Instead of demanding the construction of a second BART tube for $10 billion, perhaps we should be asking why everybody and their grandmother absolutely, positively has to work in downtown San Francisco to begin with.I'm pretty sure San Francisco's CBD only has a certain small share of the region's overall jobs, perhaps 10-15% at most. I'm guessing here but for the most part this is the case in most of the country. But the reality is that since the jobs are clustered so tightly, they demand usage of alternative transport. They also are places of agglomeration and its not an issue of the execs getting a corner office but where face to face meetings and deals happen at lunch. (This is a whole other topic but I don't believe E-working is every going to replace working in an office with other people) There is a reason why the first BART system was built, because leaders of the area wanted to be the Banking Center of the West Coast and needed that critical mass of density and prestige to achieve it.
Another issue here is that of sprawl. There is this belief that the highways and housing policies were what caused the sprawl with the thought that more people could just drive into the central city. But in reality its even more nuanced than that. We've been building these roads out but when we do that we create these job centers and edge cities on the periphery that increase the outward migration pattern. People keep moving out and towards the exact point at which they can have a thirty minute commute or less from their job center. For jobs such as finance or research or science that are transit oriented, this means less people taking transit and more people deciding to drive their cars. I'm fairly confident that less Chevron employees take transit to work these days. It also means less urban office parks with parking lots that increase reliance on SOVs even more. We see this with Pleasanton and the continued movement of people out to Stockton.
If we're truely going to be transit oriented and sustainable in this region, we can't put a cap on the jobs in the center cities and continue to push jobs out to the periphery. If you don't spend that $10B on a second tube and push for more development (residential and employment) in BART's current reach in the inner East and West bay and even more money on an actual urban rapid transit network to connect to the existing bus network, I would argue that you're going to be spending much much more money to try and get people to and from their exurban and suburban job centers let alone the difference in city services (water sewer police fire) that must be supplied to all of these new suburbs and growth.