Adaptive pedestrian behaviour for the preservation of group cohesion

A crowd of pedestrians is a complex system in which individuals exhibit conflicting behavioural mechanisms leading to self-organisation phenomena. Computer models for the simulation of crowds represent a consolidated type of application, employed on a day-to-day basis to support designers and decision makers. Most state of the art models, however, generally do not consider the explicit representation of pedestrians aggregations (groups) and their implications on the overall system dynamics. This work is aimed at discussing a research effort systematically exploring the potential implication of the presence of groups of pedestrians in different situations (e.g. changing density, spatial configurations of the environment). The paper describes an agent-based model encompassing both traditional individual motivations (i.e. tendency to stay away from other pedestrians while moving towards the goal) and an adaptive mechanism representing the influence of group presence in the simulated population. The mechanism is designed to preserve the cohesion of specific types of groups (e.g. families and friends) even in high density and turbulent situations. The model is tested in simplified scenarios to evaluate the implications of modelling choices and the presence of groups. The model produces results in tune with available evidences from the literature, both from the perspective of pedestrian flows and space utilisation, in scenarios not comprising groups; when groups are present, the model is able to preserve their cohesion even in challenging situations (i.e. high density, presence of a counterflow), and it produces interesting results in high density situations that call for further observations and experiments to gather empirical data. The introduced adaptive model for group cohesion is effective in qualitatively reproducing group related phenomena and it stimulates further research efforts aimed at gathering empirical evidences, on one hand, and modelling efforts aimed at reproducing additional related phenomena (e.g. leader-follower movement patterns)

Modeling Environmental Operative Elements in Agent-Based Pedestrian Simulation

Models for pedestrian simulation are employed on a day-to-day basis for supporting the design and planning of the built environment in normal and evacuation situations. One of the aspects that are least investigated in the community, probably because it is considered closer to technology transfer than to research, is the modelling of operational elements of the simulated environment. The present paper briefly describes an agent-based approach to the representation of operative elements of the environment with particular attention to the mechanisms of interaction between these active objects and pedestrians

Do Groups Matter? An Agent-based Modeling Approach to Pedestrian Egress

Festivals in city parks attended by individuals and families are a universal feature of urban life. These venues often have the common attributes of vendors and other obstacles that restrict pedestrian movement through certain areas, as well as fixed number of exits. In this study, the authors build an agent-based model (ABM) that incorporates group cohesion forces into this type of pedestrian egress scenario. The scenario considered was an evacuation of 500 people through a single exit. This allowed an investigation into the use of two different simulated pedestrian\u27s heading updating rules

A Hybridized Approach to Validation: The Role of Sociological Research Methods in Pedestrian Modeling

AbstractPedestrian and crowd-movement models are difficult to validate using traditional empirical methods because of data-related issues such as generalizability, collection ethics, and costs. Commonly used validation methods make strong assumptions about emergence and the importance of crowd structure, leaving a gap in validation literature. The paper reviews the most common methods of validating pedestrian models and proposes a hybridized qualitative approach to validating models that covers more complex group dynamics and possible situations of panic

A Hybridized Approach to Validation: The Role of Sociological Research Methods in Pedestrian Modeling

Pedestrian and crowd-movement models are difficult to validate using traditional empirical methods because of data-related issues such as generalizability, collection ethics, and costs. Commonly used validation methods make strong assumptions about emergence and the importance of crowd structure, leaving a gap in validation literature. The paper reviews the most common methods of validating pedestrian models and proposes a hybridized qualitative approach to validating models that covers more complex group dynamics and possible situations of panic

Social aspects of collision avoidance: A detailed analysis of two-person groups and individual pedestrians

Pedestrian groups are commonly found in crowds but research on their social aspects is comparatively lacking. To fill that void in literature, we study the dynamics of collision avoidance between pedestrian groups (in particular dyads) and individual pedestrians in an ecological environment, focusing in particular on (i) how such avoidance depends on the group's social relation (e.g. colleagues, couples, friends or families) and (ii) its intensity of social interaction (indicated by conversation, gaze exchange, gestures etc). By analyzing relative collision avoidance in the ``center of mass'' frame, we were able to quantify how much groups and individuals avoid each other with respect to the aforementioned properties of the group. A mathematical representation using a potential energy function is proposed to model avoidance and it is shown to provide a fair approximation to the empirical observations. We also studied the probability that the individuals disrupt the group by ``passing through it'' (termed as intrusion). We analyzed the dependence of the parameters of the avoidance model and of the probability of intrusion on groups' social relation and intensity of interaction. We confirmed that the stronger social bonding or interaction intensity is, the more prominent collision avoidance turns out. We also confirmed that the probability of intrusion is a decreasing function of interaction intensity and strength of social bonding. Our results suggest that such variability should be accounted for in models and crowd management in general. Namely, public spaces with strongly bonded groups (e.g. a family-oriented amusement park) may require a different approach compared to public spaces with loosely bonded groups (e.g. a business-oriented trade fair).Comment: 25 pages, 15 figures, 3 table

