Just the same, cars can be driven almost bumper to bumper, at arbitrarily low speeds, in ten foot wide lanes. The realities of wind and minimum forward speed a

Just the same, cars can be driven almost bumper to bumper, at arbitrarily low speeds, in ten foot wide lanes. The realities of wind and minimum forward speed and prop wash dictate that aircraft will need a lot more clearance than a car does. I'm sure it will depend on the particular air vehicle and the rules of traffic in the sky, but I for one would have to be convinced that aircraft can give better throughput than a road can. On the face of things, I'm not sure that's the case.