I'm not sure what problem you think you're solving here: the existence of a queue suggests that they're slightly over capacity in cars, and thus something like Uber would still have to rotate the fares between the drivers.
Of course, there are perfectly sensible reasons that you need to have extra capacity available at an airport as a metro area, and thus we have the question of how best to provide surge capacity to the airport.
All the answers I can think of, including an "on demand app", involve waiting in some kind of queue managed by someone.
... then they could take fares around the airport and get matched for an actual ride at the airport without having to wait in line idly. The difference here is that they can make better use of their time while still possibly getting an airport fare, if that's what they desire for some reason.
That's what airport cabbies near where i live in India now do. The queue is really long (such that they may only get 1 or 2 rides the whole day), but now they take Uber/Olacab rides while waiting for their slot.
..then when they make their drop off, they'll have another fare request waiting for them and their downtime will be absolutely minimal.
If increased demand exists at the airport, pricing increases until capacity is met. This is a much more natural governor than simply creating a queue at projected in demand areas.
