Federal Way link extension is a planned 12.5km-long light rail link between Angle Lake Station in SeaTac and the Federal Way Transit Centre in Federal Way.

The project also includes the construction of three new stations along the link.

Estimated to involve an investment of $1bn, the extension project is being executed by Sound Transit. Construction is scheduled to begin in 2019 and is expected to be completed by 2024.

The light rail extension is anticipated to reduce travel time by 12 minutes and increase daily ridership to 36,500.

Federal Way link extension background

The Federal Way link extension is designed to provide an efficient alternative for travel, improve connections and deliver high-capacity transit infrastructure.

The proposed extension project will provide efficient and reliable regional transit connectivity and offer better service during peak hours of the day, while resolving the increasing congestion issue on I-5.

The final environmental impact statement for the project was issued in November 2016. Sound Transit received a record of decision from the Federal Transit Administration in March 2017.

Federal Way link extension route and station details

The Federal Way link extension will originate at Angle Lake Station in SeaTac and include three new stations at Kent Des Moines Road, South 272nd Street, and the Federal Way Transit Centre, which will also serve as the terminus of the line.

Stations will feature a light rail platform and canopy, surrounding plaza, parking garage, bike storage, passenger drop-off facility, short-term parking, and a service building.

Kent Des Moines, South 272nd Street and Federal Way Transit Centre stations will have 500, 1,200 and 400 parking spaces respectively.

The project will also have provision for further extension of high-capacity transit service between SeaTac and Tacoma, which is known as the South Corridor.

Construction details

“Vehicles will offer 74 seats each with dynamic passenger information displays and LED destination signs installed on board.”

The Federal Way link extension project will be completed in two phases. Work under the design-build phase includes resident engineering, project control and scheduling, change management, technical support and inspection, as well as quality assurance and quality control.

Kent Des Moines station will be built as an elevated structure with a landscaped pedestrian path to improve access to Highline College and surrounding areas.

Station development will also involve the construction of two large modern plaza areas.

Rolling stock details

The extension will deploy light rail vehicles supplied by Siemens. Each vehicle will feature large windows, extra standing space in the centre aisle, more luggage space under seats, and four bicycle hooks.

Vehicles will offer 74 seats each with dynamic passenger information displays and LED destination signs installed on board.

Contractors involved with Federal Way Link extension

Mott MacDonald and SNC-Lavalin joint venture South County Transit Partners received the design-build contract from Sound Transit for the Federal Way link extension project in March 2018.

South County Transit Partners will support the execution of the design-build contract during phase one and provide project management services during design and construction throughout the phase two.

In April 2017, Sound Transit awarded a contract to Siemens for providing vehicles for the line extension.

Proposed alternatives for the extension

Five alternatives evaluated for the Federal Way link extension included the no-build alternative, SR 99, I-5 alternative, SR 99 to I-5 and I-5 to SR 99.

The preferred alternative for the extension project is I-5, which starts from the Angle Lake Station and crosses to the east side of SR 99 near the proposed SR 509 extension.