Introduction of Frictional and Turning Function for Pedestrian Outflow with an Obstacle

TL;DR

This paper enhances pedestrian flow modeling by introducing a variable frictional function and a turning cost, demonstrating how obstacles can improve evacuation efficiency through simulations and experiments.

Contribution

It introduces a frictional function dependent on conflict size and a turning cost, advancing pedestrian evacuation models with validated theoretical and experimental results.

Findings

Pedestrian flow increases with an obstacle in front of the exit.

The obstacle reduces conflict by blocking pedestrian movement.

Shifting the obstacle from the center enhances its effectiveness.

Abstract

In this paper, two important factors which affect the pedestrian outflow at a bottleneck significantly are studied in detail to analyze the effect of an obstacle set up in front of an exit. One is a conflict at an exit when pedestrians evacuate from a room. We use floor field model for simulating such behavior, which is a well-studied pedestrian model using cellular automata. The conflicts have been taken into account by the friction parameter. However, the friction parameter so far is a constant and does not depend on the number of the pedestrians conflicting at the same time. Thus, we have improved the friction parameter by the frictional function, which is a function of the number of the pedestrians involved in the conflict. Second, we have newly introduced the cost of turning of pedestrians at the exit. Since pedestrians have inertia, their walking speeds decrease when they turn, and the pedestrian outflow decreases. The validity of the extended model, which includes the frictional function and the turning function, is verified by both a mean field theory and experiments. In our experiments, the pedestrian flow increases when we put an obstacle in front of an exit. The analytical results clearly explains the mechanism of the effect of the obstacle, i.e., the obstacle blocks pedestrians moving to the exit and decreases the average number of pedestrians involved in the conflict. We have also found that an obstacle works more effectively when we shift it from the center since pedestrians go through the exit with less turning.