30-hour closure of SR 520 floating bridge begins late Saturday, Jan. 21

Mercer on-ramp to northbound I-5 slated for additional, full-weekend closure

SEATTLE – Travelers should plan ahead and find alternate routes for a portion of their trips across Lake Washington at Montlake this weekend. At 11 p.m. Saturday, Jan. 21, crews will close both directions of State Route 520 and all associated ramps between Montlake Boulevard in Seattle and 92nd Avenue Northeast in Clyde Hill. The closure will extend until 5 a.m. Monday, Jan. 23.

During the 30-hour closure, contractor crews working for the Washington State Department of Transportation will pour concrete for a section of the new eastbound lanes between Montlake Boulevard and the floating bridge and place 13 girders over the highway. The beams are part of the foundation for a new 3-acre lid under construction in Seattle’s Montlake neighborhood.

The SR 520 Trail will remain open during the weekend closure. People can watch this weekend’s girder placement on WSDOT’s construction camera, which updates every 10 minutes.

The work is part of the $455 million SR 520 Montlake Project. The project also builds three new eastbound lanes over Union Bay between Montlake Boulevard and the floating bridge on Lake Washington.  

Mercer on-ramp closed

Meanwhile, contractor crews plan to close the Mercer Street on-ramp to northbound Interstate 5 beginning at 9 p.m. Friday, Jan. 20, through 4 a.m. Monday, Jan 23. Detours will be in place.

Because of a Seattle Kraken hockey game Saturday, Jan. 21, and a Kraken skills event Sunday, Jan. 22, crews will reopen the on-ramp for three hours following the game Saturday and two hours following the end of the event Sunday to allow traffic to make its way out of the area. Drivers should be aware that there could be steel plates on the ramp and drive with caution.

The ramp work is part of the SR 520 I-5 Express Lanes Connection Project.

Keeping travelers informed

Drivers crossing Lake Washington during the weekend should take Interstate 90 as an alternate route or consider delaying their trips if possible. The most up-to-date information on closures is available by visiting the SR 520 Construction Corner.

WSDOT provides other resources to help travelers stay informed:

Slow down – lives are on the line. 

In 2023, speeding continued to be a top reason for work zone crashes.

Even one life lost is too many.

Fatal work zone crashes doubled in 2023 - Washington had 10 fatal work zone crashes on state roads.

It's in EVERYONE’S best interest.

95% of people hurt in work zones are drivers, their passengers or passing pedestrians, not just our road crews.