Study on Driving Deceleration Model on Horizontal Curve Sections of Mountain Highways

2012 ◽  
Vol 479-481 ◽  
pp. 1660-1664
Author(s):  
Yu Zhuo Men ◽  
Hai Bo Yu ◽  
Hua Wang ◽  
Liang Xu
Keyword(s):  
Traffic Safety ◽  
Theoretical Method ◽  
Control Model ◽  
Reference Object ◽  
Considerable Proportion ◽  
Vehicle Speed ◽  
Horizontal Curve ◽  
Line Features ◽  
Pass Through ◽  
Object Of Study

Mountain highways are traffic accident-prone locations. Such factors as vehicle speed and trajectory hold a considerable proportion in the accidents. Highway line features is the basis to determine vehicle speed. In this paper, the running speed of vehicles on mountain highways is taken as the main object of study and the observation and survey data on vehicles deceleration behaviors before they enter a curve on the curved sections of mountain highways are taken as the reference object to establish the drivers driving speed control model on the horizontal curve sections of mountain highways, and an example is used to conduct comparative validation on the driving deceleration model. Calculation results show that the deceleration control model established in this paper is feasible and effective, can better simulate vehicles deceleration behaviors when they pass through speed limit signs or the sections with road surface deceleration signs and provides a new theoretical method and guiding basis for the line features design, traffic safety analysis and evaluation and traffic safety improvements of mountain highways.

scholarly journals Analysis of Freeway Safety Influencing Factors on Driving Workload and Performance Based on the Gray Correlation Method

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Lian Xie ◽  
Chaozhong Wu ◽  
Min Duan ◽  
Nengchao Lyu
Keyword(s):  
Standard Deviation ◽  
Influencing Factors ◽  
Traffic Safety ◽  
Vehicle Speed ◽  
Horizontal Curve ◽  
Lane Departure ◽  
Correlation Degree ◽  
Driving Workload ◽  
The Mean ◽  
And Performance

Human-related factors are a crucial inducement of traffic accidents. Understanding the influence of freeway environments on the driving behavior and workload experienced by drivers has been demonstrated to be of primary importance for improving traffic safety. To study the effect of alignment, traffic flow, and sign information on drivers’ mental workload and behavior, 16 scenarios were constructed using the orthogonal design method, and simulated driving experiments were carried out with 45 participants. During driving, indicators such as the mean and standard deviation of vehicle speed and lane departure were collected, and the NASA-TLX questionnaire was adopted to measure workload. Analysis of variance results indicated that the radius of the horizontal curve, gradient, flow, and sign information level have a significant influence on drivers’ workload and speed keeping ability. In addition, the horizontal curve radius has a significant effect on lane keeping ability. The importance of safety influencing factors on driving workload and performance was quantitatively ranked by integrating the trend of Deng’s correlation degree, comprehensive correlation degree, and similar correlation degree, whose weight was calculated using the entropy method. Traffic sign information was found to have the greatest impact on workload. In terms of driving performance, traffic volume has the greatest influence on the mean and standard deviation of vehicle speed, followed by the amount of sign information. Lane departure is most affected by the radius of the horizontal curve. These findings provide guidance for freeway traffic safety regulation, including workload control and road facility optimization.

Analysis on the Anti-Glare Plate Setting Distance on Horizontal Curve Sections of Expressway

2014 ◽  
Vol 587-589 ◽  
pp. 2156-2159 ◽  
Author(s):  
Tian Xiao ◽  
Ji Shu Sun ◽  
Can Zhang Jin
Keyword(s):  
Traffic Safety ◽  
Calculation Formula ◽  
Horizontal Curve ◽  
Distance Calculation ◽  
Element Simulation ◽  
Curved Section ◽  
Curve Radius ◽  
The Relationship ◽  
Plate Distance ◽  
Glare Effect

Glare is one of the most important factors threating expressway traffic safety an night. The most commonly way to prevent glaring night is to set anti-glare plate. Different from the straight sections of expressway, the relationship between the front light of vehicles and the distance of anti-glare plate on the horizontal curved section has some-what changed. Through a lot of tests and finite element simulation, the relationship between the distance of anti-glare plate, horizontal curve radius and anti-glare effect were analyzed systematically. Distance calculation formula of anti-glare plate in horizontal curve sections was revised in this paper. The anti-glare plate distance requirement under different expressway alignment design indexes and its calculation formula was proposed. The achievement was beneficial to confirm the anti-glare effect and improve traffic safety. It can provide us with a reference and a supplement of the specification.

