Effects of the direction and speed strategies on pedestrian dynamics.

In this work, we propose a velocity-based model for pedestrian movements containing two sub-models to study how the direction and speed selection strategies affect pedestrian dynamics. Affected by others in the view, pedestrians deviate their moving direction from the desired one to resolve space and velocity conflicts, the sensitivity to which is adjusted by two proportional parameters. After determining the moving direction, they choose a reasonable speed to avoid immediate collisions. The tolerance of personal-space violations is considered given that people accept physical contacts in some contexts and may squeeze despite the lack of space instead of matching the speed of the one in front. Simulation results demonstrate that the direction and speed selection strategies affect pedestrian dynamics in several aspects, including the time and metabolic energy cost, density-velocity relations, and crowd stability. Intriguingly, the discrepant empirical fundamental diagrams of pedestrians can be reproduced and explained in a natural way.