Road proximity and traffic flow perceived as potential predation risks: evidence from the Tibetan antelope in the Kekexili National Nature Reserve, China

2011 ◽  
Vol 38 (2) ◽  
pp. 141 ◽  
Author(s):  
Xinming Lian ◽  
Tongzuo Zhang ◽  
Yifan Cao ◽  
Jianping Su ◽  
Simon Thirgood
Keyword(s):  
Traffic Flow ◽  
Human Disturbance ◽  
Avoidance Behaviour ◽  
Risk Avoidance ◽  
Time Frequency ◽  
The Road ◽  
Road Design ◽  
Focal Animal ◽  
Tibetan Antelope ◽  
Disturbance Hypothesis

Context The risk-disturbance hypothesis predicts that animals exhibit risk-avoidance behaviours when exposed to human disturbance because they perceive the disturbance as a predatory threat. Aims This study aimed to examine whether Tibetan antelopes (Pantholops hodgsoni) exhibit risk-avoidance behaviour with proximity to a major highway and with increasing traffic flow consistent with the risk-disturbance hypothesis. Methods Focal-animal sampling was used to observe the behaviour of Tibetan antelopes. The behaviours were categorised as foraging, vigilance, resting, moving, or other. The time, frequency, and duration of foraging and vigilance were calculated. Key results As distance from the road increased, time spent foraging and foraging duration increased while foraging frequency, time spent being vigilant and vigilance frequency decreased, indicating that there is a risk perception associated with roads. Tibetan antelopes presented more risk-avoidance behaviours during high-traffic periods compared with low-traffic periods. Conclusions Tibetan antelopes exhibited risk-avoidance behaviour towards roads that varied with proximity and traffic levels, which is consistent with the risk-disturbance hypothesis. Implications The consequences of risk-avoidance behaviour should be reflected in wildlife management by considering human disturbance and road design.

Do pronghorn (Antilocapra americana) perceive roads as a predation risk?

2006 ◽  
Vol 84 (12) ◽  
pp. 1775-1780 ◽  
Author(s):  
S.D. Gavin ◽  
P.E. Komers
Keyword(s):  
Risk Perception ◽  
Road Traffic ◽  
Avoidance Behaviour ◽  
Antilocapra Americana ◽  
Risk Avoidance ◽  
Human Disturbances ◽  
Close Proximity ◽  
Natural Predator ◽  
Traffic Level ◽  
Disturbance Hypothesis

The risk–disturbance hypothesis proposes that organisms respond to generalized threat stimuli; therefore, human disturbances that elicit these behaviours will cause individuals to behave similarly to avoid a natural predator. Studies have shown that pronghorn antelope, Antilocapra americana (Ord, 1815), are influenced by human disturbances. We examined several intensities of human activity and distance from disturbances as indicators of risk perception in pronghorns. We investigated whether pronghorns exhibited risk-avoidance behaviour towards road traffic consistent with the risk–disturbance hypothesis by comparing vigilance and foraging behaviour observations across increasing traffic levels and proximity to roads. Pronghorns showed higher vigilance and lower foraging times along high traffic roads during the spring season compared with lower traffic levels, suggesting that risk perception is related to traffic level. Moreover, individuals within close proximity to roads regardless of traffic level exhibited higher vigilance levels, indicating that there is an overall risk perceived towards roads. Our results also suggest that individuals in herds with young are more risk averse than other social groupings and individuals in larger groups perceive less risk. We suggest that consequences of risk-avoidance behaviour should be reflected in land-use plans that address road densities and traffic levels to better manage wildlife.

The Analysis of the Traffic Flow Running along the Horizontal Curve of the Approach Bridge

2014 ◽  
Vol 1049-1050 ◽  
pp. 1707-1712
Author(s):  
Xin Ye ◽  
Wei Deng ◽  
Tao Hong
Keyword(s):  
Traffic Flow ◽  
Traffic Management ◽  
Traffic Density ◽  
Data Traffic ◽  
Volume Data ◽  
Horizontal Curve ◽  
The Road ◽  
The North ◽  
Road Design ◽  
And Control

The horizontal curve is a very common linear in the road design. On the other hand, the horizontal curve in the approach bridge may affect the traffic flow in many ways. The north approach span of Nanjing Yangtze River Bridge is herein taken as an example. With the help of the traffic speed data ,traffic density data and traffic volume data from the traffic survey and analysis, the features of traffic flow,which change with the morning peak appearing, have been found by modeling. Finally, the paper gives several ways to optimize the traffic management and control, improve transport and security.

scholarly journals The method of calculating emissions of pollutants from road transport in an urban environment

