31 August 2016

Entwining BART and Caltrain Elegantly in San Francisco

Figuring out where a new rail line will go is a complicated thing. Figuring out where to put a new BART or Commuter Rail tube AND a Caltrain extension, all interacting with existing rail, AND taking sea level rise into consideration will make your head implode.

Below are a few ideas I've put together. I've included five feet of sea level rise as a reference, as it would seem to be wise to include sea level rise into the planning when the infrastructure will be around for 100 to 150 years.

All of the options attempt to achieve the following:
  • A second transbay crossing for capacity increase and redundancy (2 tracks or bores)
    • In some cases a third crossing is included for a total of (4 tracks or bores)
  • A Downtown San Francisco station where most of the ridership goes
  • A transfer station between an existing Downtown Market St station and the new 2nd Tube in the event that the original Transbay Tube is shut down for major repairs
  • Focus on the Transbay Transit Center as the major transportation hub, especially because it will eventually have High Speed Rail.
  • Create stations in areas that are developing and lack a regional station or to areas that could accommodate significant new growth in the future.
Note that whichever idea gets put forward to eventually build will be built in phases. In the maps shown its assumed that the first phase of these regional rail plans would be the Downtown Extension (DTX), linking Caltrain and HSR to the Transbay Transit Center (aka Transbay Center). The second phase could be either a 2nd tube for BART, Caltrain or both, and later a third transbay crossing, or new rail westward into San Francisco.

Avoiding Sea Level Rise Zones
4 bores
Caltrain: 7th St and Howard to Transbay Center
BART: 2nd St and Post St to Cathedral Van Ness

Transfers: Montgomery and the Transbay Center would be connected by a new Mission Transbay BART station under 2nd Street. It would mean you could transfer from Caltrain to BART along Market St, or to the new BART line to reach places like Cathedral Van Ness or to Muni Metro to reach Castro Station.
When the First Transbay Tube is shut down, passengers from BART line in SF and peninsula would cross bay by transferring to new BART line at Montgomery/Mission Transbay station.
New Station Areas: Showplace Brannan, Cathedral Van Ness

The Realistic and Practical
2 bores - BART Only
Caltrain: Townsend St and 2nd St to Transbay Center
BART: Mission St and Geary to Fillmore

Transfers: Embarcadero and the Transbay Center would be connected by a new Fremont Transbay BART station under Mission Street. It would mean you could transfer from Caltrain to BART along Market St, or to the new BART line to reach places like Fillmore or to Muni Metro to reach Church Station.
When the First Transbay Tube is shut down, passengers from BART line in SF and peninsula would cross bay by transferring to new BART line at Embarcadero station to Fremont Transbay station.
New Station Areas: Fillmore, Cathedral Van Ness