The "faster-is-slower" (FIS) effect was first predicted by computer simulations of the egress of pedestrians through a narrow exit [Helbing D, Farkas I J, Vicsek T, Nature 407:487-490 (2000)]. FIS refers to the finding that, under certain conditions, an excess of the individuals' vigor in the attempt to exit causes a decrease in the flow rate. In general, this effect is identified by the appearance of a minimum when plotting the total evacuation time of a crowd as a function of the pedestrian desired velocity. Here, we experimentally show that the FIS effect indeed occurs in three different systems of discrete particles flowing through a constriction: (a) humans evacuating a room, (b) a herd of sheep entering a barn and (c) grains flowing out a 2D hopper over a vibrated incline. This finding suggests that FIS is a universal phenomenon for active matter passing through a narrowing.
@article{arxiv.1507.05110,
title = {Experimental proof of Faster-is-Slower in multi-particle systems flowing through bottlenecks},
author = {José M. Pastor and Angel Garcimartín and Paula A. Gago and Juan P. Peralta and César Martín-Gómez and Luis M. Ferrer and Diego Maza and Daniel R. Parisi and Luis A. Pugnaloni and Iker Zuriguel},
journal= {arXiv preprint arXiv:1507.05110},
year = {2015}
}