The Energy of Crowds on a Stairway

People keep an average distance of about 75 centimeters away from other people while moving through crowds. About one out of every thousand people will turn around and go back the way they came to avoid bumping into somebody else. Ye andt it seems to be the case no matter where you go. There's some sort of, there are different cultural norms in place regarding, say, like, what side of the sidewalk people moving this way should be on,. or how much space is permittable between you and the next person. But still, people are managing not to plough into each other.