With Lilium working on a functional prototype, the car sized eVTOL vehicles might be coming sooner than the regulation/coordination-conventions that are required to fly them in urban areas? These could have the technical capacity to land in very convenient places where even helicopters would not be safe or desirable(noise). It looks like before the decade is over, a number of people with luxury cars could afford to have one as an alternative to their cars to go to work, or that it could beat be living daylights out of an ambulance that can be stuck in traffic in getting to someone who's life is measured in minutes. I am assuming that to fly near airports and or at altitudes where airplanes travel, you would have to use plane conventions, unless specific VR Corridors are made for lower flying vtols to approach airports to make it easier for flight controllers (the VR corridor paths would not be intersected by planes) But for commute between urban areas where vtols take off travel and land, you cant use traditional air traffic controller method, you would probably need virtual highways above cities and make it automated friendly. The vtols should have the means to detect obstacles and other vtols, but also wires (electric cables etc) which might be more challenging to detect at night with current sensors and software?