What? How does flying mean other people don't exist? Traffic corridors exist in the air. Having this would just induce demand for those corridors and create a demand for more and more infrastructure to accommodate air cars. More corridors that can be flown over, more landing zones, more fuel stations. What makes a corridor good to fly over: fewer people who complain of overhead traffic -> more air highways over poor neighborhoods/unused land. And while you're waiting for your car to get clearance to enter the overhead traffic stream, which seems to take long each month, more and more fuel and time gets spent in your flying car. What you need is the ability to get where you need to go, not necessarily the fastest possible means because traffic will inevitably reduce that speed to a crawl. What you need is a train.