On Monday, the Sound Transit West Seattle and Ballard Link stakeholder advisory group, which includes transit advocates, prominent community members, and business and labor leaders, moved further along the process of selecting alignments and station locations for the West Seattle and Ballard light rail lines.
In Monday’s meeting in Union Station’s Sound Transit boardroom, agency staff briefed the group on siting and alignments in Sodo and Chinatown. They also briefed the group on water crossings at Salmon Bay and the mouth of the Duwamish river.
The advisory group will eventually pass recommendations to a subcommittee of the Sound Transit board, which in turn will recommend the ultimate preferred alternative to the board as a whole.
In breakout sessions conducted over pad thai, the advisory group discussed the alignment and station locations of the new West Seattle line’s Sodo station. The advisory group also discussed the location of the new Chinatown/ID station, which will have far-reaching impacts on the future of the light rail system.
The Chinatown station, and the segment of the new line closest to it, was the subject of intense discussion, with good reason. It’s the centerpiece of the project, and it could have the most disruptive construction impacts of any Link project so far.
Tough choices for Chinatown/ID station and alignment
The future Chinatown station is one of the most critical elements of the new Link line. It will be the southern terminus of the new downtown tunnel, the site of hundreds of thousands of intra-Link transfers every day, and the light rail network’s busiest multimodal hub, with connections to Sounder, Amtrak, public and private buses, and the Seattle streetcar.
The station and alignment’s siting and design will have permanent impact on Link’s capacity, headways, and expansion potential. Sound Transit is committed to making the Chinatown station a central transfer hub, so it has to be built adjacent to the existing Chinatown/International District Link stop next to Union Station.
Construction in Chinatown and Pioneer Square is complicated. Much of the area is infilled tideland, which would liquefy during an earthquake. Liquefaction aside, the loose soil requires deep foundations for newer construction, and would force Sound Transit to make a deep bore tunnel even deeper than in most areas of the city.
Plus, many of the buildings in the area are built on pilings, since the neighborhoods are the city’s oldest. Those pilings could be obstacles for any alignment, and might not be replaceable with a new foundation. Demolition isn’t a way out of that problem: a large slice of the area—and King Street and Union Station themselves—are historic landmarks, or in historic districts.
4th Avenue vs. 5th Avenue
Sound Transit’s “representative alignment” is under 5th Avenue, with a station perpendicular to King and Jackson streets and parallel to the current Chinatown/ID station. During the first round of outreach with the Chinatown and Pioneer Square neighborhoods, there was strong demand for siting the line and station on 4th Avenue, or under Union Station. [Read more…]