Nightly I-5 lane closures in south King County will begin Monday, June 17

Removing scaffolding around the new South 216th Street bridge over I-5 in SeaTac will require nightly lane closures of I-5 beginning Monday, June 17, 2024, the Washington State Department of Transportation (WSDOT) announced.

Construction crews working for WSDOT will close lanes starting Monday on both northbound and southbound I-5.

The new bridge – which is part of the State Route 509 Completion Project – opened to two-way traffic on Wednesday, June 5.

I-5 lane closure information

Monday, June 17 through the morning of Friday, June 21:

• 11:59 p.m. to 4 a.m. – Up to four lanes of northbound I-5 will close nightly between South 272nd Street (Exit 147) 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 nightly between South 200th Street/Military Road South (Exit 151) and South 272nd Street (Exit 147).
• Crews may start closing lanes as early as 8 p.m. This work is weather-dependent and may be rescheduled in the event of rain.

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.