Collective Dynamics (E-Journal)
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Understanding the Characteristics of Pedestrians when Passing Obstacles of Different Sizes: An Experimental Study
Full text linkThe aim of this study is to understand the collective movements of individuals and to observe how individuals interact within a physical environment in a crowd dynamic, which has drawn the attention of many researchers. We conducted an experimental study to observe interactions in the collective motions of people and to identify characteristics of pedestrians when passing obstacles of different sizes (bar-shaped, 1.2 m, 2.4 m, 3.6 m and 4.8 m), going through one narrow exit and employing three different flow rates in walking and running conditions. According to the results of our study, there were no differences in collision-avoidance behaviour of pedestrians when walking or running. The pedestrians reacted early to the obstacles and changed the direction in which they were walking by quickly turning to the left or to the right. In terms of the speed of the pedestrians, the average velocity was significantly affected while performing these tasks, decreasing as the size of the obstacle increased; therefore, the size of obstacles will affect flow and speed levels. Travel time was shorter when participants were in the medium-flow rate experiments. In terms of the distance of each individual’s travel, our data showed that there was no significant difference in all the flow rate experiments for both speed levels. Our results also show that when the pedestrians crossed an obstacle, the lateral distance averaged from 0.3 m to 0.7 m, depending on the flow rate and speed level. We then explored how the body sways behaved while avoiding obstacles. It is observed that the average sway of the body was less in the high-speed conditions compared to the low-speed conditions – except for the HF & 4.8 m experiment. These results are expected to provide an insight into the characteristics of the behaviour of pedestrians when avoiding objects, and this could help enhance agent-based models
Social Distancing with the Optimal Steps Model
Full text linkWith the Covid-19 pandemic, an urgent need has arisen to simulate social distancing. The Optimal Steps Model (OSM) is a pedestrian locomotion model that operationalizes an individual's need for personal space. We present new parameter values for personal space in the OSM to simulate social distancing in the pedestrian dynamics simulator Vadere. Our approach is pragmatic. We consider two use cases: in the first, we demand that a set social distance must never be violated. In the second the social distance can be violated temporarily for less than 10s. For each use case we conduct simulation studies in a typical bottleneck scenario and measure contact times, that is, violations of the social distance rule.We conduct regression analysis to assess how the parameter choice depends on the desired social distance and the corridor width. We find that evacuation time increases linearly with the width of the repulsion potential, which is an analogy to physics modeling the strength of the need for personal space. The evacuation time decreases linearly with larger corridor width. The influence of the corridor width on the evacuation time is smaller than the influence of the range of the repulsion, that is, the need for personal space. If the repulsion is too strong, we observe clogging effects. Our regression formulas enable Vadere users to conduct their own studies without understanding the intricacies of the OSM implementation and without extensive parameter adjustment
Optimising Pedestrian Flow Around Large Stadiums
Full text linkThis study proposes a method that combines the cellular automaton model and the differential evolution algorithm for optimising pedestrian flow around large stadiums. A miniature version of a large stadium and its surrounding areas is constructed via the cellular automaton model. Special mechanisms are applied to influence the behaviour of an agent that leaves from a certain stadium gate. The agent may be attracted to a nearby business facility and/or guided to uncongested areas. The differential evolution algorithm is then used to determine the optimal probabilities of the influencing agents for each stadium gate. The main goal is to reduce the evacuation time, and other goals such as reducing the costs for the influencing agents’ behaviours and the individual evacuation time are also considered. We found that, although they worked differently in different scenarios, the attraction and guidance of agents significantly reduced the evacuation time. The optimal evacuation time was achieved with moderate attraction to the business facilities and strong guidance to the detouring route. The results demonstrate that the proposed method can provide a goal-dependent, exit-specific strategy that is otherwise hard to acquire for optimising pedestrian flow
Minimization of Mean-CVaR Evacuation Time of a Crowd using Rescue Guides: a Scenario-based Approach
