• Project

I-405/Brickyard to SR 527 Improvement Project

Project overview

The I-405/Brickyard to SR 527 Improvement Project enhances four and a half miles of the corridor, primarily in Bothell, from 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 deliver improvements that benefit all users, while addressing aging infrastructure, opening upstream fish habitat, and connecting communities, freight and Regional Growth Centers throughout the corridor.

Since implemented in 2015, express toll lanes (ETL) have helped improve reliability of trips on the north end of the I-405 corridor, however the single-lane section still experiences heavy congestion, especially for people traveling south during the morning commute. The project will extend the dual-express toll lane system on the north end of I-405 and improve access to the voter-approved Stride bus rapid transit service to address congestion and help keep all vehicles moving efficiently.

This project includes three new Stride stations and will build direct access ramps to the ETL system at SR 522, along with a partial direct access interchange at SR 527 to and from the south connecting to the Canyon Park Park & Ride. These enhancements will allow Stride vehicles to travel in the new ETLs between Lynnwood and Bellevue while stopping briefly to pick-up and drop-off passengers without having to leave the highway system. Having dedicated ETL access in the center of the freeway will make travel more efficient supporting the new Stride service with buses arriving every 10 minutes for most of the day.

Additionally, the project will address aging infrastructure, correct multiple fish barrier corrections, add noise walls and add 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

Major construction activities near SR 522

This spring we broke ground on this project and kicked off construction. Watch video highlights from the event. Mobilization and staging of construction equipment are underway. Construction crews, vehicles, and heavy equipment such as cranes, dump trucks and excavators, will be visible as the project enters the initial phases of heavy construction. This effort is preparation for the construction of the new northbound I-405 ramp from SR 522 and the widening of the interchange to accommodate the dual express toll lane system. This is the first phase to rebuild the intersection at SR 522. 

What you will see: 

  • Visible heavy construction equipment at several locations around the I-405/SR 522 interchange
  • Visible heavy construction equipment near Woodinville Drive, south of the Sammamish River
  • More construction personnel working in the area
  • Nighttime lane and ramp closures

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.

What you can do:
Drivers are encouraged to reduce speeds while traveling through the work zone for the safety of our crews. Recently we reduced the speed limit on SR 522 near the I-405 interchange to 35 MPH permanently. This is to ensure safety for both drivers and construction crews through the work zone next to SR 522 and to accommodate the future traffic configuration.


Upcoming I-405 ramp and lane closures

Highway lane closures: 

  • Monday, June 24 to Wednesday, June 26: The right lane of southbound I-405 from milepost 28.8 to milepost 26.85 will be closed nightly from 10:30 p.m. – 4:30 a.m. 

  • Monday, June 24 to Friday, June 28: The right lane northbound I-405 between SR 522 and Northeast 195th Street from milepost 22.5 to milepost 24.15 will be closed nightly from 11 p.m. – 5 a.m. 

  • Wednesday, June 26 to Thursday, June 27: The right two general-purpose lanes of southbound I-405 from milepost 27.75 to milepost 26.2 will be closed nightly from 11 p.m. – 4 a.m. 

  • Thursday, June 27: The left lane of westbound SR 522 from milepost 10 to milepost 11 will be closed nightly from 8 p.m. – 4:30a.m. 

Highway ramp closures: 

  • Monday, June 24 to Wednesday, June 26: The southbound I-405 to SR 527 ramp from milepost 27.1 to milepost 26.85 will be closed nightly from 10:30 p.m. – 4:30 a.m. 

  • Monday, June 24 to Friday, June 28: The westbound SR 522 to northbound I-405 on-ramp from milepost 12 to milepost 11.2 will be closed nightly from 11 p.m. – 5 a.m. 

  • Monday, June 24 to Friday, June 28: The northbound I-405 on-ramp between SR 522 to Northeast 195th Street from milepost 23.8 to milepost 24 will be closed nightly from 11 p.m. – 5 a.m. 

  • Wednesday, June 26 to Thursday, June 27: The southbound I-405 off-ramp to SR 527 from milepost 27.75 to milepost 26.28 will be closed nightly from 11 p.m. – 4 a.m. 

  • Wednesday, June 26 to Thursday, June 27: The southbound SR 527 off-ramp to southbound I-405 on-ramp from milepost 27.75 to milepost 26.28 will be closed nightly from 11 p.m. – 4 a.m. 

  • Monday, June 24 to Friday, June 28: The northbound SR 527 to southbound I-405 on-ramp from milepost 27.75 to milepost 26.28 will be closed nightly from 11 p.m. – 4 a.m. 

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