With South King County’s rapid growth and chronic congestion, there was a clear need for a high-capacity, reliable alternative to driving. The Federal Way Link Extension (FWLE) extended Sound Transit’s Link light rail more than 7.8 miles to address that need. The project also added a parking garage with 3,200 stalls and approximately 2.5 miles of elevated guideway, while opening for revenue service on December 6, 2025, three months ahead of the original March 2026 target.
The project’s innovative Alternative Technical Concept (ATC) pipeline was critical to its overall success. The integrated design-build team developed and advanced ATCs through an efficient review and approval process, with 34 out of 53 proposed concepts becoming buildable solutions that generated approximately $70 million in savings.
FWLE also maintained more than 350 permits across multiple jurisdictions while coordinating with partner agencies to keep the project on a rigid schedule and reduce disruptions. Throughout construction, station-area design prioritized equitable access with multi-use paths and direct pedestrian links, including connections to Highline College. The team also resolved more than 1,000 issues during the design-build process, avoiding more than 1,000 change orders that could have caused significant delays on the $1.7 billion project.
Leadership Above the Curve
A key factor in FWLE’s success was a collective leadership strategy that aligned the design, construction, systems, jurisdictions and stakeholders as “one team,” with the Owner actively involved in the project’s decision loop from start to finish. That leadership model included a regular cadence of meetings, goals documented in a Conditions of Satisfaction Matrix and a co-located workspace that brought project partners together for face-to-face problem solving. Together, these structures created a performance system that allowed FWLE to resolve issues early and avoid unnecessary churn.
FWLE’s leadership also supported improved access to regional employment and education centers throughout South King County and the broader region.
Design-Build Team
| Client/Owner: | Sound Transit |
| Owner Advisor: | South County Transit Partners; Mott MacDonald / AtkinsRéalis Joint Venture |
| Design-Builder: | Kiewit Infrastructure West Co. |
| General Contractor: | Kiewit Infrastructure West Co. |
| Architect: | Parsons Corporation |
| Engineers: | Kiewit Engineering Group Inc.; Parsons Corporation; Shannon & Wilson |
| Specialty Contractors: | Absher; Mass Electric Construction Company; KLB; Salinas; Michels |
| Project Cost: | $1,700,000,000 |
| Construction Duration: | 80 months |
Photos
Photo Credits: Mass Electric Company; Multivista; SoundTransit; Kiewit