Heads up, drivers! Part of I-5 will close overnight in King County

KING COUNTY, Wash. — A warning for anyone who drives on Interstate 5 late at night or early in the morning: a portion of the southbound HOV lane is closing Thursday night.

The closure will impact people traveling through the SeaTac, Des Moines, and Kent areas.

HOV southbound will close between South 200th Street/Military Road South (Exit 151) and State Route 516 (Exit 149).

The closure begins at 11:30 p.m. and lanes reopen around 6 a.m. Friday.

The Washington State Department of Transportation says contractor crews will perform drainage work.

The closure is a part of the State Route 509 Completion Project, which will create 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 slated to open sometime next year. 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. Read more on the project here.

WSDOT created an interactive map displaying rendered views of each part of the project. View the map here.