Big weekend lane reductions on southbound I-5 start in July for Tukwila, SeaTac and Des Moines

Drivers should plan a strategy now for weekend work on a project to rehabilitate southbound Interstate 5 south of Seattle. Starting July 8, drivers will see the first of five weekend lane reductions on southbound I-5, with sections reduced to two lanes from 10 p.m. Fridays to 5 a.m. Mondays each weekend.

The weekends are:

  • July 8-11, 15-18 and 22-25
  • August 12-15 and 19-22

Since March, contractor crews working for the Washington State Department of Transportation have been replacing concrete panels, grinding down ruts and repairing pavement during nighttime lane reductions. Reducing I-5 to two lanes on five weekends will allow crews to complete work safely and in a cost-efficient manner.

What drivers should expect during the weekend lane reductions

About 86,000 vehicles a day use southbound I-5 just south of Seattle. Based on weekend traffic volumes, congestion and delays are expected to begin around 9 a.m. and continue into the evening.

“We need drivers to adjust how and when they travel south of Seattle when we have these weekend lane reductions,” said WSDOT Traffic Engineer Mike Swires. “Using I-405, state routes 99, 167 and 509 and other routes will ease the pressure on the freeway. Ridesharing and avoiding I-5 late morning through the afternoon will help too.”

Rehabilitating southbound I-5

Lane reductions start at 8 p.m., with one lane closing each hour. Crews may reduce southbound I-5 to one lane between 11 p.m. and 4 a.m. nightly. All lanes will reopen by 5 a.m. Mondays. All weekend work on this project is weather-dependent.

During the July weekends, crews will repave a 2.7-mile section between South 188th Street in SeaTac and South 219th Street in Des Moines.

During the August weekends, crews will replace expansion joints on the southbound I-5 Duwamish River Bridge and repair drainage under the freeway.