You really have opened a can of worms ( or a bucket of spiders ) with that post. There are SO many questions to be answered, and I don't think anybody in authority is ready to answer them yet. The starting point will be what type of insurance will be required ? I don't think Joe Bloggs will be offered one for many years, too expensive.
Whilst the idea that anyone regardless of mobility, age, sobriety or other considerations will be able to use a driverless car, I feel it likely the number of questions originating even here is an indicator of the number of hurdles that will need to be overcome before they are approved to their maximum potential.
My guess would be that in the first instance a fully licensed driver under current regulations would need to be 'at the controls' in case of problems. How long it will take before this is eased is open to conjecture.
In common with others I can see a number of very valid uses for such vehicles where the current regulations with regard to physical ability would be waived. I wonder if I shall live to see it!!
Now that's going to be a massive question, considering the amount of experiments that have been undertaken over the years, were the general public have not been made aware about, yet like this scheme, the government have funded them.
And it might be a case that possibly your own local council have been deeply involved, but have not informed anyone, only a selected few.
My own council was very much involved about twenty/thirty years ago, with a government scheme of charging tolls for vehicles entering a town or city. It was mentioned that a few £million was allocated to that experimental project. The results of that final outcome was kept as a secret, but I would suspect that the zone charges now being made in London are a 'bounce-off' from that experiment all those years ago.
There's perhaps many more ideas in the pot, awaiting wakening from their slumber!.
You can make these cars fool-proof, but not IDIOT proof. Nobody has mentioned the re-boot facility when things go wrong, how do you do that half way up the main street. The idea is good but it needs a lot more work.