Central Subway: An Introduction

This is Part 1 of a five post series on the Central Subway project. Click here to navigate the table of contents for these posts.

On April 7, 2007, Muni’s 15-Third Street bus was officially retired and replaced with a new light rail line, the T-Third Street, which features over five miles of new track and 18 new stations. The T-Third, however, is only a first phase, the initial operating segment of a two-phase project to build a rail connection between Chinatown and Visitacion Valley, and also to provide rail for the Mission Bay, Dogpatch, and Bayview neighborhoods, all designated as prime spots for active development in the next few decades. The second phase is the Central Subway, a 1.7-mile extension of the T-Third which, in its broad outline, would start near the Caltrain Depot at 4th and King Streets, tunnel underneath South of Market, Market Street, Union Square, and finally terminate in Chinatown. Currently, T-Third trains follow the existing track along the Embarcadero and enter the Market Street subway through the Embarcadero Portal, but once the Central Subway is completed, the T-Third line will tunnel northward directly through South of Market, rather than following the broader curve of King Street and the Embarcadero. It will also be the only Muni Metro line that does not run underneath Market Street.

The idea of a Central Subway is not new. Decades ago, a subway tunnel underneath Kearny Street was conceived, straddling the border between the Financial District to the east and Chinatown and Union Square to the west. This alignment in many ways makes a great deal of sense, as it would serve both the transit-dependent Chinatown rider market and central business district workers. However, under former Mayor Willie Brown’s watch, the Central Subway was manipulated into a prime political tool. Not only would a rail line along Third Street connect the long-neglected Bayview neighborhood to downtown, but once it became clear that the Embarcadero Freeway was not going to be rebuilt after it was damaged in the 1989 Loma Prieta earthquake, a subway tunneling into the heart of Chinatown would pacify Chinatown power brokers and merchants who alleged that the loss of the freeway would discourage people from visiting Chinatown, thereby hurting their businesses. Through these political dealings, a project which initially was a pretty good idea became convoluted and foggy. As such, this project has morphed over the past several years, and in this time period, projected costs have increased, design errors were made, and compromises were hatched in order to keep down the price.

Nonetheless, the Central Subway persisted through these trials, and the SFMTA is now supposedly just a couple years away from completing the design and review process. As it stands now, the project is estimated to cost $1.2-1.4 billion in YOE dollars, which amounts to approximately $700 million per mile. The funding comes from a mixture of local, state, and federal sources, which include: California Proposition 1B, the half-cent sales tax approved by San Francisco voters in the 2003 Proposition K, and $762 million of FTA Section 5309 matching funds. According to the currently planned schedule, the environmental and engineering process would be completed, along with the FTA Record of Decision, during 2008. Right-of-way acquisition and the final design process would take place in 2008-2010. Construction would begin in 2010 and would be completed in 2015, with an official start to revenue service in 2016.

The purpose of the next few posts is to describe the different alignments and station configurations that are currently being studied, and also to reflect on the efficacy of this expensive transit investment. I plan on adding a new post each day, so please check back throughout the week for the rest of the posts in this series.