D.C. Duives
Please Note
26 records found
1
Using Crowd Simulation to Support Experience-Driven Police Decision-Making during Large-Scale Events
Designing and evaluating a decision framework in the Rotterdam Police context
The main challenge is therefore not the absence of simulation models, but the absence of a method that translates simulation outputs into usable decision-support information. This paper presents the Crowd Simulation Decision Framework, developed using Design Science Research at the Rotterdam Police. The framework is a method-type artefact that structures when and how crowd simulation can be used in the risk analysis and advisory phase. It links police risks, simulation questions, scenarios, outputs, interpretation, and possible measures to decision points in the event process.
The framework was demonstrated in the Meent case during a large-scale running event in Rotterdam and evaluated with police professionals. The evaluation focused on interpretability, usefulness, and usability. The findings suggest that the framework can support risk analysis by making assumptions explicit, comparing scenarios, and helping to substantiate police advice. At the same time, simulation outputs require clear explanation, transparent assumptions, a model check with practitioners, feedback loops, and a simulation expert who can translate between police practice and technical modelling. Without these conditions, outputs may be misinterpreted or may suggest more certainty than the model can provide.
The paper contributes design knowledge on how existing crowd simulation outputs can be integrated into experience-driven police decision-making. Simulation-based decision support should start with the decision-making problem, not with the model. The framework should therefore be seen as structured support for professional judgement, not as proof that simulation automatically improves decision-making. ...
The main challenge is therefore not the absence of simulation models, but the absence of a method that translates simulation outputs into usable decision-support information. This paper presents the Crowd Simulation Decision Framework, developed using Design Science Research at the Rotterdam Police. The framework is a method-type artefact that structures when and how crowd simulation can be used in the risk analysis and advisory phase. It links police risks, simulation questions, scenarios, outputs, interpretation, and possible measures to decision points in the event process.
The framework was demonstrated in the Meent case during a large-scale running event in Rotterdam and evaluated with police professionals. The evaluation focused on interpretability, usefulness, and usability. The findings suggest that the framework can support risk analysis by making assumptions explicit, comparing scenarios, and helping to substantiate police advice. At the same time, simulation outputs require clear explanation, transparent assumptions, a model check with practitioners, feedback loops, and a simulation expert who can translate between police practice and technical modelling. Without these conditions, outputs may be misinterpreted or may suggest more certainty than the model can provide.
The paper contributes design knowledge on how existing crowd simulation outputs can be integrated into experience-driven police decision-making. Simulation-based decision support should start with the decision-making problem, not with the model. The framework should therefore be seen as structured support for professional judgement, not as proof that simulation automatically improves decision-making.
Beyond the Average Pedestrian
A Qualitative Analysis of Route Choice in the Netherlands
A qualitative research approach was adopted, consisting of sixteen go-along walking interviews conducted in Amsterdam, Delft, and Rotterdam, complemented by a night-time scenario and a map-pointing task. The interviews were analysed using thematic coding based on the Four Pillars of Pedestrian Route Choice, a framework developed for this study that synthesises international and Dutch literature into four dimensions: social safety, traffic safety, aesthetic experience, and efficiency. Fourteen of the fifteen indicators identified in the literature emerged in participants’ accounts. Only physical exertion was absent, consistent with the flat and well-maintained Dutch environment. Two additional themes, visual variety and cognitive ease, emerged inductively, while familiarity influenced the interpretation of multiple other factors.
The central finding is that gender influences route choice not through differences in which environmental cues are noticed, but through differences in how those cues are interpreted and whether they lead to behavioural change. Male and female participants generally recognised the same environmental characteristics but differed in the meaning they assigned to them and in the decisions that followed. All female participants reported changing their routes in response to social-safety cues, whereas none of the male participants did, although two indicated they might do so hypothetically. While based on a small exploratory sample, this pattern was consistent across participants. Female participants interpreted cues from all four pillars through the lens of personal safety and evaluated them differently during the day and at night. Male participants considered the four dimensions more independently and rarely regarded social-safety cues as sufficient reason to deviate from the shortest route. Participants also described route choice as an overall interpretation of the streetscape rather than the result of weighing isolated factors, and most were unable to identify the precise point at which they decided to alter their route.
