Correct, self driving vehicles are illegal now as they are not mature and not safe enough. But we'll hit the opposite where they are safer than human drivers then you'd find insurance lower for self driving, then eventually illegal to drive.
That will then change the relationship we have with being on a road to how people treat trains now of it becomes work or play time.
With removal of the slow human reaction times, vehicles can go faster and closer together, so will reduce congestion. I see international standards making cars share their intentions so the other cars get out of the way such as entering and leaving a freeway.
What I can't predict is when. It would take just one high profile failure to delay it decades. But it is inevitable.
I bike to work and encounter drivers and I know a human is not far off murderous gjven they look at their mobile or simply don't look. I see the smashed plastic bumpers piled on the side from not looking and not braking. I see the traffic jams due to "accidents" (actually just stupidity cause).
I see cities saying there is no more land to concrete over and Max road space already exists so as population increases the only options are to ban humans from driving once self driving vehicles are consistently better.
In some of the high population richer cities, we're already seeing non car ownership due to parking time and parking costs and professional drivers driving around - we call them taxis. We have now phone app which summon a vehicle (Uber, Lyft). Once the app communicates with a robot driven car it's digital end to end. Then machine learning will observe then predict demand. Then the electric vehicle recharges at automated recharging places which replace gas stations in quieter periods.
The cities which embrace this will make more productive populations which they can then tax more so they become richer, then the poorer cities have to follow.
If this sounds far fetched then remember the horse.
Guessing 100 years?