One design that can expedite the flow of crowds through constrained corridors is, ironically, a column placed slightly off-center in front of the exit. This allows for "bubbles" to form in the crowd, dampening congestion ripples in much the same way that rush-hour traffic signals on entrance ramps smooth vehicular traffic flow. Here, the model is shown in "empirical mode" with minimal graphics. One agent is selected (yellow) and his speed and injury status are displayed as he navigates through the crowd. The circles show the spatial footprint of the agents and the triangles show their orientation.