Road Engineering Optimization Based on Driving Reaction

2013 ◽  
Vol 579-580 ◽  
pp. 841-844
Author(s):  
Zhao Cao ◽  
Xiao Wu ◽  
Qing Yang
Keyword(s):  
Traffic Safety ◽  
Safety Issue ◽  
Heart Beat ◽  
Driving Safety ◽  
Response Analysis ◽  
Vehicle Speed ◽  
Force Coefficient ◽  
Slope Length ◽  
Road Engineering ◽  
Positive Correlation

With the increasingly outstanding of the traffic safety issue, the human factors in People-Vehicle-Road System are being emphasized gradually. Takes Jinhua suburb asphalt mountain road (two-lane, multiple steep slopes) for example, this study focuses on road engineering response analysis on driving reaction, design optimization of road engineering base on driving response. A driver over 3 driving years steered 5-seat car in 4 kilometers long experimental road, kept the vehicle speed (V) under 40km/h. Heartbeat rate of the driver was monitored by dynamic Holter through driving process. The analysis shows that there is a linear positive correlation between Heart beat growth rate (Ni) and V, a nearly positive correlation between lateral force coefficient (μ) and Ni, and nearly inversely proportional between plane curve radius (R) and slope (i). It should decrease R appropriately when road slope (i) much sharply in road alignment design. There is a polynomial relation between Ni, V and R. As R increases, both Ni and V reduce firstly, and then rise. When R ranges from 240 to 500 meter, stress gradually ease; while R exceeds 500 meter, driving reaction tension gradually rise. R<550 m, i <6% and slope length under 300 m in the experimental road. When instructional speed <40km/h, then Ni was 30.2% and μ was 0.25. Its benefit for driving safety to keep drivers in appropriate tension in such situation.

Research on Safety Vehicle Distance Recognition Based on Stereo Vision and DSP

2013 ◽  
Vol 333-335 ◽  
pp. 805-810 ◽  
Author(s):  
Rong Bao Chen ◽  
Ning Li ◽  
Hua Feng Xiao ◽  
Wei Hou
Keyword(s):  
Stereo Vision ◽  
Traffic Safety ◽  
Traffic Accidents ◽  
Intelligent Transportation ◽  
Research Area ◽  
Measurement Range ◽  
Vehicle Speed ◽  
Target Vehicle ◽  
Operation Rate ◽  
The Right

With the development of economy, there are an increasing number of cars as well as traffic accidents, thus intensifying the need to take measures to reduce traffic accidents and protect the safety of life and property. Vehicle distance is one of the most important indexes of traffic safety. The measurement of safety vehicle distance has become an increasingly hot research area of intelligent transportation. Through analyzing the basic principle of stereo vision and calibrating the parameters of the CCD sensors both inside and outside, this paper comes up with a method to measure the former vehicle distance based on stereo vision and DSP. Once the vehicle speed and distance form a non-security association, it will give a warning, and upload data or force speed-limiting. According to the different coordinates of the obtained images of the target vehicle from the left and the right sensor, this method can identify feature points, calculate distance to the target vehicle, and analyze the security of vehicle distance. The experimental results show that this method has wide measurement range, high measurement accuracy, and fast operation rate, thus it can meet the actual needs of the measurement of safe vehicle distance in intelligent transportation.

scholarly journals School-Aged Pedestrian–Vehicle Crash Vulnerability

2019 ◽  
Vol 11 (4) ◽  
pp. 1214 ◽  
Author(s):  
Kinga Ivan ◽  
József Benedek ◽  
Silviu Ciobanu
Keyword(s):  
Traffic Safety ◽  
Local Level ◽  
Urban Traffic ◽  
Vehicle Speed ◽  
Vehicle Crashes ◽  
Time Intervals ◽  
Local Authorities ◽  
Traffic Crashes ◽  
Triggering Factors ◽  
Pedestrian Crashes

