Subway seating in NYC tends to follow the same laws that govern the distribution of gasses: molecules spread out to fill a large, empty space rather than clump together in one area. When an empty subway car pulls up to a crowded platform, people rush to occupy the least-crowded areas, ensuring a more or less even spacing of passengers; likewise, as train cars empty out, people tend to seek out distance and reposition themselves. One notable exception to this occurs when a train car which has been extremely full gradually empties out, and two strangers are left sitting pressed up each other on an otherwise unoccupied bench. Whether out of apathy, lack of attention, or avoiding the appearance of rudeness, neither moves to an empty spot, and the two continue to ride in awkward tandem until one arrives at his/her destination.