Major Seattle weekend road closures planned on SR 520, I-5

SEATTLE - If you’re planning to drive around the Seattle area this weekend, be prepared for significant traffic disruptions on some freeways and local roads.

Multiple road closures and construction activities are planned from August 9-12. The Washington State Department of Transportation (WSDOT) warned drivers about several projects happening across the Seattle area.

Keep reading to see which roads to avoid this weekend:

Full Highway Closure: State Route 520

SR 520 will be fully closed in both directions between I-5 and the eastside starting at 11 p.m. on Friday, August 9, through 5 a.m. on Monday, August 12.

Crews will be paving, installing utilities, and working on underlid lighting.

All associated on and off-ramps will also be closed during this period. Expect significant traffic delays and plan alternative routes if traveling through this area.

This is a map of the SR 520 closure. (WSDOT)

Ramp Closures: Southbound I-5 and Express Lanes

The southbound I-5 and I-5 Express Lane off-ramps to Mercer Street will be closed for high-impact construction starting at 11 p.m. on Friday, August 9.

Crews will be installing a new concrete barrier between the off-ramp lanes to prepare for a new reversible access point for HOV and transit entering the express lanes.

This construction will continue over two consecutive weekends, with the second closure from August 16-19. Note that while the express lanes will remain open for northbound traffic, the southbound express lane exit to Mercer Street will be impacted.

This is a map of the Mercer Street closure in South Lake Union. (WSDOT)

Street Closure: 24th Avenue East

In Montlake, 24th Avenue East will be closed between North Street and Lake Washington Boulevard from 2 a.m. on Monday, August 5, through 2 a.m. on Monday, August 12.

This closure is necessary for crews to complete roadway and landscaping work. Be prepared for detours and plan your routes accordingly.

This is a map of the Lake Washington Blvd closure. (WSDOT)

Aug 9–12 Travel Advisory:

SR 520 Closure: Plan ahead and consider alternative routes as detour options will be limited.
I-5 Ramp Closures: Expect noise and construction delays. While the express lanes remain open northbound, the southbound Mercer Street off-ramp will be closed.
24th Avenue East Closure: Use alternative streets to avoid the closure area and minimize inconvenience.

Travelers can find schedule updates on the project website, WSDOT’s Travel Center map, the WSDOT mobile app, and by signing up for King County email updates.