A comparative study of flows through funnel-shaped bottlenecks placed in the middle and corner

Upon exiting buildings, theatres, and stadiums, which house a great number of people, egress points can act as bottlenecks, resulting in crowded exits and decreased flows. Most studies investigating flow have been conducted in either narrow bottlenecks (doors) or funnel shape bottlenecks, with the latter investigating bottlenecks placed in the middle of the walkway. This study investigates, for the first time, crowd flow through funnel-shaped bottlenecks placed in the corner of the walkway and makes comparisons with similar bottlenecks of the same length, entrance and exit width placed in the middle of the walkway. The entry width and exit width of the bottlenecks were 3 m and 1 m respectively, with lengths varying from 1 m to 4 m; they continued into a 10 m corridor. Ninety-four participants of various ages were observed moving through each of the configurations. The results indicated that using funnel-shaped bottlenecks in the middle of the walkway increased the flow rate significantly compared to the corner in bottlenecks with 2 m and 3 m lengths. This is contrary to what some other researchers have found for narrow bottlenecks placed in the middle and corner of a wall, although it is recognised that the configuration of funnel-shaped bottlenecks makes the comparison more complex and further work is required in this area. Notwithstanding these results are considered valuable for consideration when designing egress points and corridors in complex buildings such as metro and train stations

A new multi-anticipative car-following model with consideration of the desired following distance

We propose in this paper an extension of the multi-anticipative optimal velocity car-following model to consider explicitly the desired following distance. The model on the following vehicle’s acceleration is formulated as a linear function of the optimal velocity and the desired distance, with reaction-time delay in elements. The linear stability condition of the model is derived. The results demonstrate that the stability of traffic flow is improved by introducing the desired following distance, increasing the time gap in the desired following distance or decreasing the reaction-time delay. The simulation results show that by taking into account the desired following distance as well as the optimal velocity, the multi-anticipative model allows longer reaction-time delay in achieving stable traffic flows

Effect of Intersecting Angle on Pedestrian Crowd Flow under Normal and Evacuation Conditions

Complex pedestrian or passenger crowd movements, such as intersecting movements, can create a bottleneck resulting in delays during emergency escape from public infrastructure such as major public transport hubs. Limited studies have examined the effect of different intersecting angles and walking speeds on pedestrian outflow. This study aims to systematically investigate the effect of different intersecting angles (30°, 90°, and 150°) and walking speeds (normal walking, faster walking) on pedestrian outflow at an intersecting path or junction through controlled laboratory experiments. Further, we consider both blocked vision and un-blocked vision in our experiments. The results from our experiments show that the acute angle of 30° has a higher flow rate and less evacuation time as compared to the other angles. The obtuse intersecting angle of 150° was the most undesirable intersecting angle in terms of outflow, evacuation time, and delays at the junction. Faster walking generally led to reduced evacuation time as compared to normal walking. It is also interesting to note that the results from both blocked vision and un-blocked vision were not statistically significant, suggesting that line of sight was not an important factor in regulating the flow at the junction. The results from our findings are a valuable resource to verify the mathematical model intended to simulate pedestrian or passenger crowd movements and behavior within major public infrastructure under both normal and evacuation conditions

Understanding the lane changing behaviour of large vehicles on arterial roads

Increased volumes of large vehicles are having an increased effect on traffic flow in urban areas. In particular their lane-changing manoeuvres can increase traffic congestion and reduce the perceived safety of traffic. The size of the vehicles can cause different driving behaviours leading to changes in the traffic flow. Many models of the behaviour of large vehicles are limited to motorways. Large vehicles have an impact on the traffic flow on arterial roads since the level of interaction between vehicles is increased at intersections. There is a need to redress this imbalance and increase our understanding of large vehicle behaviour on urban arterial roads. This paper investigates the factors that influence a large vehicle driver’s lane changing manoeuvres. It reviews the existing literature on lane changing models and outlines a study of the lane changing of large vehicles on arterial roads. The decision process of large vehicle drivers on urban arterials is then compared to that on motorways. The paper closes by outlining areas of further research

A multinomial logit model of motorcycle crash severity at Australian intersections

Introduction: Motorcyclists are exposed to more fatalities and severe injuries per mile of travel as compared to other vehicle drivers. Moreover, crashes that take place at intersections are more likely to result in serious or fatal injuries as compared to those that occur at non-intersections. Therefore, the purpose of this study is to evaluate the contributing factors to motorcycle crash severity at intersections. Method: A data set of 7,714 motorcycle crashes at intersections in the State of Victoria, Australia was analyzed over the period of 20062018. The multinomial logit model was used for evaluating the motorcycle crashes. The severity of motorcycle crashes was divided into three categories: minor injury, serious injury and fatal injury. The risk factors consisted of four major categories: motorcyclist characteristics, environmental characteristics, intersection characteristics and crash characteristics. Results: The results of the model demonstrated that certain factors increased the probability of fatal injuries. These factors were: motorcyclists aged over 59 years, weekend crashes, midnight/early morning crashes, morning rush hours crashes, multiple vehicles involved in the crash, t-intersections, crashes in towns, crashes in rural areas, stop or give-way intersections, roundabouts, and uncontrolled intersections. By contrast, factors such as female motorcyclists, snowy or stormy or foggy weather, rainy weather, evening rush hours crashes, and unpaved roads reduced the probability of fatal injuries. Practical Applications: The results from our study demonstrated that certain treatment measures for t-intersections may reduce the probability of fatal injuries. An effective way for improving the safety of stop or give-way intersections and uncontrolled intersections could be to convert them to all-way stop controls. Further, it is recommended to educate the older riders that with ageing, there are physiological changes that occur within the body which can i

Comparing heavy vehicle and passenger car lane-changing maneuvres on arterial roads and freeways

This paper investigates the behaviour of heavy vehicle drivers when making a decision or 4 executing a lane changing manoeuvre on arterials and freeways. Vehicle lane changing 5 manoeuvres often result in instability in traffic flow. The impact of heavy vehicle lane 6 changes can be even more serious than those of passenger vehicles because of the different 7 characteristics of the vehicle and the consequent driver behaviour. This is exacerbated 8 because the number of heavy vehicles and their share in traffic steam are increasing in many 9 countries, in particularly Australia. This paper presents an intensive literature review of 10 models of lane-changing behaviour. It was found that the lane changing manoeuvre of heavy 11 vehicles has not received enough attention. This is particularly true for heavy vehicle lane 12 changing on arterials, which has received no attention. This study applied real world data to 13 compare this behaviour to that of passenger cars. The behaviour of drivers is explored for 14 both arterial roads and freeways considering the impacts of the size of vehicles on the lane 15 changing manoeuvre. The results indicate the type and the size of vehicles influence the lane 16 changing manoeuvre in particular on arterial roads. This paper opens a new area for further 17 studies to investigate the microscopic behaviour of heavy vehicles in traffic steam with more 18 details. It leads us to develop a model incorporating the different characteristics of heavy 19 vehicle

Exploring the Relationship of Exit Flow and Jam Density in Panic Scenarios Using Animal Dynamics

There are few studies investigating crowd dynamics in panic situations. They used measures such as exit flow rate to explore the exit performance in evacuation scenarios. However, there is limited research exploring the relationship of exit flow rate and density behind the exit for panic scenarios. This study presents a macro level analysis to investigate the relationship of exit flow and exit jam characteristics. Animal group behavior (i.e. panicked woodlice experiments) is utilized for data analysis. The results reveal that change in woodlice escaping behavior cause an increasing trend in exit capacity as the jam behind the exit increases.Transport & PlanningCivil Engineering and Geoscience