These findings suggest that the apparent gender neutrality reported in Dutch aggregate travel statistics may result from analysing behaviour at the mode-choice level rather than the route-choice level. Differences in route choice can therefore remain hidden despite similar overall walking rates. Spatially, these differences manifested themselves in recurring avoidance of parks, alleys, and poorly lit streets after dark by female participants, reducing their effective accessibility to urban space. Because route choice depends on how pedestrians interpret environmental cues rather than simply on the presence of those cues, the study also indicates that quantitative walkability indices may overlook important aspects of pedestrian decision-making.
This research contributes empirical evidence of gendered pedestrian behaviour at the route-choice level in the Netherlands, a country widely regarded as a benchmark for pedestrian-friendly infrastructure. The findings suggest that even high-quality infrastructure alone is insufficient to ensure an equitable walking experience for women and men. ...
A qualitative research approach was adopted, consisting of sixteen go-along walking interviews conducted in Amsterdam, Delft, and Rotterdam, complemented by a night-time scenario and a map-pointing task. The interviews were analysed using thematic coding based on the Four Pillars of Pedestrian Route Choice, a framework developed for this study that synthesises international and Dutch literature into four dimensions: social safety, traffic safety, aesthetic experience, and efficiency. Fourteen of the fifteen indicators identified in the literature emerged in participants’ accounts. Only physical exertion was absent, consistent with the flat and well-maintained Dutch environment. Two additional themes, visual variety and cognitive ease, emerged inductively, while familiarity influenced the interpretation of multiple other factors.
The central finding is that gender influences route choice not through differences in which environmental cues are noticed, but through differences in how those cues are interpreted and whether they lead to behavioural change. Male and female participants generally recognised the same environmental characteristics but differed in the meaning they assigned to them and in the decisions that followed. All female participants reported changing their routes in response to social-safety cues, whereas none of the male participants did, although two indicated they might do so hypothetically. While based on a small exploratory sample, this pattern was consistent across participants. Female participants interpreted cues from all four pillars through the lens of personal safety and evaluated them differently during the day and at night. Male participants considered the four dimensions more independently and rarely regarded social-safety cues as sufficient reason to deviate from the shortest route. Participants also described route choice as an overall interpretation of the streetscape rather than the result of weighing isolated factors, and most were unable to identify the precise point at which they decided to alter their route.
These findings suggest that the apparent gender neutrality reported in Dutch aggregate travel statistics may result from analysing behaviour at the mode-choice level rather than the route-choice level. Differences in route choice can therefore remain hidden despite similar overall walking rates. Spatially, these differences manifested themselves in recurring avoidance of parks, alleys, and poorly lit streets after dark by female participants, reducing their effective accessibility to urban space. Because route choice depends on how pedestrians interpret environmental cues rather than simply on the presence of those cues, the study also indicates that quantitative walkability indices may overlook important aspects of pedestrian decision-making.
This research contributes empirical evidence of gendered pedestrian behaviour at the route-choice level in the Netherlands, a country widely regarded as a benchmark for pedestrian-friendly infrastructure. The findings suggest that even high-quality infrastructure alone is insufficient to ensure an equitable walking experience for women and men.
Right to The City
Drawing on Urban Experiences in The Pursuit of Gender Inclusivity in Amsterdam’s Built Environment
The thesis first develops a conceptual framework that links built-environment elements to experience through affordances, temporal context, and positionality. Based on this framework, selected survey findings were translated into a demonstration model for Amsterdam through a limited set of measurable spatial indicators and scenario-specific weights. The resulting UEI was then applied to selected routes and places and validated against lived experience.
