http://www.pewresearch.org/fact-tank/2015/04/16/car-bike-or-...
That said the average car costs $34k in the US and lasts say 10 years, that's $3,400 a year. Maintenence, taxes, etc another $1500 at least, that's $5k/yr before you move an inch.
While automatic cars may not get rid of everything, many 2 or 3 car families, especially in the suburbs, may drop to 1.
That's why suburbs exist. Financially, it's a much better deal for families on just about any axis.
Depending on the car, gas is probably between about 20% and a third of a car's operating costs (which are typically in the 30 cent to 60 cent per mile range). Although there are a few vehicle costs, like excise taxes, that are more or less independent of distance driven, most car expenses will scale with mileage--especially in regions where rust isn't a major issue.
- Uber/Lyft would cost about $5k/year for me, and I live about 4 miles from work.
- Bus $360/year, but it would take 60-90 minutes vs 10 via car.
- Cab $7k/year
By the time you add grocery trips, recreational drives, vacations, etc cars make a shit-ton of sense. Not only does a car save money, but it saves time and provides flexibility. There's a reason our entire society is organized around cars.
And, in any case, full door to door autonomy, in at least most locations, is likely a long ways off. Certainly outside of the relevant horizon for Uber investors.