14 research outputs found
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Trapped on the seashore, seaborne evacuation, impact of exposure to PM2.5: demonstration of the urbanEXODUS evacuation model
The 2021 wildfire season affected large communities in over ten countries around the Mediterranean basin consuming an area almost double the area burnt by wildfires over the past twelve years. In many cases, people were exposed to hazardous combustion products that caused mass multimodal evacuations, including pedestrian, vehicle, and seaborne evacuations as well as a large number of fatalities. Evacuation modelling can be used to better understand the processes involved, including the interactions between those processes. Such a model is urbanEXODUS, utilised during the final exercise (FSX3) for the European Commission’s Horizon 2020 project IN-PREP. The tool was used as part of a training platform for incident managers in collaborative response to large scale disasters. The scenario deployed during the FSX3, and presented in this work, involved a traffic accident and cascading effects that start a wildfire at a forested area, initiating a multi-modal evacuation of the local community. The model, able to simulate multi-modal evacuations, includes pedestrian and vehicle evacuation, and through the development of a flow model, a simplistic representation of boat evacuation. The model is also able to determine the effect of wildfire products using two different datasets that include (a) wildfire perimeter data and (b) smoke plume data that include PM2.5 concentration levels. The former limits the escape routes, causing engulfment and fatalities. The latter, through the development of a novel fractional dose model, determines the acute exposure of agents to PM2.5 in relation to the World Health Organisation (WHO) daily mean Air Quality Guidelines (AQG). The model demonstrates key evacuation performance results, including evacuation times, escape route usage and number and locations of fatalities. The results indicate that 6% of the entire population were unable to leave the area and are considered as fatalities. With regard to the evacuees, 69% utilised the road network to leave the area, while 31% utilised the seaborne evacuation. Exposure to PM2.5 was zero for 84% of the evacuees, while for 1% it was less than the AQG. However, 15% of the agents received a dosage of PM2.5 on average of 7.6 times the AQG (range 1.0 – 28.3, SD = 5.8). This level of exposure is expected to cause health problems including respiratory, cardiovascular and cerebrovascular disorders. The model offers detailed evacuation information that is practically impossible to obtain otherwise, allowing crisis managers to make risk-informed decisions when planning for a crisis
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Trapped on the seashore, seaborne evacuation, and impact of exposure to PM2.5: Live demonstration of the urbanEXODUS large-scale evacuation model
Wildfires can trigger large-scale pedestrian, vehicle and seaborne evacuations, and cause injuries and fatalities. Evacuation models are employed to better understand the involved processes and their interactions. During the final exercise of the European Commission’s H2020 IN-PREP project, urbanEXODUS was used within a training platform, by incident managers, to aid their response to a simulated disaster. The scenario involved a traffic accident escalating to a wildfire, causing the local community to evacuate. The model combined pedestrian and vehicle evacuation, and through a flow model, a simplistic representation of boat evacuation. The effects of wildfire on escape routes and possible fatalities were evaluated using fire perimeter data. The development of a novel fractional dose model allowed the software to determine agents’ acute exposure to PM2.5, in relation to the WHO daily mean Air Quality Guidelines (AQG).
The simulation results comprise key evacuation performance parameters including evacuation times, fatalities, and escape route usage. Results indicate that 6% of the population was unable to leave the area and are treated as fatalities. The road network and boats were used by 69% and 31% of the evacuees respectively. PM2.5 exposure was zero for 84% of the evacuees, and below the AQG, for 1%, while 15% received, on average, a dosage of 7.6 times the AQG (range 1.0 – 28.3, SD = 5.8), which may cause respiratory and cardiovascular disorders.
The model offers detailed evacuation information that is practically impossible to obtain otherwise, allowing crisis managers to take risk-informed decisions when planning for a crisis
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The development of pedestrian gap acceptance and midblock pedestrian road crossing behavior utilizing SUMO
While there are several published studies for modelling pedestrian behavior at signalized crossings in SUMO, the behavior of pedestrians crossing a road at a location other than a designated crossing, has not been considered to date. This work looks at how to represent pedestrian agents selecting to cross a road at arbitrary locations along the length of the road. The pedestrian agents utilize a gap acceptance model that represents how a pedestrian decides when to cross a road, based on the frequency and speed of approaching vehicles, while considering the spacing between them. Furthermore, the gap acceptance model allows the pedestrians to choose to cross all lanes in one go, when safe to do so, known as Double Gap or one stage crossing. Alternatively, if an agent is identified as a risk-taker, they may choose to cross lane by lane, sometimes waiting in the middle of the road, known as Rolling Gap or risk-taker crossing behavior. The inclusion of these two crossing behaviors allows for situations where urgency plays an important role in behavioral decision making, such as in emergencies, rush hour or in crowd management events. The outlined pedestrian crossing model is attained by integrating the pedestrian model EXODUS with SUMO, via the TraCI API
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Evacuation modelling for rapid multi-hazard tabletop exercise deployment
To prepare for large-scale emergencies and crisis affecting communities, authorities, and emergency commanders use several types of training methods ranging from seminars to full-scale exercises. Within this continuum of exercise types, tabletop exercises (TTXs) are habitually used to familiarise participants with mitigation strategies, population management and evacuation procedures conducted as a response to natural or technological hazards. Commonly, TTXs are paper-based, and if computerised, use basic electronic maps, tend to be scripted and have a linear nature. Information flow is unidirectional as the script dictates how the exercise unfolds. These exercises have little capacity for producing qualitative or quantitative feedback related to the impact that the received scenario injects (i.e., incoming messages including scripted events and hazard locations), the authorities’ decisions, and the impact of hazards have on the wellbeing of the community and the evacuation process. While informative during training, this type of feedback may prove vital in assessing the likely impact of real incident. In this work an evacuation simulation model is proposed to augment the TTX experience in real time, offering feedback and insights on the impact that such injects, decisions and hazards have on the simulated community.
