We propose a pedestrian position update rule,which is added to a microscopic pedestrian model to avoid pedestrian overlap.In the rule,the step size of a pedestrian moving in a selected direction at each update is in inverse proportion to the repulsive actions imposed by other pedestrians moving in a direction with an exponential rate.The positions of the pedestrians are then updated in each small time interval.In this way,a barrier between the pedestrians can be generated,and after updating their positions the pedestrians do not overlap with each other.The modified model is compared to the original model through a simulation of the evacuation process of pedestrians in a closed area.The simulation results indicate that the modified model is superior to the original model in several aspects.
