Overnight lane and ramp closures on I-5 in the Des Moines, SeaTac and Kent area continue Monday, Nov. 4 through the morning of Friday, Nov. 8.

The closures will allow contractor crews to set concrete barriers and install guardrails.

Crews will also close lanes on local roads in SeaTac Monday, Nov. 4 through Friday, Nov. 8 for improvements.

This work is part of the State Route 509 Completion Project.

I-5 lane closure information 

Monday, Nov. 4 through the morning of Tuesday, Nov. 5

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

Tuesday, Nov. 5 through the morning of Wednesday, Nov. 6

  • 9 p.m. to 4 a.m. – Up to three lanes of northbound I-5 will close overnight between SR 516 (Exit 149) and South 200th Street/Military Road South (Exit 151).
  • 11:30 p.m. to 6 a.m. – Up to three lanes of southbound I-5 will close overnight between South 200th Street/Military Road South (Exit 151) and SR 516 (Exit 149).

Wednesday, Nov. 6 through the morning of Friday, Nov. 8

  • 9 p.m. to 4 a.m. – Up to two lanes of northbound I-5 will close nightly between SR 516 (Exit 149) and South 200th Street/Military Road South (Exit 151).
  • 11:30 p.m. to 6 a.m. – Up to two 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 

Wednesday, Nov. 6 through the morning of Friday, Nov. 8

  • 11:30 p.m. to 6 a.m. – The northbound I-5 on-ramp from SR 516 will be closed nightly. A signed detour will be in place.

Local road closure information 

Monday, Nov. 4 through Friday, Nov. 8

  • 7 a.m. to 3 p.m. – One lane of South 208th Street and 34th Avenue South in SeaTac will close. Flaggers will alternate traffic.

Monday, Nov. 4 through Wednesday, Nov. 6

  • 7 a.m. to 3 p.m. – One lane of 33rd Avenue in SeaTac will close. Flaggers will alternate traffic.

An interactive project map that allows people to explore the new SR 509 Expressway, the SR 516 interchange and other elements of the completion project is also available online.

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 currently 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 in 2028.

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.

Know before you go 

Before heading out the door, travelers can find the latest information on the WSDOT app, the real-time travel map, or by subscribing to WSDOT’s email and text alerts.