The findings show that translating urban experience into a spatial index is possible, but only in a selective and transparent way. The clearest patterns concern the safety side of experience. Discomfort increases sharply after dark, especially where poor lighting, weak visibility, low social presence, and desolate atmospheres coincide. Route-level outcomes are more sensitive to scenario changes than place-level outcomes, and the strongest shifts appear between day and night rather than between women and men within the same light condition. Women responded more negatively than men to dark and empty conditions, and in the model results, men scored higher than women on every selected route in the night scenario and on all selected places in both day and night scenarios.
The validation interviews broadly support the direction of the model, while also showing that the UEI captures some dimensions of experience better than others. It identifies patterned conditions of discomfort well, but cannot fully represent the social meaning of presence, behaviour, belonging, or anticipation. The thesis concludes that the UEI is most useful as a screening and conversation tool rather than as a definitive measure of inclusivity. Its main value lies in making uneven urban conditions more visible and in helping planners identify where gender-sensitive and time-sensitive interventions are most needed. ...
The thesis first develops a conceptual framework that links built-environment elements to experience through affordances, temporal context, and positionality. Based on this framework, selected survey findings were translated into a demonstration model for Amsterdam through a limited set of measurable spatial indicators and scenario-specific weights. The resulting UEI was then applied to selected routes and places and validated against lived experience.
The findings show that translating urban experience into a spatial index is possible, but only in a selective and transparent way. The clearest patterns concern the safety side of experience. Discomfort increases sharply after dark, especially where poor lighting, weak visibility, low social presence, and desolate atmospheres coincide. Route-level outcomes are more sensitive to scenario changes than place-level outcomes, and the strongest shifts appear between day and night rather than between women and men within the same light condition. Women responded more negatively than men to dark and empty conditions, and in the model results, men scored higher than women on every selected route in the night scenario and on all selected places in both day and night scenarios.
The validation interviews broadly support the direction of the model, while also showing that the UEI captures some dimensions of experience better than others. It identifies patterned conditions of discomfort well, but cannot fully represent the social meaning of presence, behaviour, belonging, or anticipation. The thesis concludes that the UEI is most useful as a screening and conversation tool rather than as a definitive measure of inclusivity. Its main value lies in making uneven urban conditions more visible and in helping planners identify where gender-sensitive and time-sensitive interventions are most needed.
Building-level pedestrian trip generation
For Dutch urban areas using open data
To address this gap, this study develops a building-level pedestrian trip-generation model with fine spatial and temporal resolution, tailored to Dutch conditions and relying exclusively on widely available open data. The central research question is: To what extent can an existing pedestrian trip-generation model be adapted to reflect pedestrian trip-generation dynamics in the Dutch urban context?
The study adapts Sevtsuk’s Urban Network Analysis (UNA) framework into a Dutch-specific, building-level model referred to as BPT-Gen (Building-level Pedestrian Trip Generation). The UNA framework was selected because it offers a practical balance between spatial detail and data requirements while remaining transparent and reproducible. Several key adaptations are introduced to ensure applicability to Dutch cities.
First, buildings are identified and classified using the Dutch BAG dataset, supplemented with OpenStreetMap (OSM) data to capture land use, amenities, and public transport facilities. This enables a detailed and consistent representation of pedestrian trip origins and destinations at the building level.
Second, the derivation of building activity weights is modified. These weights represent the estimated number of unique daily users per building. Where detailed local data are available, weights are calculated directly; otherwise, Dutch building and occupancy standards or carefully selected proxy indicators are applied. This approach allows the model to remain operational across data-limited contexts while explicitly acknowledging uncertainty.
Building on the UNA framework, the model incorporates accessibility-adjusted activity weights. Each building is connected to the pedestrian network, and destination-specific Reach indices are calculated using a walking radius relevant to Dutch conditions. These indices adjust baseline activity weights to account for behavioural tendencies and destination attractiveness. Sensitivity analyses examine how assumptions regarding walking radius and normalisation methods influence model outcomes.
