💩 Niklas
I can't imagine there will be departure slots for cars, at least not of notable lengths. Cars can be controlled in a much more fine-grained way than planes and -- more importantly -- can start driving anywhere, so there aren't any high-traffic areas like airports, except intersections which are nothing compared to an airport. It also won't be the case that there's a constant stream of cars on the streets, at least I hope so...