Grand Loop
New Subway for Western San Francisco
The Grand Loop is the overall concept for a new subway in San Francisco to connect the western neighborhoods to downtown. It updates the flexibility of the original MUNI Metro, providing a fast (50mph) subway operation, street operation, and integration with existing MUNI lines. It will operate using modern low-floor vehicles, each with a capacity of up to 540 passengers.
Goal:
Define a phaseable, high capacity transit project to improve travel times from western San Francisco to downtown and Daly City BART.
Solution:
A new MUNI subway, to be operated with low-floor, high-capacity 180' rail vehicles, such as the CAF Urbos. Subway portals would be located downtown, Geary near Arguello, Noriega near 24th, St Francis Circle, and near SF State. This provides for surface connections out Geary, Noriega, and to integrate the M line and grade seperate it from 19th Avenue. MUNI's Presidio Yard would be excavated and redeveloped to provide the base for the new fleet, and the project could be segmented by portal location.
The line would leave the existing MUNI along the Embarcadero at Main Street and descend into a subway north of Bryant Street. Turnback facilities and some storage would be located underground between the portal and the Embarcadero-SFTC Station.
The Embarcadero-SFTC station would be under Main Street, between Mission and Market. Deeper than both the rail level at the SFTC and the BART platforms at Embarcadero Station, the platform level connecte directly to the BART platform and railway mezzanine at SFTC. It would also provide an underground gallery bewtween the two existing stations with additional exits to street level.
The Financial District Station would be accessed from the southwest corner of Sansome and Clay Streets, in the base of a new highrise. The subway would then run west from here, in a very deep tunnel. The Chinatown Station would be accessed from a connection into the existing MUNI Rose Pak-Chinatown Station. The Van Ness Station, at California, would be accessed from the base of a new residential development built on the existing Bank of America site.
The Masonic Station sits deep beneath a development site that covers a rebuilt MUNI storage and repair facility and x-thousand units of new housing above and on the surrounding blocks. West of the station, a junction allows trains to pass to the surface of Geary Boulevard to run deep into the Richmond District. It also provides a convenient location for the end of the first phase of the subway.
Proceeding from Masonic, the subway travels diagonally with stations near USF and UCSF. South of the UCSF station, a second junction connects to the surface near Judah and 5th Avenue, leading to the outer N line. This permits a second MUNI surface on Judah that enters the Grand Loop for its run to Downtown.
Sunset District stations are located near Noriega and Taraval Streets, linking to new developments in the area and connecting to MUNI surface lines.
After passing deep under Stern Grove, the loop moves to an open cut as it enters the Stonstown area. The M line, dropped into a subway south of Junipero Serra Boulevard to pass beneath Sloat and SR 1, merges with the loop north of the Stonestown Station.
The line emerges from tunnel but remains grade seperated south of the Stonestown Station to cross the SF State campus. After a station at the college, the line Park Merced station is at grade, and where the line splits, with aerial structures returning one branch to the M line and the other skirting SR-1 to cross I-280 and end at the Daly City BART station.