The proposed methodology is utilised in an actual TTX co-organised and executed by the Municipality of Rhodes, Greece, where the evacuation model is used to (a) develop the standard, non-incident specific evacuation procedures for the Medieval City of Rhodes (MCR), (b) to adapt these procedures based on the injects (generated on-site or telecommunicated, emulating receipt from the field), producing the TTX scenario and (c) to provide information on the impact that the TTX hazards have on the evacuation process. The integration of evacuation modelling into the TTX process demonstrated that it is possible to gain a deeper understanding of the complexities related to route choices in response to path closures, the assembly and evacuation performance, as well as the management of the simulated incident by analysing qualitative and quantitative simulation results
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Simulating the interaction of occupants with signage systems
This paper describes the introduction of chained signage systems into evacuation simulation models. Signage systems are widely used in buildings to provide information for wayfinding, thereby providing exiting information during emergencies and assisting in navigation during normal circulation of pedestrians.
Recently a system was developed to introduce simple signs into egress models. The system, known as Visibility Catchment Area or VCA, allowed similated agents to interact with signs which point directly to an exit and signs which are located directly above the exit. However, this approach was not able to represent the more general situation of a sign netwokr within an arbitrarily complex building. In this paper we extend the method to include chained signage systems which provides simulated agents that are unfamiliar with the structure a means by which to navigate to an emergency exit.
The model includes the associated navigation behaviours exhibited by occupants that rely on a signage system for navigation including: Searching behaviours, Backtracking behaviours, Lost behaviours and Communication behaviours. The new features are demonstrated through a series of demonstration cases and are shown to produce plausible results
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Experimental study of the effectiveness of emergency signage
Signage systems play an important role in aiding occupants during both circulation and evacuation. Despite the fact that signage systems are an important component in building wayfinding systems, there is a lack of relevant data regarding how occupants detect, interpret and use the information conveyed by emergency signage. The effectiveness of signage systems is therefore difficult to assess.
In this paper we address this issue through experimentation. The experiment involved measuring the impact of a signage system on a population of 68 test subjects who were instructed to individually vacate a building as quickly as possible via any means they thought appropriate. The evacuation path involved a number of decision points at which emergency signage was available to identify the appropriate path. Through analysis of video footage and data derived from questionnaires, the number of people who saw and utilised the signage information to assist their egress is determined.
The results are then incorporated within the buildingEXODUS software and used in a demonstration of agent interaction with signage systems in a hypothetical evacuation scenario
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Predicting the performance of passenger ships using computer simulation
When designing a new passenger ship or naval vessel or modifying an existing design, how do we ensure that the proposed design is safe from an evacuation point of view? In the wake of major maritime disasters such as the Herald of Free Enterprise and the Estonia and in light of the growth in the numbers of high density, high-speed ferries and large capacity cruise ships, issues concerned with the evacuation of passengers and crew at sea are receiving renewed interest. In the maritime industry, ship evacuation models are now recognised by IMO through the publication of the Interim Guidelines for Evacuation Analysis of New and Existing Passenger Ships including Ro-Ro. This approach offers the promise to quickly and efficiently bring evacuation considerations into the design phase, while the ship is "on the drawing board" as well as reviewing and optimising the evacuation provision of the existing fleet. Other applications of this technology include the optimisation of operating procedures for civil and naval vessels such as determining the optimal location of a feature such as a casino, organising major passenger movement events such as boarding/disembarkation or restaurant/theatre changes, determining lean manning requirements, location and number of damage control parties, etc. This paper describes the development of the maritimeEXODUS evacuation model which is fully compliant with IMO requirements and briefly presents an example application to a large passenger ferry
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Large-scale evacuations: they worked last time. Will they work again?
The 2021 wildfire season affected many countries around the Mediterranean basin. In most incidents, large-scale multi-modal evacuations were conducted to transfer the population at risk to safe locations. Overall, tens of thousands of people were evacuated with modes of transportation including pedestrian, private or public transport, and sea vessels. In Greece, full evacuations were conducted in almost all incidents. However, despite the maximum protection offered to life, questions arose regarding the universality of this measure. Evacuation modelling can be used to better plan evacuations, providing insights on safety margins and, through educational programs, strengthening community resilience
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The development and validation of a rail car evacuation
In this paper we present a specialist rail car evacuation model railEXODUS, and some validation of the software capabilities using experimental data. As part of this development, an extensive review of past train accidents and rail car evacuation experimentation was undertaken. Analysis of 70 rail accidents from 1999 to 2007 involving passenger rail cars suggests that there are a number of common themes that emerge in emergency situations which will influence the way in which persons will behave and the resulting human dynamics which must be represented within the model. While accident data is useful in identifying aspects of human behaviour that must be included in evacution models, they do not provide an opportunity to quantify human performance in emeregency situations. To achieve this, evacuation experiments are essential. As part of this project, data from a series of rail car egress trials undertaken in the U.S. using U.S. rolling stock was analysed and used as part of model calibration and validation. The resulting model has the capability to simulate sgress from multi-level rail cars to high and low platforms, the Right-Of-Way and inter-car egress. The model can also take into consideration the impact of fire hazards and adverse vehicle orientation on passenger behaviour and performance during emergency egress