G-Geary: Clay-Geary Street Alignment

The 19th and 20th century hearts of San Francisco lie north of Market street; Jackson Square / the Barbary Coast districts were the historic center during the gold rush era and period of early growth, followed by Polk Street and the Tenderloin after the earthquake, and the Financial District and Union Square / Downtown in the modern era. Once it passes beneath the Market Street Subway, this proposal for a G-Geary train serves all of these areas as well as Cathedral Hill, Japantown and the Western Addition before running along the surface of Geary Boulevard in the Richmond District.

Sectional diagram of the Clay-Leavenworth-Geary Street Subway portion of the proposed G-Geary. South of Market the subway continues under Beale; West of Webster the alignment continues above grade, eventually becoming a Geary streetcar.

• The first stop is located under Clay Street at Sansome, on the north flank of the Financial District. This location counter-balances the strong transit presence on the southern side of this district (flanked by the Market Street Subway), and also provides right-of-way-separated access to Jackson Square and southern Columbus Avenue. The huge daily influx of workers to this district, home to all of San Francisco's Fortune 500 companies, makes it a natural fit for transit.
• Also under Clay, between Powell and Mason Streets lies the next station stop at Nob Hill, transfer point for the T-Third under Stockton Street at Chinatown. 
• By far the most populous part of San Francisco is the Tenderloin. If the rest of the city were equally populated, the City and County would boast over 1.6 million denizens overall. A metro station under Leavenworth between Sutter and Post would serve this district directly, with upwards of 17,500 people located within easy walking distance of the stop.
• After transitioning to a Geary Street alignment, the subway stops at Franklin,  serving the western edge of the Tenderloin and lower Polk along with the population on Cathedral Hill.
• Trains heading west transition to an aerial alignment at Laguna Street,  then stop between Fillmore and Webster Streets for their last Phase 1 station stop. Serving Japantown,  Fillmore and the Western Addition,  this station also allows for easy vertical connection for busses on the Geary bus rapid transit route.