Quote Originally Posted by 02gpgt88 View Post
how do they open the doors?
Door solenoids. Basically remote-controlled device the activates the door mechanism (as if there were a handle and you were pulling it) and then pushes the door ajar so you can grab the side of the door and open it.

Obviously it's a ***** if it breaks or if it's used in winter and you start getting ice in the door jambs.