SEATTLE — State Route 520 will be closed this weekend for construction work as crews demolish an overpass that’s been in place for decades.
SR 520 will be closed from Interstate 5 to the Eastside from Oct. 22 at 9 p.m. to Oct. 25 at 5 a.m. All on- and off-ramps for Montlake Boulevard and Lake Washington Boulevard as well as the SR 520 Trail will also be closed.
Since Montlake Boulevard has been shifted to a new lid, it will remain open.
During the closure, the Washington State Department of Transportation (WSDOT) urges drivers to either delay their trips or take Interstate 90 to get between Seattle and the Eastside.
During the closure, crews will remove the old Montlake Boulevard overpass and support structures, which are at risk of failing in an earthquake and have been in place since the 1960s. This will make room for a new crossing and highway interchange.
The public can watch the demolition work on a web camera from WSDOT.
“Four pieces of machinery will crunch it from the top and bottom to get it down,” said Steve Peer, WSDOT media manager. “It’s not going to be blown up with dynamite or anything dramatic like that.”
Sand will be placed on SR 520 so the road isn’t harmed.
Once this overpass is removed, crews will extend the new lid west. Pieces of the overpass will be sorted so they can be recycled.
The work is part of WSDOT's SR 520 Montlake Project, which will construct a new Montlake Boulevard interchange, a landscaped lid over 520, a bicycle and pedestrian bridge east of the lid and a West Approach Bridge South over Union Bay. Work is expected to be complete in 2023 or 2024.