Washington State Department of Transportation
Travel Advisory
SEATAC – Ramp closures on Interstate 5 in SeaTac and lane closures on State Route 509 in Burien continue Tuesday, Jan. 20 through the morning of Thursday, Jan. 22. Ramp closures on I-5 will allow crews to perform landscaping work. Lane closures on SR 509 will allow crews to pave the road and install signage. The paving 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 ramp closure information
Wednesday, Jan. 21 through the morning of Thursday, Jan. 22
- 9:30 p.m. to 3:30 a.m. – The northbound I-5 exit to 24th Avenue South will close overnight. A signed detour will be in place.
SR 509 lane closure information
Tuesday, Jan. 20 through the morning of Wednesday, Jan. 21
- 8 p.m. to 5 a.m. – One lane in each direction of SR 509 will close overnight from South 156th Street to South 168th Street.
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.
Photos of construction work are available on the project’s Flickr page. A 3D video tour is also available on WSDOT’s YouTube page.
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.
Hyperlinks within the release:
- SR 509 Completion Project: wsdot.wa.gov/construction-planning/search-projects/sr-509-completion-project
- Project’s Flickr page: www.flickr.com/photos/wsdot/collections/72157720074594578/
- 3D video tour: www.youtube.com/watch?v=fz6PGrNRaGM
- Puget Sound Gateway Program: wsdot.wa.gov/construction-planning/major-projects/puget-sound-gateway-program
- SR 167 Completion Project: wsdot.wa.gov/construction-planning/search-projects/sr-167-completion-project
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