If you look at an historical chart of GDP growth by city you'll find others[1], since I believe the issue of increasingly coveted zones that push out lower income inhabitants has been a problem in rapidly growing large urban centers since before history. I read how it was a common complaint in ancient Rome. I experienced it myself working in London during the 90's, and now too in the Bay Area.

I wonder how self-driving cars will impact conurbation size when compared to other advancements like boats, horses, carts, roads, canals, trams, steam-engines, trains, tarmac, subways, combustion-engines, bikes, cars, steel bridges, and mechanized roadway construction?

[1] http://www.best-cities.org/2014/best-performing-cities-repor...