What I was saying, is to "share" passengers requires another order of magnitude calculation.

Right now, the airports use hubs and spokes. So if you want to go from A to D, you also might go to B or C, depending.

The next airport goes from A to D via 1 and 2. If they have the same ultimate destination. So instead of a non-stop from A-D, like you might have, you could end up, for the same trip, making 2 stops. Or something.

The airlines currently juggle who's on the plane, with what planes are needed - If 20 people miss a flight, and all were connecting somewhere else, then you might not need as big a plane for a later stage.

If every airline flew the same routes, with comparable planes, it wouldn't be as problematic, but right now it would be very difficult to have "sharing" work.

Add to that, that for instance, I won't fly United, and prefer not to fly US Air, for instance.. the only airline I *like* is SouthWest... Now you swap me to United so they can get money for being utter bastards?

Addison