There's a second Oakland/SF bridge that doesn't exist. Well, I assume it would go to Oakland. It's marked with "???" and just says "Crossing". I presume that hypothetical bridge wouldn't have Yerba Buena Island to connect through, so would be really impressive and long (compared to the Golden Gate and Bay bridges).
At one point it was also planned to be just north of SFO. Have you ever taken I-380 east instead of one of the exits to 101N/S? There's a huge multi-lane road that dwindles to basically an airport access road exit.
Oh man, thanks for those links. TIL. A causeway or something that extends off of Alameda? It's wild to think about what that would have done to the area.
