• 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

Speed limit is 35 MPH through the work zone on SR 522

For all travelers on SR 522, the speed limit near the I-405 interchange is now 35 miles per hour. This speed limit change will ensure safety for both drivers and construction crews through the work zone and accommodate the future traffic configuration.

Why did we reduce the speed on SR 522? The I-405/Brickyard to SR 527 Improvement Project will include three new traffic signals on SR 522.

The new traffic signals will allow access for regional transit services to a new Stride Bus Rapid Transit (BRT) stop and direct access in and out of the Express Toll Lanes (ETL) system for transit and ETL users. The signals will be operated by WSDOT and timed to work together to make sure traffic is flowing smoothly.

We have a lot of helpful resources on our website that can make your plans much easier, including our blog, real-time travel map, email alerts, our WSDOT app, and more.

 


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:

  • Thursday, April 25 to Friday, April 26 The right general-purpose lane and shoulder of southbound I-405 from milepost 23.5 to milepost 21.43 will be closed nightly from 10 p.m. – 5 a.m.  

  • Monday, April 22 to Friday, April 26: 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. 

  • Thursday, April 25 to Friday, April 26: The left express toll lane and shoulder of northbound I-405 from milepost 21.5 to milepost 23.5 will be closed nightly from 8 p.m. – 4:30 a.m. 

  • Thursday, April 25 to Friday, April 26: The left express toll lane and shoulder of northbound I-405 from milepost 24.1 to milepost 27.1 will be closed nightly from 8 p.m. – 4:30 a.m. 

  • Monday, April 22 to Thursday, April 25: 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. 

  • Tuesday, April 23 to Thursday, April 25: The right collector distributor lane between Northeast 160th Street and SR 522 for the Northeast 160th on-ramp and northbound I-405 off-ramps to eastbound/westbound SR 522 ramps will be closed nightly from 3 a.m. – 5 a.m. 

  • Tuesday, April 23 to Thursday, April 25: The left collector distributor lane between Northeast 160th Street and SR 522 from northbound I-405 off-ramp to eastbound/westbound SR 522 ramps will be closed nightly from 3 a.m. – 5 a.m. 

Highway ramp closures:

  • Wednesday, April 24 to Friday, April 26: The eastbound SR 522 to southbound I-405 ramp to the right general-purpose lane and shoulder of southbound I-405 from milepost 23.5 to milepost 21.43 will be closed nightly from 10 p.m. – 5 a.m.  

  • Monday, April 22 to Friday, April 26: The right collector distributor lane between Northeast 160th Street and SR 522 for the Northeast 160th on-ramp and northbound I-405 off-ramps to eastbound/westbound SR 522 ramps will be closed nightly from 3 a.m. – 5 a.m. The Northeast 160th Street on-ramp to northbound I-405 and SR 522 will be closed. 

  • Monday, April 22 to Tuesday, April 23: The left collector distributor lane between Northeast 160th Street and SR 522 from northbound I-405 off-ramp to eastbound/westbound SR 522 ramps will be closed nightly from 3 a.m. – 5 a.m. The northbound I-405 off-ramp to SR 522 will be closed. 

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