• 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 SR 522 interchange and ending at the SR 527 interchange. The communities in this vicinity will see major improvements in added express toll lane capacity, direct access to state highways and improved connections to regional transit service at both the UW Bothell Station (SR 522) and Canyon Park Park and Ride (SR 527), integrating corridor investments with Sound Transit’s planned opening of I-405 Bus Rapid Transit. The Brickyard station in Bothell will be a new transit-only inline BRT station facility to support I-405 Bus Rapid Transit, improving connections to the existing park and ride.

We will enhance four and a half miles of the corridor with a focus on both the main project expansion and overall operational improvements. We will build one new express toll lane in each direction between south of SR 522 and SR 527 (extending the existing dual express toll lane system), widen I-405 through the SR 522 interchange and build direct access ramps to the express toll lanes at SR 522, and build a partial direct access interchange at SR 527 to and from the south connecting to the Canyon Park Park and Ride. The project will include additional local roadway improvements, fish barrier corrections, noise walls, and new stormwater facilities.

The project is expected to complete construction in 2027 in alignment with Sound Transit Bus Rapid Transit.
Project status
Legislature allocated $605 million
Project hotline

What to expect

We are currently in the pre-construction phase. Building on extensive input from the community, FHWA and WSDOT recently released the environmental decision document – a Finding of No Significant Impact in July 2021. We are working through right of way acquisitions and permitting required to prepare the project for construction.

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