Northbound Interstate 405 is going offline between Renton and Bellevue this weekend, cutting off a major Eastside commute route from North Southport Drive/Northeast Sunset Boulevard (Exit 5) to Coal Creek Parkway Southeast (Exit 10). The closure runs from 11:30 p.m. Friday, April 17, through 4 a.m. Monday, April 20, and drivers are being warned to brace for heavy backups on I-405 and jammed surface streets as traffic follows signed detours.
What is closing and when
The Washington State Department of Transportation will shut down all northbound lanes between North Southport Drive/Northeast Sunset Boulevard (Exit 5) and Coal Creek Parkway SE (Exit 10) for the entire weekend. A signed detour along Coal Creek Parkway SE will carry northbound drivers around the work zone. For the official advisory and detour map, check the City of Renton's notice.
Why crews need the weekend
WSDOT says contractor crews will spend the weekend excavating drainage crossings, completing full pavement replacements and setting up a traffic switch as part of the I-405/Renton to Bellevue Widening and Express Toll Lanes Project. The work is described as a milestone in the multiyear effort to add capacity and support future bus rapid transit along the corridor. More on the project is available on the WSDOT project page.
Plan your trip: detours and delays
Several northbound ramps are set to close, including the Sunset Boulevard on-ramp along with NE 30th (Exit 6), NE 44th (Exit 7) and Lake Washington Boulevard (Exit 8). All of that traffic has to go somewhere, which likely means more cars spilling onto local streets throughout the closure.
Local reporting and traffic advisories warn that the shutdown could send ripples across the region. See Kirkland Reporter, KIRO 7 and KING 5 for maps, visuals and route suggestions. Officials recommend traveling during off-peak hours, using transit where possible or building in extra time if you have to drive.
Where this fits in the big picture
This weekend's full shutdown is one of several full-weekend and overnight closures tied to the broader I-405 widening and express toll lanes program, which will eventually extend express toll lanes between Renton and Lynnwood. City officials say the construction is intended to improve speeds, trip reliability and transit service along the corridor; see the City of Bellevue for project background.
If you have to travel this weekend, plan on leaving early, considering alternate routes and checking live traffic maps before you head out. WSDOT posts route maps and real-time conditions on its Travel Center and the project page, and you can sign up for alerts through WSDOT for the latest closure and construction updates.
