I-405 – Northbound Peak-Use Shoulder Lane Project, SR 527 to I-5

Location: Bothell, WA

Interstate 405 provides a bypass to the east of Seattle, connecting the city with several major suburbs on the east shore of Lake Washington and serving as the most direct route to Redmond, home of Microsoft. The northern section between SR 527 in Bothell and I-5 in Lynnwood required improvements to increase capacity and relieve congestion in order to efficiently accommodate the significant traffic volumes of125,000 vehicles every day. This project converted the existing northbound I-405 shoulder between SR 527 and I-5 into a peak-use shoulder lane to provide additional capacity during periods of heavy congestion. This was the first implementation of this new traffic management strategy in Washington state.

Graham opened the new lane to traffic in April 2017, a year ahead of the original schedule identified by the state legislature. Since opening the peak-use shoulder lane, congestion during the northbound afternoon commute has improved significantly, with travel times decreasing by almost half, providing benefits for drivers and transit riders alike.

Graham’s successful leadership and innovative environmental design, while constructing in one of the wettest seasons on record, garnered two significant AGC and WSDOT awards “in recognition of diligent work opening new freeway capacity to the public ahead of schedule”.

Contract Value

$7.2M USD

Prime Consultant

David Evans and Associates, Inc. (DEA)

Project Owner


Contract Format


Completion Date

November 2017

Contract Duration

11 months