Lane and ramp closures on I-5, SR 516 and SR 509 in south King County continue this week

Lane and ramp closures on I-5, SR 516, and SR 509 will disrupt traffic in south King County until July 3, 2025, due to ongoing construction work. Northbound I-5 will close up to four lanes nightly from 11:59 p. m. to 4:30 a. m.

for sign installation and paving, while southbound lanes will also see closures from 11:59 p. m. to 6 a. m. for similar work.

SR 516 will experience lane closures overnight for drainage work, affecting eastbound and westbound traffic. Detours will be in place for the northbound I-5 exit to SR 516, which will close overnight from 9:30 p. m. to 4 a. m.

This construction is part of the SR 509 Completion Project, which aims to build a new tolled highway linking I-5 to South 188th Street, enhancing the transportation network. The project began with the opening of a section on June 28, and a new tunnel under I-5 is expected to open in mid-July. The entire SR 509 Completion Project is scheduled for completion by 2029, addressing critical links in Washington's highway and freight network. This construction is significant for local commuters and freight transport, improving access to Seattle-Tacoma International Airport.