[Daus]

How about setting up a system of short haul and long haul airports. Say, Chicago for long haul and Milwaukee for short routes. Set up a high speed train between the two.

Because it's already been accomplished with much less infrastructure cost. Private, for profit airlines do a very effective job of moving people (within the timeframe you mentioned 30-40 mintes) between Milwaukee and O'Hare, plus you havent forced ALL of the long haul traffic onto O'Hare in the process, and I can take Midwest Express direct to DC five minutes from my door stop. :)

Part of the answer to the problems trying to be addresses with trains will come about as some of these large airlines begin to break apart and decentralize their hub based systems. The best, most efficient way to get from my house to Orlando is on a direct flight, on a well run airline (maybe someday, there will be more than 3 of those....)

[balrog666]

How about setting up a system of short haul and long haul airports.

That's called a hub system. Almost all the big airlines already use it.