El Botellón: Modeling the Movement of Crowds in a City

A simulation of crowd movement in a city is studied under various assumptions about interactions between people. We find, in general, that there are two modes of steady-state behavior. The crowd may be distributed across the city, or it may end up gathered in one place. A mathematical model describes the long-term behavior and shows that this change in behavior is sensitive to a critical parameter setting in our model. Some alternative interpretations of the results are formulated.