City events are getting popular and are attracting a large number of people. This increase needs ... more City events are getting popular and are attracting a large number of people. This increase needs for methods and tools to provide stakeholders with crowd size information for crowd management purposes. Previous works proposed a large number of methods to count the crowd using different data in various contexts, but no methods proposed using social media images in city events and no datasets exist to evaluate the effectiveness of these methods. In this study we investigate how social media images can be used to estimate the crowd size in city events. We construct a social media dataset, compare the effectiveness of face recognition, object recognition, and cascaded methods for crowd size estimation, and investigate the impact of image characteristics on the performance of selected methods. Results show that object recognition based methods, reach the highest accuracy in estimating the crowd size using social media images in city events. We also found that face recognition and object ...
Free speeds are defined as the speeds pedestrians like to walk with when they are not
hindered b... more Free speeds are defined as the speeds pedestrians like to walk with when they are not
hindered by other pedestrians. Since pedestrians have different characteristics influencing their choices, free speeds will differ among individuals. These pedestrian characteristics are often not taken into account explicitly, which makes it necessary to describe free speeds as a stochastic variable with a distribution. Moreover, (free) speeds will be influenced by the characteristics of the walking infrastructure, such as grade, length, width, the type of pedestrian facility, and weather and other external conditions. Free speeds and their distribution play an important role in many traffic flow models, but are also relevant in other applications. The aim of this research is to derive free speed distributions for a number of traffic flow conditions. The data on which the distributions are estimated come from large-scale laboratory walking experiments. In these experiments different traffic conditions are simulated,
such as unidirectional flows, opposite flows, and crossing flows. Free speeds are highest in unidirectional flows (1.54 m/s), somewhat lower for opposite flows (1.41 m/s), and lowest for crossing flows (1.35 m/s). Reduction of this free speed is
due to the interaction with other flows. For opposite flows, this interaction is reduced by lane formation (effect of self-organisation). For crossing flows however, this interaction cannot be reduced, since the flows have to interact during the crossing.
2009 Chinese Control and Decision Conference, 2009
ABSTRACT The steadily increasing numbers and lengths of traffic jams on freeways have led to the ... more ABSTRACT The steadily increasing numbers and lengths of traffic jams on freeways have led to the use of dynamic traffic management (DTM) measures all over the world. Ramp metering control has proven to be one of the most efficient means to reduce freeway congestion. It is expected that integrated and coordinated application of DTM measures will further improve its impact. This paper studies a new coordinated ramp metering control algorithm called HERO/RWS. This algorithm has been developed for the current Dutch ramp metering systems and it will be applied on the Amsterdam A10 freeway network in the near future. The aim of this algorithm is to postpone congestion on freeways by effectively using ramp storage space from upstream on-ramps. The control scheme is simple and real-time operable. VISSIM-based microscopic simulation results show that the HERO/RWS coordinated control outperforms non-coordinated control. This control algorithm turns out to provide less congestion, higher mean speeds and lower travel time spent on the freeway.
Transportation Research Record: Journal of the Transportation Research Board, 2011
Estimation of the time needed to evacuate a population from a threatened area in case of a disast... more Estimation of the time needed to evacuate a population from a threatened area in case of a disaster is one of the main issues in the design of an evacuation plan. The challenge is to develop a strategy that optimally uses the network capacity to minimize the total evacuation time. In this paper, the impacts of various departure time spans on evacuation time and network performance are investigated with a microscopic traffic simulation model. The network performance has been analyzed with the use of the macroscopic fundamental diagram (MFD). Although the MFD usually shows a decrease in travel production after a peak is reached, this is not the case in the simulation of evacuation scenarios. The outflow of the network remains constant because it depends on the capacity of local bottlenecks upstream of the limited number of destinations, but the number of vehicles in the network increases because of an increase in congestion. Although the overall network performance is insensitive to t...
Transportation Research Record: Journal of the Transportation Research Board, 2012
Emergency doors may be bottlenecks in the evacuation of a building. When a pedestrian simulation ... more Emergency doors may be bottlenecks in the evacuation of a building. When a pedestrian simulation model is used to assess designs of buildings, the model should accurately predict the behavior of pedestrians around emergency doors and thus the doors’ capacity. Data from laboratory experiments were used to calibrate the pedestrian simulation model Nomad. In these experiments, large heterogeneous groups of people passed through a door under evacuation conditions. The collected trajectory data were used as input for an automated calibration procedure, which yielded parameter estimates for individual pedestrians. This automated calibration procedure has been extended through inclusion of data from multiple pedestrians into a single estimate. This change overcomes convergence problems because the log likelihood is insensitive to changes in some of the parameters and because of the problems of unrealistic parameter estimates. The resulting parameter distributions provided insight into pede...
