I-405 and SR 522 closures in Bothell begin Feb. 20 to remove ramps and open space for I-405 expansion

BOTHELL – A visible shift is about to take place at the Interstate 405/State Route 522 Interchange in Bothell. Beginning Feb. 20, crews will start removing large flyover ramps that once carried northbound I-405 traffic to SR 522. Taking down these structures opens the center of the interchange so crews can widen I-405 and continue construction on the I-405/Brickyard to SR 527 Improvement Project.

This work will happen over a sequence of weekend closures stretching into mid-March. While the ramp removal work can happen in most weather conditions, certain steps, such as restriping temporary detours, require dry pavement. The Washington State Department of Transportation will confirm each closure as schedules are finalized.

Closure schedule

• Feb. 20-21: All lanes of westbound SR 522 at the I-405 Interchange will close from 9 p.m. Friday, Feb. 20, to 6 a.m., Saturday, Feb. 21, to remove the first section of the ramp over the westbound lanes of SR 522. Crews will start closing lanes as early as 8 p.m.
• Feb. 27-March 2: All lanes of 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, to remove the remaining portion of the ramp over SR 522. Crews will start closing lanes as early as 9 p.m.
• As early as March 6-9: All lanes of northbound and southbound I-405 in Bothell will close from Friday night, March 6, to Monday morning, March 9, to remove portions of the ramps over mainline I-405. Times for the closure will be released when the schedule is finalized. 
• As early as March 13-16: All lanes of northbound and southbound I-405 in Bothell will close Friday night, March 13, to Monday morning, March 16, to remove the remaining portion of ramps over mainline I-405. Times for the closure will be released when the schedule is finalized. 

People should expect delays and congestion and follow signed detours or use alternate routes during the closures.

Why full closures are necessary

Removing these ramps requires heavy equipment and carefully sequenced work. For public safety, we must close roadways during removal. We also have to protect the I-405 bridge deck underneath. This means as we work, crews will strategically remove pieces of the ramp and carry them away so we don’t add extra weight or damage the roadway below. 

“We understand these closures are challenging for the public, and we have thoughtfully looked at how we can remove the structures safely while minimizing the effect on those who need to travel,” said Lisa Hodgson, I-405/SR 167 Program Administrator. “During the work, crews will continue to look for opportunities to open lanes to traffic sooner, however these are large structures that will take significant time and effort to remove.”

The infrastructure in this corridor is aging and operating beyond its original design capacity. The ramp removal makes space to:

• Add new express toll lanes in each direction.
• Build direct access ramps to the ETLs.
• Support future Stride bus rapid transit service.
• Improve freight and overall mobility through Bothell.

The work cannot be paused indefinitely. It must happen while the region continues to travel.

A larger regional moment

The weekend of Feb. 27 will mark the first major overlapping construction weekend of 2026 in the greater Puget Sound region.

While SR 522 closes in Bothell, northbound I-5 will remain reduced to two lanes across the Ship Canal Bridge as part of the Revive I-5 program. In March, both directions of I-405 are scheduled to close while northbound I-5 continues operating with lane reductions.

This will be the first time in this phase of construction that both of the region’s primary north–south corridors are constrained at the same time. When multiple major routes are limited at the same time, traffic patterns can shift in ways that are difficult to predict and extend beyond the immediate work areas. WSDOT continues to use lessons learned from prior high-impact weekends to improve coordination, real-time traffic monitoring and keep the public informed during these overlapping closures.

These weekends mark the beginning of a busy period of high-impact work through mid-March. They reflect a sustained construction schedule that will continue throughout the year as improvements advance across the corridor.

What travelers should expect

Detour routes will be signed, but they cannot carry normal SR 522 or I-405 freeway volumes. 

People should plan for longer trips and congestion that may extend beyond the immediate closure areas. Travel patterns may shift week to week as work locations change. Travelers with flexibility should consider adjusting travel times or exploring alternate modes where possible.

Real-time information will be available through the WSDOT mobile app and the Travel Center Map or by signing up for WSDOT's email updates.