  We studied the room evacuation problem within the context of the Social Force
Model. We focused on a system of 225 pedestrians escaping from a room in
different anxiety levels, and analyzed the clogging delays as the relevant
magnitude responsible for the evacuation performance. We linked the delays with
the clusterization phenomenon along the "faster is slower" and the "faster is
faster" regimes. We will show that the "faster is faster" regime is
characterized by the presence of a giant cluster structure (composed by more
than 15 pedestrians), although no long lasting delays appear within this
regime. For this system, we found that the relevant structures in the "faster
is slower" regime are those blocking clusters that are somehow attached to the
two walls defining the exit. At very low desired velocities, very small
structures become relevant (composed by less than 5 pedestrians), but at
intermediate velocities (vd = 3 m/s) the pedestrians involved in the blockings
increases (not exceeding 15 pedestrians).