2019 ◽  
Vol 298 ◽  
pp. 00084
Author(s):  
I. A. Teterina ◽  
E. V. Parsaev
Keyword(s):  
Traffic Flow ◽  
Traffic Engineering ◽  
Road Traffic ◽  
Road Transport ◽  
Environmental Indicators ◽  
Pollutant Emissions ◽  
The Road ◽  
Road Design ◽  
Traffic Organization

To assess the quality of road traffic organization on environmental indicators, two methods of five regulations operating in the Russian Federation, which take into account the parameters of traffic flow, affecting the volume of emissions Pollutants. The parameter that affects the results of calculations in both methods is the average speed of movement. In real-world conditions on urban highways there are areas where the traffic flow is uneven (braking, acceleration, stopping), which entails an increase in the amount of pollutants from vehicles. At the same time, this uneven traffic is largely due to the existing the road design and traffic engineering on certain elements of the road network. This is the basis for the development of a methodology for calculating pollutant emissions to assess the quality of the traffic engineering, taking into account the uneven flow of traffic.

Safety at Curves and Road Geometry Standards in Some European Countries

1996 ◽  
Vol 1523 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Thierry Brenac
Keyword(s):  
Urban Areas ◽  
National Standards ◽  
European Countries ◽  
Design Standards ◽  
The Road ◽  
Horizontal Curves ◽  
Road Design ◽  
Road Geometry ◽  
Design Speed ◽  
Curve Geometry

This paper deals with safety at horizontal curves on two-lane roads outside urban areas and the way the road design standards of different European countries account for this safety aspect. After a review of some research results, the main aspects of curve geometry and the curve's place in the horizontal alignment are analyzed. The main conclusions are that the traditional design speed approach is insufficient and that formal complementary rules in road design standards, especially to improve compatibility between successive elements of the alignment, must be introduced. If such complementary rules already exist in some national standards, they are neither frequent nor homogeneous throughout the different countries, and it seems that they are not based on sufficiently developed knowledge.

scholarly journals Development of Driving Simulation Scenarios Based on Building Information Modeling (BIM) for Road Safety Analysis

2021 ◽  
Vol 13 (4) ◽  
pp. 2039
Author(s):  
Juan F. Dols ◽  
Jaime Molina ◽  
F. Javier Camacho-Torregrosa ◽  
David Llopis-Castelló ◽  
Alfredo García
Keyword(s):  
Road Safety ◽  
Data Exchange ◽  
Building Information Modeling ◽  
Cost Savings ◽  
Safety Analysis ◽  
Information Modeling ◽  
Driving Simulators ◽  
The Road ◽  
Road Design ◽  
Building Information

The analysis of road safety is critical in road design. Complying to guidelines is not enough to ensure the highest safety levels, so many of them encourage designers to virtually recreate and test their roads, benefitting from the evolution of driving simulators in recent years. However, an accurate recreation of the road and its environment represents a real bottleneck in the process. A very important limitation lies in the diversity of input data, from different sources and requiring specific adaptations for every single simulator. This paper aims at showing a framework for recreating faster virtual scenarios by using an Industry Foundation Classes (IFC)-based file. This methodology was compared to two other conventional methods for developing driving scenarios. The main outcome of this study has demonstrated that with a data exchange file in IFC format, virtual scenarios can be faster designed to carry out safety audits with driving simulators. As a result, the editing, programming, and processing times were substantially reduced using the proposed IFC exchange file format through a BIM (Building Information Modeling) model. This methodology facilitates cost-savings, execution, and optimization resources in road safety analysis.

Sustainable design of rural roads with 2+1 road design: Levels of service and traffic flow performance

2016 ◽  
Vol 20 (3) ◽  
pp. 1032-1039 ◽  
Author(s):  
Jaisung Choi ◽  
Youngrok Kim ◽  
Torsten Bergh ◽  
Sangyoup Kim ◽  
Sungkyu Kim
Keyword(s):  
Traffic Flow ◽  
Sustainable Design ◽  
Rural Roads ◽  
Road Design ◽  
Levels Of Service

Research and Improvement of the Keep-Right-Except-to-Pass Rule

2014 ◽  
Vol 915-916 ◽  
pp. 459-463
Author(s):  
He Quan Zhang
Keyword(s):  
Fluid Mechanics ◽  
Traffic Flow ◽  
Influence Factors ◽  
Traffic Model ◽  
Light Traffic ◽  
The Road ◽  
Model Based ◽  
Light Passing ◽  
Improved Model ◽  
The Impact

In order to deal with the impact on traffic flow of the rule, we compare the influence factors of traffic flow (passing, etc.) into viscous resistance of fluid mechanics, and establish a traffic model based on fluid mechanics. First, in heavy and light traffic, we respectively use this model to simulate the actual segment of the road and find that when the traffic is heavy, the rule hinder the further increase in traffic. For this reason, we make further improvements to the model to obtain a fluid traffic model based on no passing and find that the improved model makes traffic flow increase significantly. Then, the improved model is applied to the light traffic, we find there are no significant changes in traffic flow .In this regard we propose a new rule: when the traffic is light, passing is allowed, but when the traffic is heavy, passing is not allowed.

