Until the 1960s the upper deck ( wide between curbs) carried three lanes of traffic in each direction and was restricted to automobiles only. The lower deck carried three lanes of truck and bus traffic, with autos allowed, on the north side of the bridge. In the 1950s traffic lights were added to set the direction of travel in the middle lane, but there still remained no divider. Two interurban railroad tracks on the south half of the lower deck carried the electric commuter trains. In 1958 the tracks were replaced with pavement, but the reconfiguration to what the traffic eventually became did not take place until 1963.