Effects of step time and neighbourhood rules on pedestrian evacuation using an extended cellular automata model considering aggressiveness

Cellular automaton (CA) models have been used to study pedestrian evacuation for many years. The time step and pedestrian evacuation neighbourhood rules are core elements of the CA models for the study of pedestrian dynamics, which have different consequences under different conditions and, therefore, need to be taken seriously. In this paper, we combine pedestrian aggressiveness with the individual’s environment and consider the pros and cons of each of their choices to optimise aggressiveness, and we discuss the impact of time step and neighbourhood rules on pedestrian dynamics under competitive conditions. Multi-velocity two-dimensional floor field cellular automaton (FFCA) is used to consider the impact of aggressiveness on speed and spatial competitiveness. After we optimise aggressiveness, the total evacuation time differs greatly from before in the multi-step method model (MSMM) when pedestrian evacuation follows Moore’s neighbourhood rule. When pedestrian evacuation follows von Neumann’s neighbourhood rule, in the velocity ratio method model (VRMM) and the MSMM, the total evacuation time changes with aggressiveness in the same trend, first showing the phenomenon of ‘faster is faster’ and then ‘faster is slower’, but the greater aggressiveness is, the greater the difference in evacuation time is between the two models. When pedestrian evacuation follows Moore’s neighbourhood rule, the total evacuation time has opposite trends to aggressiveness under the VRMM and the MSMM. In addition, in the VRMM, the total evacuation time of pedestrians following von Neumann’s neighbourhood rule is always much greater, almost twice as long, than when following Moore’s neighbourhood rule. In the MSMM, the difference in the total pedestrian evacuation time following different neighbourhood rules is much more complicated.