Another Grueling Weekend of I-405 and I-5 Closures Tests Puget Sound Patience

WSDOT is warning travelers and contractors alike to brace for another disruptive weekend of highway construction across the Puget Sound region, running Friday, Aug. 21 through Monday, Aug. 24. The closures include a full shutdown of southbound I-405 between Bellevue and Renton and a full closure of the SR 520/Montlake Boulevard interchange, with congestion expected on I-5 and SR 99 as well.

This is the latest in a string of overlapping closures that resumed this month after a pause during the international soccer matches hosted in the region over June and July. The scale and frequency of these closures — nearly every weekend since early August — reflects how much backlogged infrastructure work WSDOT is trying to push through the region’s compressed summer construction season.

For our readers, the story isn’t just the traffic impact — it’s what this tells us about the volume of active WSDOT contracts running concurrently in one metro area, and how that concentration of work is affecting material deliveries, crew scheduling, and access for other private construction projects nearby.

Source: WSDOT, “Plan ahead for another busy weekend of highway construction across Puget Sound, Aug. 21-24,” Aug. 17, 2026 — https://wsdot.wa.gov/about/news/2026/plan-ahead-another-busy-weekend-highway-construction-across-puget-sound-aug-21-24