Starting Monday, Aug. 24, multiple I-405 lanes and SR 9 will close for construction, with some closures extending to late August. The most significant changes include three southbound I-405 lanes closing nightly from milepost 5 to SR 167 until Aug. 27, and a single-lane SR 9 stretch near Kalloch Road lasting until Sept. 14. SR 20 near Loup Loup Pass will have alternating traffic Mondays to Thursdays through Aug. 27.
WSDOT reports drivers should expect slowdowns, detours, and reduced speed limits. The HOV lane on southbound I-405 will close nightly until Aug. 28, and a northbound I-405 closure will begin Aug. 28 for three days. SR 9 traffic will alternate daily through Sept. 3 for fish passage construction. WSDOT encourages drivers to check for real-time updates before traveling.