Double-Decker Tunnel

This photograph clearly illustrates the double-decker nature of the Bay Bridge. As originally designed, two-way traffic ran on the top deck, while trucks and interurban trolleys utilized the bottom deck. In the late 1950s and early 1960s, the trolley tracks were removed, and automobile traffic redirected so that the upper deck carried west-bound traffic, and the lower deck the east-bound vehicles. Traffic crosses the bridge in this fashion today.

Identification Information: Dept. of Public Works, San Francisco-Oakland Bay Bridge Construction Photographs (F2516:1-93), Tunnel -- East Portal, 09/06/1935: Box 5 (C5229), photograph 5-1637.