Skip Top Navigation

SR 520 - West Approach Bridge North Project: What's Happening Now?

Updated: Dec. 2, 2016

Stay Connected

  • Receive email updates
  • SR 520 Orange Page
  • Email us
  • 24-hour construction hotline:
  • Twitter: @WSDOT_520
  • Learn about potential construction effects in the Community Construction Management Plan (pdf 1.1 mb).
  • Join us for our WABN monthly, public meeting from 5:30 to 6:30 p.m. on Wednesday, Dec. 7, at the Graham Visitors Center. Both the WABN and Montlake Phase teams will provide short presentations with key project updates. Meeting attendees will have the opportunity to ask questions and share their thoughts.

Project photos

See more photos of SR 520 construction
on our Flickr site .

Project overview

The West Approach Bridge North (WABN) project is underway in the Montlake area and on Lake Washington. Work hours may vary depending on the construction activity. Construction crews will continue to employ best management practices throughout construction to minimize impacts on the community and environment. Due to the dynamic nature of construction activities, construction plans are subject to change. WSDOT will provide the public with ample notice before construction activities or closures occur.

In the next few weeks, crews will begin the following activities within project boundaries:


Construction activities under a city of Seattle temporary noise variance

  • No activities currently under a city of Seattle TNV

Construction activities


Heads up: Upcoming nighttime and weekend closures of SR 520 in early December

Crews are preparing to close westbound SR 520 on Friday night, Dec. 2 to place concrete deck near the floating bridge. The closure, previously scheduled, for Saturday, Dec. 3, has been cancelled due to inclement weather.

Closure details
Crews will close westbound SR 520 between 92nd Avenue Northeast and Montlake Boulevard from:

  • 11 p.m. Friday, Dec. 2, to 7 a.m. Saturday, Dec. 3

During the nighttime closures, please plan to take alternative westbound routes across I-90 or around Lake Washington when traveling west. Eastbound SR 520 will remain open.

Closure map

Click image for larger, printable version. (pdf 488 kb)

Reminder: Full SR 520 weekend closure scheduled for Dec. 9 through Dec. 12

From 11 p.m. Friday, Dec. 9, to 5 a.m. Monday, Dec. 12, all lanes and ramps between Montlake Boulevard and 92nd Avenue Northeast will be closed. The SR 520 bicycle and pedestrian path on the floating bridge will also be closed over the weekend.

During the highway closure crews plan to:

  • Begin removing the remaining portion of the old westbound SR 520 off-ramp to Lake Washington Boulevard that extends over SR 520.
  • If weather permits and as necessary, evaluate lane striping and restripe lanes.
  • Pour new sections of roadway deck for the permanent WABN structure.
  • Complete various maintenance projects on the eastside of Lake Washington.

What to expect:

  • Nighttime construction lights to illuminate the work site.
  • Trucks delivering concrete for roadway-deck pouring.
  • Construction vehicles moving in and out of the old-MOHAI site for concrete delivery.
  • Noise from construction activities as crews use a concrete “muncher” to remove the old off-ramp. Crews may also use a hoe ram to remove the old off-ramp. Hoe ram activity will end by 10 p.m. each day.

A temporary noise variance will be in place to complete this work. Crews will follow all city of Seattle noise requirements and WSDOT inspectors will be on site to verify that construction activities comply with the city of Seattle noise code.

Closure mapFull Weekend Closure Map
Click image for larger, printable version. (pdf 716 kb)

These closures are weather dependent and subject to change. We will keep you updated and provide more details regarding the closure in the coming weeks through these emails, our Orange Page and our SR 520 Twitter feed.

Girder delivery and installation

Crews plan to deliver girders to the West Approach Bridge North Project (WABN) construction site via truck along East Lake Washington Boulevard and 24th Avenue East up to five nights per week, Monday through Friday, for the next few months. 

Crews will start installing girders over Foster Island and work their way west towards the shoreline. Crews plan to install them nightly as they are delivered.

As girders are delivered and installed, you can expect:

  • Nighttime truck deliveries: Intermittent deliveries will occur at night using the route in the map below. Girders may be delivered any night of the week. However, typical deliveries will occur on weekday nights. Sunday through Thursday deliveries will occur between 9 p.m. and 5 a.m. Friday and Saturday deliveries will occur between 11 p.m. and 5 a.m.
  • Intermittent flagging: Flaggers will briefly hold traffic traveling in both directions on East Lake Washington Boulevard and on the westbound SR 520 off-ramp to East Lake Washington Boulevard. There will also be a rolling slowdown on the eastbound SR 520 on-ramp from Montlake Boulevard.
  • Parking restrictions: Parking will be restricted at night on East Lake Washington Boulevard between Montlake Boulevard and 24th Avenue East. Follow the information on posted no parking signs.
  • Construction lights: Bright lights may be seen as crews install girders overnight. For safety, crews may use flood lights in addition to lights from construction equipment to illuminate the work area.
  • Noise: At night, you may hear crews bringing girders in by truck and using cranes to install them. Crews will also use hammers to attach brackets to the girders in the MOHAI site. 

Click image for larger, printable version. (pdf 2.03 mb)

If you have concerns about noise or lights when girders are being installed, please call our 24-hour construction hotline (206-708-4657). 

Continued bicycle/pedestrian detour on Montlake Boulevard

Since the 24th Avenue overpass closed last fall, bicyclists and pedestrians have been detoured from 24th Avenue to the Montlake Boulevard sidewalk, via East North Street. For your safety, please continue to use the signed detour route along Montlake Boulevard, as shown in the map below. To avoid potential conflicts between bicyclists and pedestrians with construction vehicles and off-ramp drivers, the bicycle-pedestrian path across 24th Avenue East bridge will remain closed during this temporary configuration. For more information on this topic, check out our "Frequently Asked Questions" document.

Stay tuned for updates on bicycle-pedestrian access through this area as the WABN project is completed in 2017. WSDOT secured full funding in 2015 to build the remaining west side portions of SR 520 and is currently evaluating how to phase the remaining portions of the SR 520 Bridge Replacement and HOV Program. There may be additional changes as we identify how the next phase of construction interfaces with the WABN project.

Detour route

Click image for larger, printable version. (pdf 5 mb)

City of Seattle temporary noise variances

When needed, a temporary noise variance can be granted to Flatiron by the city of Seattle to allow the contractor to conduct noisier work outside the typical hours of construction.

  • The city's noise ordinance allows for variances for nighttime work between 10 p.m. and 7 a.m. on weekdays and 10 p.m. to 9 a.m. on weekends.
  • Use of noisy impact equipment, like jackhammers, will occur before 5 p.m. as required by the temporary noise variance.
  • WSDOT inspectors will monitor nighttime activities to be sure work complies with city of Seattle requirements.

Watercraft restrictions

Crews will continue on-lake construction activities near the Montlake shoreline and the Arboretum. Cranes and other waterborne construction equipment limit water access under SR 520 near the Arboretum. Canoers and kayakers should use caution when navigating near the construction zone and stay at least 150 feet away from all construction equipment.

During construction, many of the canoe/kayak landings in the area will remain open but we recommend using the launches in the Arboretum or the University of Washington's Waterfront Activities Center. If you are unsure which boat launch to use, take a look at the map below and/or contact our construction hotline at 206-708-4657.

Click image for larger, printable version.
(pdf 262 kb)

Tree protection and removal

To make way for the temporary bridge and staging areas, crews removed trees as necessary on Foster Island and in the Montlake area. WSDOT worked with the city of Seattle to remove as few trees as possible, and will continue to mark trees for protection with orange fencing and will coordinate on replacement plantings.