SR 520 bridge lane closures begin today, continue through September

State Route 520 drivers should plan ahead for five closures of the floating bridge and highway, one direction at a time, starting today through mid-September.

State Route 520 drivers should plan ahead for five closures of the floating bridge and highway, one direction at a time, starting today and will end mid-September.

During the closures, construction crews will tackle a variety of work throughout the corridor – from pouring concrete column foundations for the new west end bridge to shifting traffic onto new highway lanes near Bellevue.

Westbound-only full closures: 92nd Avenue Northeast to Montlake Boulevard

  • 11 p.m. Thursday, Aug. 22 to 5 a.m. Friday, Aug. 23
    – Note: A single lane will be closed from 9-11 p.m. and 5-6 a.m.
  • 11 p.m. Thursday, Aug. 29 to 5 a.m. Friday, Aug. 30
    – Note: A single lane will be closed from 9-11 p.m. and 5-6 a.m.
  • 11 p.m. Friday, Sept. 6 to 5 p.m. Saturday, Sept. 7
  • 9 p.m. Saturday, Sept. 14 to 9 a.m. Sunday, Sept. 15

The four westbound SR 520 closures mark the first major steps to build the interim structure that will join the new SR 520 floating bridge to the existing highway near the west high rise, Washington Department of Transportation officials say.

Crews will park trucks on the existing highway to pump concrete into shafts in Lake Washington. When hardened, the concrete will form the bases of columns that will hold up the new highway lanes.

“Concrete delivery trucks and a huge pump will block both westbound lanes of the bridge so we need drivers to find another way across the lake,” said Dave Becher, engineering manager for the Washington State Department of Transportation’s SR 520 West Connection Bridge Project.

Each of these 10- to 12-foot diameter column foundations will require about four hours of continuous concrete pouring and we appreciate help from drivers while we complete this critical work.

Eastbound-only full closure: Montlake Boulevard to Interstate 405

  • 11 p.m. Friday, Aug. 23 to 9 a.m. Saturday, Aug. 24

All lanes of eastbound SR 520 will close overnight Aug. 23 between Montlake Boulevard and I-405 when SR 520 Eastside Transit and HOV Project crews move eastbound traffic onto new highway lanes between 92nd Avenue Northeast and 108th Avenue Northeast. This shift makes room to build new, wider westbound lanes.

Full details about the closures, including a chronological graphic, are provided on the SR 520 highway closures website.

SR 520 West Connection Bridge Project overview

Contractor Mowat-American A Joint Venture is building a 1,330-foot-long, four-lane structure parallel to and north of the current bridge. This key link will allow travelers from the new SR 520 floating bridge to connect to the existing west-side structure while the remainder of the corridor is being replaced in Seattle.

WSDOT awarded the contract for the West Connection Bridge Project in April. Mowat-American’s $22,129,243 bid was lowest among four firms that competed for the job. Construction is scheduled for completion in late summer 2014.

SR 520 Eastside project overview

Crews working on the Eastside Transit and HOV Project are widening SR 520 to six lanes between Medina and Bellevue, rebuilding interchanges, constructing highway lids and transit stops in the center of the highway and installing fish-friendly culverts.

In 2010, WSDOT awarded a $306 million design-build contract to Eastside Corridor Constructors, a joint venture of Granite Construction Company and PCL Construction Services. The completed Medina-to-Bellevue corridor is scheduled to open to traffic in December.