• Project

I-405/Brickyard to SR 527 Improvement Project

Join us for a community meeting on April 2 from 12 - 1 p.m. to introduce the project and answer your questions as we get ready to start major construction. Register to attend the webinar at this link.

If you want to attend this meeting without registering, we will add a join link to this project webpage at 11:30 a.m. on Tuesday, April 2 (30 minutes before the meeting starts).

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

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 early construction 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 is expected to begin this spring. 

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: 

  • Monday, March 25 to Wednesday, March 27: 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, March 25 to Friday, March 29: 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. 

  • Thursday, March 28 to Friday, March 29: The left express toll lane and shoulder of northbound I-405 from milepost 24.1 to milepost 27.1 will be closed from 8 p.m. – 4:30 a.m. 

  • Thursday, March 28 to Friday, March 29: 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. 

  • Monday, March 25 to Saturday, March 30: 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. 

  • Thursday, March 28 to Saturday, March 30: The right general-purpose lane of northbound I-405 from milepost 23 to 24.2 will be closed from 11:59 p.m. – 7 a.m.  

 

Highway ramp closures: 

  • Thursday, March 28 to Saturday, March 30: The westbound SR 522 on-ramp to northbound I-405 and Northeast 195th Street will be closed nightly from 11:00 p.m. – 5:00 a.m. 

  • Thursday, March 28 to Saturday, March 30: The northbound I-405 to Northeast 195th Street will be closed nightly from 11:59 p.m. – 7:00 a.m. 

  • Thursday, March 28 to Saturday, March 30: The westbound SR 522 on-Ramp to northbound I-405 and Northeast 195th Street will be closed nightly from 11:59 p.m. – 7 a.m.  

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