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According to the accident investigation data, the accident rate of honghuawan hub interchange on the small radius ramp is significantly higher than that of other locations. Vehicles often collide with the waveform beam guard rails outside the curve and occasionally the truck rolls over. In order to study the cause of the accident here, the vehicle dynamics software CarSim and TruckSim were used to conduct experimental analysis under different simulation conditions, and the influencing factors of vehicle side slip and rollover on the small radius ramp and the formation mechanism of the accident were obtained. The research results show these as follows. The driving speed of the small passenger car has a significant effect on the driving stability of the small radius ramp, and the lateral offset and driver comfort are significant. When the ramp radius value is 60 ~ 65 m, in order to ensure the safety and comfort of the curve sex, the speed should not exceed 50 km/ h. In order to ensure driving safety, the long line segment should be set to the long line segment before the radius ramp curve, and the length of the sliding track is guaranteed. The larger the speed, the road surface The smaller the adhesion coefficient, the more serious the side slip of the vehicle, and the color anti-skid pavement should be added to the vertical turnover to improve the pavement attachment coefficient in this vertical turn. When the speed limit value is 40 km/ h, the tire load transfer rate is the smallest. The tire load transfer rate decreases with the increase of road superelevation and road adhesion coefficient, and increases with the increase of load and center of mass height. [ABSTRACT FROM AUTHOR]

In order to analyze the driving risks of drivers of vehicles of different driving styles, a high-density interchange driving test was carried out on the Chongqing Inner Ring Expressway. Vehicle-board instruments were used to collect vehicle driving trajectory, speed and other operating parameters, and parameters such as vehicle speed, acceleration and transverse displacement were extracted through factor analysis and clustering analysis. Based on this, the driving style was divided into three types, namely conservative, conventional and adventurous. Through the trajectory offset in the process of vehicle departure and integration into the main line, the trajectory characteristics of different driving styles were analyzed. The results show that the trajectory offset of adventure drivers is higher than that of the drivers of the other two driving styles, and the distribution of trajectory offset is more scattered. When driving away/ instreaming the main line, the adventure driver needs. The lane change time is shorter, the starting position of lane change is higher, and the frequency of lane change is more than the other two driving styles. Speed fluctuation and acceleration fluctuation are used as driving risk evaluation indicators, both sizes are adventurous > conventional > conservative. The entropy weight method is used to determine the index weight and get the driving risk rate, which is not Classifying the same driving style, the results show that at the exit of the main line, there are obvious distribution characteristics, that is, the adventure type > conventional type > conservative type, while at the entrance of the main line, the driving risk rate of the adventure type and the conventional type is no different, but the distribution of adventure drivers is more discrete. Analyzing the driving risk rates of drivers of different driving styles will help improve the driving safety of drivers. [ABSTRACT FROM AUTHOR]

In order to clarify the lateral acceleration characteristics of vehicles in the turning curve section of low-grade highway in mountainous areas, a section of mountain road with 12 reversing curve sections in Pengshui County, Chongqing was selected as the experimental object, and a driving test of 20 drivers was carried out. The vehicle operating parameters in the driving state, including speed, trajectory and lateral acceleration, etc., were analyzed for the amplitude characteristics, change mode and peak position distribution of lateral acceleration in the turning curve segment. The results show as follows. The overall variation characteristics of vehicle lateral acceleration in the reverse curve segment can be divided into three stages: increasing stage of entering, stable stage of turning and decreasing stage of exiting. According to the overall change trend of 85 th percentile value of lateral acceleration, the lateral acce-leration can be divided into four variation modes. The 85 th percentile value of left and right lateral acceleration is 3.85 m/s² and 3.69 m/s² respectively. Compared with the general curve, the driver can tolerate a higher degree of lateral discomfort in the curve. In the process of left and right turns, the lateral peak acceleration of each turn is mainly concentrated between the middle point of the curve and the slow point of the circle, that is, the latter half of the circle curve. [ABSTRACT FROM AUTHOR]