On the dynamic of crowd movement and its application in the future

When I read the title above I immediately think of being part of a huge crowd of people and I associate it with danger. How comes? Maybe I don`t like the feeling of dependence or maybe I just need some private space around me.

Crowd researching is both focused on physical and psychological effects. In this blog-entry, however, I want to emphasize the modeling of crowd movement that is extremely important to prevent catastrophes in urban areas and at concerts or sport events where people gather and want to have fun. This is only possible if you can predict how a human mass is going to behave in a critical situation.

Mass movement is often simulated as a liquid containing molecules that move in different directions. However, if we treat moving masses of people as thought they were fluids we forget the fact that the density increases and the movement gets chaotic. And that is not true, not every human crowd movement ends in chaos.
But what happens if you treat a human mass exactly for what it is? You have to give it some kind of volition. We are actually not passive in a huge mass but seeking actively to get where we want.

Dr Moussaid, a professor at Paul Sabatier University in Toulouse, France has tried to find an answer. His recent research is based on three rules: first, each human being wants to get through the mass as straight as possible and avoids obstacles. Second, each human being adjusts its speed depending on the distance from obstacles. You can watch this behavior every morning on your way to your working-place: people sort themselves in lanes to avoid a crock and adjust their speed by choosing different lanes. In other words, just follow the line of least resistance. And finally, the third rule: a lack of volition for people at random – when the jam gets tight you have to stop your movement.

So what happens when crowds of people move? At first the crowd moves smoothly. When the mass is getting tighter you can observe a stop-and-go-pattern but sometimes even extreme crushing. Finally you can observe turbulence that lead to disaster.
Once you have simulated the process you can develop a solution. Which behavior of a crowd is critical? How should a future tram, a future stadium or other public spaces be constructed to avoid people being trapped there? Hopefully Dr Moussaids research (http://mehdimoussaid.com/projects.html) will find the answer.