Cluster Risk of Walking Scenarios Based on Macroscopic Flow Model and Crowding Force Analysis

Abstract

Abstract:In recent years, accidents always happen in confined space such as metro stations because of congestion. Various researchers investigated the patterns of dense crowd behaviors in different scenarios via simulations or experiments and proposed methods for avoiding accidents. In this study, a classic continuum macroscopic model was applied to simulate the crowded pedestrian flow in typical scenarios such as at bottlenecks or with an obstacle. The Lax-Wendroff finite difference scheme and artificial viscosity filtering method were used to discretize the model to identify high-density risk areas. Furthermore, we introduced a contact crowding force test of the interactions among pedestrians at bottlenecks. Results revealed that in the most dangerous area, the individual on the corner position bears the maximum pressure in such scenarios is 90.2 N, and there is an approximate exponential relationship between crowding force and density indicated by our data. The results and findings presented in this paper can facilitate more reasonable and precise simulation models by utilizing crowding force and crowd density and ensure the safety of pedestrians in high-density scenarios.

Experiment Calibrated Simulation Modeling of Crowding Forces in High Density Crowd

“…Wu et al [11] investigated the crowding forces in a metro system and found that the maximum forces during boarding, travelling, and alighting are 650 N, 133 N, and 89 N, respectively. Li et al [12] found the maximum crowding force in bottleneck situation is 90.2 N, and the relationship between crowding force and crowd density is an exponential function.…”

“…Simulation models of high density crowds [1], [4], [12], [16] include microscopic and macroscopic models. Microscopic models include discrete models, continuous models, and agent-based models (ABM) [17].…”

“…To efficiently simulate higher density crowds, macroscopic fluid dynamics models were introduced because of the resemblance between mass gatherings and fluid flow [12]. Li et al [12] simulated high density crowd movements based on Hughes' continuum flow model [22], and the crowd density could be greater than 5 people/m 2 . To effectively reproduce the movement of denser and larger crowds, a hybrid continuum-based method, integrating discrete agents, was proposed [23], [24].…”

“…Because crowd densities in these simulation model studies are not high enough to generate obvious crowding forces [12], researchers have paid more attention to model formulation and modification to reach higher densities and describe observed aggregate dynamics features, and ignore an important term, the crowding force, which is a real physical force relative to social force in high density crowds. Crowding forces in high density crowds are sensory input information that can affect individual movement [13].…”

“…Wu et al [11] measured crowding forces during the boarding, travelling, and alighting processes in a metro system. Li et al [12] measured the contact crowding force of pedestrians under a bottleneck situation. Preliminary analysis of the relationship between crowding force and crowd density showed that the maximum crowding force increases with crowding density.…”