Lane and ramp closures on I-5 and SR 509 in Burien, SeaTac, Des Moines and Kent continue through the morning of Friday, Jan. 16, according to the Washington State Department of Transportation (WSDOT).

Lane and ramp closures on I-5 will allow crews to pave the roadway.

Lane and ramp closures on SR 509 will allow crews to pave and stripe the roadway.

This work is weather dependent and may be canceled in the event of rain.

This work is part of the SR 509 Completion Project.

I-5 lane closure information 

Wednesday, Jan. 14 through the morning of Friday, Jan. 16:

  • 11:59 p.m. to 4 a.m. – Up to four lanes of southbound I-5 will close nightly from SR 516 (exit 149) to South 272nd Street (exit 147).

I-5 ramp closure information 

Monday, Jan. 12 through the morning of Friday, Jan. 16:

  • 9:30 p.m. to 3:30 a.m. – The northbound I-5 exit to 24th Avenue South will close nightly. A signed detour will be in place.

Tuesday, Jan. 13 through the morning of Friday, Jan. 16:

  • 10:30 p.m. to 4 a.m. – The 24th Avenue South ramp to the SR 509 Expressway and southbound I-5 will close nightly. A signed detour will be in place.

SR 509 lane closure information 

Monday, Jan. 12 through the morning of Tuesday, Jan. 13:

  • 8 p.m. to 5 a.m. – One lane in each direction of SR 509 will close overnight from South 188th Street to South 176th Street.

Thursday, Jan. 15 through the morning of Friday, Jan. 16:

  • 8 p.m. to 5 a.m. – One lane of southbound SR 509 will close overnight from South 188th Street to South 176th Street.

SR 509 ramp closure information 

Monday, Jan. 12 through the morning of Tuesday, Jan. 13:

  • 9 p.m. to 5 a.m. – The South 160th Street on-ramp to southbound SR 509 will close overnight. A signed detour will be in place.

Tuesday, Jan. 13 through the morning of Wednesday, Jan. 14:

  • 7 p.m. to 5 a.m. – The Des Moines Memorial Drive South on-ramp to northbound SR 509 will close overnight. A signed detour will be in place.

Wednesday, Jan. 14 through the morning of Friday, Jan. 16:

  • 10 p.m. to 5 a.m. – The southbound SR 509 off-ramp to South 188th Street will close nightly. A signed detour will be in place.

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 between I-5 and 24th Avenue South opened on June 28, 2025 and a new tunnel under I-5 at the SR 516 interchange opened on July 16, 2025. The final stage builds 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. Together, the two completion projects finish critical missing links in Washington’s highway and freight network.