  To minimize property loss and death count in terror attacks and other
emergent scenarios, attention given to timely and effective evacuation cannot
be enough. Due to limited evacuation resource, i.e., number of available exits,
there exists interdependence among pedestrians such as cooperation, competition
and herd effect. Thus human factors - more specifically, pedestrians' behavior
in emergency evacuation - play a significant role in evacuation research.
Effective evacuation can only be reached when route planning are considered in
conjunction with psychological dynamics, which is often ignored. As another
drawback, previous research assumes the environment including available exits
as stationary. However, we note that during emergency, some exits which are not
often utilized in normal times are opened, which potentially helps if
pedestrians are aware of them. In this paper, we analyze the effect of
pedestrians' behavior, i.e., herd effect and knowledge of changing environment
with Cellular Automata (CA) simulation. Results of the simulation show the
harmful effect of herd effect as well as highlight the importance of timely
informing pedestrians of environmental change. Accordingly, we propose policy
and procedural recommendations for emergency management of large, crowded
structures. Our future work includes considering more human factors and
applying our model to log data provided by videos in public venues, which can
further show effectiveness of our model in real scenarios.
