  We present simulations of evacuation processes using a recently introduced
cellular automaton model for pedestrian dynamics. This model applies a bionics
approach to describe the interaction between the pedestrians using ideas from
chemotaxis. Here we study a rather simple situation, namely the evacuation from
a large room with one or two doors. It is shown that the variation of the model
parameters allows to describe different types of behaviour, from regular to
panic. We find a non-monotonic dependence of the evacuation times on the
coupling constants. These times depend on the strength of the herding
behaviour, with minimal evacuation times for some intermediate values of the
couplings, i.e. a proper combination of herding and use of knowledge about the
shortest way to the exit.