The analysis of pedestrian–vehicle crashes makes a significant contribution to sustainable pedestrian safety. Existing research is based mainly on the statistical analysis of traffic crashes involving pedestrians and their causes, without the identification of areas vulnerable to traffic crashes that involve pedestrians. The main aim of this paper is to identify areas vulnerable to school-aged pedestrian–vehicle crashes at a local level to support the local authorities in implementing new urban traffic safety measures. The vulnerable areas were determined by computing the severity index (SI) based on the number of fatal, serious, and slight casualties throughout the 2011–2016 period in a large urban agglomeration (Bucharest). As well as the vulnerable areas, the triggering factors and the time intervals related to school-aged pedestrian–vehicle crashes were identified. The outcomes of the study showed that the vulnerable areas were concentrated only in districts 2 and 4 of Bucharest, and they were associated with high vehicle speed and pedestrians’ unsafe crossing behavior. The findings revealed that speed and age are triggering factors in generating school-aged pedestrian–vehicle crashes. The identified time peaks with a high number of traffic crashes correspond to the afternoon time intervals, when scholars go home from school. The identification of the areas vulnerable to school-aged pedestrian crashes may help local authorities in identifying and implementing measures to improve traffic safety in large urban agglomerations.

scholarly journals Determination of Curve Speed Zones for Mountainous Freeways

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yongtao Liu ◽  
Jie Qiao ◽  
Yanting Hu ◽  
Tengyuan Fang ◽  
Ting Xu ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Warning Signs ◽  
Driving Safety ◽  
Warning Sign ◽  
Speed Limit ◽  
Vehicle Speed ◽  
Estimation Model ◽  
Traffic Efficiency ◽  
Safety Warning ◽  
The Difference

Different vehicular speed limits may have an impact on the balance between safety and efficiency of travel on mountainous road corners associated with complex road conditions. Placing suitable speed limit warning signs does not merely effectively improve traffic safety but can also improve traffic efficiency. In this study, a global positioning system (GPS) terminal and Metrocount were used to collect vehicle speed data from more than 40 provincial-level curves in 8 provinces over the course of 1 year. Each road data collection time-period lasted approximately 8 hours. A descriptive statistics method was adopted by means of data screening and pretreatment. Additionally, both a velocity difference estimation model was established and a linear model of velocity differential estimation was constructed. Quantitative analysis was carried out on the safe speed, the driver’s expected speed, and the location of the speed limit warning signs. This demonstrated a positive correlation with the initial speed. When the difference in speed was greater than 15 km/h, a safety warning sign was required to limit the design speed to 80 km/h. A safety warning sign was also required when the corner radius was less than 300 m. The location of safety warning signs could be calculated based on the operating speed and taking driving safety and the visual range of drivers into consideration. The results can provide a theoretical reference for setting up appropriate safe speed limiting signs on road corners in mountainous areas.

scholarly journals A Novel Left-Turn Signal Control Method for Improving Intersection Capacity in a Connected Vehicle Environment

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1058 ◽  
Author(s):  
Chuanxiang Ren ◽  
Jinbo Wang ◽  
Lingqiao Qin ◽  
Shen Li ◽  
Yang Cheng
Keyword(s):  
Traffic Safety ◽  
Control Strategy ◽  
Control Method ◽  
Control Model ◽  
Signal Control ◽  
Signal Phase ◽  
Phase Duration ◽  
Left Turn ◽  
Intersection Signal Control ◽  
And Control

Setting up an exclusive left-turn lane and corresponding signal phase for intersection traffic safety and efficiency will decrease the capacity of the intersection when there are less or no left-turn movements. This is especially true during rush hours because of the ineffective use of left-turn lane space and signal phase duration. With the advantages of vehicle-to-infrastructure (V2I) communication, a novel intersection signal control model is proposed which sets up variable lane direction arrow marking and turns the left-turn lane into a controllable shared lane for left-turn and through movements. The new intersection signal control model and its control strategy are presented and simulated using field data. After comparison with two other intersection control models and control strategies, the new model is validated to improve the intersection capacity in rush hours. Besides, variable lane lines and the corresponding control method are designed and combined with the left-turn waiting area to overcome the shortcomings of the proposed intersection signal control model and control strategy.

