there were a couple automated urban lines in pre-90s. If we hadn't cannibalized the inter-urban trolley cars for public roads but private rails in the 1920s, who knows what would have happened.
Unlikely given the computation required for this feature.
Highways are well defined spaces. You wouldnt need much computation at all.
It's the edge cases that are difficult.
That is why it is highway driving only. This is no different than aircraft autopilot of the 90s.