Motorists in the areas of Burien, Des Moines, SeaTac, and Kent should prepare for lane and ramp closures on I-5, SR 516, and SR 509 from Monday, July 14 to Sunday, July 20, 2025.
These closures are a part of ongoing construction activities associated with the SR 509 Completion Project.
On I-5, contractors will be performing vital work such as final striping and repairs, including the replacement of existing bridge expansion joints.
Specific closures on I-5 will affect both northbound and southbound traffic.
From Monday, July 14 through the morning of Friday, July 18, there will be nightly closures of up to four lanes of northbound I-5 between SR 516 (Exit 149) and South 200th Street/Military Road South (Exit 151).
Closure times are scheduled from 11:59 p.m. to 4 a.m.
Meanwhile, between the same dates, up to three lanes of southbound I-5 will close nightly in the same area from 11:59 p.m. to 6 a.m.
To facilitate these highway improvements, ramp closures on I-5 will also take place.
From Monday, July 14 through the morning of Wednesday, July 16, the exit from southbound I-5 to SR 516 will be closed nightly from 11:30 p.m. to 4 a.m.
A similar closure for the northbound I-5 exit to SR 516 will occur at the same times.
On SR 516, one lane in both directions will be closed overnight between SR 99 and Military Road South from Monday, July 14 through the morning of Friday, July 18.
Lane closure periods are from 8 p.m. to 5 a.m.
Additionally, ramp closures on SR 516 will be implemented during a similar time frame.
From Monday, July 14 through the morning of Wednesday, July 16, the westbound SR 516 ramp to northbound I-5 will be closed nightly from 11 p.m. to 3:30 a.m.
During the same period, the eastbound SR 516 ramp to northbound I-5 will close nightly from 11:59 p.m. to 2:30 a.m.
Finally, there will be closures on SR 509.
From Wednesday, July 16 through the morning of Thursday, July 17, the westbound South 188th Street on-ramp to northbound SR 509 will be closed overnight from 7 p.m. to 5 a.m.
In addition, from Wednesday, July 16 through the morning of Sunday, July 20, the eastbound South 188th Street on-ramp to northbound SR 509 will close nightly from 8 p.m. to 5 a.m.
Throughout these construction periods, signed detours will be established to assist motorists in navigating around closed areas.
The SR 509 Completion Project builds a 3-mile stretch of new tolled highway between I-5 and South 188th Street, nearing the south entrance of Seattle-Tacoma International Airport.
This project is being completed in stages, with the section between I-5 and 24th Avenue South already having opened on June 28.
A new tunnel under I-5 at the SR 516 interchange is set to open mid-July.
The remaining 2 miles of the expressway between 24th Avenue South and South 188th Street represent the final phase of the project, which is expected to be fully completed by 2029.
The SR 509 Completion Project is a component of WSDOT’s broader Puget Sound Gateway Program, which includes the SR 167 Completion Project in Pierce County.
Together, these initiatives aim to complete essential missing links in Washington’s highway and freight transportation network.
image source from：seatacblog
