405
This three-sided pole on an airport tram
(sh.itjust.works)
I had never seen one of these before today. They're great. Way better than reaching for a single pole in a crowded car and wrapping your hand around some stranger's fingers. And If you have the whole thing to yourself you can hook your arm through it.
Especially since I think this is in the Denver airport where the trains are all computer controlled and going in a loop
E: ah I was wrong, but the comment still applies to the ones in Denver