I have actually been in an autonomous vehicle, a buddy who’s into ex-forces transport of every kind purchased a modified Unimog with the full Lidar system installed (inc remote takeover) and he drove around the countryside in auto mode and I have to say I was impressed, never once strayed out of lane (apart from the fact it’s huge and almost straddles the centre line anyway). He did say he had already run that route before as part of the “mapping” procedure but it still coped well when we went off route.
Can’t say how cars would cope but it was great fun especially when you don’t have to worry about running into anything that could harm you as it’s almost a tank! ?