letiole writes
The trouble comes at the airports ... you still have limited landing capacity so even if the planes are all in the air and picking their own routes they may get to the airport faster, but then be stuck in a holding stack for a very long time.
Well, this is true if there was no accounting for nominal takeoff and transit times. But, I assume that an ATC departure clearance, complete with a wheels-up time, would be part of the system. I would think that with continuous monitoring and feedback of positional data and vectors for aircraft in the system, it would be easier to adjust terminal sequencing than in the present system. It seems to me that the published routes and approaches, which occupy such a tiny fraction of the available airspace, are really nothing more than virtually continuous choke points when a bit of weather, or some other off-nominal event happens.
Other than launching more programs to put up more VLA's like the A380, and convincing municipal planners across the nation that airport expansion must be given much higher priority than it currently has, I don't see a lot more that can be done to handle the forecast demand for air travel, other than to reform airspace, ATC, and air traffic procedures.