Yes, but you really have to make sure that it is indeed just and accident of history with no other side effects. I can imagine a case where some of the BART tunnels are too short for some trains that run on standard gauge rails, and you don't want someone to accidentally run a standard train over those tracks and get stuck. There is no way to know this without looking. We cannot imagine all contingencies, but we should probably at least look for the ones that we can imagine.