Here is how it is going to be.

1. BART gets 1000 cars running. This eliminates the car shortage in the East Bay but doesn't help transbay as the tube is at max capacity with the existing half century old control system.

2. New control system is instituted, moving block. Bog standard. This allows all lines to run on 12 minute intervals instead of 15, a 25% increase in capacity.

3. (possibly) A contra-flow lane for transit only is put in place on the Bay Bridge. This would require a moving divider as on the Golden Gate Bridge.

4. (I'll be dead) Four tracks are added under the bay, two standard gauge for HSR and whatever and two broadgauge for BART. If the new BART tracks are not the same gauge as the existing ones one loses the ability to do maintenance on a tube while still running 24/7 service. This is something people have been complaining about since the beginning of service across the bay.