People heading to various Seattle-area events this weekend, including Seattle Pride festivities, the Bellevue Strawberry Festival or Shoreline Arts Festival, should plan ahead for the weekend’s closure of State Route 520. Event attendees and travelers are encouraged to take alternative routes, such as Interstate 90, or use transit or carpools.

Construction of a temporary, westbound off-ramp to Montlake Boulevard in Seattle is the key driver behind the highway closure, scheduled from 11 p.m. Friday, June 26, to 5 a.m. Monday, June 29.

Contractor crews working on the West Approach Bridge North Project – part of the Washington State Department of Transportation’s SR 520 Bridge Replacement and HOV Program – will use the closure to pour concrete and connect SR 520’s westbound lanes to a newly built, temporary off-ramp to Montlake Boulevard. The temporary westbound off-ramp, expected to open in mid-July, will carry traffic until a permanent off-ramp to Montlake is completed in summer 2017.

Steve Strand, a senior WSDOT engineer on the Seattle project, said completion of the temporary off-ramp “sets the stage for a series of major highway improvements to follow in the Montlake area.” Those improvements, he noted, include new off-ramps at Montlake Boulevard and 24th Avenue East, removal of the ‘Ramps to Nowhere’ (in the Washington Park Arboretum) and, ultimately, the opening of a regional bicycle/pedestrian path and safer west approach bridge across Union Bay.

In advance of this weekend’s work, crews will close just the westbound lanes of SR 520 from 11 p.m. Tuesday, June 23, to 5 a.m. Wednesday, June 24, to pour concrete for the temporary off-ramp.

SR 520 closure details

• All westbound lanes of SR 520 will close from 11 p.m. Tuesday, June 23, to 5 a.m. Wednesday, June 24, between 92nd Avenue Northeast and Montlake Boulevard.
• All lanes of SR 520 will close, in both directions, from 11 p.m. Friday, June 26, to 5 a.m. Monday, June 29. The eastbound ramps and lanes, including the Portage Bay Bridge, will close from Interstate 5 to 92nd Avenue Northeast. The westbound lanes and ramps will close from 92nd Avenue Northeast to Montlake Boulevard. Crews also will close a single northbound lane on Montlake Boulevard.
• During the weekend closure, crews also will install new tolling equipment along SR 520’s westbound lanes on the Eastside near 84th Avenue Northeast. Other weekend work includes improvements to the eastbound SR 520 ramps to and from Montlake Boulevard, as well as utility installation in the Montlake area.

The West Approach Bridge North is a 6,100-foot-long approach structure that will carry westbound traffic from the new floating bridge across Union Bay to the Montlake area. The three-lane approach bridge, which will include an HOV lane and a path for bicyclists and walkers, will open in 2017.

For up-to-date information on highway closures and construction activity associated with SR 520, please visit the SR 520 Orange Page and follow the project on Twitter.