scholarly journals Overtaking Safety Evaluation and Setting of Auxiliary Lane on Two-Lane Highway in China

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Guozhu Cheng ◽  
Lixin Wu ◽  
Liang Xu ◽  
Lihui Qin ◽  
Yuxia Wang
Keyword(s):  
Traffic Safety ◽  
Delphi Method ◽  
Safety Evaluation ◽  
Cauchy Distribution ◽  
Traffic Volume ◽  
Safety Level ◽  
Traffic Conflict ◽  
Relationship Model ◽  
Design Speed ◽  
The Relationship

Overtaking experiments on four two-lane highways were conducted. The data of overtaking conflict time (the time difference between the time of driving back to the original lane and the time of meeting with the first opposing vehicle) and experimental drivers’ risk feeling were observed. Membership was adopted to denote the experimental drivers’ risk feelings which also denote the severity of traffic conflict. Membership ranges from 0 to 1 and corresponding risk becomes higher; that is, traffic conflict becomes more serious. According to the observed relationship between overtaking conflict time, and drivers’ risk feeling membership, Cauchy distribution function was adopted as membership function. The thresholds of the severity of traffic conflict were determined through Delphi method. The relationship model among traffic volume, overtaking conflict time and design speed was established according to experimental data. Then the idea of setting auxiliary lane on two-lane highway in China was presented. And the traffic volume values that need setting auxiliary lane corresponding to different design speed and traffic conflict degree were given according to the established model. It is expected to improve the traffic safety level of two-lane highway in China through setting auxiliary lane.

scholarly journals A Safety Evaluation Model of Intersections under Mixed Traffic Conditions Using Traffic Conflicts and Cloud Model

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xuan Can Vuong ◽  
Rui-Fang Mou ◽  
Trong Thuat Vu ◽  
Van Hung Tran ◽  
Chi Trung Nguyen
Keyword(s):  
Traffic Safety ◽  
Traffic Accidents ◽  
Cloud Model ◽  
Evaluation Model ◽  
Safety Evaluation ◽  
Actual State ◽  
Practical Implementation ◽  
Safety Level ◽  
Traffic Conflict ◽  
Accident Data

Safety evaluation of traffic conflict is a very important and challenging issue in evaluating intersection safety under incomplete traffic accident data conditions and is also one of the main safety surrogate measures of analyzing accident data recently. It helps to analyze and solve intersection problems comprehensively and deeply. From there, it helps to improve traffic safety as well as reduce the risk of traffic accidents at intersections. Various evaluation methods based on traffic conflict have been proposed to make conflict safety levels at intersections more consistent and objective. However, a major concern is that many existing measurements are still subjective and are not easy to obtain uniformly. This study aimed to develop a model for safety evaluation at intersections in a comprehensive way that may be expected to directly link to the severity of the accident from different evaluation indicators. First, the three factors, including time to collision (TTC), conflicting speed (CS), and deceleration rate (DR) to avoid a crash, are introduced into safety evaluation of conflicts as the indicators. And then, as regards the fuzziness and randomness of the evaluation indicators, the qualitative concept has to be converted into a quantitative one utilizing cloud model, which implements the natural transformation between the qualitative concept of the safety level of traffic conflict and the membership degree of the evaluation indicators corresponding to the different safety levels. Finally, an indicator weight model is built based on the information entropy and the AHP method to determine the safety level. We illustrate the practical implementation of the proposed method using actual data of a typical signalized intersection from Hanoi City of Vietnam. The results indicate that traffic conflict analyzed by the proposed method was appropriate with actual state of the intersection, and the proposed method is simple, effective, and feasible, so it has a certain application value.

scholarly journals Modeling and Application of Pedestrian Safety Conflict Index at Signalized Intersections

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Cheng ◽  
Ning Zhang ◽  
Wei Li ◽  
Jianfeng Xi
Keyword(s):  
Safety Evaluation ◽  
Pedestrian Safety ◽  
Evaluation Study ◽  
Signalized Intersections ◽  
Safety Level ◽  
Intersection Safety ◽  
Road Users ◽  
Traffic Conflict ◽  
Vulnerable Road Users ◽  
The City

Traffic conflict between turning vehicles and pedestrians is the leading cause of pedestrian fatalities at signalized intersections. In order to provide a solution for evaluating intersection safety for vulnerable road users, this paper first determines the most important factors in analyzing pedestrian-vehicle conflict and puts forward a pedestrian safety conflict index (SCI) model to establish a quantitative standard for safety evaluation of two- or multiphase intersections. A safety level system is then designed based on SCI to help categorize and describe the safety condition of intersections applicable to the model. Finally, the SCI model is applied to the evaluation of two intersections in the city of Changchun, the result of which complies with expectation, indicating the model’s potential in providing an improved approach for pedestrian-vehicle conflict evaluation study.

