What Are Rolling & Banked Hubs in Aviation?

The major carriers in the US, such as American Airlines and Delta Air Lines, saw a pronounced shift from the concept of banked hubs around the turn of the millennium. This was done to ease the traffic congestion at the airports. American Airlines reverted to a rolling hub at the Dallas/Fort Worth International Airport (DFW) airport, and Chicago O’Hare International Airport (ORD).