Nightly I-5 lane closures in south King County continue through Wednesday, July 18

Multiple lanes will close overnight on I-5 in the SeaTac, Des Moines and Kent area from July 15-18, 2024, as crews working for the Washington State Department of Transportation (WSDOT) remove concrete forms from the new northbound I-5 ramp to northbound SR 509.

There will also be local road closures for survey work.

This work is part of the SR 509 Completion Project.

I-5 lane closure information

Monday, July 15 through the morning of Tuesday, July 16:

• 11:59 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).

Tuesday, July 16 through the morning of Thursday, July 18:

• 11:30 p.m. to 5 a.m. – The SR 516 ramp to southbound I-5 will close nightly.

Wednesday, July 17 through the morning of Thursday, July 18:

• 9:30 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).

Local road closures:

Monday, July 15 through the morning of Wednesday, July 17:

• 7 p.m. to 5 a.m. – One lane of South 160th Street will close between First Avenue South and Des Moines Memorial Drive South.
• 9 p.m. to 4 a.m. – One lane of South 188th Street will close between Eighth Avenue South and Des Moines Memorial Drive South.

Wednesday, July 17 through the morning of Thursday, July 18:

• 8 p.m. to 5 a.m. – One lane of Des Moines Memorial Drive South will close between South 194th and South 196th streets. Flaggers will alternate traffic.
• 9 p.m. to 4 a.m. – One lane of South 188th Street will close between Eighth Avenue South and Des Moines Memorial Drive South.

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 by 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.