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.

Research on the Method of Dynamic Speed Limit on Expressway under Complex Climate Based on Pavement Skid-Resistant Performance

2013 ◽  
Vol 723 ◽  
pp. 189-195
Author(s):  
Yong Fang ◽  
Zhong Yin Guo
Keyword(s):  
Traffic Safety ◽  
Water Film ◽  
Calculation Model ◽  
Climatic Conditions ◽  
Driving Safety ◽  
Maximum Speed ◽  
Speed Limit ◽  
Vehicle Speed ◽  
Climate Conditions ◽  
Pavement Condition

To solve the problems in the current deterministic method of a maximum speed limit for expressway, a method of dynamic speed limit on expressway under complex climate was presented which was based on pavement skid-resistant performance. Firstly, the variation of pavement skid-resistant performance under complex climate conditions was analysed based on research results and certain experimental statistic data. By analysing the influence rule of AC-16 and SMA-16 pavement texture, pavement temperature, water film thickness, ice thickness, vehicle speed to pavement Skid-Resistant Performance, pavement actual friction coefficient calculation model and reference standard were established under different pavement condition Then, by analysing the geometry line indexes, pavement conditions and vehicle dynamics, the critical sideslip speed and critical longitudinal-driving safety speed was formulated; therefore, with critical speed as a constraint of safety driving and interval classification of complex climatic conditions, the dynamic speed calculate method and safety speed control standard were proposed under various pavements conditions, visibilities and traffic environments. This method for overcoming the weakness of a maximum speed limit of expressway operation and improving traffic safety is helpful.

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.

scholarly journals Research on the Influence of Vehicle Speed on Safety Warning Algorithm: A Lane Change Warning System Case Study

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2683
Author(s):  
Rui Fu ◽  
Yali Zhang ◽  
Chang Wang ◽  
Wei Yuan ◽  
Yingshi Guo ◽  
...  
Keyword(s):  
Warning System ◽  
Relative Distance ◽  
Driving Safety ◽  
Lane Change ◽  
Vehicle Speed ◽  
Accuracy Rate ◽  
Safety Warning ◽  
Change Characteristics ◽  
Speed Level

Speed has an important impact on driving safety, however, this factor is not included in existing safety warning algorithms. This study uses lane change systems to study the influence of vehicle speed on safety warning algorithms, aiming to determine lane change warning rules for different speeds (DS-LCW). Thirty-five drivers are recruited to carry out an extreme trial and naturalistic driving experiment. The vehicle speed, relative speed, relative distance, and minimum safety deceleration (MSD) related to lane change characteristics are then analyzed and calculated as warning rule characterization parameters. Lane change warning rules for a rear vehicle in the target lane under four-speed levels of 60 ≤ v < 70 km/h, 70 ≤ v < 80 km/h, 80 ≤ v < 90 km/h, and v ≥ 90 km/h are established. The accuracy of lane change warning rules not considering speed level (NDS-LCW) and ISO 17387 are found to be 87.5% and 79.8%, respectively. Comparatively, the accuracy rate of DS-LCW under four-speed levels is 94.6%, 93.8%, 90.0%, and 92.6%, respectively, which is significantly superior. The algorithm proposed in this paper provides warning in the lane change process with a smaller relative distance, and the accuracy rate of DS-LCW is significantly superior to NDS-LCW and ISO 17387.

The Prediction of Vehicle Collision Risk in Traffic Conflict Zone Based on Bayesian Network

2015 ◽  
Vol 744-746 ◽  
pp. 1953-1959 ◽  
Author(s):  
Li Xin Yan ◽  
Song Gao ◽  
Hao Cai ◽  
Hui Wan
Keyword(s):  
Bayesian Network ◽  
Traffic Safety ◽  
Driving Safety ◽  
Posteriori Probability ◽  
Vehicle Speed ◽  
Collision Risk ◽  
Traffic Environment ◽  
Traffic Conflict ◽  
Probability Table ◽  
Probability Of Collision

The external traffic environment has a big influence to the traffic safety during the area of traffic conflict place，and to analysis the relationship between the external traffic environment factors and driving safety is helpful to improve the traffic safety. The method of comprehensive analysis the historical data and expert survey data is used to explore this question. And at the same time, the collision risk prediction model during the traffic conflict place is built by the Bayesian network. According to the data analyzing, the node variable, the state of variable and the conditional probability table of this model is also built. Finally, the software of Hugin is used to deal with the posteriori probability of collision risk, and the result proved that this model can predict the collision risk accurately during the traffic conflict area, and the data analyzing showed that the factor of the driver's intention, the vehicle speed and the headway have a significance influence to the traffic safety.

