Two Weekend Closures of SR 520 Starting 10/12-10/13

Two weekend closures of SR 520 coming in October, starting Oct. 12-13

Closures will shift all traffic between Montlake and floating bridge, with two lanes in each direction  

Crews reconstructing State Route 520 will close the highway’s westbound and eastbound lanes across Lake Washington on separate weekends this month, the first coming Oct. 12-13. Following these closures, all SR 520 traffic will shift onto the new West Approach Bridge North, with two travel lanes in each direction.

This configuration will last three to four years, allowing crews to remove SR 520’s 1960s-era west approach bridge over Union Bay, and then build a new bridge in its place. The new, seismically stronger bridge will carry three lanes of eastbound traffic from Montlake Boulevard East to the new floating bridge, with the West Approach Bridge North then reverting back to a three-lane, westbound-only structure.

The October highway closures and traffic shifts will occur in two steps.

Step 1:

• Oct. 11-14: Westbound SR 520 will close from 11 p.m. Friday, Oct. 11, to 5 a.m. Monday, Oct. 14, between 92nd Avenue Northeast in Clyde Hill and Montlake Boulevard in Seattle. Westbound traffic will shift to its new configuration that Monday morning, with two general-purpose lanes and no transit/HOV lane for the approximately 1.5 miles between the floating bridge and Montlake.
• Crews will install concrete barrier down the middle of the West Approach Bridge North, and pave and stripe the roadway to create two lanes of traffic in both directions on the westbound bridge. Eastbound travelers may see crews breaking up concrete pavement, conducting electrical work and replacing directional signs.
• The SR 520 Trail across Lake Washington also will close for the weekend.

Step 2:

• Oct. 25-28: Eastbound SR 520 will close from Montlake to the Eastside for this entire weekend.
• Crews will use this closure to move concrete barriers and pave and stripe the roadway to shift eastbound traffic onto the West Approach Bridge North. On Monday morning, Oct. 28, SR 520 will be reduced to two general-purpose lanes in each direction between Montlake and the floating bridge, with no transit/HOV lanes – similar to the highway’s configuration before the westbound bridge opened in 2017.

Slow down and stay safe

These traffic shifts require reducing the speed limit to 40 miles per hour in the work zone. We work hard to ensure the safety of our crews and the traveling public, and we need your help to keep everyone safe. Please drive carefully and observe the new, posted speed limit.

SR 520 Trail update: new cover plates on the way!

During the Oct. 11-14 weekend of work, the SR 520 Trail will also be closed across Lake Washington. Crews will use this time to replace all the narrow cover plates along the floating bridge portion of the trail.