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Originally divided into three lanes in each direction, the upper deck of the Bay Bridge was designed for automobiles and other light vehicles. Trucks and buses used three lanes on the lower level of the bridge, sharing it with the Key System and Interurban Electric (Southern Pacific), which operated trains using two standard gauge electric railway tracks, separated from vehicular traffic. Ten-car trains ran directly from Alameda, Berkeley and Oakland to the newly constructed terminal in San Francisco. The trains were scheduled to run as closely as 63 seconds apart in order to handle the passenger load. The first year of bridge traffic was estimated to be approximately 6 million vehicles. This number would gradually increase until it reached 9 million by 1950. However, the bridge actually carried 9 million vehicles the first year. The train tracks were removed from the Bay Bridge, and the bridge decks were converted to their present traffic configuration, during a 4-year project begun in 1958 (at a cost of $35 million), after the Key System abandoned transbay service due to decreased patronage.

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Copyright © 1999 UC Berkeley Library
Data owner: R. Brandt
Updated 12/9/99