A major extension beyond the original UNA framework is the integration of temporal dynamics through hourly walking trip rates. Trip purposes derived from the Dutch ODiN travel survey are mapped to building types, and corresponding hourly origin–destination trip rates are applied. Combining these rates with accessibility-adjusted weights yields hourly, building-level pedestrian trip-generation estimates for the study area.
Model performance is assessed through face validation using observed pedestrian counts. Results show that the adapted model reproduces realistic spatial and temporal patterns for building types supported by reliable activity data, particularly housing and major train stations. Underprediction is observed for offices and leisure facilities, where activity weights rely on proxy indicators and where walking trips are likely underreported in ODiN. Sensitivity analyses confirm that trip-generation outcomes depend strongly on proxy selection and accessibility assumptions, revealing structural uncertainties.
Despite these limitations, the BPT-Gen model provides clear practical value. It identifies key generators of walking trips, peak periods, and accessibility-driven hotspots using only open data. By linking trip purposes to building types at hourly resolution, the framework fills an important gap in Dutch pedestrian modelling and offers a transparent foundation for future extensions. The findings demonstrate that open-data pedestrian models can provide meaningful planning insights while highlighting the need for improved activity indicators and further validation using street-level pedestrian flow data.
...
To address this gap, this study develops a building-level pedestrian trip-generation model with fine spatial and temporal resolution, tailored to Dutch conditions and relying exclusively on widely available open data. The central research question is: To what extent can an existing pedestrian trip-generation model be adapted to reflect pedestrian trip-generation dynamics in the Dutch urban context?
The study adapts Sevtsuk’s Urban Network Analysis (UNA) framework into a Dutch-specific, building-level model referred to as BPT-Gen (Building-level Pedestrian Trip Generation). The UNA framework was selected because it offers a practical balance between spatial detail and data requirements while remaining transparent and reproducible. Several key adaptations are introduced to ensure applicability to Dutch cities.
First, buildings are identified and classified using the Dutch BAG dataset, supplemented with OpenStreetMap (OSM) data to capture land use, amenities, and public transport facilities. This enables a detailed and consistent representation of pedestrian trip origins and destinations at the building level.
Second, the derivation of building activity weights is modified. These weights represent the estimated number of unique daily users per building. Where detailed local data are available, weights are calculated directly; otherwise, Dutch building and occupancy standards or carefully selected proxy indicators are applied. This approach allows the model to remain operational across data-limited contexts while explicitly acknowledging uncertainty.
Building on the UNA framework, the model incorporates accessibility-adjusted activity weights. Each building is connected to the pedestrian network, and destination-specific Reach indices are calculated using a walking radius relevant to Dutch conditions. These indices adjust baseline activity weights to account for behavioural tendencies and destination attractiveness. Sensitivity analyses examine how assumptions regarding walking radius and normalisation methods influence model outcomes.
A major extension beyond the original UNA framework is the integration of temporal dynamics through hourly walking trip rates. Trip purposes derived from the Dutch ODiN travel survey are mapped to building types, and corresponding hourly origin–destination trip rates are applied. Combining these rates with accessibility-adjusted weights yields hourly, building-level pedestrian trip-generation estimates for the study area.
Model performance is assessed through face validation using observed pedestrian counts. Results show that the adapted model reproduces realistic spatial and temporal patterns for building types supported by reliable activity data, particularly housing and major train stations. Underprediction is observed for offices and leisure facilities, where activity weights rely on proxy indicators and where walking trips are likely underreported in ODiN. Sensitivity analyses confirm that trip-generation outcomes depend strongly on proxy selection and accessibility assumptions, revealing structural uncertainties.
Despite these limitations, the BPT-Gen model provides clear practical value. It identifies key generators of walking trips, peak periods, and accessibility-driven hotspots using only open data. By linking trip purposes to building types at hourly resolution, the framework fills an important gap in Dutch pedestrian modelling and offers a transparent foundation for future extensions. The findings demonstrate that open-data pedestrian models can provide meaningful planning insights while highlighting the need for improved activity indicators and further validation using street-level pedestrian flow data.
...
Safer Together
How do Parents Assess Street Safety when Biking with their Children?
