[felipemnoa]

The other thing is that they could still be flown a few feet above ground but without an actual road. It would eliminate the need to maintain a road system and if the thing fails at least it will not be the high altitude crash landing that kills you( although traveling at 300km/hour and loosing power will still be really bad even if you are just a few feet above ground). I think it would make it an easier sell to the public.

[Edit] Obviously I know nothing about aviation. So based on the comments below I stand corrected.

[nradov]

That's totally unrealistic. Low altitude flight is extremely dangerous due to the risk of hitting trees, towers, power lines, hills, etc. Military helicopter pilots are well trained and have good equipment but they still have frequent crashes during low-level training missions. If anything goes wrong you impact the ground and die with no chance to recover. The general public won't tolerate that level of risk, and the FAA would certainly never permit it.