This paper addresses predicting the impact of access gates on pedestrian flow operations in terms... more This paper addresses predicting the impact of access gates on pedestrian flow operations in terms of level of service, congestion levels, average walking times, delays incurred at the gates, etc. The paper predicts pedestrian traffic operations for different station design alternatives using the microscopic pedestrian flow model NOMAD. This is done for reference situations (validation), as well as for the design alternatives. The model provided realistic results. Furthermore, the simple design guidelines used to set up the design alternatives provided satisfactory levels of service to transferring pedestrian and the gates would be installed without compromising passenger safety.
Nowadays, there is a need for tools to support city planners in assessing the performance of cycl... more Nowadays, there is a need for tools to support city planners in assessing the performance of cycling infrastructure and managing bicycles and mixed flows. Microscopic and macroscopic bicycle traffic models can be used to fulfill this need. However, fundamental knowledge on individual cyclist interaction behavior (which should underpin these models) is hardly available in literature. Detailed bicycle traffic data are necessary if we want to gain insight into cyclist interaction behavior and develop sound behavioral theories and models. Laboratory experiments have been proven to be one of the most effective ways to collect detailed traffic data. For this reason, a controlled experiment aimed to investigate cyclist interaction behavior has been carried out at Delft University of Technology. This paper describes the experimental design, the resulting microscopic bicycle trajectories, and some preliminary results regarding one of the most common interaction situations: the bidirectional ...
City events are getting popular and are attracting a large number of people. This increase needs ... more City events are getting popular and are attracting a large number of people. This increase needs for methods and tools to provide stakeholders with crowd size information for crowd management purposes. Previous works proposed a large number of methods to count the crowd using different data in various contexts, but no methods proposed using social media images in city events and no datasets exist to evaluate the effectiveness of these methods. In this study we investigate how social media images can be used to estimate the crowd size in city events. We construct a social media dataset, compare the effectiveness of face recognition, object recognition, and cascaded methods for crowd size estimation, and investigate the impact of image characteristics on the performance of selected methods. Results show that object recognition based methods, reach the highest accuracy in estimating the crowd size using social media images in city events. We also found that face recognition and object ...
Free speeds are defined as the speeds pedestrians like to walk with when they are not
hindered b... more Free speeds are defined as the speeds pedestrians like to walk with when they are not
hindered by other pedestrians. Since pedestrians have different characteristics influencing their choices, free speeds will differ among individuals. These pedestrian characteristics are often not taken into account explicitly, which makes it necessary to describe free speeds as a stochastic variable with a distribution. Moreover, (free) speeds will be influenced by the characteristics of the walking infrastructure, such as grade, length, width, the type of pedestrian facility, and weather and other external conditions. Free speeds and their distribution play an important role in many traffic flow models, but are also relevant in other applications. The aim of this research is to derive free speed distributions for a number of traffic flow conditions. The data on which the distributions are estimated come from large-scale laboratory walking experiments. In these experiments different traffic conditions are simulated,
such as unidirectional flows, opposite flows, and crossing flows. Free speeds are highest in unidirectional flows (1.54 m/s), somewhat lower for opposite flows (1.41 m/s), and lowest for crossing flows (1.35 m/s). Reduction of this free speed is
due to the interaction with other flows. For opposite flows, this interaction is reduced by lane formation (effect of self-organisation). For crossing flows however, this interaction cannot be reduced, since the flows have to interact during the crossing.
2009 Chinese Control and Decision Conference, 2009
ABSTRACT The steadily increasing numbers and lengths of traffic jams on freeways have led to the ... more ABSTRACT The steadily increasing numbers and lengths of traffic jams on freeways have led to the use of dynamic traffic management (DTM) measures all over the world. Ramp metering control has proven to be one of the most efficient means to reduce freeway congestion. It is expected that integrated and coordinated application of DTM measures will further improve its impact. This paper studies a new coordinated ramp metering control algorithm called HERO/RWS. This algorithm has been developed for the current Dutch ramp metering systems and it will be applied on the Amsterdam A10 freeway network in the near future. The aim of this algorithm is to postpone congestion on freeways by effectively using ramp storage space from upstream on-ramps. The control scheme is simple and real-time operable. VISSIM-based microscopic simulation results show that the HERO/RWS coordinated control outperforms non-coordinated control. This control algorithm turns out to provide less congestion, higher mean speeds and lower travel time spent on the freeway.
Transportation Research Record: Journal of the Transportation Research Board, 2011
Estimation of the time needed to evacuate a population from a threatened area in case of a disast... more Estimation of the time needed to evacuate a population from a threatened area in case of a disaster is one of the main issues in the design of an evacuation plan. The challenge is to develop a strategy that optimally uses the network capacity to minimize the total evacuation time. In this paper, the impacts of various departure time spans on evacuation time and network performance are investigated with a microscopic traffic simulation model. The network performance has been analyzed with the use of the macroscopic fundamental diagram (MFD). Although the MFD usually shows a decrease in travel production after a peak is reached, this is not the case in the simulation of evacuation scenarios. The outflow of the network remains constant because it depends on the capacity of local bottlenecks upstream of the limited number of destinations, but the number of vehicles in the network increases because of an increase in congestion. Although the overall network performance is insensitive to t...
