In general aviation (anything other than the airlines for our purposes) midair collisions happen with alarming regularity anywhere there is any congregation of aircraft (typically within 10mi of a non-towered airport). Add to this that they are nearly 100% fatal, unlike traffic collisions, and you have a recipe for disaster. There are systems coming online to help mitigate this issue (ADS-B) but they've been in the pipeline for years and won't see universal adoption until 2020 in theory.
I doubt it, there's just so much space up there. So first, no concept of lanes. Thinking in 2D space, everything becomes a road. Increase that another dimension, so now everything is a road and there's hundreds of levels of road.
As long as the flight software keeps the cars/planes a decent distance from each other traffic will never be an issue when flying.
A much bigger problem will be parking, since no traffic means everyone will fly everywhere all the time. Parking will be an extreme issue for city centers. The wait in traffic will probably turn into a wait to park
I suspect that, even in 3d space, there will be a concept of lanes. You still want volumes of space designated for one direction or another, at the very least to reduce the number of collision-calculations the guiding system has to make.
Parking shouldn't be an issue? We'll have vertical parking structures that can be entered/exited on every level.
I wouldn't want to fly any kind of helicopter or multicopter into a door in the side of a traditional multi story parking building. the sudden and asymmetric entrance into ground-effect will roll the aircraft, and I'm not sure what having a roof above your rotors would do - possible choke them of airflow and force them into high-speed-stall.
airflow near walls is turbulent, and the funneling effect may suck the aircraft towards the wall.
Solvable problems - you just have to build a landing pad away from the side of the building.
Totally true. I imagine you'd have to have some kind of checkerboard of landing pads.
And, if our flying cars are helicopters or multicopters, we've got more problems, because we can't actually stack that many helicopters over eachother, due to the interference of their air columns. :-/
I think realistically all of the caroplanes will be built more like quadrocopters than normal aircraft. It's much less efficient but the only thing that really meets manuevability and safety constraints
