BART promised 90 sec headways at the same time they claimed everyone would have a seat (no ceiling handrails in the first batch of cars when delivered). building cars with inadequate doors (takes too long to exit/enter), exacerbates the dwell in the downtown SF stations. Even with the new generation cars and 10 cars on every rush hour train, the current tube is essentially maxed out. A second tube is needed. Whether it should be wrong guage or standard guage, 2 or 4 tracks and where it should go are all questions to be answered.

As to Alameda, leaving out the socio-political issues, the island does not have enoigh population density to support a direct tunnel to SF.