• Project

I-405/Brickyard to SR 527 Improvement Project

Project overview

The I-405/Brickyard to SR 527 Improvement Project lies primarily in Bothell on Interstate 405 (I-405), starting just south of the State Route 522 interchange and ending at the SR 527 interchange. WSDOT, Sound Transit, and design-build contractor Skanska USA Inc., will work to enhance four and a half miles of the corridor in the area, focusing on improving transportation mobility and reliability throughout the region.

Improvements will include increased express toll lane (ETL) capacity and direct access to state highways. This includes building one new express toll lane in each direction between south of SR 522 and SR 527 (extending the existing dual express toll lane system), widening I-405 through the SR 522 interchange, and building direct access ramps to the express toll lanes at SR 522, and a partial direct access interchange at SR 527 to and from the south connecting to the Canyon Park Park and Ride.

We will also improve connections to regional transit service at both the UW Bothell Station (SR 522) and the park and ride at Canyon Park (SR 527) and add a new transit-only Bus Rapid Transit (BRT) station to connect to Sound Transit’s BRT service along the I-405 corridor, improving connections to the existing park and ride.

The project will include additional local roadway improvements, fish barrier corrections, noise walls, and new stormwater facilities.

Timeline
The project is expected to complete construction in 2028 in alignment with Sound Transit Bus Rapid Transit.
Project status
Pre-construction
Funding
$834 Million
Project hotline

What to expect

Weekend closures on SR 522 near I-405 interchange
Work will begin first on SR 522 near the I-405 interchange to establish the new alignment for westbound SR 522 and the northbound I-405 on ramp.

The scheduled dates for the closures are:

  • 10 p.m. Friday, April 12 to 4 a.m. Monday, April 15
  • 10 p.m. Friday, April 19 to 4 a.m. Monday, April 22


During the closures, crews will close the left general-purpose lane of westbound SR 522 and all lanes of eastbound SR 522 near the I-405 interchange. Drivers heading eastbound on SR 522 will follow the signed detour route via I-405.

Drivers heading eastbound on SR 522 will detour onto southbound I-405 and can exit at Northeast 160th Street (Exit 22), turn left over the highway and re-enter northbound I-405 at the I-405/SR 522 interchange.

WSDOT expects traffic delays and backups in both directions on SR 522 and on southbound I-405 at SR 522 and on Northeast 160th Street during the closures. All residents, travelers, and commuters are encouraged to plan for extra travel time during the weekend lane closures between Woodinville and Bothell.

For the most up-to-date information about travel impacts, check out our real-time travel mapWe also encourage people to stay informed by subscribing to our email updates or calling our construction hotline with questions, concerns or for more information at 425-354-3232.


Activities to prepare project sites for construction began in the fall of 2023 and will continue throughout the winter of 2024. These activities include field surveys, potholing and geotechnical borings, plant and tree removal, and adding signage around the project areas and on the Sammamish River Trail. 

Active project construction began Spring of 2024. 

Upcoming construction work

  • As early as March 4, crews will remove trees and vegetation to clear a section of the hillside area directly east of the I-405 northbound off-ramp to SR 522 to access future construction work areas. This work will be completed during daytime hours between 9 a.m. – 3 p.m. and nighttime hours between 11:00 p.m. – 5:00 a.m.  

Upcoming I-405 ramp and lane closures

Highway lane closures:

  • Tuesday, April 16 to Friday, April 19: The northbound I-405 on-ramp right lane from southbound SR 527 will be closed nightly from 11 p.m. – 4:30 a.m. (not closing ramp access to NB I-405) 

  • Monday, April 15 to Friday, April 19: The right general-purpose lane and shoulder of northbound I-405 from milepost 24.2 to milepost 27.05 will be closed nightly from 8:30 p.m. – 5 a.m. 

  • Monday, April 15 to Wednesday, April 17: The left express toll lane and shoulder of southbound I-405 from milepost 23.8 to milepost 27.2 will be closed nightly from 8 p.m. – 4:30 a.m. 

  • Monday, April 15 to Thursday, April 18: The right off-ramp lane and shoulder of southbound I-405 from milepost 27.1 to milepost 26.8 will be closed nightly from 10:30 p.m. – 4 a.m. 

  • Wednesday, April 17 to Thursday, April 17: The left general-purpose lane of eastbound and westbound SR 522 from milepost 10.7 to milepost 12.05 will be closed nightly from 8 p.m. – 4 a.m. 

  • Monday, April 15 to Friday, April 19: The right general-purpose lane of northbound I-405 from milepost 23 to milepost 24.2 will be closed nightly from 11:59 p.m. – 5:00 a.m.  

  • Friday, April 19 to Saturday, April 20: The right general-purpose lane of eastbound SR 522 from milepost 10.80 to milepost 11.3 will be closed nightly from 10 p.m. – 1 a.m.  

  • Saturday, April 20 at 1 a.m. to Sunday, April 21 at 11 a.m. (Full Weekend Operation): The two general-purpose lanes of eastbound SR 522 from milepost 10.5 to milepost 12 and the left general-purpose lane of westbound SR 522 from milepost 12 to milepost 10.5 will be closed. The eastbound SR 522 through traffic will be detoured to southbound I-405 then to Northeast 160th Street. The ramp from eastbound SR 522 traffic to northbound I-405 on-ramp from eastbound SR 522 collector distributor is closed. Detour to southbound I-405 then to Northeast 160th Street to turn around for northbound I-405. All from 1 a.m. – 11 a.m. 

  • Sunday, April 21 to Monday, April 22: The right general-purpose lane of eastbound SR 522 from milepost 12 to milepost 10.85 will be closed from 11 a.m. – 4 a.m. 

  • Sunday, April 21 to Monday, April 22: The right general-purpose lane of northbound I-405 from milepost 23 to milepost 24.2 will be closed nightly from 11 a.m. – 4 a.m.  

Highway ramp closures:

  • Monday, April 15 to Friday, April 19: The northbound I-405 off-ramp to Northeast 195th Street will be closed nightly from 11:59 p.m. to 5 a.m.  

  • Monday, April 15 to Friday, April 19: The westbound SR 522 -on-ramp to northbound I-405 and Northeast 195th Street will be closed nightly from 11:59 p.m. – 5 a.m.  

  • Friday, April 19 to Saturday, April 20: The eastbound SR 522 to northbound I-405 will be closed nightly from 10 p.m. – 1 a.m.  

  • Friday, April 19 to Saturday, April 20: The southbound I-405 to eastbound SR 522 will be closed nightly from 10 p.m. – 1 a.m.  

  • Saturday, April 20 at 1 a.m. to Sunday, April 21 at 11 a.m. (Full Weekend Operation): The ramp from eastbound SR 522 traffic to northbound I-405 on-ramp from eastbound SR 522 collector distributor is closed. Detour to southbound I-405 then to Northeast 160th Street to turn around for northbound I-405.  

  • Sunday, April 21 to Monday, April 22: The westbound SR 522 on-ramp to northbound I-405 and Northeast 195th Street will be closed from 11 a.m. – 4 a.m. 

  • Sunday, April 21 to Monday, April 22: The northbound I-405 off-ramp to Northeast 195th street will be closed nightly from 11 a.m. – 4 a.m. 

  • Sunday, April 21 to Monday, April 22: The westbound SR 522 on-ramp to northbound I-405 and Northeast 195th Street will be closed nightly from 11 a.m. – 4 a.m. 

Map of I-405 showing the area that will be improved, from SR 522 to SR 527, highlighted in orange.