If Cars could Fly

Suppose we invented a type of four-passenger vehicle about the size of a car that could fly. Clearly such an invention would revolutionize transportation. But there would be a couple of things to sort out before allowing such vehicles on the road.

First, these vehicles would be able travel to places and through places that cars could not go. And noise-making vehicles are undesired in many otherwise quite areas. So landowners would have to start making claims to "airspace" in response to such vehicles flying directly over homes and other buildings; we might have the same noise problem as airplanes, just more crafts but less noise per craft. Clearly it would be absurd to have every landowner make claims to the space above his land, so there would have to be designated "roads", columns of air where these crafts are allowed to fly.

An initial response would be that such technology wouldn't be so revolutionary taking such a restriction into account. However, suppose you are stuck in traffic. When you are unable to drive to either side or forward, imagine if you could drive up. Clearly, such transportation would more than quadruple the efficiency of roads.

But it would also be much, much harder to drive. Inevitably, there will be "levels" of travel, just like lanes in today's roads. And in each level, the normal traffic rules still apply. But now, you have four directions to drive: left, right, up, and down. And you also have to pay attention in four directions, that is, all around you, to other cars. Such technology would result in much more efficient travel, but would also result in driving being much more dangerous. But computer-driven cars will likely be invented before the personal flying craft, so this is not that big of a problem.

Now a general note about me: I find it interesting and liberating to think about situations like these, to break the rules with a whimsical invention. Not only does it test your creativity, it also forces you to realize the reasons behind the rules. Traffic rules and the existence of roads would be as much a presence with flying cars as with normal cars. And it would be harder to drive. So I don't think its fair to say that I shun all practicality; rather, I like to change some rules and see what conclusions follow.

So what do you think? What traffic rules and driving challenges would carry over to flying cars, and what is the importance of these rules now?