An agent-based model for staircase evacuation considering agent’s rotational behavior

Staircase is the major vertical evacuation route in high-rise building during emergent situation, such as when fire or earthquake occurs. Thus it is critical to understand pedestrian dynamics on staircase for a safe and quick evacuation process. Agent-based model is a microscopic modeling approach that accounts for individual and combined behavior of a group of autonomous agents. It is ideally suitable to study the evacuation process which involves complex interactions between evacuees and their surrounding environment. Most of previous studies on the staircase evacuation ignore the rotational or turning behavior of pedestrians. This paper aims to address this limitation by extending the optimal step model to account for agent’s rotational behavior. To this end, mathematical formulas for the attractive and repulsive potential are proposed. The formulation of agent-based model explicitly takes geometry of staircase, as well as characteristics of agent’s movement on stairwell into consideration, thus making it suitable to study the staircase evacuation problem. Both agent’s translational and rotational behavior are guided by minimizing the total potential in a discrete sense. Simulation result with the proposed agent-based model shows agreement with the fundamental diagram for regular staircase evacuation. Other common scenarios during evacuation, such as counter flow or merging of two groups of pedestrians, are also investigated and validated. It is shown that lane formulation during evacuation and dodging behavior of an individual agent can be observed with the agent-based simulation.