That's some long-term planning, but it's an interesting concept that should be trialled at some point.
What I love about this is that it makes sense -- our 'flying car' future should not be one where we all own our own flying cars and flight our way in a 3D maze of aerial on and off ramps. Our future should not be one where we all own our own cars anymore. It's more about vehicles on-demand, picking up and dropping off when and where we need to be.
The aviation safety body also said there could be issues with the vehicles, which would assumedly be fitted with surveillance, navigation and obstacle-detection technology, flying in the same space as other aircraft that did not have the latest technology.
There's a LOT to be worked out to make something like this work.