Relationship Between Volume-to-Capacity Ratios and Accident Rates

1997 ◽  
Vol 1581 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Min Zhou ◽  
Virginia P. Sisiopiku
Keyword(s):  
Traffic Volume ◽  
The Other ◽  
Explanatory Factors ◽  
Traffic Conflict ◽  
Single Vehicle ◽  
Driver Inattention ◽  
Detroit Area ◽  
Accident Rates ◽  
The Relationship ◽  
Shaped Pattern

The general relationships between hourly accident rates and hourly traffic volume/capacity ( v/c) ratios were examined. A 26 km (16 mi) segment of Interstate I-94 in the Detroit area was selected as the study segment. The v/c ratios were calculated from average hourly traffic volume counts collected in 1993 and 1994 from three permanent count stations. Accident rates were derived from hourly distributed number of accidents in the same 2 years. The correlation between v/c values and accident rates follows a general U-shaped pattern. The study of all observed accidents combined indicates that accident rates are highest in the very low hourly v/c range, decrease rapidly with increasing v/c ratio, and then gradually increase as the v/c ratio continues to increase. U-shaped models also explain the relationship between v/c and accident rates for weekdays and weekend days, multivehicle, rear-end, and property-damage-only accidents. On the other hand, single-vehicle, fixed-object, and turnover accidents, and accidents involving injury and fatality follow a generally decreasing trend with increasing v/c ratio. Traffic conflict is viewed as a major contributing factor to high accident rates observed in the high v/c range, whereas night conditions and driver inattention were identified as explanatory factors for the occurrence of high accident rates in the low v/c ranges.

scholarly journals Research on the Safety Audit Methods for Two-Lane Highway Based on HRV

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zhan-dong Zhu ◽  
Ying-chih Lu ◽  
Cheng-hong Fu ◽  
Ting Xu
Keyword(s):  
Velocity Gradient ◽  
Road Safety ◽  
Evaluation Criteria ◽  
Safety Evaluation ◽  
Operating Speed ◽  
Acceleration Rate ◽  
Design Speed ◽  
Route Safety ◽  
The Relationship ◽  
Speed Gradient

In order to explore stable route safety evaluation indicators, this study discusses the relationship between the heart rate variability (HRV) and other factors, such as design speed, operating speed, acceleration rate, and velocity gradient through a lot of experiments. The results show that operating speed coordination and velocity gradient (Gv) outperform others as road safety indicators. Speed coordination evaluation criteria:|ΔV85|≤10 km/h, good coordination; 10 km/h≤|ΔV85|≤ 20 km/h, general coordination, route indicators of adjacent sections should be adjusted, so that the speed difference is not more than 10 km/h;|ΔV85|≥20 km/h, poor speed coordination, it needs to readjust the design of the adjacent sections. Speed gradient evaluation criteria:Gv≤0.10, good road safety;0.10≤Gv<0.15, common road safety;Gv>0.15, poor road safety and the adjacent sections need to readjust. The conclusions provide the theoretical reference for highway safety evaluation.

scholarly journals Research on Truck Traffic Volume Conditions of Auxiliary Lanes on Two-Lane Highways

2021 ◽  
Vol 13 (23) ◽  
pp. 13097
Author(s):  
Guozhu Cheng ◽  
Changru Mu ◽  
Liang Xu ◽  
Xuejian Kang
Keyword(s):  
Evaluation Method ◽  
Traffic Volume ◽  
Truck Traffic ◽  
Time Model ◽  
Traffic Efficiency ◽  
Vehicle Test ◽  
Design Speed ◽  
Auxiliary Lanes ◽  
The Impact ◽  
The Relationship

