From February 24 to February 28, 2025, overnight lane and ramp closures will take place on I-5 and SR 516 in the Des Moines, SeaTac, and Kent areas, significantly impacting local traffic. The Washington State Department of Transportation is overseeing this work as part of the SR 509 Completion Project, which aims to enhance traffic management through the installation of monitoring loops and roadway striping. Northbound I-5 will face nightly closures of up to three lanes, while southbound I-5 may see up to four lanes closed during specific hours. Furthermore, the northbound I-5 to SR 516 off-ramp will be closed, with a signed detour provided for affected drivers. On SR 516, one lane will close nightly in both directions during the specified time frame.

This project is part of a larger initiative to complete critical missing links in Washington’s transportation network, with a final completion date projected for 2029. The SR 509 Completion Project is crucial for improving regional traffic flow and safety, making these closures particularly relevant for local residents and commuters. As the project progresses, it will contribute to a more efficient highway and freight system in the Puget Sound region.