How to avoid the faster-is-slower effect in competitive evacuation?

Abstract

The faster-is-slower (FIS) effect is an interesting phenomenon in crowd dynamics. However, the validity of FIS was not universally accepted without objection. A series of experiments was conducted by using a group of young students in a room evacuating through a narrow exit at two locations, i.e. a center exit and a corner exit. The mean time intervals of two consecutive persons passing through a center exit were 1.14 ± 0.09, 1.31 ± 0.43 and 1.42 ± 0.93 s at low, medium and high competitiveness, respectively, i.e. which was the FIS effect. However, the mean time intervals of two consecutive persons passing through a corner exit were 1.04 ± 0.07 and 0.85 ± 0.17 s at low and high competitiveness, respectively, which was contrary to the FIS effect. Furthermore, two series of circulation movement at high competiveness were studied in which all students were required to re-enter the room from another opening after getting out of the room and this process continued until the end of a test. The mean time interval of consecutive persons passing through the exits was around 2.39 ± 4.29 and 0.77 ± 0.25 s for the center exit and corner exit respectively, and the flow rate of the corner exit was around 3 times that of the center exit. The complementary cumulative probability distribution of the time intervals between consecutive students Δt was studied and it followed a power law, i.e. . However, the study showed that alpha alone cannot well represent the efficiency of an evacuation. The experiment demonstrated that the FIS effect can be avoided by relocating the exit to the corner and the flow rate can be greatly improved, particularly in high competiveness conditions.