Freeway Speed Limit Considering the Traffic Efficiency

2012 ◽  
Vol 598 ◽  
pp. 135-138
Author(s):  
Zhang Yi ◽  
Yang Dong Zhao
Keyword(s):  
Traffic Safety ◽  
Service Level ◽  
Shanxi Province ◽  
Speed Limit ◽  
Important Indicator ◽  
Safety Issues ◽  
The Road ◽  
Traffic Efficiency ◽  
Multiple Factors ◽  
Traffic Operation

The speed is an important indicator of the traffic flow. The speed also reflects the road service level, and it is especially important on the freeway. The speed that is reasonable or not will influence the traffic operation situation, traffic safety issues and so on. This paper considered factors of three aspects to set the speed limit of freeway and analyzed the speed limit with the case Xi-Bao Freeway, Shanxi Province. Because of considering multiple factors of multiple aspects, the speed limit of freeway will be much rational and much scientific.

scholarly journals Variable Speed Limit Control Method of Freeway Mainline in Intelligent Connected Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xingju Wang ◽  
Rongqun Zhang ◽  
Yang Gou ◽  
Jiayu Liu ◽  
Lin Zhao ◽  
...  
Keyword(s):  
Traffic Congestion ◽  
Traffic Management ◽  
Control Method ◽  
Driving Safety ◽  
Speed Limit ◽  
Connected Vehicle ◽  
Variable Speed ◽  
Control Effect ◽  
Variable Speed Limit ◽  
Traffic Efficiency

Freeway is an important component of transportation system. Bottleneck areas on freeway reduce driving safety and traffic efficiency. The development of intelligent connected technology provides a new idea for traffic management. In order to alleviate traffic congestion on the freeway bottleneck area, this paper proposes a variable speed limit (VSL) control method in intelligent connected environment. In this paper, the METANET model is improved by combining intelligent connected environment and VSL control theory. The total traffic capacity (TTC), total travel time (TTT), and total speed difference (TSD) are used to build multiobjective function. The microsimulation at SUMO by using the data from PeMS is employed as a case study to validate the proposed model. The results show that the VSL online control method in intelligent connected environment has better control effect. And the improvement is more obvious with increasing penetration rate of intelligent connected vehicle (ICV).

scholarly journals Relationship between heavy vehicle speed limit and fleet fuel consumption on minor roads

2015 ◽  
Vol 230 (9) ◽  
pp. 1461-1478
Author(s):  
G Wilson ◽  
G Morrison ◽  
W Midgley ◽  
D Cebon
Keyword(s):  
Fuel Consumption ◽  
Traffic Safety ◽  
Traffic Congestion ◽  
Driver Model ◽  
Speed Limit ◽  
Vehicle Speed ◽  
Selection Scheme ◽  
Vehicle Trajectories ◽  
Model Fuel ◽  
Heavy Goods Vehicles

This paper investigates the traffic-related effects of a proposal to increase the speed limit from 40 mile/h to 50 mile/h, for heavy goods vehicles greater than 7.5 tonnes, on single carriageway roads. A ‘microscopic’ single carriageway traffic simulation is developed by combining the ‘enhanced intelligent driver model’ with a single carriageway gap-acceptance passing model. Fuel consumption estimates are made using engine characteristic maps and a ‘fuel optimal’ gear selection scheme, where vehicle trajectories from the traffic simulations are taken as input drive-cycles. Traffic congestion and fleet fuel consumption are specifically addressed, though implications regarding passing behaviour and traffic safety are also noted. Results indicate that the proposed 50 mile/h heavy goods vehicles speed limit would reduce traffic congestion by over 37% and increase fleet fuel consumption by approximately 0.5 L/100 km.

Theoretical Calculation of the Maximum Speed Limit Value on Freeway in Adverse Weather

2012 ◽  
Vol 209-211 ◽  
pp. 663-666
Author(s):  
Yu Feng Guo ◽  
Guo Zhu Cheng
Keyword(s):  
Theoretical Calculation ◽  
Traffic Safety ◽  
Road Traffic ◽  
Driving Safety ◽  
Maximum Speed ◽  
Speed Limit ◽  
Safety Level ◽  
Road Traffic Safety ◽  
Limit Value ◽  
Adverse Weather

In order to increase driving safety level on freeway, the paper analyzed the affecting mechanism of rainy day, snowy day and foggy day on road traffic safety. Considering that the sum of running distance and braking distance is less than visible distance, theoretical calculation formula of maximum speed limit value on freeway in adverse weather was presented based on the safe distance. Suggestions values of corresponding speed limit were given according to different visible distance, road fiction coefficient and grade.

Research on the Traffic Safety on the Section of Expressway with Crosswind in Mountainous Area

2014 ◽  
Vol 694 ◽  
pp. 102-108
Author(s):  
Zheng Yi Zhang ◽  
Gao Lu Qian ◽  
Qiang Wang ◽  
Ling Wu
Keyword(s):  
Traffic Safety ◽  
High Speed ◽  
Lateral Force ◽  
Driving Safety ◽  
Horizontal Wind ◽  
Mountainous Area ◽  
Speed Limit ◽  
Mountainous Areas ◽  
Factors Affecting ◽  
Security Issues

When we drive vehicle on expressway in the mountainous areas, there are many factors affecting driving safety. Especially when we drive at a high speed, pneumatic lateral force under the effect of horizontal wind will cause wheels cornering and unsteady steering, which affects the safety of driving. Based on the driving characteristics on the section of expressway with crosswind in mountainous areas, and three security issues that are vehicle roll, cornering and sideslip under the action of crosswind, this paper gives the various speed limit and proposes effective measures to ensure traffic safety, all of which can offer decision-making basis for traffic safety administration of the mountain expressway.

The difference in the warning effect of different warning signs

2020 ◽  
pp. 1-11
Author(s):  
Wuji Lin ◽  
Jingyuan Lin ◽  
Yang Yang ◽  
Jiejie Liao ◽  
Weijie Chen ◽  
...  
Keyword(s):  
Warning Signs ◽  
The Difference ◽  
Warning Effect
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