Skip Top Navigation

SR 520 - Floating Bridge and Landings Project: What's Happening Now?

Project photos

Aerial view of the SR 520 floating bridge construction site See more photos from Lake Washington, Tacoma, and Kenmore on our Flickr site.

Updated: April 1, 2014

Construction activities for the new SR 520 floating bridge and landings are underway.

We are currently assembling the new floating bridge on Lake Washington and continue to build bridge components at locations in Aberdeen, Tacoma and Kenmore. 

Current work

Lane and Ramp Closures

Driver Alert: Ongoing westbound closures through the summer

Crews will close one lane of westbound SR 520 two to three nights a week through the summer.

Crews will also close both lanes of westbound SR 520 on Thursday nights through May.

Visit the Orange Page for specific dates and times.

Lake Washington

In February, crews completed repairs to Pontoon V from within an attached coffer cell. In early March, crews began repairs on Pontoon U. These repairs will be completed later this spring.

Crews continue to construct the cross beam on both cross pontoons: A and W. At the end of April, Cross Pontoon A will move to its permanent location at the west end of the floating bridge.

Construction of the segmental bridge, or balanced cantilever, near Lake Washington's Medina shoreline is well underway for the south (eastbound) section of roadway.

Pontoons are currently being stored in the lake's west side staging area. Crews have also begun adding rock to some of the pontoons to prepare them for joining.

West Connection Bridge
construction is underway on Lake Washington near Madison Park. Crews have completed pile driving activities and have begun to install girders for this new bridge. Check out the progress graphic for more information on current construction activities.

Construction activities and project barges completely block the east navigation channel. These obstructions alter use of the east navigational channel and SR 520 drawspan. Read more information for boaters and SR 520 drivers.


See the latest activity on our Medina construction camera. Curious what you're looking at? Check out this guide.

On land in Medina, crews have completed construction of the first sections of roadway for the new eastbound lanes. Crews continue to construct a segmental bridge at Pier 1, located in Lake Washington, and expect to join the sections in late April.

Recently, crews also began constructing the foundation for the new bridge maintenance facility, located beneath the east approach.

Joining of longitudinal pontoons for the new floating bridge will begin in summer 2014.


See the latest activity on our Kenmore construction camera. Curious what you're looking at? Check out this guide.

The casting facility where the new roadway deck sections are being constructed is complete. Casting of the concrete deck sections began in March 2014.

Crews will continue to construct the roadway deck sections throughout 2014. A total of 766 sections are needed to complete the roadway for the new floating bridge.

For more information about the work planned in Kenmore, view our project page.


See the latest activity on our Tacoma construction camera. Curious what you're looking at? Check out this guide.

Crews continue work on the fifth of six cycles of supplemental stability pontoons being constructed in Tacoma. The eight fifth-cycle pontoons will be completed and floated out of the casting basin in May 2014.

Check out photos on our Tacoma Flickr page.


Crews have nearly completed the fourth cycle of six pontoons at the casting facility in Aberdeen and plan to float them out in April 2014.

You can find more information on the Pontoon Construction Project on the project website.

Watch our YouTube video to learn more about the float-out process.