Predicting Crowd Behavior In Dense Urban Settings

One of the most interesting talks I sat through during my visit at IEEE VR 2008 was by Paul Torrens of Arizona State University talking about geosimulation as an engine for synthetic actors in urban models. Scientists who want to see how a crowd behaves in an emergency can now shout “Fire!” on a city street and watch everyone panic and run thanks to a newly developed computer simulation. The 3D model starts with patterns of human behavior and movement and uses them to simulate the behavior of a crowd in mob situations and pedestrian habits under certain building configurations, resulting in a virtual crowd video.

"Crowds are vital to the lifeblood of our cities,” said Paul. But, he adds, it is impractical “to establish live experiments with hundreds or thousands of people along busy streetscapes, to reproduce mob behavior during riots for the purposes of academic experimentation, or, to expect to replicate the life and death behavior under emergency situations in a fabricated fashion”. Torrens’s model uses what he calls an “agent-based methodology.” He can put individual people, or “agents,” each with different characteristics of age, sex, size and health, into the model and have them process information about the world around them. Their unique characteristic combinations make the agents interpret that information and react in different ways.

“It’s the same way we process information in the real world". Though you’re not aware of it, when you walk down a crowded street, your brain is constantly monitoring your surroundings and planning the path you will take to your destination while simultaneously monitoring for obstacles.

A prototype that Torrens has developed models the evacuation of a crowded area during a fire when there is only one point of escape, but he has used his method to develop a primitive model of a situation in which a disease spreads through casual contact, and he is attempting to create scenarios in which agitated crowds turn into unruly mobs. The model could also be used in planning cities to optimize walking space for pedestrians and alleviate congestion.

For more info check http://geosimulation.org/