There is a conflict between through motor vehicles and the left-turn non-motorized vehicles, and the capacity of straight-line motor vehicles decreases. This study analyzes the impacts of left-turn non-motorized vehicles on the capacity of through motor vehicle lanes. A correction coefficient model for calculating the reduced capacity of through motor vehicle lanes has been developed based on analysis of the conflicting points at an intersection and the negative exponential function of traffic flow distribution. With consideration of intersection geometric design, channelization, and traffic characteristics, the correction coefficient model was further enhanced by regression to capture the impacts of left-turn non-motorized vehicles from the same and the opposite directions. A simulation with VISSIM is used to validate the developed model. It shows that the calculated capacity from the correction coefficient model is close to the simulation results. The experiment indicates that the derived model is highly accurate in calculating the capacity of through motor vehicle lanes and has potential application for situations of mixed traffic in China. The study shows that the capacity of a through traffic lane at the permitted phase decreases with the increase of left-turning non-motorized vehicles, and the impact of left-turning non-motorized vehicles from the same direction is more significant. The results show that the traffic capacity of straight-line motor vehicle decreases with the increase of the left-turn non-motorized vehicles flow rate and the influence of the left-turn non-motor vehicle is more obvious. It is suggested that in practice, the correction coeffi-cient of non-motor vehicle on the left turn should be 0.88, and the correction coefficient on the left turn should be 0.95, respectively. The study recommends coefficient values for both non-motorized vehicles from the same and opposite directions for use in real applications.

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Highway guardrail is a kind of important road traffic safety facility. When a vehicle is travelling on a highway, it can lose control because of accident. The guardrail can prevent the vehicle from rushing directly out of the road, so as to reduce the injury to the driver in the vehicle. Therefore, the guiding performance, anti-collision performance and buffer performance of the guardrail are important indexes to reflect the highway guardrail safety in the traffic accidents between vehicle and guardrail. The process of collisions between vehicles and guardrails is a complex motion, affected by multiple factors such as the movement patterns and types of vehicles, the types of guardrail, the bending stiffness of the beams, the speed of collision, the angle of collision, etc. The accuracy of energy estimation when vehicle collides with guardrail is the foundation of highway guardrail design, installation and improvement. Many experts and scholars at home and abroad have done a lot of theoretical research and experimental verifications on the safety performance of highway guardrail, and analyzed the anti-collision ability and energy absorption effect of highway guardrail. Single degree of freedom model is the most widely used mathematical model of vehicle collision in highway guardrail. The traditional model is more suitable for calculating the maximum impact force of small vehicles, but it is not accurate for large vehicles. However, due to the unreasonableness of the model in the theoretical derivation process, there is a large error in the mathematical model, especially in estimating the accuracy of the energy value of the large vehicle collision guardrail. Practice shows that the current guardrail cannot withstand the impact of large vehicles. Once large vehicles collide with the corrugated beam guardrail, the guardrail will collapse in most cases, and the vehicle will rush out of the road directly, so it is very difficult to exert the protective function of the guardrail. The anti-collision performance of guardrail is poor, which is related to the existing calculation model, which results in insufficient strength in the design of guardrail.

There is a certain gas phase space in the filling of tank trucks, and the position of the liquid center of mass in the tank will change when the tank truck is being steered, which affects the driving stability of the vehicle. Taking the elliptical cross section of the tank truck body as the research object and based on the quasi-static mechanical model, the exact algorithm model of liquid centroid positions in different steering conditions of tank trucks have been deduced. Then, taking centrifugal acceleration, the liquid filling ratio, and the tank shape and dimension as independent variables and the centroid coordinates as the dependent variables, respectively, and applying MATLAB to describe the change of the liquid centroid position, the liquid centroid position in the elliptical tank truck is described when the elliptical tank truck is being steered. The factors affecting the steering stability of the tank truck are also analyzed. The conclusion provides a theoretical basis for further research into the running stability of tank trucks, the optimization of a tank’s shape and size, the modeling of lateral sloshing mechanics, and the software algorithm for the reconstruction of tank truck accidents.

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