Flying cars' most significant hurdle is not energy, but safety. Commercial air travel is only safer than automobile travel because of the high levels of coordi

Flying cars' most significant hurdle is not energy, but safety. Commercial air travel is only safer than automobile travel because of the high levels of coordination and regulation that exist around it. Think of all of the humans (nevermind software) and their cooperation involved in planes taking off and landing safely. Then add in the fact that planes are constantly being maintained by mechanics, on much more frequent intervals than automobiles. Compare what is considered a safe distance between two moving automobiles, and two moving planes. When these safe distances are violated by planes, even when no actual collision occurs, investigations occur. Inherent to the success of flying cars is widespread adoption by the masses. If they're only available to multimillionaires, why would they be any more attractive than private jets, which are already available to those same people? Thus, the success of flying cars would require similar levels of coordination and regulation, only for many many more times the number of aircraft. If instead, its every pilot for themselves, as it is with automobiles, flying cars will end up being far more deadly than autos, given that low speed car accidents don't often result in deaths, whereas an aircraft collision of any kind can be catastrophic. More aircraft in the air will also mean higher density of aircraft in the air, making coordination even more critical than it already is. The easy answer to all of this is to say that software will replace all of these currently human roles. But just think of how far away level 5 autonomy is for cars. In the case of a car, most dangerous scenarios can be mitigated by slowing down or stopping. The aircraft equivalent of stopping is to land, which is obviously not as simple as decreasing speed, and is also not feasible without a runway of some kind.