Another case of "everything old is new again."

The proposal is characterized as a public-transit route connecting Peninsula to East Bay. As I understand, the original 1910 Dumbarton Rail Bridge (which connected Peninsula to East Bay 111 years ago) enabled transcontinental freight (linking US rail services to the peninsula's north-south line -- now Caltrain -- and thus to SF) when trains were the main overland freight method (long before the interstate freeway system).

In 1910, San Francisco had been for 60 years the major population center and port on North America's Pacific coast. The rail bridge connected the busy Port of SF with the mainland US by rail. A big deal at the time (long before the Bay Bridge or Golden Gate Bridge existed).

If you'd predicted in 1910 that the growing local rail systems would be abandoned in the 1950s for private cars, you'd have been laughed at. Just as if in turn you'd predicted in the 1950s that private car commutes might later revert back to rail travel.