Pedestrian Evacuation: Vulnerable Group Member Influence on the Group Leaders’ Decision-Making and the Impact on Evacuation Time

As pedestrian evacuations of buildings, outdoor venues, and special events occur, dynamic interactions between pedestrians and vehicles during egress are possible. To model pedestrian and vehicle evacuations, simulation models have evolved to incorporate more realistic crowd characteristics and behaviors to provide improved results. Past studies using modeling and simulation, specifically agent-based modeling, have explored pedestrian behaviors such as decision-making, navigation within a virtual environment, group formations, intra-group interactions, inter-group dynamics, crowd behaviors such as queuing and herding, and pedestrianvehicle interactions. These studies have led to relevant insights helpful to improving the accuracy of evacuation times for normal and emergency egress for preparedness and management purposes. As evacuating crowds are composed of individual pedestrians and social or familial groups, this project contributes to the study of pedestrian evacuation by exploring the incorporation of a subgroup not often considered in this area. Vulnerable individuals, such as the physically disabled, elderly, and children, can change the decision-making dynamic of a group leader while evacuating to safety. Current agent-based simulation models explore the intra- and inter- action and the effects on evacuation times; however, the vulnerable group members\u27 influence is neglected. This project presents enhancements to pedestrian evacuations with vehicle interaction using an agent-based simulation model that includes the presence of vulnerable group members and their impact on decision-making and evacuation times. This project explores how changing behaviors due to the presence of vulnerable group members can collectively cause delays and increase evacuation times. Utilizing verification and validation methods, the credibility and reliability of the simulation model and its results are increased. The results show that the group leaders\u27 decision-making differs when leading a vulnerable group versus a non-vulnerable group. Also, evacuation times increase with increased percentages of vulnerable groups within an evacuating crowd. A simulation tool can be utilized by end-users to explore specific evacuation scenarios in preparation for upcoming events and glean insight into how evacuation times may vary with differing crowd population sizes and compositions. Including vulnerable pedestrians in simulation models for evacuations would improve output accuracy and ultimately improve event training and preparation for future evacuations

How can people’s spatial behaviour be used to dynamically lay out content on multi-user, interactive screens, and how does this dynamic layout affect people’s spatial behaviour?

This thesis aims to explore the influencing factors of layout and presentation changes of large interactive and adaptive displays in multi-user interactions and social organisation. While significant bodies of work have considered the interactivity of digital displays to identify phenomena of use, these have been conducted in localised isolation, and do not address the wider ecological impacts for the influences of emergent organisations of simultaneous use where a system or display may support this. Through considerations of how display presentation and layout can influence the emergence of social organisations, a series of iterative lab-based studies have been carried out to assess and inform a number of interaction modalities. This leads to a series of design recommendations around a system-led approach in presenting a mechanism to support approach behaviours and the maximised utility of a large display, whilst mitigating conflict between social boundaries and impact to user experience. This has identified a range of factors in both the mechanisms of natural social organisation and supporting layout changes and adaptations in maintaining user experience leading towards wider use, scaffolding features of the environment, on-going use, and adaptation within a novel system-led approach. This has presented clear implications to the field, and identified significant areas for further research to refine the subtle factors of interaction which have been identified here

How can people’s spatial behaviour be used to dynamically lay out content on multi-user, interactive screens, and how does this dynamic layout affect people’s spatial behaviour?

This thesis aims to explore the influencing factors of layout and presentation changes of large interactive and adaptive displays in multi-user interactions and social organisation. While significant bodies of work have considered the interactivity of digital displays to identify phenomena of use, these have been conducted in localised isolation, and do not address the wider ecological impacts for the influences of emergent organisations of simultaneous use where a system or display may support this. Through considerations of how display presentation and layout can influence the emergence of social organisations, a series of iterative lab-based studies have been carried out to assess and inform a number of interaction modalities. This leads to a series of design recommendations around a system-led approach in presenting a mechanism to support approach behaviours and the maximised utility of a large display, whilst mitigating conflict between social boundaries and impact to user experience. This has identified a range of factors in both the mechanisms of natural social organisation and supporting layout changes and adaptations in maintaining user experience leading towards wider use, scaffolding features of the environment, on-going use, and adaptation within a novel system-led approach. This has presented clear implications to the field, and identified significant areas for further research to refine the subtle factors of interaction which have been identified here