Bay Area Rapid Transit (BART) has connected the East Bay with San Francisco and the Peninsula for over 40 years (history summarized here). Since 2010, ridership has increased from 335,000 daily riders to 423,000, representing a 25 percent increase. Overcrowding and delays have also increased throughout the system, while punctuality and user satisfaction have decreased significantly.

The first article of this series (Part 1: Operations) discussed how BART plans to evolve its current operations to accommodate the distinct needs of suburban commuters and frequent transit users within the region’s core. Nonetheless, the existing system can only be upgraded to a certain point before new physical infrastructure will need to be built. This second article will evaluate current capital construction proposals to better link the Bay Area.

Transit Design 101

Transit system ridership is determined by several factors, including but not limited to location, time, and convenience. In general, stations should be located where people want to go, whether it be work, home, commercial, etc.

Currently, BART primarily runs in highway medians or along old railroad right-of-ways, with subway stretches in urban areas such as SF, Oakland, and Berkeley. Unsurprisingly, the stations with the highest ridership are all located in the urban areas, as those subway stations have dense walksheds that serve large numbers of people. Moreover, urban passengers are more likely to use the transit system during off-peak hours; as such, it is more cost-efficient to extend transit service along these urban corridors with heavy all-day traffic.

BART has several capital plans it could pursue, each of which will be analyzed below. The infographic below provides a high-level overview of various proposals that have circulated in recent years.

Crossovers

A crossover is a section of track that enables trains traveling on one track to switch over to the adjacent track. Crossovers are typically found at the terminals of the lines to enable trains to reverse, but they are also interspersed throughout the system to reroute trains past certain track sections when normal service is disrupted (e.g. construction, disabled trains). BART’s most recent capital construction project, the Contra Costa Crossover between Pleasant Hill and Walnut Creek stations, was completed in April 2015. This crossover not only reduces the impact of track construction in the area, but enables more trains to reverse direction at Pleasant Hill, reducing the number of train cars needed to provide service on the Pittsburg/Bay Point Line and freeing up capacity for other lines.

BART aims to build more crossovers in the existing system to facilitate reversing of trains. One major opportunity lies at the Richmond terminal, where arriving trains must currently proceed past the station into the Richmond Operations Facility to reverse. BART intends to build a crossover immediately before the facility, which will enable trains to turn back in 3 minutes instead of the current 8. Fewer train cars will then be needed on the two lines serving Richmond, freeing up capacity on other scheduled trips.

BART also intends to build an additional crossover in San Francisco. Currently, only certain peak-hour Pittsburg / Bay Point trains reverse at Montgomery St in the morning and 24th St Mission in the afternoon. In BART’s SCOA plan, Fremont – Daly City trains will permanently reverse at 24th St / Mission upon the opening of the extension to Berryessa in order to reduce the number of cars needed to run the service. When peak headways are reduced to 12 minutes and the number of trains on the line increase, the existing crossovers at Montgomery St and 24th St Mission will become unusable during rush hour. To prevent reversing trains from blocking regular service, BART will need to build a dedicated pocket track, either at Glen Park station or the proposed 30th St Mission infill station (see next section).

Infill Stations

Due to BART’s unique track gauge and elaborate station designs, line extensions are expensive. The SFO extension cost $1.5 billion, and Phase 2 of the Silicon Valley extension is projected to cost $4 billion. Outwards extensions also increase the mileage of the existing fleet and raise operating costs.

Given the expense of laying new track, new riders can be gained at significantly less expense by building infill stations, i.e. stops between existing stations, to better serve passengers along the existing corridor. BART currently has two infill stations – Embarcadero in SF, added midway through initial construction and now the busiest station in the system, and West Dublin/Pleasanton, which offers substantial ridership at reasonable price. (For reference, the West Dublin / Pleasanton station serves ~3500 riders at a cost of $110 million, compared to the ~2000 riders served by the Oakland Airport line at a cost of $500 million.)

Compared to existing subway systems and even commuter rail lines such as Caltrain, BART has very wide stop spacing, especially south of Oakland. Thus, there exist several opportunities for infill stations on the BART line:

30th St Mission: The most commonly cited location for an infill station lies at the midpoint between 24th St Mission and Glen Park. Serving the Mission, Bernal Heights, Upper Noe Valley, and Fairmont Heights neighborhoods, the station would likely have ridership similar to that of the other Mission St stations (i.e. 15,000). Underground infill stations are expensive, however (projected cost: $500 million), and the slope of the tracks at that location may make construction technically challenging. Nonetheless, the potential benefits of such a station may be too much to ignore.

