I'll believe levels 4 and 5 when I see them operating in cars that are free to go where-ever. I don't think that's going to happen during this decade, and maybe not even during the next.
I have somewhat mixed feelings: I'd like for people with disabilities to have an easier time getting around.
But I dislike the hubris of H. sapiens who think that technology can do any **bleep** thing they can think of.
I also think that self driving takes most of the adventure out of road trips. Three cross country trips were formative experiences of my early life--during the late '50s and early '60s. We never knew exactly where we were going to spend the night, unless it was with the cousins in Indianapolis or the cousins in Colorado. And we did a lot of stopping for local scenery or institutions--for example, the Quivira (sp?) specialty shop in Topeka, I think, from which my brother and I had gotten lizards that we kept as pets.
I drove myself across the country for the first time when I was 17, in an 8 year old '62 Falcon. We (two riders and I) stopped at one of the rider's parents' house for a couple of days, in Iowa City. We got into Iowa City at about 3 in the morning, haven't left a park in Syracuse at 2AM the previous morning, because I couldn't sleep in the car (and I don't think either of them was having an easy time of it). She--26--had been on her own, and we stopped somewhere to try to get directions to her house, and she said, "You won't believe this, but I don't know where my parents live," or something like that.
None of that stuff would have happened in a self driving car.