Planners Tout Subway-and-Bridge Option to Speed M Line on 19th Avenue; $520M Price Tag Cited

The San Francisco County Transportation Authority on Thursday told the Planning Commission it has completed a feasibility study showing how moving the M Ocean View line off the median of Nineteenth Avenue and through Park Merced could speed service, increase capacity and improve pedestrian safety. "This pretty much takes the M underground from Saint Francis Circle to the university through Park Merced," Liz Bryson, the study’s project manager, said in a presentation to the board.

Bryson said the highest‑performing alternative identified in the study would put most of the alignment underground and carry the line over Highway 1 on a bridge to Randolph Street. That longer subway-and-bridge option would boost transit travel speeds by an estimated 35 to 45 percent — about seven to eight minutes of saved running time — and enable stations that could accommodate three‑car, possibly four‑car, light‑rail trains.

“That’s twice as much capacity,” Bryson said, adding that the proposal would also create safer, more attractive transit access and substantial walking and bicycle benefits.

The presentation reported an illustrative cost of about $520,000,000 for the subway option, of which Park Merced has committed roughly $70,000,000 as part of its development agreement. Bryson said the study’s next step is a project study report required by Caltrans, a phase she expects to run through July 2015 and to be followed by an environmental review that could take about three years.

Commissioners pressed staff on two frequently‑asked questions: whether the project design would preclude later extensions — to West Portal or Daly City — and how recently revised state environmental standards might affect the review. Bryson said the study was framed so it would not preclude a West Portal subway or an extension to Daly City, and that the Office of Planning and Research’s new guidance on level of service was likely to be in place before the environmental review begins, potentially streamlining certain analyses. “If you really figure out all the details of what you want to do before you do your review, you can make that period more streamlined,” she said.

Public comment at the hearing was broadly supportive, with several commissioners urging staff to study options that would also address adjacent multimodal and pedestrian priorities. A handful of commissioners asked the project team to examine whether tunneling farther back — for example at Saint Francis Circle so the M could be taken under Nineteenth Avenue earlier — would be cost‑effective, and to coordinate study assumptions with SFMTA’s broader rail strategy.

The planning department will receive the study materials and expects further public meetings as the project moves into its next phases. The commission did not take any formal action Thursday; the presentation was informational.