Transportation Research Record: Journal of the Transportation Research Board, 2012
Emergency doors may be bottlenecks in the evacuation of a building. When a pedestrian simulation ... more Emergency doors may be bottlenecks in the evacuation of a building. When a pedestrian simulation model is used to assess designs of buildings, the model should accurately predict the behavior of pedestrians around emergency doors and thus the doors’ capacity. Data from laboratory experiments were used to calibrate the pedestrian simulation model Nomad. In these experiments, large heterogeneous groups of people passed through a door under evacuation conditions. The collected trajectory data were used as input for an automated calibration procedure, which yielded parameter estimates for individual pedestrians. This automated calibration procedure has been extended through inclusion of data from multiple pedestrians into a single estimate. This change overcomes convergence problems because the log likelihood is insensitive to changes in some of the parameters and because of the problems of unrealistic parameter estimates. The resulting parameter distributions provided insight into pede...
This paper addresses predicting the impact of access gates on pedestrian flow operations in terms... more This paper addresses predicting the impact of access gates on pedestrian flow operations in terms of level of service, congestion levels, average walking times, delays incurred at the gates, etc. The paper predicts pedestrian traffic operations for different station design alternatives using the microscopic pedestrian flow model NOMAD. This is done for reference situations (validation), as well as for the design alternatives. The model provided realistic results. Furthermore, the simple design guidelines used to set up the design alternatives provided satisfactory levels of service to transferring pedestrian and the gates would be installed without compromising passenger safety.
Nowadays, there is a need for tools to support city planners in assessing the performance of cycl... more Nowadays, there is a need for tools to support city planners in assessing the performance of cycling infrastructure and managing bicycles and mixed flows. Microscopic and macroscopic bicycle traffic models can be used to fulfill this need. However, fundamental knowledge on individual cyclist interaction behavior (which should underpin these models) is hardly available in literature. Detailed bicycle traffic data are necessary if we want to gain insight into cyclist interaction behavior and develop sound behavioral theories and models. Laboratory experiments have been proven to be one of the most effective ways to collect detailed traffic data. For this reason, a controlled experiment aimed to investigate cyclist interaction behavior has been carried out at Delft University of Technology. This paper describes the experimental design, the resulting microscopic bicycle trajectories, and some preliminary results regarding one of the most common interaction situations: the bidirectional ...
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Papers by W. Daamen
hindered by other pedestrians. Since pedestrians have different characteristics influencing their choices, free speeds will differ among individuals. These pedestrian characteristics are often not taken into account explicitly, which makes it necessary to describe free speeds as a stochastic variable with a distribution. Moreover, (free) speeds will be influenced by the characteristics of the walking infrastructure, such as grade, length, width, the type of pedestrian facility, and weather and other external conditions. Free speeds and their distribution play an important role in many traffic flow models, but are also relevant in other applications. The aim of this research is to derive free speed distributions for a number of traffic flow conditions. The data on which the distributions are estimated come from large-scale laboratory walking experiments. In these experiments different traffic conditions are simulated,
such as unidirectional flows, opposite flows, and crossing flows. Free speeds are highest in unidirectional flows (1.54 m/s), somewhat lower for opposite flows (1.41 m/s), and lowest for crossing flows (1.35 m/s). Reduction of this free speed is
due to the interaction with other flows. For opposite flows, this interaction is reduced by lane formation (effect of self-organisation). For crossing flows however, this interaction cannot be reduced, since the flows have to interact during the crossing.
hindered by other pedestrians. Since pedestrians have different characteristics influencing their choices, free speeds will differ among individuals. These pedestrian characteristics are often not taken into account explicitly, which makes it necessary to describe free speeds as a stochastic variable with a distribution. Moreover, (free) speeds will be influenced by the characteristics of the walking infrastructure, such as grade, length, width, the type of pedestrian facility, and weather and other external conditions. Free speeds and their distribution play an important role in many traffic flow models, but are also relevant in other applications. The aim of this research is to derive free speed distributions for a number of traffic flow conditions. The data on which the distributions are estimated come from large-scale laboratory walking experiments. In these experiments different traffic conditions are simulated,
such as unidirectional flows, opposite flows, and crossing flows. Free speeds are highest in unidirectional flows (1.54 m/s), somewhat lower for opposite flows (1.41 m/s), and lowest for crossing flows (1.35 m/s). Reduction of this free speed is
due to the interaction with other flows. For opposite flows, this interaction is reduced by lane formation (effect of self-organisation). For crossing flows however, this interaction cannot be reduced, since the flows have to interact during the crossing.