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.
Traffic switch on westbound SR 522 to northbound I-405 on-ramp
If you have any questions and/or would like to subscribe for project updates, please email I405SR167Program@wsdot.wa.gov. Stay informed by subscribing to WSDOT updates for King County.
Notification of pile driving at the SR 522 interchange
Starting as early as Oct. 30, design-builder Skanska will perform pile driving work that will support foundation work for the new northbound I-405 bridge to eastbound SR 522. The pile driving will take place on the south side of the Sammamish River near Northeast Woodinville Drive and last into December.
During this work, Skanska will minimize noise by using a vibratory hammer to install the piles and reserve the impact hammer only when absolutely necessary. When in use, people nearby often hear pings from impact hammer strikes. Factors such as soil conditions, depth and location dictate the difference between equipment.
During the pile driving work, you can expect to experience the following nearby the work area:
- Loud noises during the day:
- Noise from trucks and machinery that support the work including staging, loading, moving equipment and material and backup beeps.
- Possible noise associated with the impact hammer (pings from each strike) when in use.
- Vibration, especially associated with the vibratory hammer.
- Short term closures to nearby roadways and the Sammamish River Trail.
Upcoming work
Highway lane closures:
- The right general-purpose lane of northbound I-405 from milepost 19.65 to milepost 22.55 will be closed overnight from 8 p.m. Tuesday, Nov. 26 to 5 a.m. Wednesday, Nov. 27.
Highway ramp closures:
None planned.
Map of I-405 showing the area that will be improved, from SR 522 to SR 527, highlighted in orange.
