Northbound State Route 99 will be reduced to one lane over bridges in south Seattle and Tukwila from Friday, July 21, to early Monday, July 24, 2023, for bridge deck repairs.

Ramps connecting northbound SR 99 and Tukwila International Boulevard in Tukwila also will close for part of the weekend.

Contractors working for the Washington State Department of Transportation will primarily work between 9 p.m. and 11 a.m., except for Monday, July 24, when construction will end by 5 a.m.

Crews will repair one lane at a time on each bridge starting with the left lane. Once work is finished, they will reopen the left lane and close the right lane. This could lead to brief periods where both lanes are closed, likely after 12:01 a.m. on Sunday, July 23.

Lane closure details

One lane of northbound SR 99 will close at 9 p.m. nightly starting Friday, July 21, at South Cloverdale Street in Seattle and at Tukwila International Boulevard in Tukwila. All lanes will reopen at 11 a.m. Saturday, July 22, and Sunday, July 23, then at 5 a.m. Monday, July 24.

Ramp closure details

The ramp from northbound Tukwila International Boulevard to northbound SR 99 will close overnight:

  • 9 p.m. Friday, July 21, to 11 a.m. Saturday, July 22.
  • 9 p.m. Saturday, July 22 until about 1 a.m. Sunday, July 23.

The ramp from northbound SR 99 to southbound Tukwila International Boulevard will close:

  • 1 to 11 a.m. Sunday, July 23.
  • 9 p.m. Sunday, July 23, to 5 a.m. Monday, July 24.

Contractors are repaving nearly 2.5 miles of SR 99 between Tukwila International Boulevard and South Cloverdale Street in south Seattle. The work involves grinding off old pavement and laying a fresh course of smooth asphalt. The project is scheduled to finish in August.

For the latest construction closure information, visit WSDOT’s real-time travel map, download the WSDOT mobile app or follow the WSDOT Traffic account on Twitter.