Originally Posted by
5khours
Keep in mind a lot of this has to do with the airport and is outside of the carrier's control.
True, though I would expect that at hub airports, UA has a bit more control over the process than elsewhere, and given the amount of traffic they control at some of those airports, it would behoove UA to make sure the process is as smooth as possible.
I suspect most of the delays occur in aspects of the process which are completely under UA's control, too, but that's just a hunch.