Examining the Societal Costs and Benefits of Integrating Bike Sharing Systems and Public Transport
A Case Study of the OV-fiets in the Netherlands
Several modelling frameworks for the measuring, monitoring and forecasting of motorized, and in some instances bicycle, traffic are already in existence and are broadly used in the practical field. The direct application of these frameworks to pedestrian traffic is, however, not possible due to the absence of the required input data at the proper (spatial) resolution or on pedestrians at all. Nevertheless, for several elements of these frameworks, the application to pedestrian traffic is possible given the data available and so a new framework could be developed that takes inspiration from the existing transport modelling frameworks.
The core of the developed modelling framework consists of an optimisation model in which local pedestrian counts are related to potential route flows over the network, or in other words, that derives the global route flows from observed segment flows for a subset of network segments. The creation of the potential routes is done beforehand in two distinct modelling steps: the OD-pair selection and the route set generation. In the first model step, a subset of the network graph nodes is selected to represent the origin and destination locations of walking trips. Next, for each combination of OD-pairs, several potential walking routes are generated. Here, the k-least-cost paths are computed with a weighted sum of several route and environmental attributes as the cost. Moreover, the optimisation model is extended by incorporating information on real pedestrian behaviour in Dutch urban contexts. Hereby, the model's optimal solution is ensured to represent these mobility patterns and hence improve the result’s validity by combining various data sources on pedestrian behaviour.
The modelling framework's performance was tested by applying a case study on the city centre district of The Hague, The Netherlands for the year 2019. The model returns a modest set of route flows, providing a flow over 22.06% of the network segments. In reality, however, more network segments have pedestrians traversing and the performance of a cross-validation experiment on the observed segment flow vector was poor. This indicates that the developed modelling framework does not model pedestrian flow accurately and improvements to the framework and input data are necessary.
Although the developed framework showed not to be ready for practical applications, this study did provide a good starting point for the development of a practical tool for modelling pedestrian flows and steps for further improvement of the model could be derived. For instance, the model can advance from introducing the logit formula for the distribution of OD-flows over routes, improving the route set, and incorporating pedestrian link counts as sequential data sets. Additionally, the pedestrian count data can improve in quality through a better network coverage of the observation locations, or by measuring the directionality of the passers-by and on a higher temporal resolution. ...
Several modelling frameworks for the measuring, monitoring and forecasting of motorized, and in some instances bicycle, traffic are already in existence and are broadly used in the practical field. The direct application of these frameworks to pedestrian traffic is, however, not possible due to the absence of the required input data at the proper (spatial) resolution or on pedestrians at all. Nevertheless, for several elements of these frameworks, the application to pedestrian traffic is possible given the data available and so a new framework could be developed that takes inspiration from the existing transport modelling frameworks.
The core of the developed modelling framework consists of an optimisation model in which local pedestrian counts are related to potential route flows over the network, or in other words, that derives the global route flows from observed segment flows for a subset of network segments. The creation of the potential routes is done beforehand in two distinct modelling steps: the OD-pair selection and the route set generation. In the first model step, a subset of the network graph nodes is selected to represent the origin and destination locations of walking trips. Next, for each combination of OD-pairs, several potential walking routes are generated. Here, the k-least-cost paths are computed with a weighted sum of several route and environmental attributes as the cost. Moreover, the optimisation model is extended by incorporating information on real pedestrian behaviour in Dutch urban contexts. Hereby, the model's optimal solution is ensured to represent these mobility patterns and hence improve the result’s validity by combining various data sources on pedestrian behaviour.
The modelling framework's performance was tested by applying a case study on the city centre district of The Hague, The Netherlands for the year 2019. The model returns a modest set of route flows, providing a flow over 22.06% of the network segments. In reality, however, more network segments have pedestrians traversing and the performance of a cross-validation experiment on the observed segment flow vector was poor. This indicates that the developed modelling framework does not model pedestrian flow accurately and improvements to the framework and input data are necessary.
