When a crowd of people tries to exit a room (or stadium) the experience is usually one of a traffic jam. Everyone at the doorway jostles and pushes, trying to exit, resulting in a slow movement of people through the exit.

Researchers in Japan discovered that a stationary obstacle, placed at a thirty degree angle from the doorway, actually speeds up the process, and that everyone exits more rapidly, even those who have to detour around the pole.

My guess is that the placement of the stationary pole forces a semi-line to form. A single file line is still, after all these years of resistance to it, the fastest way to evacuate a room or arena.

When I taught school, this was one experience lesson I taught every class. After they learned how to use a stop watch, I had the students exit in three ways: free form, two lines, and a single line. Each mode of exit was timed from leaving their desk seats to the arrival of the last student on the other side of the door. The student with the stopwatch timed the whole procedure.

The students were quiet and orderly (no massive pushing or shoving) in all three modes (some giggline and whispering), and the quickest mode was always the single line. One year my class wouldn't believe it, so we did it over again. Same result, though they tried their darnedest to make the free form the fastest way out.

After that experiment, I never had to tell them to line up to leave the room. They knew what they had to do and why to get to lunch or recess or home as fast as possible.

Experiment and experience beats lecturing every time.