Crowds exiting through a narrow doorway exhibit a “faster is slower” effect: when individuals push harder to exit, they clog the doorway more frequently, reducing overall flow rate. The intuitive fix: add polite, contact-averse individuals to the crowd. If some people yield rather than push, the clogging should decrease.
Research on bottleneck flows (arXiv:1806.03112) shows this intervention fails. Including polite pedestrians amid a competitive crowd does not reduce evacuation time when the doorway is acceptably large. The polite individuals yield at exactly the moments when yielding creates gaps that competitive individuals fill — redistributing flow without increasing it. The total throughput stays the same because politeness doesn't change the geometry of the bottleneck; it changes who goes through it.
The deeper finding from pedestrian dynamics modeling (arXiv:2501.05106): the bottleneck flow rate depends on the arch formation dynamics at the exit. Arches — semicircular arrangements of people who are mutually blocking each other — form spontaneously at narrow exits. The arch lifetime determines the clogging duration, and arch lifetime depends on the geometry and the force distribution, not on the psychology of the individuals.
This is why evacuation engineering focuses on doorway geometry (width, approach angle, obstacle placement) rather than behavioral training. An obstacle placed upstream of the exit — counterintuitively — can increase flow by disrupting arch formation. Adding a column near the door reduces the probability of symmetric arch configurations and allows asymmetric, unstable arches that collapse quickly.
The lesson: in systems where throughput is limited by self-organized blockages, the fix is structural (change the geometry) not behavioral (change the agents). The agents are responding rationally to the geometry; changing their behavior without changing the geometry just rearranges who gets stuck.