Although the developed framework showed not to be ready for practical applications, this study did provide a good starting point for the development of a practical tool for modelling pedestrian flows and steps for further improvement of the model could be derived. For instance, the model can advance from introducing the logit formula for the distribution of OD-flows over routes, improving the route set, and incorporating pedestrian link counts as sequential data sets. Additionally, the pedestrian count data can improve in quality through a better network coverage of the observation locations, or by measuring the directionality of the passers-by and on a higher temporal resolution.
Exploring bicycle parking potential near public transport stops
A case study in The Hague
The qualitative part of the research involved structured interviews with residents of The Hague. The results showed that people are open to considering the bicycle-PT combination but have not yet adopted it. The main barriers are the lack of safe, accessible, and well-maintained bicycle parking at public transport stops. Respondents emphasized the need for more bike parking and cited bad weather and convenience as common reasons for choosing the car.
The quantitative analysis, based on a stated preference survey and a multinomial logit model, confirmed the interview findings. Residents are more likely to opt for the bicycle-PT combination if certain bicycle parking facilities, such as bike racks or lockers, are available. These specific facilities could shift up to 2 percentage points of trips toward the bicycle-PT combination and reduce short car trips by up to 3 percentage points.
Additionally, the results indicate that cost and travel time are important factors in transport choice. Increasing car-related costs and reducing public transport fares were tested and could further contribute to a modal shift from car to bicycle-PT. Tested scenarios showed a potential increase of up to 5 percentage points in bike-transit usage and a reduction of up to 6.5 percentage points in car trips.
Based on these findings, it is recommended to invest in user-friendly and more abundant bicycle parking at transit stops, particularly bike racks, which are cost- and space-efficient. Policymakers are also advised to explore pricing policies that make public transport more financially attractive compared to car use.
These findings are not only relevant for The Hague but also offer insights for similar cities striving to create a more sustainable mobility system by better integrating cycling with public transport. ...
The qualitative part of the research involved structured interviews with residents of The Hague. The results showed that people are open to considering the bicycle-PT combination but have not yet adopted it. The main barriers are the lack of safe, accessible, and well-maintained bicycle parking at public transport stops. Respondents emphasized the need for more bike parking and cited bad weather and convenience as common reasons for choosing the car.
The quantitative analysis, based on a stated preference survey and a multinomial logit model, confirmed the interview findings. Residents are more likely to opt for the bicycle-PT combination if certain bicycle parking facilities, such as bike racks or lockers, are available. These specific facilities could shift up to 2 percentage points of trips toward the bicycle-PT combination and reduce short car trips by up to 3 percentage points.
Additionally, the results indicate that cost and travel time are important factors in transport choice. Increasing car-related costs and reducing public transport fares were tested and could further contribute to a modal shift from car to bicycle-PT. Tested scenarios showed a potential increase of up to 5 percentage points in bike-transit usage and a reduction of up to 6.5 percentage points in car trips.
Based on these findings, it is recommended to invest in user-friendly and more abundant bicycle parking at transit stops, particularly bike racks, which are cost- and space-efficient. Policymakers are also advised to explore pricing policies that make public transport more financially attractive compared to car use.
These findings are not only relevant for The Hague but also offer insights for similar cities striving to create a more sustainable mobility system by better integrating cycling with public transport.
Preferences of visitors of mass events towards travel information messages
Identifying visitor profiles using Latent Class Cluster Analysis
Shared Micromobility, Shared by Everyone?
A Qualitative Study of Non-Users' Perspectives to Explore The Challenges of Achieving Inclusivity in Shared Micromobility Systems
Impact of leader-follower behavior on evacuation performance
An exploratory modeling approach
Ecology in Urban Development
The potential of systems thinking to make ecology a more prominent concept in urban development
The search for cycling routes
Analysing the influence of spatial characteristics on cycling route choices in Amsterdam
Space Syntax is an analysis method that studies the urban morphology of a city. Until recently, the implementation of Space Syntax has mainly focused on the analysis of pedestrian flows, with a limited number of studies applying the methodology to cyclist behaviour. This master thesis presents exploratory research into the application of Space Syntax – in combination with other built environment characteristics – to study cyclist route choice. GPS data from the 2016 Bicycle Counting Week shows the cycling counts of every street segment.
