LYNNWOOD LINK EXTENSION, L300 NE 200TH TO LYNNWOOD TRANSIT CENTER

Seattle

EXCELLENCE IN SAFETY and Award of Merit, Highway/Bridge

Submitted by: Skanska USA Civil

OWNER: Sound Transit

LEAD DESIGN FIRM/CIVIL/STRUCTURAL: HNTB | Jacobs Trusted Design Partner JV

GENERAL CONTRACTOR: Skanska USA Civil West

MEP ENGINEER: IMEG (Formerly Rushing)

ARCHITECT: LMN Architects

CONSULTING ENGINEER: KPFF Consulting Engineers


Extending Sound Transit’s Link Light Rail Line 3.7 miles from Shoreline to the Lynnwood Transit Center required two elevated stations with vertical circulation, 2.3 miles of elevated guideway and 1.4 miles of at-grade track. Additional work on this $914.85-million project included demolition, clearing and grubbing, utility relocations, track work, retaining walls, sitework and a 1,650-stall parking garage at the Lynnwood Transit Center.

A key feature is a 900-ft parabolic cast-in-place bridge over the I-5 freeway. The team employed 3D modeling to identify rebar clashes, correct camber diagrams and ensure accurate placement of ducts that house 60 miles of post-tensioning cable before construction began. When the bridge was post-tensioned, it lifted up as much as 4 in. to remain in tolerance. This approach also ensured installation proceeded within the required +/- ¼-in. rail tolerance.

Lynnwood Link Extension

Photo courtesy Skanska USA Civil

With so many new hires on the project, the contractor developed a two-fold approach using a Plan, Do, Check, Act culture that aligned employees on safety. First, the team developed a learning program for all forepersons and supervisors. Weekly training educated the workforce on policies relevant to project risks, with an emphasis on subgrade soil dynamics, crane operations, human-machine interface, mass concrete, public protection and working at elevated heights. Then, once work began in the field, the contractor created a focused inspection schedule that helped verify training efficacy and ensure policies were executed correctly.

To prioritize mental health across the jobsite, the team implemented the Green Sticker program and actively integrated mental health awareness into daily operations with toolbox talks and strategically placed signs throughout the jobsite displaying contact information for support services.

Lynnwood Link Extension

Photo courtesy Skanska USA Civil

Across more than 3.6 million worker hours, the project team logged an OSHA recordable incident rate of 1.32 and a lost-time accident rate of 0.11. There were two lost-time safety incidents throughout the entire project’s duration, both serving as learning opportunities for the entire team.

In the early stages of the project, a subcontractor’s ironworker sustained injuries from an unsecured rebar cage. This underscored the critical need for comprehensive safety integration across all teams. Experienced ironworkers on Skanska’s team were specifically tasked with overseeing and coordinating activities with ironworking subcontractors, facilitating a deeper integration of these teams into an established safety culture.

The second incident occurred in 2022 when a wall form collapsed due to the failure of an engineered bolt, resulting in lost-time injuries to a Skanska carpenter. This technical failure impacted the morale and emotional well-being of the team, highlighting the importance of psychological support in handling workplace incidents. The contractor immediately provided grief and counseling services in multiple languages and revised its red bolt policy, mandating multiple methods of protection when securing structures to eliminate reliance on any single safety system.