If you've got plans in downtown Seattle on the night of July 19, it's time to rethink your route. The Washington State Department of Transportation (WSDOT) is set to close the southbound Interstate 5 mainline on Friday night, directing all traffic to switch over to the express lanes until early Saturday morning. The closure will begin at 11 p.m. and is expected to last until 6 a.m. the following day, as crews perform maintenance under the Seattle Convention Center. According to a WSDOT statement, drivers should allow for additional commute time or find an alternate route during this period.
The mainline closure will affect the stretch from the Stewart Street off-ramp to the Spring Street on-ramp, so make sure to exit at Stewart Street to avoid any unwanted detours. Aim to plan ahead to seamlessly navigate this temporary inconvenience. Closure details, outlined on WSDOT's website, include several ramp closures that night, including the eastbound Mercer Street and Yale Avenue/Howell Street on-ramps, and both the Union Street and James Street off-ramps.
As an available detour, the I-5 express lanes will open southbound to those needing to access downtown, though they come with a flammable cargo restriction. To add to the logistics, the northbound express lanes will close earlier than usual on the same night to accommodate the switch. WSDOT has scheduled fire system testing for the northbound I-5 the following week on July 25 and 26, which will involve lane reductions but allow use of the express lanes.
It's not just I-5 feeling the squeeze. A sudden flammable cargo restriction is also in effect for the Mount Baker and Mercer Island Lid tunnels on Interstate 90, with no clear indication of when it will be lifted. Drivers with flammable loads will need to find alternative paths around these restrictions. For updates and more details on the I-5 closure and detours, keep an eye on WSDOT's website as July 19 approaches.
