Why own a car?
The idea of the "robo-taxi" is ancient and has even been used in a few movies, most notably in Total Recall. If you live in a city then owning a car is mostly pointless. You will rarely get out of 2nd gear and will use more fuel whilst stationary than when moving. It will cost you a small fortune in fuel, parking fees, tax, insurance and depreciation and will probably get nicked due to being parked on the street in full view.
Far better to call a Robo-Taxi which will pick you up from wherever you are and drop you wherever you want to go. For longer distances it is proposed that they would link up into trains and travel on tracks far more efficiently than any car.
Lets face it, there are not many places in modern Britain where you can't get a taxi even now.
You just have to put up with having a human (mostly!) driver. ;-)