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.

What to expect

This spring we broke ground on this project and kicked off construction. Watch video highlights from the event. Construction at the I-405/SR 522 interchange continues to progress as crews prepare to begin work on the new bridge that will connect northbound I-405 to eastbound SR 522. Construction of the new bridge will allow us to widen the SR 522 interchange to accommodate the dual toll express lane system on 4.5 miles of the corridor. 

Full closures of northbound I-405 in Bothell for paving and southbound I-405 in Renton for drainage installation, Sept. 20-23

Travelers should plan for two closures on northbound Interstate 405 in Bothell and southbound I-405 in Renton starting Friday, Sept. 20 to Monday, Sept. 23. 

Contractor crews working for the Washington State Department of Transportation will conduct paving work on northbound I-405 as part of the I-405/Brickyard to SR 527 Improvement Project. Crews will also replace pavement panels and install drainage on southbound I-405 as part of the I-405/Renton to Bellevue Widening and Express Toll Lanes Project.

Northbound I-405 closure details

Northbound I-405 will be closed from State Route 522 to SR 527 beginning 11 p.m. Friday, Sept. 20 to 5 a.m. Monday, Sept. 23. The following on and off-ramps will be closed on northbound I-405:

• Eastbound/westbound SR 522 on-ramps to northbound I-405
• Northeast 195th Street/Beardslee Boulevard on- and off-ramps
• SR 527 off-ramp (Exit 26)

 A signed detour route is in place.

Southbound I-405 closure details

Southbound I-405 will be closed from Sunset Boulevard Northeast (Exit 5) to SR 167 beginning 11:59 p.m. Friday, Sept. 20 to 4 a.m. Monday, Sept. 23. The following on and off-ramps will be closed on southbound I-405:

• Sunset Boulevard Northeast on-ramp to southbound I-405
• Southport Drive on-ramp to northbound I-405
• SR 900/SR 169 on- and off-ramps (Exit 4)
• Talbot Road South on and off-ramps (Exit 3)

A signed detour route is in place.

Detour routes cannot accommodate normal I-405 traffic volume, so travelers are advised to “know before you go,” travel during off-peak hours or, if possible, delay discretionary travel to help minimize backups.

This work is dependent on the weather and may be rescheduled due to rain. Check out the WSDOT real-time travel map for up-to-date information. If you have any questions and/or you would like to sign up for project updates, please email I405SR167Program@wsdot.wa.gov. Stay informed by subscribing to WSDOT updates for King County.

Sammamish River Trail Reroute 

The Sammamish River Trail is scheduled for reroute in mid-August as contractor crews work on constructing a new shoring wall and remove the existing wall along the trail. In preparation for this work, the trail will have potential night closures from 10 p.m. to 5 a.m. that will take place beginning as soon as August 2024. If you travel along the trail, here is what to expect: 

• A short reroute around the shoring wall underneath the I-405/SR 522 interchange
• Potential nighttime closures as soon as August 2024, so please take caution when traveling along the trail outside of daytime hours
• Reroute will be made with temporary asphalt while crews work along the actual trail
• Signage and traffic control along the trail ahead of the reroute to direct you where to go