A linear regression analysis found that “through-movement potential” represented by Normalised Angular Choice (NACH) explained more than 22% of variance in cycling activity. The results indicate that Space Syntax is an interesting indicator to locate which street segments could potentially see large numbers of cyclists. More research encompassing multiple cities in a variety of different contexts is recommended, as Amsterdam is a city with a rich cycling culture that spans multiple decades, making it difficult to generalize any conclusions.
...
Space Syntax is an analysis method that studies the urban morphology of a city. Until recently, the implementation of Space Syntax has mainly focused on the analysis of pedestrian flows, with a limited number of studies applying the methodology to cyclist behaviour. This master thesis presents exploratory research into the application of Space Syntax – in combination with other built environment characteristics – to study cyclist route choice. GPS data from the 2016 Bicycle Counting Week shows the cycling counts of every street segment.
A linear regression analysis found that “through-movement potential” represented by Normalised Angular Choice (NACH) explained more than 22% of variance in cycling activity. The results indicate that Space Syntax is an interesting indicator to locate which street segments could potentially see large numbers of cyclists. More research encompassing multiple cities in a variety of different contexts is recommended, as Amsterdam is a city with a rich cycling culture that spans multiple decades, making it difficult to generalize any conclusions.
A case study applies the proposed method in a pre-pandemic music festival and shows its capability of revealing the general infection risk and the relation of influence factors to the transmission scale, and it also identifies risk-prone areas in an event. Comparing the different scenarios at each activity space, the general trend is identified that the transmission of SARS-CoV-2 is limited when the facility is located outdoor, the queue distance is increased, the density is lowered, and the respiratory activities are calmer. Compared to the real-life experimental events, the simulated results tend to be underestimating the risks due to assumptions of the event scale, infrastructure, compliance to measures, heterogeneity in the emission rate, activity schedules, group behavior, number of infectious individuals, and such factors that directly influence the amount of virus transmitted in the event. Nevertheless, this research has shown when and where major risks can occur during an event. It also gives indications on crowd management measures and interventions that can help reduce the virus transmission scale.
The proposed method allows future exploration and comparison of the transmission scales of large events, without posing ethical controversy of exposing people in infection risks. Yet, it has its limitations of not considering group behavior at the event, which is commonly observed at large events and may potentially increase the transmission scale. Another major limitation is its heavy dependency on detailed virus transmission parameters and activity patterns. The former needs to be validated under different scenarios, and the latter needs to be identified from the data collected at the same type of event in future research. ...
A case study applies the proposed method in a pre-pandemic music festival and shows its capability of revealing the general infection risk and the relation of influence factors to the transmission scale, and it also identifies risk-prone areas in an event. Comparing the different scenarios at each activity space, the general trend is identified that the transmission of SARS-CoV-2 is limited when the facility is located outdoor, the queue distance is increased, the density is lowered, and the respiratory activities are calmer. Compared to the real-life experimental events, the simulated results tend to be underestimating the risks due to assumptions of the event scale, infrastructure, compliance to measures, heterogeneity in the emission rate, activity schedules, group behavior, number of infectious individuals, and such factors that directly influence the amount of virus transmitted in the event. Nevertheless, this research has shown when and where major risks can occur during an event. It also gives indications on crowd management measures and interventions that can help reduce the virus transmission scale.
The proposed method allows future exploration and comparison of the transmission scales of large events, without posing ethical controversy of exposing people in infection risks. Yet, it has its limitations of not considering group behavior at the event, which is commonly observed at large events and may potentially increase the transmission scale. Another major limitation is its heavy dependency on detailed virus transmission parameters and activity patterns. The former needs to be validated under different scenarios, and the latter needs to be identified from the data collected at the same type of event in future research.