Friction effects and clogging in a cellular automaton model for pedestrian dynamics

TL;DR

This paper extends a cellular automaton model for pedestrian dynamics by introducing a friction parameter to better simulate conflicts and clogging, revealing both quantitative and qualitative effects on evacuation behavior.

Contribution

It introduces a friction parameter into a pedestrian cellular automaton model, highlighting its importance for realistic conflict and clogging dynamics.

Findings

Friction influences evacuation times significantly.

High density regions exhibit clogging and arching effects.

Friction can cause qualitative changes in flow behavior.

Abstract

We investigate the role of conflicts in pedestrian traffic, i.e. situations where two or more people try to enter the same space. Therefore a recently introduced cellular automaton model for pedestrian dynamics is extended by a friction parameter $\mu$. This parameter controls the probability that the movement of all particles involved in a conflict is denied at one time step. It is shown that these conflicts are not an undesirable artefact of the parallel update scheme, but are important for a correct description of the dynamics. The friction parameter $\mu$ can be interpreted as a kind of internal local pressure between the pedestrians which becomes important in regions of high density, ocurring e.g. in panic situations. We present simulations of the evacuation of a large room with one door. It is found that friction has not only quantitative effects, but can also lead to qualitative changes, e.g. of the dependence of the evacuation time on the system parameters. We also observe similarities to the flow of granular materials, e.g. arching effects.