Bold statement: Weekend closures on I-405 and SR-522 in Bothell aren’t just routine detours—they’re a crucial step in a major highway widening project that will reshape traffic for weeks to come. And this is the part most people miss: these temporary shutdowns are designed to safely dismantle flyover ramps and clear space for a larger, more efficient interstate corridor. If you drive in the Bothell-Woodinville area, here’s what to expect, why it’s happening, and how to plan around the disruption.
What’s happening
- Washington State Department of Transportation (WSDOT) is entering a new phase of the I-405 widening project, which includes the removal of flyover ramps that connected northbound I-405 to SR-522 in Bothell.
- The goal is to open up the interchange center to allow I-405 to be widened, enabling construction to continue on the I-405/Brickyard to SR-527 Improvement Project.
Upcoming closures (tentative schedule; times may shift as work progresses)
- Feb. 20–21: Westbound SR-522 at the I-405 interchange will close from 9 p.m. Friday, Feb. 20, to 6 a.m. Saturday, Feb. 21 (lanes may start closing as early as 8 p.m.). The first section of the ramp over westbound SR-522 will be removed.
- Feb. 27–Mar. 2: Both eastbound and westbound SR-522 at the I-405 interchange will close from 10 p.m. Friday, Feb. 27, to 4 a.m. Monday, March 2. The remaining ramp portion over SR-522 is removed; lane closures may begin as early as 9 p.m.
- Early March (as soon as March 6–9): Northbound and southbound I-405 in Bothell will close from Friday night to Monday morning to remove ramp sections over the mainline.
- Early March (as soon as March 13–16): Northbound and southbound I-405 in Bothell will close again to remove the last ramp portions over the mainline; times will be announced closer to final scheduling.
Why these closures are necessary
- WSDOT’s Lauren Penning explains that the ramp removals are essential for safely taking down structures and enabling the wider I-405 configuration. While the closures are disruptive, the agency says they’re planned to minimize risk and support long-term improvements.
- Detours will be posted during closures, and officials caution that routes used for detours won’t handle the usual SR-522 or I-405 freeway volumes. Plan alternate routes and anticipate slower speeds and longer trips.
Traffic impact and volumes
- WSDOT provided KOMO News with typical weekend traffic volumes to illustrate the burden:
- Saturdays: I-405 carries about 170,000 daily trips; SR 522 east of I-405 handles about 87,000.
- Sundays: I-405 carries about 150,000 daily trips; SR 522 east of I-405 handles about 72,000.
What to expect and tips for drivers
- Expect significant weekend congestion and longer travel times in Bothell and Woodinville during closures.
- Check the latest detour routes before you travel, and allow extra time for commutes.
- If possible, adjust plans to avoid peak weekend times or use alternative modes of transportation.
Questions to consider
- Do the long-term benefits of the I-405 widening justify the short-term disruption for drivers, residents, and local businesses?
- Could the schedule be adjusted to reduce weekend wear on already busy corridors, or are there smarter detour designs that would ease bottlenecks?
What would you do differently to cope with these closures? Share your thoughts in the comments: would you favor earlier openings when feasible, or stricter safety margins to speed up the dismantling work?"}
