キー・システム
The Key System operated a fleet of ferries between the Key Route Pier and the San Francisco Ferry Building until 1939 when a new dual track opened on the south side of the lower deck of the San Francisco–Oakland Bay Bridge, bringing Key System trains to the then-new Transbay Terminal in San Francisco's downtown. The bridge railway and Transbay Terminal were shared with the Southern Pacific's Interurban Electric and the Western Pacific's Sacramento Northern railroads.