G-Geary: Beale Street Alignment

South of Market Street near the verge of the San Francisco Bay lie the most quickly densifying neighborhoods in San Francisco, namely the Financial District South, the Transbay District (surrounding a transit terminal of the same name), and Rincon Hill.

The South-of-Market (SoMa) component of this proposal includes an alignment along Beale Street to serve these neighborhoods, with a station stop at the Transbay Terminal to tie CalTrain, AC Transit, Golden Gate Transit and others in the new intermodal Terminal to the Muni Metro and BART systems under Market Street; the alignment then continues south, with a station utilizing an existing cut under Harrison Street through Rincon Hill to keep cost of construction low, finally connecting the new FiDi South Subway to the Southern Embarcadero light rail corridor at the end of Beale, where trains can run along the surface to serve the existing Giants Stadium as well as the future Golden State Warriors Stadium on the waterfront.

Sectional diagram looking south and west from the new FiDi South Muni Metro alignment. North of Market the alignment continues into the Clay-Geary Subway; South of I-80 it joins the Southern Embarcadero 

• The location of the Transbay Muni Metro Station at Mission and Beale allows easy access from the east end of the Transbay Terminal mid-block on Beale between Howard and Mission, with pedestrian tunnels constructed alongside the subway tunnel under Beale Street to tie the Transbay cluster of services to existing and to-be-expanded BART and Muni Metro service at Embarcadero Station.
• A right-of-way separated surface station under the existing overpass at Harrison Street keeps construction costs relatively low, and allows for connections up to the flank of Rincon Hill, above, with its thousands of new housing units proposed and under construction. With more than half of a dozen proposed and under construction high-rises within a two block radius, the usage of this station could be staggering within a decade; the new MTC offices on Main would have their own transit stop. Potential use of the Bay Bridge Maintenance Facility just south of the overpass as Muni train maintenance and staging could be highly beneficial in such a central location.
• An additional line serving the Muni Metro Extension (MMX) along the Southern Embarcadero with service to the existing Giants and future Warriors Stadia would help alleviate overcrowding of the N-Judah trains during game periods.

G-Geary: Northern Subway in San Francisco

Many of San Francisco Municipal Railway's first established rail lines were along the Geary Street corridor; this major East-West axis in received early and heavy transit investment with the A-Geary-10th, B-Geary, C-Geary-California and D-Geary-Van Ness all in operation one hundred years ago. The corridor's current service (the 38-Geary cluster of busses) boasted over 55,000 daily boardings in 2007 — as real estate in eastern San Francisco continues to soar skyward, the western parts of this corridor are densifying and are ripe for the return of train service.

The G-Geary first phase subway connects Rincon Hill to the Financial District, Nob Hill, the Tenderloin and Japantown; the second phase extension continues with rail service to Western Addition/NoPa and the Richmond district.

This is a dream for rail service on the Geary Street Corridor. Stretching from the Rincon Hill, Transbay and FiDi South neighborhoods south of Market Street through downtown, Cinatown, Nob Hill and the Tenderloin to Japantown and the Western Addition, this alignment creates a skip-stop transfer network with the existing Market Street and currently under construction Central Subway. Utilizing an existing undercrossing through Rincon Hill and keeping the line shallow to allow cut-and-cover connection between the new Transbay station and Embarcadero keep the eastern alignment costs relatively low; a tunneling machine would be required only for the deep bore under Nob and Cathedral Hills, a tunnel which would serve three of the most densely populated and still densifying portions of the City of San Francisco, namely the Financial District, Chinatown/Downtown, and Nob Hill/Tenderloin/Polk Gulch.

Phase 1 / Subway

(view phase 1 G-Geary Subway in a larger map _ read methodology for proximal population statistics)


A scheme to provide Bus Rapid Transit (BRT) along the Geary Street corridor is currently in the planning stages, and hopefully opening for service before 2020. Terminating phase 1 rail constuction in an elevated station at Webster allows for vertical loading and unloading of trains from busses below, which with timed transfers which would speed movement from the Richmond District downtown hugely. When ready, phase 2 light rail could replace the BRT.

Phase 2 / Light Rail Transit

(view phase 2 GRx-Geary Richmond Extension in a larger map)

Methodology: Proximal Resident Population

To estimate the possible frequent use population incident on a station, I'm using data pulled from 2010 Census Block Groups within a 2-block radius of the center of the station. Take for example a proposed station centered at Leavenworth and Sutter streets in the TenderNob neighborhood of Downtown San Francisco.

First, locate the centerpoint of the station.

Next, draw a circle two blocks in radius (using streets not alleyways) along the major axis of the metro line at this point in its run (two blocks north and south along Leavenworth in this case).

Sum the population of all census block groups partially or completely encompassed by the circle.

In the case of this station, the following block groups are incident on the circle:
111bg2 - population 2,084
119.01bg1 - population 898
111bg3 - population 914
119.01bg2 - population 1,510
120bg1 - population 1,983
121bg1 - population 2,725
120bg2 - population 1,850
122.01bg1 - population 2,699
123.02bg1 - population 1,763
123.02bg1 - population 1,310
Population of proximal block groups — 17,736.

For the purposes of this comparison, an exact science is not what I'm looking for; after all it has been proven time and time again that "ridership estimations" are sorely lacking exactitude. Take, for example the BART SFO extension, originally estimated at 17,000 daily trips but only providing 20-30% of that amount in daily ridership during its first year of operation. Rather than try to divine how many people will use each station, I'm only identifying how many people are within an easily walkable distance (under seven blocks in this case) and could conceivably make use of the station with regularity.

Market Street Subway

Remapping the Market Street Subway + streetcar network, circa 2000 (after S. Embarcadero Extension opened).

View Market Street Subway in a larger map _ read methodology for proximal resident population statistics.

Geary Street to Marin

More than one traveler upon arriving in San Francisco on a BART train from the airport has voiced as one of their first questions "— where is the train to the Golden Gate Bridge?" The two-fingered peace sign of heavy rail transit through the core of this city seems a mistake, an underinvestment, a faux pas of the largest magnitude.

It may help to know that the BART system was originally imagined with Downtown San Francisco the recipient of a loose cross of transit lines, one path Richmond to Daly City (as currently operated), but a second was Fremont to Marin line envisioned service along the Geary Street corridor before the train swooped across the Golden Gate Bridge and headed to points northward.

San Francisco BART plan with Marin Line (San Francisco Bay Area Rapid Transit, 1961)

Once across the bridge, Sausalito, Mill Valley, Corte Madera, San Rafael and Santa Venetia were to be served by heavy rail transit.

Plan and section of BART line through Marin County ((San Francisco Bay Area Rapid Transit, 1961)