Narrow Results

Pedestrian behavioral modeling is an important topic to reproduce rich pedestrian dynamics phenomena. In this paper, a modified lattice gas model is proposed to simulate pedestrian counter flow under periodic boundary conditions by considering the variable transition probability, which can quantitatively describe complex human subconscious behaviors and distinguish the individual and common characteristics of pedestrians. Four types of walkers are involved in the model, and their dynamical characteristics are discussed in some complex situations. The simulation results show that the presented model can reproduce some essential features of pedestrian counter flows, such as the lane formation, segregation effect and phase separation. For the mixed pedestrian flows, the comparison between the subconscious behaviors of obeying the traffic rules and those of breaking the traffic rules indicates that the former could effectively reduce the occurrence of jam cluster. In addition, it is found that with increase of the strength of drift D₁, the jam transition threshold decreases. Finally, the simulation results are compared with our previous study (see Ref. 32). It is shown that the mean velocity and the mean flow are always larger at the free moving phase, and the underlying mechanism is discussed in detail.

There often exist behaviors of moving against the main direction of evacuation in order to rescue or find the important missing people in real situations. However, the traditional social force model (SFM) often lacks consideration of such “counter flow”. Motivated by this, we improve the traditional SFM to study the counter flow and its influence on evacuation out of multi-exit rooms. We call the person to be rescued “superior” and the rescuers “subordinate”. Two different rescue situations are proposed: superior waiting in place (case 1) and superior moving towards the exit (case 2). The results show that the counter flow will always reduce the evacuation efficiency to a certain extent, and the evacuation efficiency of case 1 is lower than that of case 2. At the same time, for these two cases, increasing the number of rescuers increases the evacuation time. We also find that the existence of counter flow can enlarge the effect of “faster-is-slower”, while increasing the number of exports can significantly improve the rescue efficiency. We hope that this result can help to improve the efficiency of emergency evacuation with rescue.