influence on macroscopic quantities like flow and evacuation time. We like to point out that friction as introduced here does not reduce the velocity of a freely moving particle. Its effects only show up in local [*interactions*]{}.

As one can see it is necessary for such kind of investigations to use a parallel update in the model. Any other form of random or ordered sequential update will disguise the real number of arising conflicts between the pedestrians in the system.

Simulations and results
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In the following we describe results of simulations for a typical situation, i.e. the evacuation of a large room (e.g. in case of fire). In [@aki0] it is shown that by variation of the sensitivity parameters $k_S$ and $k_D$ (see Sec. \[update\]) three main regimes for the behaviour of the particles can be distinguished. For strong coupling $k_S$ and very small coupling $k_D$ we find an [*ordered regime*]{} where particles only react to the static floor field. The behaviour then is in some sense deterministic. The [*disordered regime*]{} characterized by strong coupling $k_D$ and weak coupling $k_S$ leads to a maximal value of the evacuation time $T$. Here the behaviour is typical for panic situations. Between 