Project Profile: Federal Way Link Extension, Seattle

The Federal Way Link Extension is a 7.8-mile light rail transit (LRT) project engineered to expand high-capacity transit south from Seattle-Tacoma International Airport. Developed by Sound Transit, this critical infrastructure initiative directly addresses severe vehicular congestion on the Interstate 5 corridor by providing reliable, grade-separated rail service. The project involves the construction of an elevated guideway, three modern stations, and integration with the regional Link light rail network.

Technical Specifications

The core infrastructure of the Federal Way Link Extension consists of a dual-track elevated guideway constructed primarily within the Interstate 5 (I-5) right-of-way to minimize property acquisition and environmental impact. The alignment extends from the existing Angle Lake Station to the Federal Way Transit Center, featuring three new stations: Kent Des Moines, Star Lake (S. 272nd Street), and Federal Way Downtown. Station structures are predominantly elevated, incorporating robust pedestrian access, park-and-ride facilities, and integrated connections for local bus services to create multi-modal transit hubs. The project utilizes Communications-Based Train Control (CBTC) for signaling, enabling efficient headways and safe operations. Power is supplied via a DC overhead catenary system consistent with the existing Link network.

Rolling stock for the extension consists of Siemens S700 Light Rail Vehicles (LRVs). These vehicles are configured for high-capacity service with enhanced passenger amenities, including increased standing room, dedicated bicycle and luggage storage, and real-time passenger information displays. The fleet expansion is a critical component of accommodating the projected daily ridership of over 35,000 passengers upon full operational deployment.

Key Takeaways

• Congestion Mitigation: Provides a high-capacity, reliable alternative to the chronically congested I-5 corridor, projected to reduce peak travel times significantly.
• Regional Connectivity: Integrates major suburban centers in South King County (Kent, Federal Way) into the regional light rail system, connecting them directly to Sea-Tac Airport, Downtown Seattle, and the University of Washington.
• Economic Development Catalyst: The three new stations are designed to anchor Transit-Oriented Development (TOD), stimulating localized economic growth, housing density, and walkable communities.

Frequently Asked Questions

When will the Federal Way Link Extension open?

The Federal Way Link Extension is scheduled to begin passenger service in 2026. This new line will connect the existing Angle Lake station in SeaTac to the Federal Way Transit Center, with two intermediate stops.

Who is building the Federal Way light rail?

The project is owned and operated by Sound Transit, the regional transit authority. The primary design-build contractor responsible for constructing the alignment, guideway, and stations is Kiewit Infrastructure West Co.