Down the road: Contract awarded for I-405 corridor improvements including multimodal mobility, bus rapid transit

Construction begins later this year; project also includes express toll lane extension, direct access interchanges

BOTHELL – The Washington State Department of Transportation and Sound Transit awarded a design-build contract last week for a multiyear project along a segment of Interstate 405 that will extend the dual express toll lane (ETL) system and improve the flow of traffic on the Eastside.

Design-build contracts combine a project’s final design and its construction into a single contract. Contractor Skanska’s $834 million bid had the winning combination of price and technical expertise, meeting the “apparent best value” bid requirements. Construction is expected to begin in late 2023, and the new-look roadways will open to traffic in 2028.

Once complete, Sound Transit’s Stride bus rapid transit (BRT) service will use the ETLs and center freeway stations, thus removing buses from general-purpose traffic lanes. The new BRT system along I-405 will increase connectivity and improve access to the regional transit system and save time for travelers and residents in Bothell, Kirkland and surrounding communities.

About the project

The I-405, Brickyard to SR 527 Improvement Project lies primarily in Bothell on Interstate 405, starting south of the SR 522 interchange near the Brickyard Park and Ride and ending at the SR 527 interchange. The project will enhance and expand 4.5 miles along the corridor.

Contractor crews will create one new ETL in each direction just south of SR 522 to SR 527, providing relief to the general-purpose lanes and moving more people through all lanes. It also creates direct access ramps to the ETLs at SR 522 and a partial direct access interchange at SR 527 connecting to the Canyon Park Park-and-Ride, relieving bottlenecks in key areas.

Significant improvements for transit riders and carpoolers are also components of this project. For people who ride transit locally and regionally, improvements include additional connections to regional transit service at the Canyon Park Park-and-Ride and the future UW Bothell Station. The Brickyard station will serve Bothell and Kirkland with a new transit-only inline BRT station facility to support the I-405 Stride BRT service, improving connections to the community and existing park and ride. The project will ensure the community has better local connections and improved roadways for people who walk, bike, roll, drive, and ride transit to—and through—the area.

“Our partnership with Sound Transit is crucial for this project. By creating more connections to regional transit service and aligning with Sound Transit's plans for bus rapid transit, we're enhancing convenience and accessibility,” said Lisa Hodgson, WSDOT I-405/SR 167 program administrator. “The inclusion of the second express toll lane will provide more opportunity for a faster, reliable trip when you need it, providing a better commute for all lanes.” 

“The new inline station at Brickyard will be integral to delivering fast, frequent Stride bus rapid transit service to people who live and work in Bothell, Kirkland, Lynnwood and all along the I-405 corridor,” said Sound Transit Program Executive of Stride BRT Bernard van de Kamp. “By working together, we’ve developed a project that will make transit more accessible along the I-405 corridor and increase connectivity throughout the region to improve overall mobility.”

Funded by toll revenue, the Move Ahead Washington package and Sound Transit, this project also includes local roadway improvements, fish barrier corrections, noise walls and new stormwater facilities.

About Stride bus rapid transit

Sound Transit's new Stride bus rapid transit provides fast, frequent and reliable bus service connecting to light rail and to communities north, east and south of Lake Washington.

166,800 electric vehicle

registrations in Washington in 2023, up from 114,600 in 2022.

87 wetland compensation sites

actively monitored on 918 acres in 2023.

25,000 safe animal crossings

in the Snoqualmie Pass East Project area since 2014.