D. R. Parisi, C. O. Dorso, Physica A 385, 343 (2007)
We study the evacuation of a set of 200 pedestrians from a room under a state of panic. The dynamics of the pedestrians is given by the Social Force Model. The degree of panic is controlled by a parameter vd which represents the velocity at which pedestrians wish to move. We show that the ‘‘faster is slower effect’’ can be understood in terms of the works performed by the different forces present in the system and the role played by dissipative terms in the model. Beyond the maximum flow rate the ‘‘granular cluster’’ mass distribution displays a transition from exponentially decaying to ‘‘U-shaped’’ as this value of vd evacuation efficiency begins to decrease rapidly.