The Cry Wolf Effect in Evacuation: a Game-Theoretic Approach

In today's terrorism-prone and security-focused world, evacuation emergencies, drills, and false alarms are becoming more and more common. Compliance to an evacuation order made by an authority in case of emergency can play a key role in the outcome of an emergency. In case an evacuee experiences repeated emergency scenarios which may be a false alarm (e.g., an evacuation drill, a false bomb threat, etc.) or an actual threat, the Aesop's cry wolf effect (repeated false alarms decrease order compliance) can severely affect his/her likelihood to evacuate. To analyse this key unsolved issue of evacuation research, a game-theoretic approach is proposed. Game theory is used to explore mutual best responses of an evacuee and an authority. In the proposed model the authority obtains a signal of whether there is a threat or not and decides whether to order an evacuation or not. The evacuee, after receiving an evacuation order, subsequently decides whether to stay or leave based on posterior beliefs that have been updated in response to the authority's action. Best-responses are derived and Sequential equilibrium and Perfect Bayesian Equilibrium are used as solution concepts (refining equilibria with the intuitive criterion). Model results highlight the benefits of announced evacuation drills and suggest that improving the accuracy of threat detection can prevent large inefficiencies associated with the cry wolf effect.Comment: To be published in Physica

Evacuation modelling for wildland-urban interface fires in touristic areas

This technical note presents a brief overview of the models available for the simulation of fire evacuation at the wildland-urban interface in touristic areas. Depending on the scale of the scenarios under consideration and the evacuation mode considered, models are split into macroscopic vs microscopic tools and 1) pedestrian models, 2) traffic models, 3) coupled evacuation models, 4) modelling unconventional evacuation modes. The key findings of this review are: 1) When pedestrian movement is the main mode of evacuation transport, the scale of the analysis will have a strong impact on the choice of the most appropriate modelling approach although at building scale and not very large area size, the use of microscopic modelling based on a continuous approach seems to be a suitable method. 2) When multiple modes of transport are considered (e.g., pedestrian and traffic), the modeller should make a call into modelling explicitly or implicitly the pedestrian response and movement layer, 3) most evacuation models are currently not able to model explicitly unconventional means of evacuations such as displacement via sea or air. The scenario complexity and the uncertainty in the available input will affect the choice of modellers to represent evacuation modelling layers (e.g., pedestrian response, pedestrian movement, and traffic movement) and their interaction with the wildfire explicitly or implicitly

Interim Report: Flashing Lights for Road Tunnel Emergency Exit Portals - A Virtual Reality Experiment

A virtual reality (VR) experiment with 96 participants was carried out to provide recommendations on the design of flashing lights on emergency exit portals for road tunnel emergency evacuation. The experiment was carried out in a Cave Automatic Virtual Environment (CAVE) laboratory at Lund University. A set of variables has been investigated, namely 1) Colour of flashing lights, 2) Flashing rate, 3) The type of light source, 4) the number and layout of the lights on the portal (1 light on top of the exit door, 3 lights of which 1 on top and 2 on the sides of the exit door, or 2 bars on the sides of the exit door). An additional portal design variable has also been investigated, i.e. 5) the use of a window vs a painted running man on the exit door. Participants were immersed in a VR road tunnel emergency evacuation scenario and they were then asked to rank different portal designs using a questionnaire based on the Theory of Affordances. Results show that green or white flashing lights perform better than blue lights in the emergency exit portals. Flashing rate of 1 Hz and 4 Hz performed better than flashing rates at 0.5 Hz. A LED light source performed better than single and double strobe lights. Although the three layouts of the lights under consideration performed similarly, the use of a higher number of lights is deemed to be beneficial. If the door is visible (i.e., if no smoke is taken into consideration in the emergency scenario), the scenario with the running man painted on the door provides equal results than a door with a window. Nevertheless, the use of the window is recommended since it allows seeing behind the door (including the possibility to see the traffic), and reduce people’s hesitation

Traffic Information Signs, Colour Scheme of Emergency Exit Portals and Acoustic Systems for Road Tunnel Emergency Evacuations

This work presents a literature review and a questionnaire study with 62 participants aimed at providing recommendations on the design of a set of evacuation systems for road tunnels: 1) Traffic Information Sign (TIS) - message and size of the sign (large or small), colour scheme, and use of pictograms and/or flashing lights, 2) Emergency exit portal layout - colour scheme, 3) Acoustic systems - voice message and/or warning signals. The TIS is recommended to include the use of two panels which present text (in amber) and flashing lights in one panel and the emergency exit pictorial symbol in green in the other panel. An increased size of the panels has a positive effect on capturing participants’ attention. The recommended colour scheme for the emergency exit portal is safety green for the portal and a “green darker than the safety green” for the door. Vocal messages are not recommended since they may be quite difficult to perceive in tunnels. The use of a warning signal (F_SAW signal) based on British Standards is recommended

Revisiting the paper Simulating dynamical features of escape panic: What have we learnt since then?

