When People Are as Predictable as Water [video]

There was a video I watched years ago about a specialist who studies the flow of pedestrians and redesigns walkways to improve flow of pedestrians. I remember she was working on an airport and there were two hallways joined at a 45 degree angle with a minor outcropping of walkway right at the joint. A lot of people seemed to float around in the outcropping like turbulence, greatly bottlenecking the flow of people. She installed a clever partition to smooth the transition from one hall to the next and the bottle neck was resolved. Still can’t find that video. I always found it interesting.

Resume: moving of a crowd can be simulated using fluid mechanics.

Video is a video of researcher talking about it.

Obligatory incredible reddit comment about crowd crush https://np.reddit.com/r/worldnews/comments/3pcvfb/saudi_arab...

The paper they're reporting on is pretty clever in its sourcing of observations.

Abstract:

>Modeling crowd motion is central to situations as diverse as risk prevention in mass events and visual effects rendering in the motion picture industry. The difficulty of performing quantitative measurements in model experiments has limited our ability to model pedestrian flows. We use tens of thousands of road-race participants in starting corrals to elucidate the flowing behavior of polarized crowds by probing its response to boundary motion. We establish that speed information propagates over system-spanning scales through polarized crowds, whereas orientational fluctuations are locally suppressed. Building on these observations, we lay out a hydrodynamic theory of polarized crowds and demonstrate its predictive power. We expect this description of human groups as active continua to provide quantitative guidelines for crowd management.

http://science.sciencemag.org/content/363/6422/46

On the computer graphics side of things, there's a 2006 paper based on essentially the same underlying idea:

video: https://www.youtube.com/watch?v=lGOvYyJ6r1c

paper: https://grail.cs.washington.edu/projects/crowd-flows/