Understanding differences in emergency escape and experimental pedestrian crowd egress through quantitative comparison

Abstract

Models of pedestrian crowd behavior in panic or emergency situations rarely have complementary empirical data to calibrate or validate the model's prediction. Till date, there is no systematic study that has attempted to conduct a quantitative comparison of emergency escape with the laboratory experimental data for the underlying differences in crowd behavior.In this paper, an attempt is made to explore the differences between experimental data on pedestrian crowd egress and emergency egress at a bottleneck and their implication for crowd safety. The laboratory experiments consist of pedestrians passing through a bottleneck of varying widths. The emergency egress data has been extracted from the publicly available rare video footage of panic escape at a shopping center during an Earthquake in China. The extracted data are then used to test a force-based crowd simulation model.It was found that there are underlying differences on the crowd egress behavior (headway distribution and flow) under emergency conditions as compared to controlled laboratory experiment. There is significant number of group exits and less lone exits in emergency egress. It was observed that the force-based model was able to replicate the normal egress as well as panic egress. It is recommended that any pedestrian crowd evacuation simulation model be tested to reproduce this fundamental headway distribution as observed in this study which includes >85% of headway as short headway (≤0.5s) with predominately group exits (0–0.1s headway) rather than lone exits for the bottleneck widths between 1.7 and 2.1m.