Also there was a fairly steep grade westbound from the toll plaza up to the tunnel througn Yerba Buena Island and the suspension portion of the bridge. Electric passenger trains could handle that grade, but heavy freight trains would have had trouble.

In San Francisco, the Bridge Railway did not drop down to street level, it was on the second story above ground level in the Transbay Terminal. A long fill or viaduct would have been required to bring a freight railroad down to ground level. Either of these structures would have required condemnation of lots of property close to downtown San Francisco.