Full text linkIn case of a threat in a public space, the crowd in it should be moved to a shelter or evacuated without delays. Risk management and evacuation planning in public spaces should also take into account uncertainties in the traffic patterns of crowd flow. One way to account for the uncertainties is to make use of safety staff, or guides, that lead the crowd out of the building according to an evacuation plan. Nevertheless, solving the minimum time evacuation plan is a computationally demanding problem. In this paper, we model the evacuating crowd and guides as a multi-agent system with the social force model. To represent uncertainty, we construct probabilistic scenarios. The evacuation plan should work well both on average and also for the worst-performing scenarios. Thus, we formulate the problem as a bi-objective scenario optimization problem, where the mean and conditional value-at-risk (CVaR) of the evacuation time are objectives. A solution procedure combining numerical simulation and genetic algorithm is presented. We apply it to the evacuation of a fictional passenger terminal. In the mean-optimal solution, guides are assigned to lead the crowd to the nearest exits, whereas in the CVaR-optimal solution the focus is on solving the physical congestion occurring in the worst-case scenario. With one guide positioned behind each agent group near each exit, a plan that minimizes both objectives is obtained
Glossary to Support Applied International Research on Decision Making for High Conflict Urban Marches and Parades
Full text linkThis article was created in context of OPMoPS (Organized Pedestrian Movement in Public Spaces), a French-German interdisciplinary collaboration on high conflict urban marches and parades. As OPMoPS aims to support decision making for authorities of public order, both a French and a German police institution are members of the consortium. Communication with target group was insofar challenging, as their experts' language is close to everyday terms. Thus the authors are proposing the following glossary to support applied international research in this field. Both authors are not skilled language experts but pragmatic members of OPMoPS's police institutions. All terms can be found in English, German and French, with a focus on police and on German police procedure. It is firstly classed in thematic order, and secondly in alphabetical order
Movement parameters of persons with disabilities on evacuation by lifts
Full text linkIn 2010 it was defined five challenges for the solution of evacuation of persons in buildings to 2020. One of the challenges is to implement helpfull technologies during evacuations from buildings – lifts. Needed steps for fulfilling this challenge are also quantification of missing data which are dealing with evacuation of persons with disabilities. From 2002 all public buildings in Slovak Republic have to be also accessible to persons with disabilities, but it is also a global problem. In present exists just small number of informations of movement parameters of persons with disabilities during evacuation by lift. There for, this work was focused on collecting these informations. The data collection was realized by using an in-situ experiment. The aim of the work was to quantify the phase stages of evacuation by elevators for persons with disabilities (speed, time, movement and capacity parameters). Person's movements were monitored during the measurements, arrival to lift, cabin entry and exit from the cabin, including leaving the bounded area. Arrival to lift included movement in the bounded area in front of the lift, until the moment of pushing the button was pressed to call the lift. The time of cabin entering includes the time from the beginning of opening the lift doors to the beginning of closing of the lift doors. The exit from the cabin includes the time from opening the lift doors, passing through the lift doors to leaving the bounded area. In total, ten participating persons in the experiments imitated wheelchair movement and movement with leg fracture. Measurements were made on two lifts, where person evacuating himself or with the help of another person. Everyone performed each measurement three times. A total of 720 measurements were performed in the work. According to the results of the experiment it can be stated that cabin entry is longer for a person on the wheelchair than for a person with a leg fracture, but the difference is even bigger during exit from the cabin, including leaving the bounded area. During the experiment, various movement techniques have been observed that may affect their overall the time of cabin entry and exit from the cabin. Obtained results can extend existing evacuation model to the possibility of using the lift. The obtained results quantify the individual phase stages of entering to the lift and exiting of the lift for persons with limited movement
Safe Evacuation for All A top 10 List of Requirements
