Original plans for BART in 1956 (Picture)

Not sure it would have been all that useful. You’d spend a LOT of time on the peninsula going from San Jose to San Francisco, so you’d need something like the BART bullet trains [ETA: It looks like that’s actually part of the design], and a Cupertino to San Jose connection would be nice, too.

The one thing on this map that I’m really missing in the current system, speaking for the South Bay, is light rail style service “southwest” of Caltrain, e.g. along Stevens Creek Blvd and maybe some of the expressways.