Effect of horizontal curve geometry on vehicle speed distribution: a four-lane divided highway study

2019 ◽  
Vol 12 (10) ◽  
pp. 713-722 ◽  
Author(s):  
Gourab Sil ◽  
Suresh Nama ◽  
Avijit Maji ◽  
Akhilesh Kumar Maurya
Keyword(s):  
Vehicle Speed ◽  
Horizontal Curve ◽  
Speed Distribution ◽  
Curve Geometry

scholarly journals The shape of the continuous β -spectrum of thorium C. C'

1937 ◽  
Vol 162 (910) ◽  
pp. 391-403 ◽  
Author(s):  
H. O. W. Richardson ◽  
Alice Leigh-Smith ◽  
James Chadwick
Keyword(s):  
Low Energy ◽  
Considerable Proportion ◽  
Secondary Electrons ◽  
Fast Electrons ◽  
Low Energies ◽  
Ionisation Chamber ◽  
Pass Through ◽  
Slow Electrons ◽  
Primary Electrons ◽  
Apparent Conflict

The theories of β -decay based on the neutrino hypothesis predict that a considerable proportion of the electrons emitted from a heavy nucleus will have low energies, owing to the Coulomb attraction between the electron and the nucleus. This prediction has been in apparent conflict with most experimental curves (Madgwick 1927; Scott 1935 ), which show the ordinate of the energy distribution falling to zero at the origin or even before it, thus even indicating a low energy end-point below which no β -rays are emitted. It is, however, probable that the experimental uncertainties in the methods which have been used are such that no definite conclusion can be drawn from them about the shape of the low energy end of the spectrum. In these methods the source is deposited on a solid mounting and the emitted β -particles pass through a window in entering the detecting apparatus, which may be a counter, a cloud chamber or an ionisation chamber. The window stops all β -particles below a certain energy, while those which pass through are reduced in energy and considerably scattered. These effects, which are well shown in curves given by Eddy (1928), produce a marked falling off in the observed number of β -particles of low energy. The use of a solid mounting for the source introduced opposite effects giving an increased number of slow electrons; for firstly, the fast electrons will eject slow secondary electrons from the solid mounting and, secondly, if the mounting is thick, a considerable reflexion of the primary electrons will occur with varying losses of energy inside the solid, so that the reflected spectrum will contain relatively more low energy rays.

scholarly journals Modelling and Simulation of Cooperative Control for Bus Rapid Transit Vehicle Platoon in a Connected Vehicle Environment

2017 ◽  
Vol 29 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Jiahui Liu ◽  
Peiqun Lin ◽  
Jing(Peter) Jin
Keyword(s):  
Cooperative Control ◽  
Control Model ◽  
Bus Rapid Transit ◽  
Time Interval ◽  
Connected Vehicle ◽  
Rapid Transit ◽  
Vehicle Platoon ◽  
Connected Vehicle Technology ◽  
Pass Through ◽  
Set Up

The aim of this paper is to develop a cooperative control model for improving the operational efficiency of Bus Rapid Transit (BRT) vehicles. The model takes advantage of the emerging connected vehicle technology. A connected vehicle centre is established to assign a specific reservation time interval and transmit the corresponding dynamic speed guidance to each BRT vehicle. Furthermore, a set of constraints have been set up to avoid bus queuing and waiting phenomena in downstream BRT stations. Therefore, many BRT vehicles are strategically guided to form a platoon, which can pass through an intersection with no impedance. An actual signalized intersection along the Guangzhou BRT corridor is employed to verify and assess the cooperative control model in various traffic conditions. The simulation-based evaluation results demonstrate that the proposed approach can reduce delays, decrease the number of stops, and improve the sustainability of the BRT vehicles.

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