SHUPirate- There are many factors that contribute to this. This post sort of rambles, but hits many of them. If leaving a High B gate especially, aircraft will almost always take the bridge (taxiways A&B) if heading to the the South runways. On the frequent days with bad weather delays, taxiing south out of T1 (counterclockwise) becomes a hassle because of aircraft parked all over the tarmac. Much of taxiway B can become penalty box. The taxi to 22L is probably shorter than the taxi to 22R if the 22s are in use even though 22R is on the north side. If the 9s are in use, widebodes will almost always use 9L
because it is 2000 feet longer than 9R
. In fact, all three south runways are longer than their north counterparts. It isn't really a "priority" issue; it's often a matter of which runways are open and long enough. Generally, I find that most ORD
departures, regardless of airline, occur from one of the three southern runways.
if you don't have a map of ORD