Sound Transit and the Federal Transit Administration have published the Final Environmental Impact Statement (EIS) for the West Seattle Link Extension, marking a significant milestone in the project's development. This 4.1-mile light rail expansion aims to connect SODO to West Seattle, with stations planned at SODO, Delridge, Avalon, and Alaska Junction.

The Final EIS, released in compliance with both federal and state environmental regulations, provides a comprehensive analysis of the project's preferred alternative and other options. It details potential environmental impacts and outlines strategies to avoid, minimize, and mitigate these effects.

Notably, the West Seattle Link Extension, originally part of a larger project including the Ballard Link Extension, is now proceeding as a separate entity. This decision follows a July 2022 directive from the Sound Transit Board to conduct additional studies for the Ballard extension, allowing the West Seattle project to move forward independently.

The document evaluates multiple build alternatives, including various alignments and design options, as well as a No Build Alternative for comparison. It also considers a minimal operable segment from SODO to Delridge, should the full project face construction delays.

From the Executive Summary: 

The West Seattle Link Extension is expected to alleviate the constrained bus network capacity within the corridor and allow for passengers to sit. Existing p.m. peak hour transit travel times from downtown to West Seattle are 22 minutes and are expected to increase to 30 minutes by 2042 as traffic congestion in the region grows.
With the West Seattle Link Extension, this would improve by 14 minutes, or 47 percent. Furthermore, transit travel time reliability would greatly improve from unreliable under existing conditions to reliable service on the exclusive light rail right-of-way.

While the Sound Transit Board has identified preferred alternatives for each project segment, the Final EIS emphasizes that this does not constitute a final decision. The Board retains the flexibility to select from any of the alternatives evaluated in the EIS after its publication.

Interestingly, recent cost estimates suggest that tunneling alternatives in West Seattle may not be more expensive than elevated options, contrary to earlier projections. However, current estimates indicate that the preferred alternatives may exceed the assumptions in Sound Transit's realigned financial plan.

The cost, estimated to be close to $3.9 billion in 2022 have risen to a range of $5.1 billion to $5.6 billion, according to the statement. The West Seattle Link Extension, part of the voter-approved Sound Transit 3 Plan, is scheduled to open in 2032. The original vote in 2016 approved a $1.6 billion expenditure. This expansion represents a significant step in enhancing public transportation in the Puget Sound region's most densely populated county.

The cost breakouts show that the new bridge over the Duwamish and Alaska Junction stations will be the most expensive components:

• SoDo: $750-800 million

• Crossing: $1.9-2.15 billion

• Delridge: $700-750 million

• Alaska Junction: $1.75-1.9 billion

Worth noting is that Sound Transit states that the project could be built in stages, which could extend the time of construction. It would result in Minimum Operable Segment (M.O.S)

The EIS states:

"Due to funding or other factors, Sound Transit could construct a smaller portion of the project, deferring completion of the full project to Alaska Junction. Sound Transit has developed a M.O.S. for analysis in the event the full project cannot be built at one time. The West Seattle Link Extension M.O.S. consists of the West Seattle Link Extension from just north of the proposed new SODO Station to the Delridge Station. This M.O.S. can be applied to all of the West Seattle Link Extension alternatives and design options."

The Final EIS is now available for public review, with electronic copies accessible online and physical copies available upon request. This publication marks a crucial phase in the project's progression, bringing the West Seattle community closer to an expanded, efficient light rail system.

The Executive Summary and a flash drive including the Final EIS, appendices, and technical reports are available at no charge. Final EIS hard copies are available for $25, and hard copies of the separately bound appendices and technical reports are available for $15 each by contacting Dominique Jones at 206-689-4783 or dominique.jones@soundtransit.org.

Read the Executive Summary of the project HERE

West Seattle Link Extension Final Environmental Impact Statement - Purpose and Need

 West Seattle Link Extension Final Environmental Impact Statement - Alternatives

 West Seattle Link Extension Final Environmental Impact Statement - Transportation Environment and Consequences

West Seattle Link Extension Final Environmental Impact Statement - Affected Environment and Environmental Consequences

West Seattle Link Extension Final Environmental Impact Statement - Cumulative Impacts

 West Seattle Link Extension Final Environmental Impact Statement - Alternatives Evaluation

West Seattle Link Extension Final Environmental Impact Statement - Comment Summary