The paper "Simulating dynamical features of escape panic" by Helbing, Farkas, and Vicsek, published over two decades ago in Nature, has left an indelible mark on the field of crowd dynamics. With nearly 3,000 citations to date, according to the Web of Science records, and significant influence, it has shaped the crowd dynamics field. This analysis investigates the overall influence of this paper through a variety of indicators, mapping its reach across research areas. The intellectual foundation of the paper is traced, examining the references cited. The terminological impact is also explored, showing how the paper made use of terms like "panic" and "herding". Moreover, the alignment of the assumptions of the paper with empirical evidence is discussed, finding discrepancies in key assertions about panic behaviour. The numerical simulations of the paper and observations have significantly influenced the field, such as for the case of the "faster-is-slower" phenomenon. The paper remains a key pillar in crowd dynamics, nevertheless, we advocate for a new course of the field shifting away from the terminology adopted in the paper and focusing more on empirical evidence.Comment: Submission to the Special Issue of the Pedestrian and Evacuation Dynamics conference 202

A risk analysis methodology for the use of crowd models during the Covid-19 pandemic

Pandemics such as Covid-19 have posed a set of questions concerning safe space usage given the risk of virus transmission in confined and open spaces. In this context, this report presents a risk analysis methodology for the use of crowd modelling tools as an aid to assess safety in confined and open spaces. Crowd models can be used to investigate people movement in the built environment, thus they have a great potential for the performance of proximity analysis. The report presented here addresses first the psychological and physical aspects linked to physical distancing (also called social distancing). Given the limited current knowledge on human behaviour and space usage during pandemics, the changes needed in crowd modelling tools to appropriately represent people movement are listed. This includes issues associated with modifications of the fundamental relationships between the key people movement variables (speed/flow vs density), and issues linked with interactions between pedestrians (e.g. collision avoidance, queuing mechanisms, route choice). Suggestions for new crowd modelling outputs are provided in order to enhance their use during pandemics. In addition, practical solutions concerning space usage are presented in light of the assessment of human safety through a risk evaluation based on proximity analysis and/or exposure assessment. This is deemed to help identifying design and management solutions to decrease the risk of virus transmission

guidance on design and construction of the built environment against wildland urban interface fire hazard a review

Abstract Wildland-Urban Interface (WUI) fires, a worldwide problem, are gaining more importance over time due to climate change and increased urbanization in WUI areas. Some jurisdictions have provided standards, codes and guidelines, which may greatly help planning, prevention and protection against wildfires. This work presents a wide systematic review of standards, codes and guidelines for the design and construction of the built environment against WUI fire hazard from North American, European, Oceanic countries, alongside with trans-national codes. The main information reviewed includes: the definition of WUI hazards, risk areas and related severity classes, the influence of land and environmental factors, the requirements for building materials, constructions, utilities, fire protection measures and road access. Some common threads among the documents reviewed have been highlighted. They include similar attempts at: (a) defining WUI risk areas and severity classes, (b) considering land factors including the defensible space (also known as ignition zones), (c) prescribing requirements for buildings and access. The main gaps highlighted in the existing standards/guidelines include lacks of detailed and widespread requirements for resources, fire protection measures, and lacks of taking into account environmental factors in detail. The main design and construction principles contained in the reviewed documents are largely based on previous research and/or good practices. Hence, the main contributions of this paper consist in: (a) systematically disseminate these guidance concepts, (b) setting a potential basis for the development of standards/guidelines in other jurisdictions lacking dedicated WUI fire design guidance, (c) highlighting gaps in existing standards/guidelines to be addressed by current and future research

The use of multi-zone modelling for tunnel fire risk analysis

Tunnel fire risk analysis are a useful tool to ensure adequate safety levels in tunnels. This report presents the work conducted to integrate a multi-zone modelling approach into a fire risk assessment tool, called ARTU. This work was performed to improve its fire modelling predictive capabilities compared to the currently adopted 1D fire modelling representation. This is deemed to allow for the use of multi-scale modelling, i.e., to select among different modelling approaches in relation to the scenarios under consideration. The multi-zone model integrated within ARTU is based on an existing tool, i.e., the MZ Fire model developed for large spaces which has been updated and adapted for tunnel environments. The integration of MZ Fire model into ARTU involved a set of developments needed specifically for tunnel fire scenarios (e.g. considering tunnel gradient, tunnel section representations, customization of outputs for use in a tunnel fire risk assessment tool, etc.). Those new features are here presented along with a sensitivity analysis looking at zone size. Benchmarking of the results produced is performed through comparison with data from the 2006 BeNeLux tunnel experiments and the 2015 Runehamar experiments. The multi-zone model results were also compared against results from the Fire Dynamics Simulator (FDS) for a set of tunnel configurations

Statistical model fitting and model selection in pedestrian dynamics research

Pedestrian dynamics is concerned with understanding the movement patterns that arise in places where more than one person walks. Relating theoretical models to data is a crucial goal of research in this field. Statistical model fitting and model selection are a suitable approach to this problem and here we review the concepts and literature related to this methodology in the context of pedestrian dynamics. The central tenet of statistical modelling is to describe the relationship between different variables by using probability distributions. Rather than providing a critique of existing methodology or a "how to" guide for such an established research technique, our review aims to highlight broad concepts, different uses, best practices, challenges and opportunities with a focussed view on theoretical models for pedestrian behaviour. This contribution is aimed at researchers in pedestrian dynamics who want to carefully analyse data, relate a theoretical model to data, or compare the relative quality of several theoretical models. The survey of the literature we present provides many methodological starting points and we suggest that the particular challenges to statistical modelling in pedestrian dynamics make this an inherently interesting field of research

Progress Report 1: Resilience and Adaptation to Climatic Extreme Wildfires (RACE Wildfires)

This is the first progress report of the international project funded by the National Research Council of Canada called Resilience and Adaptation to Climatic Extreme Wildfires (RACE Wildfires). In this first phase, the research performed included two main tasks: 1) the development of a sub-model for the representation of the impact of reduced visibility conditions on driving speed and 2) the development of a conceptual model for the study of the impact of the pandemic on shelter availability and destination choice. An experimental dataset collected in a virtual reality environment has been used to develop a sub-model for macroscopic traffic models considering the impact of reduced visibility conditions on driving speed. An application of a calibrated traffic model considering the impact of smoke has been performed using the WUI-NITY platform, an open multi-physics platform which includes wildfire spread, pedestrian response and traffic modelling. Verification testing has been performed as well. A conceptual framework for the development of a destination choice model to be applied in wildfire scenarios has also been developed