And flying being faster implies even more energy because moving slowly is generally more efficient ?
Especially on shorter distances I wonder how the energy needs compare for flying vs driving.
Flying is much more SPACE efficient. With good computer control you could stack hundreds of "roads" worth of capacity vertically.
Can save time (and thus indirectly energy) by flying directly from A-to-B. This is ignoring the time gained by the likely much faster cruising speeds, as well.
Flying doesn't have to be THAT inefficien, either. Plenty of general aviation aircraft, especially slower ones, can achieve MPG that is really not that bad. The Mooney M20, for instance, cruises at 180mph and burns 10 gallons an hour - so 18mpg. Not bad given the speed! A car going that first will be consuming much more fuel.
Ground has a lot more traffic. Ground traffic is not only constrained to the ground, but to roads, which, comparatively, cover a minuscule amount of area. Flight opens us up to much more than the product of ground area and height.
> And flying being faster implies even more energy because moving slowly is generally more efficient?
Aircraft will be less efficient at lower speeds[0].
A Cessna 182T Skylane[1] will stall at 56mph (49 knots), cruise at 167mph (145 knots).
We don't need to fly faster than we drive to see significant time improvement.
The distance for me between home and Provo is 51 miles, but I have to drive across 75 miles of road to get there. By taking roads, I also have to stop at intersections, and wait for traffic. If I average (with stops) 55mph, I will get there in 1hr 22min. If I flew a Skylane at 60mph (just over stall speed), I would get there in 51min. (At cruise speed, I would get there in 18min.)
Obviously, I would need places to take off and land, etc.
[0]https://en.wikipedia.org/wiki/Slow_flight [1]https://en.wikipedia.org/wiki/Cessna_182_Skylane
Flying cars, or some kind of easy flying transportation would vastly benefit society: we greatly underestimate it. If you can triple the distance a person can travel in the same amount of time, you nearly 9-tuple your employment opportunities. Companies would have nearly 9-tuple the number of candidates.
Unlike land based solutions, sky based solutions can go directly from point to point without needing to follow an arbitrary arc on the ground.
And best of all, you'll have much more cost effective housing options. With housing being as bad as it is on the west coast, I bet people would pay big money to go farther and faster.