A charming, if simplistic, map of commuter rail services offered by the Key System company. Some sources on the Internet date this to 1941: however, the prominent “Exposition Ferry from Ferry Bldg.” callout box would seem to link this map to the timeframe of the Golden Gate International Exposition held on Treasure Island between February 1939 and September 1940.

These dates mean that the Bay Bridge, the Transbay Terminal in San Francisco and the transbay commuter rail routes as shown on the map are all pretty much brand spanking new. By 1958, commuter rail over the Bay Bridge had ceased operations: the Key System replaced these services with buses, and were themselves taken over by AC Transit in 1960. AC Transit’s B, C, E, and F lines still roughly follow the corresponding Key System routes today.

Source: shanan/Flickr