Mainline northbound I-5 lane and ramp closures in Seattle set for Aug. 15-18

Northbound I-5 in Seattle will close from 11:59 p. m. on August 15 to 5 a. m. on August 18 for necessary improvements to the Ship Canal Bridge.

During this closure, express lanes will remain operational, but all on- and off-ramps north of the express lanes entrance will be closed. The Dearborn and Cherry Street on-ramps will close at 9 p. m. , followed by additional closures for other ramps later in the evening. This work is part of a broader preservation project that will see further lane reductions in 2026 and 2027.

All motorists traveling to downtown Seattle must take alternate routes, including Edgar Martinez Drive and Madison Street. The Washington State Department of Transportation will finish drainage improvements and restriping during this closure. Real-time travel information is accessible via the WSDOT mobile app and Travel Center Map. Citizens are encouraged to sign up for weekly email updates regarding the project.