On kinematic waves II. A theory of traffic flow on long crowded roads

1955 ◽  
Vol 229 (1178) ◽  
pp. 317-345 ◽  
Keyword(s):  
Traffic Flow ◽  
Functional Relationship ◽  
Vehicle Speed ◽  
Main Road ◽  
The Road ◽  
Traffic Distribution ◽  
Kinematic Waves ◽  
The Subject ◽  
The Mean ◽  
Starting Flow

This paper uses the method of kinematic waves, developed in part I, but may be read independently. A functional relationship between flow and concentration for traffic on crowded arterial roads has been postulated for some time, and has experimental backing (§2). From this a theory of the propagation of changes in traffic distribution along these roads may be deduced (§§2, 3). The theory is applied (§4) to the problem of estimating how a ‘hump’, or region of increased concentration, will move along a crowded main road. It is suggested that it will move slightly slower than the mean vehicle speed, and that vehicles passing through it will have to reduce speed rather suddenly (at a ‘shock wave’) on entering it, but can increase speed again only very gradually as they leave it. The hump gradually spreads out along the road, and the time scale of this process is estimated. The behaviour of such a hump on entering a bottleneck, which is too narrow to admit the increased flow, is studied (§5), and methods are obtained for estimating the extent and duration of the resulting hold-up. The theory is applicable principally to traffic behaviour over a long stretch of road, but the paper concludes (§6) with a discussion of its relevance to problems of flow near junctions, including a discussion of the starting flow at a controlled junction. In the introductory sections 1 and 2, we have included some elementary material on the quantitative study of traffic flow for the benefit of scientific readers unfamiliar with the subject.

Report on design of modules for the stochastic traffic simulation

2021 ◽  
Author(s):  
Christian Siebke ◽  
◽  
Maximilian Bäumler ◽  
Madlen Ringhand ◽  
Marcus Mai ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Main Part ◽  
Traffic Simulation ◽  
Cognitive Structure ◽  
Flow Simulation ◽  
Road User ◽  
The Road ◽  
Traffic Flow Simulation ◽  
Cognitive Behaviour ◽  
Traffic Simulations

As part of the AutoDrive project, OpenPASS is used to develop a cognitive-stochastic traffic flow simulation for urban intersection scenarios described in deliverable D1.14. The deliverable D4.20 is about the design of the modules for the stochastic traffic simulation. This initially includes an examination of the existing traffic simulations described in chapter 2. Subsequently, the underlying tasks of the driver when crossing an intersection are explained. The main part contains the design of the cognitive structure of the road user (chapter 4.2) and the development of the cognitive behaviour modules (chapter 4.3).

Make More Connections: Urban Traffic Flow Forecasting with Spatiotemporal Adaptive Gated Graph Convolution Network

2022 ◽  
Vol 13 (2) ◽  
pp. 1-25
Author(s):  
Bin Lu ◽  
Xiaoying Gan ◽  
Haiming Jin ◽  
Luoyi Fu ◽  
Xinbing Wang ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Road Network ◽  
Large Scale ◽  
Transportation Systems ◽  
Urban Traffic ◽  
Propagation Mechanism ◽  
Urban Road ◽  
The Road ◽  
Traffic Flow Forecasting ◽  
Gating Mechanism

Urban traffic flow forecasting is a critical issue in intelligent transportation systems. Due to the complexity and uncertainty of urban road conditions, how to capture the dynamic spatiotemporal correlation and make accurate predictions is very challenging. In most of existing works, urban road network is often modeled as a fixed graph based on local proximity. However, such modeling is not sufficient to describe the dynamics of the road network and capture the global contextual information. In this paper, we consider constructing the road network as a dynamic weighted graph through attention mechanism. Furthermore, we propose to seek both spatial neighbors and semantic neighbors to make more connections between road nodes. We propose a novel Spatiotemporal Adaptive Gated Graph Convolution Network ( STAG-GCN ) to predict traffic conditions for several time steps ahead. STAG-GCN mainly consists of two major components: (1) multivariate self-attention Temporal Convolution Network ( TCN ) is utilized to capture local and long-range temporal dependencies across recent, daily-periodic and weekly-periodic observations; (2) mix-hop AG-GCN extracts selective spatial and semantic dependencies within multi-layer stacking through adaptive graph gating mechanism and mix-hop propagation mechanism. The output of different components are weighted fused to generate the final prediction results. Extensive experiments on two real-world large scale urban traffic dataset have verified the effectiveness, and the multi-step forecasting performance of our proposed models outperforms the state-of-the-art baselines.

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