This is the third and final post in our series about the latest designs for the West Seattle and Ballard Link extensions. This post covers West Seattle.
On September 5th, Sound Transit released its latest concept work on the West Seattle and Ballard light rail extensions. We’re examining each segment in-depth, from north to south, station by station.
More detailed information, including Sound Transit’s score of each station site and track segment, can be found here. Sound Transit’s new outreach website has visualizations and other information. Here’s where you can read Part One (Ballard) and Part Two (Downtown & SLU).
Since the Level 1 analysis, ST eliminated the Delridge station options that were well off of Delridge Way, leaving only alignments that continue west on Genesee Street. Nearly all alignments that point west at Alaska Junction are also gone, as they mesh poorly with vague future plans to continue to White Center (the west-pointing ST3 representative project remains). The majority of surviving options tunnel under the Junction. All have a potential ridership of between 10,000 and 12,500 within the station walksheds.
Staff continue to make it clear that a tunnel will add costs. The three tunnel options here increase the overall project costs by anywhere from $500M to $1.2B, in addition to creating increased schedule risk. If a tunnel were to be selected, supplemental funding from the City would be required.
ST presented three alignments of the water crossing: a bridge north of the West Seattle Bridge, a bridge adjacent to the south edge of the West Seattle Bridge, and a bridge south of Harbor Island with a tunnel through Pigeon Hill.
The Pigeon Hill alignment seems likely to be eliminated. It would be the most complicated feat of engineering, and therefore the most expensive option at $1.2B more than the representative project; the river crossing would be the widest, and the tunnel would have to be a deep bore through the hill. ST staff seemed lukewarm about the alignment.