Originally Posted by sailingfun

O&D traffic drives how successful a hub is. JFK is the O&D capital for international travel. Every time Delta has tried to move a flight from JFK to another hub it has failed completely. Yields and traffic drop like a stone. That is the reason for Delta's huge investment in the JFK infrastructure. It also functions perfect on a cost basis for anywhere on the eastcoast since most traffic passes over JFK going to Europe. Its a lot more expensive to fly a passenger to DTW or ATL to connect them to NYC then to fly to NYC and connect them to those destinations.