I live in central valley, California. When I want to visit downtown san Francisco, or SFO Airport, 99% of the times I park at first Bart Station, and use Bart from there. The only time I go not is if I am picking a couple of family with lots of luggage.

So, now you know a car driver who drives about 16k miles a year, and also is not lazy enough to park at city borders & use public transport. & Bart Parking is almost always 60+% full.