and updates about the SR 520 program.
  • (Please note: The Information Center is currently closed until further notice due to the COVID-19 outbreak.) Stop by in person at the Montlake Project Information Center (2209 E. North St.).

Get weekly updates via email

Visit the WSDOT email updates page, enter your email address, and under "Construction Reports" select one of the following:

"SR 520 Bridge Replacement and HOV Program"
The email update on the entire program, from I-5 to I-405. Includes information on highway closures, construction milestones, and upcoming public meetings.

"SR 520 Rest of the West News"
Construction is underway on our next stage of construction in Seattle -- the Montlake Project. This update focuses squarely on SR 520 construction activities and other project updates in Seattle.