An experimental study of pedestrian bidirectional flow through bottlenecks

Pedestrian flow passing through bottlenecks is complex, particularly for opposite movement in a room with a single doorway. These bidirectional flows would always cause congestion and further reduce traffic efficiency so the ‘Disembarking precedes embarking’ rule is widely used in the actual management of public spaces. However, the impact of the imbalance of the bidirectional movement of pedestrian numbers on the pedestrian capacity and throughput at the bottleneck still needs further exploration. Therefore, this study investigates the effects of the ratio r of pedestrians leaving the room to the total number of participants and the bottleneck widths (1.2, 1.6 and 2.0 m) on the movement behavior of pedestrians in bidirectional flow and the efficiency of passing through by conducting controlled experiments where pedestrian trajectories, speed, density, flow and time headway are analyzed. Results indicate that the bottleneck width and the pedestrian flow rate are linearly related, whereas the r and flow have a nonlinear relationship. Specifically, r = 10% is the optimal value for improving the pedestrian traffic efficiency at the bottleneck, which is even better than the unidirectional scenario. The most significant density in the measuring area is at r = 30%, corresponding to the greatest probability of clogging. The pedestrian density within the room influences the flow rate at the bottleneck, thereby indicating that wider doors are not always better from a design perspective. The findings presented in this paper can provide actual data to validate bidirectional pedestrian flow simulation models and theoretical support for pedestrian facility and crowd management optimization. © 2024 IOP Publishing Ltd and SISSA Medialab srl.