The most commonly cited location for an infill station lies at the midpoint between 24th St Mission and Glen Park. Serving the Mission, Bernal Heights, Upper Noe Valley, and Fairmont Heights neighborhoods, the station would likely have ridership similar to that of the other Mission St stations (i.e. 15,000). Underground infill stations are expensive, however (projected cost: $500 million), and the slope of the tracks at that location may make construction technically challenging. Nonetheless, the potential benefits of such a station may be too much to ignore. San Antonio / Brooklyn Basin: A San Antonio transit center would serve a dense but underserved neighborhood in the heart of Oakland, as well as close an existing three mile gap between Lake Merritt and Fruitvale stations. Between 14th and 16th Avenues in Oakland, the BART tracks lie at grade, making construction relatively easy and inexpensive (~$100 million). Ridership would likely be on par with Fruitvale (~8000 riders). Out of the stations on this list, it is the most technically and politically likely to be built, after the planned Irvington Station.

A San Antonio transit center would serve a dense but underserved neighborhood in the heart of Oakland, as well as close an existing three mile gap between Lake Merritt and Fruitvale stations. Between 14th and 16th Avenues in Oakland, the BART tracks lie at grade, making construction relatively easy and inexpensive (~$100 million). Ridership would likely be on par with Fruitvale (~8000 riders). Out of the stations on this list, it is the most technically and politically likely to be built, after the planned Irvington Station. Elmhurst / 98th Ave : As with San Antonio, the Elmhurst neighborhood between Coliseum and San Leandro Stations is underserved. With access to the International Boulevard commercial district, ridership would likely be on par with San Leandro (~6000 riders). Constructing an elevated station may prove to be difficult, however.

: As with San Antonio, the Elmhurst neighborhood between Coliseum and San Leandro Stations is underserved. With access to the International Boulevard commercial district, ridership would likely be on par with San Leandro (~6000 riders). Constructing an elevated station may prove to be difficult, however. Albany (Solano Ave): Traffic on the Eastshore Freeway has reached continuous gridlock, making the adjacent Richmond line a very appealing method for crossing the SF Bay. The station would be built between Solano and Marin Aves, serving nearby Downtown Albany and University Village. Ridership should be on par with El Cerrito Plaza (~5000 riders), but constructing an elevated station in a suburban neighborhood may not be appealing to local residents.

Traffic on the Eastshore Freeway has reached continuous gridlock, making the adjacent Richmond line a very appealing method for crossing the SF Bay. The station would be built between Solano and Marin Aves, serving nearby Downtown Albany and University Village. Ridership should be on par with El Cerrito Plaza (~5000 riders), but constructing an elevated station in a suburban neighborhood may not be appealing to local residents. Irvington : This station should have opened with Warm Springs later this year, but has been deferred due to funding issues. With a commercial district nearby, Irvington will likely be built when the City of Fremont obtains funding within the next ten years.

: This station should have opened with Warm Springs later this year, but has been deferred due to funding issues. With a commercial district nearby, Irvington will likely be built when the City of Fremont obtains funding within the next ten years. 52nd St / Children’s Hospital: A station midway between Ashby and Macarthur would serve the Children’s Hospital of Oakland, as well as the commercial zone below the elevated viaduct and the residents nearby.

Second Transbay Tube

The last project on this list involves building another crossing between SF and Oakland. While train control modernization will increase the capacity of the existing Transbay Tube by 25 percent, a second rail crossing will be needed to link the East Bay with SF and the peninsula. As transbay travel grows further, crowding will increase to a level that cannot be handled by current infrastructure, even with operational upgrades.

A second Transbay Tube would connect more neighborhoods and create more origin-destination trips while also reducing congestion on freeways. A second Transbay Tube also provides redundancy: because the SF Bay Area is a seismically active region, an additional bay crossing will help insure the region’s transportation network in the event of a serious earthquake. Lastly, building the second Transbay Tube will enable 24-hour Transbay service by allowing one of the Transbay crossings to be closed for maintenance while the other operates.

However, the second Transbay Tube should not carry BART trains. Again, BART extensions are expensive, and comparable transit service can be provided by leveraging existing traditional rail tracks in the East Bay. A future article in this series will lay out an alternative intercity rail proposal to extend Caltrain and future HSR to Oakland. For a preview, however, check out this article from the Transport Politic.