Fixing the Caltrain/HSR – SFO connection

Since BART was extended to SFO and Millbrae in 2003, the transit arrangement between Caltrain and SFO has become complicated. While the project promised a rail to rail connection, the final product results in more missed connections and frustrations. However over the last 10 years technology has advanced to a point where a more cost effective solution may be pursued to provide a quicker, more frequent, and more reliable connection between Caltrain and SFO.

1. Fully automated BART operation

Turn the BART segment between SFO and Millbrae into fully automated operation where the “operator” controls the train land side, and run shuttle service every 15 minutes or less. BART can procure cars that can support that and run single car train rather than a 3 car train which is the current minimum. BART’s operation is already primarily automated with operators controlling the doors and making announcements. Automating the shuttle operation would make the service efficient by not having the operator to switch cabs for a short ride.

MTR rail system in Hong Kong have automated trains running on a shuttle line serving Disneyland where the mainline trains from downtown have operators. Trains on the shuttle line formerly served on the mainline and were extensively modified.

An advantage for this alternative is that it would be an improvement in service for something that is already in use. But it is also complicated especially given the changes required in labor arrangement to operate this service.

2. Shuttle with PRT technology

Rather than extending the current AirTrain line from the terminals to Millbrae, this alternative would use lighter weight vehicles to connect the terminals to Millbrae and perhaps beyond. The ULTra PRT system is in use at London Heathrow Airport connecting one of the terminals to a long term parking area. The PRT system use light weight vehicle with capacity of about 6 and operate on relatively simple guideways with no mechanical switching like traditional rail systems. Users are able to choose their destinations when boarding the vehicle.

These vehicles are small enough that can operate within a parking garage. A possible system between SFO and Millbrae may involve a station inside parking garages at both locations.

2. Autonomous rubber tired shuttle


A number of vendors are showcasing driverless shuttle vehicles. These electric vehicles seat about 6 passengers and can operate without a fixed guideway. For a shuttle service between SFO and Millbrae, a central station can be placed on the service road near Garage G (at BART station) and vehicle can use the frontage road on 101 to access Millbrae Station. The service can be operated frequently and/or on demand.