Expect overnight lane and ramp closures on I-5 and SR 516 in the SeaTac, Des Moines and Kent area beginning Monday, Feb. 24 through the morning of Friday, Feb. 28, 2025.

The closures on I-5 will allow contractor crews working for the Washington State Department of Transportation to install traffic monitoring loops into the roadway, and the closures on SR 516 will allow contractor crews to stripe the roadway.

This work is part of the SR 509 Completion Project.

I-5 lane closure information

Monday, Feb. 24 through the morning of Friday, Feb. 28:

  • 9 p.m. to 4 a.m. – Up to three lanes of northbound I-5 will close nightly between SR 516 (Exit 149) and South 200th Street/Military Road South (Exit 151).

Wednesday, Feb. 26 through the morning of Friday, Feb. 28:

  • 11:59 p.m. to 6 a.m. – Up to four lanes of southbound I-5 will close nightly between South 200th Street/Military Road South (Exit 151) and SR 516 (Exit 149).

I-5 ramp closure information

Monday, Feb. 24 through the morning of Wednesday, Feb. 26:

  • 9:30 p.m. to 3:30 a.m. – The northbound I-5 to SR 516 off-ramp will close nightly. A signed detour will be in place.

SR 516 lane closure information

Monday, Feb. 24 through the morning of Wednesday, Feb. 26:

  • 8 p.m. to 5 a.m. – One lane of westbound SR 516 will close nightly between SR 99 and Military Road South.

Wednesday, Feb. 26 through the morning of Friday, Feb. 28:

  • 8 p.m. to 5 a.m. – One lane of eastbound SR 516 will close nightly between Military Road South and SR 99.

SR 509 Completion Project information

The SR 509 Completion Project builds 3 miles of new tolled highway between I-5 and South 188th Street near the south end of Seattle-Tacoma International Airport. The new highway will be completed in stages. The portion under construction between I-5 and 24th Avenue is scheduled to open in 2025. The final stage will build the remaining 2 miles of the expressway between 24th Avenue South and South 188th Street. The entire project is planned for completion by 2029.

Puget Sound Gateway Program overview

The SR 509 Completion Project is part of WSDOT’s Puget Sound Gateway Program, which also includes the SR 167 Completion Project in Pierce County. Combined, the two completion projects finish critical missing links in Washington’s highway and freight network.