"Left or right?" he asked me as we watched the commuter train approach. A group of people nearby moved into position to line up with the door, all likely thinking the same thing: How do I get a seat? "Left," I said. "These people are going to go right." He looked at me for a minute and then nodded. We followed the initial surge in and turned to the left where the smaller seating section of the train is located--sure enough, the bulk of the crowd flowed to the right.

http://blogs.scientificamerican.com/anthropology-in-practice/2012/10/17/the-story-of-grand-central-s tation-and-the-taming-of-crowd/