Lynnwood link extension
Seattle
BEST PROJECT
Presented by HNTB Corp.
owner Sound traffic
Leading design company HNTB-Jacobs JV
General Contractor Stacy & Witbeck/Hoffman JV (SKH); Skanska
Road engineer KPFF
Structural Engineer HNTB; Jacobs; KPFF
MEP engineer IMAGE
An 8.5-mile expansion brings Sound Transit’s Link light rail system from north Seattle to Snohomish County, giving the county its first light rail extension. The $3.3 billion project is expected to serve 55,000 daily users by 2026.
The scope of work included new light rail tracks and station extensions spanning four city jurisdictions and WSDOT’s I-5 right-of-way, including the realignment of a long-haul crossing over the interstate, which presented multiple technical, logistical and jurisdictional challenges and required meticulous planning to minimize disruption. Extensive stakeholder involvement was also necessary.
Early design packages allowed construction to begin prior to full design completion, a strategy that ensured completion was scheduled for August 2024. But given the project’s route through busy areas, construction activities were carefully sequenced to minimize disruption and ensure the safety of workers, commuters and nearby communities. Advanced modeling also helped reduce risks and maintain safe working conditions.
Photo courtesy HNTB
Halfway through the project, a fifth station was added to the project at NE 130th Street. The equipment changed to allow for the additional reach, and despite the addition, the extension was delivered on time and on budget. The team also managed the realignment of a long-haul interchange over I-5 and integrated multimodal transfer facilities, which helped minimize disruption and improve connectivity, ensuring minimal disruption to highway traffic.
Lynnwood City Center Station is the first Sound Transit project to achieve LEED Gold certification, with the project achieving a 30% reduction in energy cost, a 34% reduction in indoor water use and an 81% diversion of construction waste from landfills. Temporary soldier pile walls helped preserve 97% of the wetlands near McAleer Creek.
Each station throughout the expansion features custom square designs, unique color palettes, and original artwork based on community input. The stations were designed for accessibility, safety and user experience, incorporating intuitive layouts, ADA-compliant features and multi-modal connections.
