  The transition between low and high density phases is a typical feature of
systems with social interactions. This contribution focuses on simple
evacuation design of one room with one entrance and one exit; four
passing-through experiments were organized and evaluated by means of automatic
image processing. The phase of the system, determined by travel time and
occupancy, is evaluated with respect to the inflow, a controlled boundary
condition. Critical values of inflow and outflow were described with respect to
the transition from low density to congested state. Moreover, microscopic
analysis of travel time is provided.
