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

Updated: Oct. 17, 2017

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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:

Project milestones

Stay tuned for updates about the opening date of the SR 520 trail. As soon as a date is set we will post it here and announce it through our email update.


Construction activities under a city of Seattle temporary noise variance

  • No activities currently under a city of Seattle noise variance

Construction activities

SR 520/local road closures 

Heads up: Nighttime geotechnical fieldwork scheduled between Oct. 20 and Oct. 30

To prepare for the upcoming Montlake Phase, WSDOT is continuing to evaluate the soil and geotechnical conditions within the project’s footprint. Upcoming work is planned for approximately five nights between Friday, Oct. 20 and Monday, Oct. 30.

Crews will use drilling equipment to bore five holes into the roadway near the intersections of SR 520 and Montlake Boulevard. They plan to complete one boring per night. WSDOT has received a temporary noise variance to complete this work, and nearby neighbors may see lights, hear intermittent noise and feel intermittent vibrations from drilling equipment and vactor trucks. Each boring will also have associated lane closures, but access to SR 520 and Montlake Boulevard will remain open at all times. Typical work hours will be from 9 p.m. to 8 a.m. each night. 


Arboretum Waterfront Trail closures

The Arboretum Waterfront Trail is open.

Construction activities near the MOHAI and Old Canal Reserve staging areas

Activities in the next few weeks (October 2017)

Nighttime work

  • Nighttime work is not anticipated to disrupt Shelby-Hamlin neighbors.

Daytime work: Preparation for MOHAI restoration

  • Overview: As you are all well aware, in recent weeks crews have transitioned from using the MOHAI area as an active staging area to conducting restoration work on the site. Below are more details of the work neighbors should expect as crews continue to work to restore the MOHAI site in the coming weeks.

Landscaping in MOHAI and new median areas: Oct. 18 – Oct. 20

  • Where: Crews will complete placing and spreading landscaping materials, including soil amendments and mulch, in preparation for grass seeding.
  • Impact: Neighbors may smell the mulch. 
  • Note: After paving work at East Park Drive East is complete, additional landscaping work will take place.

Paving of new parking spaces on East Park Drive East: RESCHEDULED again to Oct. 20

  • Where: Crews will pave the final bay of parking spaces on East Park Drive East near East Montlake Park. Now scheduled for Oct. 20.
  • Impact: Nearby neighbors may hear a paver, a grader and rollers as crews perform the paving work. Crews will close East Park Drive East when the paving work occurs.

Daytime work: General

24th Avenue East Bridge roadway improvement: Continuing through October

  • Installing new barrier - Through Oct. 20
    - Where:
    Crews will install new traffic-pedestrian barrier on the 24th Avenue East Bridge.
    - Impact:
    Neighbors may hear crews tying rebar in preparation to place the new barrier. Neighbors may hear concrete trucks as crews place the concrete for new barrier on Oct. 20. All barrier work will take place during regular daytime hours, 8 a.m. to 5 p.m.

Landscaping and fencing in the Old Canal Reserve: Ongoing through October

  • Where: The contractor continues to install landscaping amendments in the Old Canal Reserve. 

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 louder 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

For boater information, please visit our SR 520 Boater webpage.


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.