CHOKEPOINTS

Multiple major closures planned across Seattle this Mother’s Day weekend

May 8, 2026, 6:15 PM | Updated: 6:35 pm

SR 99 tunnel...

Freshly painted lane stripes on the northbound SR 99 tunnel. (Photo courtesy of WSDOT)

(Photo courtesy of WSDOT)

Mother’s Day weekend is going to be a busy one for the Washington State Department of Transportation (WSDOT).

There are a number of closures planned that drivers need to be aware of.

SR 99 closures in Seattle, SeaTac

Closures are planned in multiple locations along the State Route 99 (SR 99) corridor in Seattle and SeaTac, the weekend of May 8 to 11, for construction and maintenance work.

People who travel along this corridor should prepare for delays or signed detours that will guide them around work zones.

Construction is also planned along southbound I-405 in Bellevue and Renton, along with ongoing preservation work that has reduced the northbound I-5 Ship Canal Bridge in Seattle to two lanes.

Northbound SR 99 closure across First Avenue South Bridge 

All lanes of northbound SR 99 across the First Avenue South Bridge will close from 9 p.m. Friday, May 8, to 5 a.m. Monday, May 11, as the second phase of a three-part repair strategy begins on the bridge.

Northbound State Route 509 (SR 509)/SR 99 traffic will exit at South Cloverdale Street and follow a signed detour back to northbound SR 99.

Additionally, multiple on-ramps to northbound SR 509/SR 99 in south Seattle will close through the weekend.

Both directions of SR 99 tunnel will close

Both directions of the SR 99 tunnel in Seattle will close from 10 p.m. Friday, May 8, to 6 a.m. Saturday, May 9, for routine maintenance.

The Royal Brougham/Colorado Avenue South on-ramp to northbound SR 99 and the Sixth Avenue North on-ramp to southbound SR 99 will also close during this time.

Eastbound SR 520 closes between I-5 and Montlake

Beginning at 11 p.m. Friday, May 8, through 5 a.m. Monday, May 11, crews will close eastbound SR 520 between I-5 and Montlake Boulevard to prepare for an upcoming traffic shift. The Montlake Boulevard on-ramp to eastbound State Route 520 (SR 520) will also close during this time.

Off-ramp closure from eastbound I-90 to SR 18/Snoqualmie Parkway

A weekend-long closure of the eastbound I-90 off-ramp to State Route 18 (SR 18) and Snoqualmie Parkway will begin at 9 p.m. Friday, May 8, as part of the I-90/SR 18 Interchange Improvements and Widening project.

From 9 p.m. Friday, May 8, to 5 a.m. Monday, May 11, the off-ramp of eastbound I-90 to SR 18/Snoqualmie Parkway will close, along with the right lane of westbound SR 18 between the diverging diamond interchange and Southeast 104th Street.

Drivers in the Snoqualmie area should plan ahead and add extra time for travel during this closure.

Nate Connors is a traffic reporter for KIRO Newsradio. Follow him on X. Read more of his stories here. Submit news tips here.

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Multiple major closures planned across Seattle this Mother’s Day weekend