Full 520 Bridge Closure Begins Friday Night: What To Know

SEATTLE — The State Route 520 bridge will be closed across Lake Washington for 54 hours, starting Friday night, as contractors work to install more girders for a new bridge on the Montlake side of the highway.

According to the Washington State Department of Transportation, SR 520 will close in both directions, between Interstate 5 in Seattle and 92nd Avenue Northeast in Clyde Hill, from 11 p.m. Friday to 5 a.m. Monday. The around-the-clock work will also require a full closure of the SR 520 trail.

"During the weekend closure, contractor crews working for the Washington State Department of Transportation will place 30 girders, or support beams, over the highway for a future pedestrian and bicycle bridge," WSDOT said. "Seven girders will also be added for new HOV ramps that will lead to and from a new 3-acre lid under construction in Seattle’s Montlake neighborhood."

The $455 million project started in the summer of 2019 and is scheduled for completion next year. It includes a new eastbound bridge over Union Bay and a three-acre lid over the highway in Montlake that incorporates new transit stops and open green space.

The new bicycle and pedestrian bridge will be located just east of the lid. WSDOT officials said the bridge will be the first of its kind in Seattle, measuring 72 feet wide, and lined with trees and shrubs, allowing walkers and rollers to safely cross over the SR 520. That portion of the project is slated for completion by the end of the year.

Most drivers with weekend trips planned over Lake Washington should plan to take Interstate 90 as an alternative. Residents can also keep tabs on the work by checking out WSDOT's live construction camera.