Plans have been done for a Geary subway several times since the early 1900s. Muni probably could have done one as a Muni Metro line in conjunction with the original BART construction, but the city govt at the time was more intent on turning Geary into a pseudo-freeway (didn't turn out so well in the long run). It would still be better to do it as a Muni line now, but the 3rd St. Chinatown Extension is probably in the way underground. I don't see the traffic potential on Geary for a BART (e.g. East Bay Commuter) route. Yes, Graft and Corruption could always have a role, but since Federal $$ would be needed to make anything happen I'd expect FTA to provide a semblance of adult supervision over the process (lots of other places around the country have needs and wants, so BART would have to make a case with actual backup data - call PB?).

None of this, really, has anything to do with SMART. SMART is a local North Bay operation, and will remain so for the foreseeable future. Even if the mouse's worst fears about BART and Geary come true, it would take 20 years or more to get a first phase on Geary done. Marin's NIMBYs can, I think, be relied on to keep BART out of Marin itself (they did it before, when the system was first proposed, and they can do it again). Don't worry about it; just try to make SMART a good local system, well-integrated with the County and GGT bus & ferry systems.

As far as the T line being slow - of course! It's a local, not a commuter line. Back in the olde dayze, we didn't take the 15 downtown (from Geneva/Mission area) because it took over an hour to get to the Financial District stopping everywhere along 3rd (bad neighborhood too). We took the 30 Express, which used the freeway from Bayshore to 4th Street. Despite the traffic jams that were normal even then, it was faster due to less local traffic. Would probably use BART now.