Yes, I agree with your premise here. Personal anecdote, I lived in San Francisco in the city 8 years. It was by far more economical for me to have both Zipcar and taxis (later UberX and Lyft) combined per month than to have a vehicle lease + parking costs + insurance/maintenance/gas. By far. In both $ and time.
I'm not certain that other elements of your vision work in non-metro areas.
What percentage of people live in metro areas though?
Re:G.M. Invests $500M in Lyft
by JumpCrisscross on Tuesday January 05, 2016 @12:02AM
(#10841322)
In 2010, 80.7% of Americans live in an areas with an overall population density of 2,534 people per square mile [1].
[1] http://www.reuters.com/article/usa-cities-population-idUSL2E...
How much cheaper would a driverless Lyft or taxi be? 50%? How many more people would forego driving, in Manhattan, if ridesharing were half as expensive as it is today? If half do we're at 11.5% car ownership, a 7-fold reduction from the present-day U.S. average. If 2/3 do, we get to 10-fold.