In downtown Chicago most of the building entrances are revolving doors. Otherwise the lobbies would be freezing from the doors being wide open. I hate it when the people that are too good for revolving doors use the regular doors. Cold air just whooshes through the lobby. On top of that, the regular doors are their for handicapped people in wheelchairs, so when you open one of those doors, it goes into automatic mode and opens up all the way, and stays open for like 30 seconds. Jerks.