New York City’s subway system is one of the biggest and most efficient in the world (though those who regularly take it would rather die than admit it.) The subway is filled with all different types of people, but there are a few types that are more homogeneous than not.
Not in that way, silly. These people will dance using the poles on the subway. The poles are meant to be held onto in order to prevent falling, obviously, but these dancers see an alternative use for them.