Can you describe a driving scenario where the correct action couldn't be determined "mechanically"? Are you thinking of something like the trolley problem?
That is such a contrived phenomenon, it has taken decades of lobbying and destruction of political accountability to create the conditions where a person considered sane would touch that idea instead of immediately skipping over to driverless trains.
Incredibly wasteful gimmick, I don't get why the usians are still struggling away at it now that the chinese seem to have already done it.
I don't know where you've gotten the idea that cars are something you can "skip over" on the way to trains. Public transit is great, and the US should do it better, but it doesn't obsolete every other form of transit. The vast majority of people in every country who can afford access to cars use them regularly.
