"No, because unlike a train, a car can go between two arbitrary points without need of switches or other restricting mechanisms. As long as there's road between A and B, you can almost always reach it."
Hmmm, and there's me wondering what all that tarmac and concrete is for. Oh, you've pointed out that "two arbitrary points" need to be connected by a road for a car to work. Not so very different to a train then.
Automated trains work because a railway is a very artificial and sterile environment. There's nothing in that environment that isn't controlled by the system. And where mother nature can intrude (e.g. a fox on the line) there's little prospect of passengers being hurt, or even delayed... In short, the only thing an automated train has to worry about is another automated train. That's a comparatively easy problem to deal with.
And even the the train may well be driver-less, but that's a long way from saying that it isn't monitored by people. There's a control room. There's a lot of data and video feedback of train position. There's people watching that, or at least poised to glance at a set of screens should an alarm go off.
In comparison a road is far from a car-only environment. Even in America there's things like foxes, moose, potholes, floods, snow, ice, fog, road works, fallen trees, fallen bridges, turnips, rocks and geckos which are all a severe threat to the occupants of a car. And I haven't even started on the other road users; kids, postmen, other drivers, cyclists, protesters, motorcyclists, policemen, estate agents, road menders, binmen, politicians, drunks, grannies, flashers; they have a right to not be run over by anything.
Now, if you excluded all of those (and more) from being able to access the roads then maybe, just maybe, we could have a provably reliable self driving car that isn't just more train track. Though in effect it would be a train without the steel rails.
"That's why many people insist on a personal car: the ability to take it anywhere, anytime whenever the need arises. Unless you can do that, practically door-to-door, trains will never replace cars.
So you've never been stuck in a traffic jam? They're big queues of cars going nowhere, and they mean that your car cannot take you anywhere at all at the time you want no matter how urgent it is. Sometimes they last for days.