Full text linkEvacuations are an important aspect of emergency planning. Many persons with special needs could reach a safe area on their own or with assistance by other people around, if evacuation planning and guidance considered them. The so-called self-rescue is crucial for safe evacuation, as fire services and other first-responders need some time to arrive at the scene. In general, people should find the conditions to arrive at a safe area on their own. In many buildings and infrastructures today, self-rescue is difficult for persons with special needs, e.g. wheelchair users. Sometimes it appears that designers and fire safety engineers only think of “average”, healthy and agile people in evacuations. But for safe and effective evacuations, different groups of people and their needs have to be considered. The paper suggests a top 10 list of requirements for safe evacuation and improvement of self-rescue from a psychological point of view. Universal Design or Design for All in evacuation has become more relevant in recent times, since accessibility as a political goal has made it possible for persons with special needs to participate more easily in public life. Nonetheless, regulations focus on how people enter a building but not on how to evacuate safely. Preparing for safer evacuations requires knowledge about different occupant groups and their needs. Requirements for different phases of evacuations are discussed and their implications for simulation and modelling, e.g. the potential impact of physiological requirements. The need for a multi-method approach to gather and integrate data, factors to foster safe evacuations, just as practical and design requirements are included. When self-rescue is not possible, assisted evacuation will rely on good leadership fostering social motivation. Last but not least, implementing design for all will help everyone to evacuate safely
Movement Characteristics of Processions
Full text linkProcessions are a scientifically not much investigated traffic system. Recent studies found that the first participant in the Cologne Rose Monday parade has a remarkable higher travel time than the last participant. The velocity profiles of the participants are explained by the constant moving vehicle driving ahead of the parade leaving the pathway and partly due to a spatial contraction of the parade during the procession. This contribution compares the traffic kinematics of the Cologne Rose Monday parade in Germany with other processions (Schuetzenausmarsch Hanover 2017, Niederrheinischer Kinderkarnevalsumzug 2018). The kinematics of these processions were analysed based on GPS data from participants. Their kinematics differ from those of the Cologne Rose Monday parade. In general, the observations depend on the size of a procession, the length of its pathway, the composition of the procession and especially on the catching up behaviour, of the participants, when gaps occur in front of them. Furthermore, we examine the influence of the pathway on the traffic flow. This can be used to choose a parade’s pathway avoiding flow reducing infrastructure characteristics like traffic area transitions, narrow curves etc. In summary, this work extends the understanding of the kinematics of processions. It can serve as a basis upon which the parade’s movement can be predicted and so the duration of such events can be estimated better
Understanding Crowd Dynamics in Processions during Mass Religious Gatherings A case study of Shahi Snan in Kumbh Mela
Full text linkLarge people gatherings in public places exhibit crowd dynamics that are quite complex. Such mass events with high densities are fraught with potentially serious consequences if not understood and managed properly. In mass religious processions, the participants in the crowd are emotional and mostly impulsive and often crowd disasters occur due to the behaviour of the crowd. These events have great potential to cause safety hazards to the people. This paper attempts to narrate the typical situations of crowd dynamics observed in the Kumbh Mela procession-2016 and to describe the characteristics of the crowd that have not been reported in literature so far but have a significant impact on the crowd. Extreme crowd pressures resulting in individual loss control due to psychological and physiological factors, heterogeneity in the crowd, group behaviour and their induced competitiveness, unexpected behaviour exhibited due to the motivation behind participating in such procession makes it a typical crowd concentrated event to study the potentially critical dynamics of crowd. Physical and psychological forces acting on the people and their resulting dynamics of crowd in the Kumbh Mela procession 2016 lead to serpentine behaviour, which can possibly lead to crowd crushes, or any such crowd risk situations. Therefore, the characteristics of crowd participating in the Kumbh Mela procession have to be clearly understood so that it helps in better planning and well-organized movement patterns
Investigating pedestrians’ obstacle avoidance behaviour
Full text linkModelling and simulating pedestrian motions are standard ways to investigate crowd dynamics aimed to enhance pedestrians’ safety. Movement of people is affected by interactions with one another and with the physical environment that it may be a worthy line of research. This paper studies the impact of speed on how pedestrians respond to the obstacles (i.e. Obstacles avoidance behaviour). A field experiment was performed in which a group of people were instructed to perform some obstacles avoidance tasks at two levels of normal and high speeds. Trajectories of the participants are extracted from the video recordings for the subsequent intentions:(i) to seek out the impact of total speed, x and yaxis (ii) to observe the impact of the speed on the movement direction, x-axis, (iii) to find out the impact of speed on the lateral direction, y-axis. The results of the experiments could be used to enhance the current pedestrian simulation models