The introduction of adaptive social decision-making in the mathematical modelling of egress behaviour

This dissertation represents an attempt at increasing the behavioural sophistication of evacuation simulations, through the study of evacuation modelling, the development of new behavioural algorithms, their implementation within an existing evacuation model and the testing of the resulting model. This aim is achieved through a number of steps. Firstly, the range of human behaviour that are exhibited by occupants during the evacuation process is studied. Next, the sophistication of the available evacuation models is investigated and a suitable model is selected and thoroughly assessed (the buildingEXODUS evacuation model). The selected model is then used as a test bed in which to implement the advanced behavioural developments. The detailed behavioural analysis was conducted to provide the necessary framework, around which an eventual model might be formulated and implemented. This involved the examination of the factors that might influence the occupant's behaviour, the occupant's decision-making process and the eventual occupant behaviour. The mechanisms implemented within the evacuation models presently available were then investigated to determine the current effectiveness of evacuation modelling. This investigation generated possible ideas as to how the modelling process may be conducted and the possible limitations that would be inherent in this process. Rather than creating a completely new behavioural shell, during which time a significant amount of resources would have been diverted into software engineering, an existing behavioural shell was sought after. The buildingEXODUS model was selected as a shell within which the proposed behavioural developments could be analysed for both practical and technical reasons. The selected model was then validated against a number of experimental and real-life validation cases. This highlighted a variety of limitations and enabled the detailed workings of the selected model to become familiar. In this process, the sophistication and limitation of this shell (the current buildingEXODUS evacuation model) was established. This was required to properly examine the extent of the proposed behavioural development over the existing model. Once these limitations were established, the proposed developments then had a realistic basis for comparison. The new behavioural features were made in response to sociological, psychological and physical limitations that had been identified in the existing evacuation models. These developments included a more detailed representation of - The occupant's familiarity with the enclosure, - A representation of the occupant's motivation based on the occupant's perception of the surrounding conditions, - Occupant communication, - Collective behaviour - And the ability of the occupant to adapt according to the information available. These proposed behavioural actions and influential factors were then implemented into the buildingEXODUS model. These features were then examined to determine their satisfactory integration into the overall buildingEXODUS model and their impact upon the sensitivity of the model through the use of hypothetical and actual data-sets. Each of the new behavioural features provided new occupant capabilities and affected the outcome of the buildingEXODUS simulations. The differences may have been centred on qualitative and/or quantitative aspects of the evacuation, depending on the proposed behaviour in question. However, all of the behavioural features examined produced notable results that enhanced the performance of the model in some manner. Overall the behavioural developments were seen to increase the flexibility and functionality of the model without compromising the previously established ability of the model to cope with the fundamentals of human behaviour. These improvements were therefore seen to further advance the capability of the model to accurately determine the safety of an enclosure during an evacuation through a better understanding of the occupant response and a better and more thorough representation of human behaviour

Using human and technological resources to manage people movement

The key purpose of any detection system is to detect deteriorating conditions sufficiently early so that an emergency response can commence in a timely manner. In reality, the detection system may be formed from a technological component (e.g., automated systems) and a human component (e.g., staff noting fire cues directly or through monitoring CCTV, etc.). The emergency response can be improved in two ways. Firstly, the available safe egress time can be increased; e.g., through actively addressing the incident with a suppression system, reducing the time of detection, etc. Secondly, the time required to reach safety can be reduced; e.g., through initiating and managing the response of the evacuating population. It is important to note that there are human and technological elements in both approaches. This paper looks at integrating the human and technological solutions available to manage the response of a population and improve the use of the information provided by the detection process. This approach should be especially valuable where the population is transient, where the potential scenarios are numerous, where security is an issue, and where possible false alarms would lead to expensive and disruptive responses

A dynamic state-based model of crowds

We consider the problem of categorizing and describing the dynamic properties and behaviours of crowds over time. Previous work has tended to focus on a relatively static "typology"-based approach, which does not account for the fact that crowds can change, often quite rapidly. Moreover, the labels attached to crowd behaviours are often subjective and/or value-laden. Here, we present an alternative approach, loosely based on the statechart formalism from computer science. This uses relatively "agnostic" labels, which means that we do not prescribe the behaviour of an individual, but provide a context within which an individual might behave. This naturally describes the time-series evolution of a crowd as "threads" of states, and allows for the dynamic handling of an arbitrary number of "sub-crowds".Comment: Presented at the 2023 Pedestrian and Evacuation Dynamics Conference, Eindhoven, The Netherlands, June 28-30 202

Agent-based models of social behaviour and communication in evacuations: A systematic review

Most modern agent-based evacuation models involve interactions between evacuees. However, the assumed reasons for interactions and portrayal of them may be overly simple. Research from social psychology suggests that people interact and communicate with one another when evacuating and evacuee response is impacted by the way information is communicated. Thus, we conducted a systematic review of agent-based evacuation models to identify 1) how social interactions and communication approaches between agents are simulated, and 2) what key variables related to evacuation are addressed in these models. We searched Web of Science and ScienceDirect to identify articles that simulated information exchange between agents during evacuations, and social behaviour during evacuations. From the final 70 included articles, we categorised eight types of social interaction that increased in social complexity from collision avoidance to social influence based on strength of social connections with other agents. In the 17 models which simulated communication, we categorised four ways that agents communicate information: spatially through information trails or radii around agents, via social networks and via external communication. Finally, the variables either manipulated or measured in the models were categorised into the following groups: environmental condition, personal attributes of the agents, procedure, and source of information. We discuss promising directions for agent-based evacuation models to capture the effects of communication and group dynamics on evacuee behaviour. Moreover, we demonstrate how communication and group dynamics may impact the variables commonly used in agent-based evacuation models.Comment: Pre-print submitted to Safety Science special issue following the 2023 Pedestrian and Evacuation Dynamics conferenc

Agent-based models of social behaviour and communication in evacuations:A systematic review

Most modern agent-based evacuation models involve interactions between evacuees. However, the assumed reasons for interactions and portrayal of them may be overly simple. Research from social psychology suggests that people interact and communicate with one another when evacuating and evacuee response is impacted by the way information is communicated. Thus, we conducted a systematic review of agent-based evacuation models to identify 1) how social interactions and communication approaches between agents are simulated, and 2) what key variables related to evacuation are addressed in these models. We searched Web of Science and ScienceDirect to identify articles that simulated information exchange between agents during evacuations, and social behaviour during evacuations. From the final 70 included articles, we categorised eight types of social interaction that increased in social complexity from collision avoidance to social influence based on strength of social connections with other agents. In the 17 models which simulated communication, we categorised four ways that agents communicate information: spatially through information trails or radii around agents, via social networks and via external communication. Finally, the variables either manipulated or measured in the models were categorised into the following groups: environmental condition, personal attributes of the agents, procedure, and source of information. We discuss promising directions for agent-based evacuation models to capture the effects of communication and group dynamics on evacuee behaviour. Moreover, we demonstrate how communication and group dynamics may impact the variables commonly used in agent-based evacuation models