Simulation study on the effect of obstacles upstream of the building exit on evacuation efficiency

Since the argument that placing obstacles upstream of the building exit can improve evacuation efficiency was put forward, how to set up obstacles to improve building evacuation efficiency has become a hot topic. Based on the actual evacuation experimental data, this paper established and verified a discrete cellular automaton model that realised the ‘faster is slower’ effect in the actual evacuation experiment and, on this basis, studied the impact of different obstacle settings on building evacuation efficiency under different emergency levels. Through research, we found that setting up obstacles opposite to the building emergency exit, not close to the building emergency exit, or in a corridor-like form at the building's emergency exit will reduce evacuation efficiency while setting up obstacles close to the building emergency exit can increase evacuation efficiency. In addition, setting up obstacles close to the side with fewer people can improve building evacuation efficiency more than setting up obstacles close to the side with more people, and setting up more obstacles on the side with fewer people can improve evacuation efficiency more than setting up more obstacles on the side with more people. Our research findings have the potential to significantly improve our understanding of the impact of obstacles near exits on building evacuation efficiency and, thereby, save lives in emergencies.