Governor Frank Merriam piloted the first (ceremonial) electric train across the bridge on 23 September 1938, although regular service did not commence until January 1939, after the terminal was complete.
Trains were controlled with a custom electric switchboard, which was considerably simpler than the typical mechanical lever system then in use.
A loop was built so trains could turn around and go back across the bridge.
Even after rail service ended, the loop continued to be used by AC Transit, Thruway Motorcoach and Greyhound buses until the station closed.
Surprisingly, a track was never made to connect to the Southern Pacific's Third and Townsend Depot so trains could go further south.
There were six tracks.
Beginning on January 15, 1939, half of all Market Street Railway trains were rerouted to a loop in front of the building; all services were eventually rerouted here in 1941.

By November 1940, the Interurban Electric Company was seeking permission to abandon East Bay service, prompting Director Clark to consider proposals for the state to assume operation of trains across the bridge.
The SP and Sacramento Northern trains ceased service across the Bay in 1941 only two years after the Terminal was completed.
Interurban stated they were forced to discontinue service, citing falling passenger counts, revenues, and a failed proposed consolidation with the Key System.
After Interurban was granted permission to discontinue service, Sacramento Northern also applied to discontinue service in 1941.
Sacramento Northern carried only a minuscule fraction (less than 1%) of the total rail traffic over the Bay Bridge, which meant Sacramento Northern likely also operated at a loss.
Trains carried 37.334 million passengers across the Bay Bridge at peak ridership in 1945, driven in part by gasoline rationing, but ridership declined precipitously, managing to move only 6.113 million passengers in 1957.
The Key System successfully petitioned the Public Utilities Commission to discontinue service across the Bay Bridge in 1955 due to falling revenues, after failing to discontinue service in an unsuccessful 1953 petition.
The Oakland City Planning Commission reported that since 1945, all the petitions from the Key System had invariably asked for cuts to service and increased fares, which also contributed to declining ridership.
The last train crossed the bridge on April 20, 1958, less than twenty years after service was inaugurated in 1939, despite the vital role the trains played.
There have been several attempts to restore rail service across the bridge (though not necessarily into the Transbay Terminal), but none have been successful.
Governor Frank Merriam piloted the first (ceremonial) electric train across the bridge on 23 September 1938, although regular service did not commence until January 1939, after the terminal was complete. Trains were controlled with a custom electric switchboard, which was considerably simpler than the typical mechanical lever system then in use. A loop was built so trains could turn around and go back across the bridge. Even after rail service ended, the loop continued to be used by AC Transit, Thruway Motorcoach and Greyhound buses until the station closed. Surprisingly, a track was never made to connect to the Southern Pacific's Third and Townsend Depot so trains could go further south. There were six tracks. Beginning on January 15, 1939, half of all Market Street Railway trains were rerouted to a loop in front of the building; all services were eventually rerouted here in 1941.
By November 1940, the Interurban Electric Company was seeking permission to abandon East Bay service, prompting Director Clark to consider proposals for the state to assume operation of trains across the bridge. The SP and Sacramento Northern trains ceased service across the Bay in 1941 only two years after the Terminal was completed. Interurban stated they were forced to discontinue service, citing falling passenger counts, revenues, and a failed proposed consolidation with the Key System. After Interurban was granted permission to discontinue service, Sacramento Northern also applied to discontinue service in 1941. Sacramento Northern carried only a minuscule fraction (less than 1%) of the total rail traffic over the Bay Bridge, which meant Sacramento Northern likely also operated at a loss. Trains carried 37.334 million passengers across the Bay Bridge at peak ridership in 1945, driven in part by gasoline rationing, but ridership declined precipitously, managing to move only 6.113 million passengers in 1957. The Key System successfully petitioned the Public Utilities Commission to discontinue service across the Bay Bridge in 1955 due to falling revenues, after failing to discontinue service in an unsuccessful 1953 petition. The Oakland City Planning Commission reported that since 1945, all the petitions from the Key System had invariably asked for cuts to service and increased fares, which also contributed to declining ridership. The last train crossed the bridge on April 20, 1958, less than twenty years after service was inaugurated in 1939, despite the vital role the trains played. There have been several attempts to restore rail service across the bridge (though not necessarily into the Transbay Terminal), but none have been successful.
San Francisco Transbay Terminal