Remember all of those "skycars" in the movie "The Fifth Element"? I don't see that happening for at least 200 years. Also, with so many vehicles in such close proximity to each other I would imagine that all of the exhaust / jet blast / prop wash would make for a very rough & interesting ride. I don' think the pedestrians below would feel very comfortable or safe! However, I bet that the military, Coast Guard & psuedo-military organizations (NIS, CIA, FBI, etc.) would put these vehicle to great use.