The larger the proportion of truck traffic volume, the greater the impact on traffic efficiency, and overtaking behavior will also have an impact. Therefore, in order to clarify the truck traffic volume of the freight two-lane highway due to the difficulty of overtaking, an actual vehicle test is carried out. This involves selecting the appropriate two-lane test section, recording each moment and speed in the driver’s overtaking behavior, performing multiple regression analysis to examine the relationship between the overtaking conflict time and design speed and traffic volume, determining a reasonable evaluation series of two-lane road overtaking risk and the corresponding overtaking conflict time threshold by the Fisher optimal segmentation method, and giving an overtaking behavior risk evaluation method based on conflict time. Finally, according to the overtaking conflict time model, different truck traffic conditions are obtained. The research results show that overtaking conflict time is negatively correlated with the traffic volume and design speed of the lane. Through the risk assessment of the corresponding overtaking behavior, the three levels of serious conflict, general conflict and non-conflict are determined, and the freight traffic volume corresponding to different conflict levels at different speeds is calculated, which provides a reference for setting auxiliary lanes for the two-lane freight highway.

scholarly journals In Search of the Consequence Severity of Traffic Conflict

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Ruoxi Jiang ◽  
Shunying Zhu ◽  
Pan Wang ◽  
QiuCheng Chen ◽  
He Zou ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Evaluation Method ◽  
Prediction Models ◽  
Safety Evaluation ◽  
Threshold Value ◽  
Two Dimensions ◽  
Trajectory Data ◽  
Traffic Conflicts ◽  
Traffic Conflict ◽  
Accident Data

Currently, many studies on the severity of traffic conflicts only considered the possibility of potential collisions but ignored the consequences severity of potential collisions. Aiming toward this defect, this study establishes a potential collision (serious conflict) consequences severity model on the basis of vehicle collision theory. Regional vehicles trajectory data and historical traffic accident data were obtained. The field data were brought into the conflict consequences severity model to calculate the conflict severity rate of each section under different TTC thresholds. For comparison, the traditional conflict rate of each section under different TTC thresholds that considered only the number of conflicts was also calculated. Results showed that the relationship between conflict severity rate and influencing factors was somehow different. The conflict severity rate seemed to have a higher correlation with accident rate and accident severity rate than conflict rate did. The TTC threshold value also affected the correlation between conflicts and accidents, with high and low TTC threshold indicating a lower correlation. The results showed that conflict severity rate that considered each single conflict consequence severity was a little better than the traditional conflict rate that considered only the numbers of conflicts in reflecting real risks as a new conflict evaluation indicator. The severity of traffic conflicts should consider two dimensions: the possibility and consequence of potential collisions. Based on this, we propose a new traffic safety evaluation method that takes into account the severity of the consequences of the conflict. More data and prediction models are needed to conduct more realistic and complex research in the future to ensure reliability of this new method.

Relationships between Road Safety and Traffic Volume Based on Fuzzy Matter-Element Model

2014 ◽  
Vol 568-570 ◽  
pp. 1875-1879
Author(s):  
Sheng Nan Zhang
Keyword(s):  
Traffic Safety ◽  
Road Safety ◽  
Evaluation System ◽  
Element Model ◽  
Flow Speed ◽  
Traffic Volume ◽  
Traffic Density ◽  
Security Level ◽  
Safety Level ◽  
Matter Element Model

In order to study road safety as well as the relationship between traffic volume and traffic safety, we introduce matter-element model to build safety evaluation system. In this model, we can get quantitative values of the degree how much it belongs to the certain safety level, including six security indexes such as traffic volume, traffic density and traffic-flow speed, as well as four different security levels. By combining two traffic conditions of the same section, we change the initial parameters of the traffic model to get security level grades of the two conditions. The results showed that with the increase in traffic volume, road safety decreases. However, when the traffic volume increases further, the road safety increases instead.

Evaluation of Road Traffic Safety in Huai Yin District of Jinan City Based on AHP

2014 ◽  
Vol 505-506 ◽  
pp. 1167-1171
Author(s):  
Ya Fei Wang ◽  
Dong Xu Zhang
Keyword(s):  
Traffic Safety ◽  
Structural Model ◽  
Road Traffic ◽  
Safety Evaluation ◽  
Self Assessment ◽  
Analytic Hierarchy ◽  
Safety Level ◽  
The Road ◽  
Road Traffic Safety ◽  
Jinan City

Analytic Hierarchy Process (AHP), which needs less information and shorter time on decision-making, is selected for road traffic safety evaluation in this paper. Combined with the instance in Huai Yin district of Jinan city, the structural model that includes road conditions, intersections, straight sections, bends and ramps is proposed. Delphi method was used to construct the judgment matrix and then the MATLAB was used to calculate the corresponding weights of the various index of the entire road system. Combined with self-assessment of each index, then the safety level of the road is figured out.

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