Risk Analysis Of Traffic Safety Based On Driving Behavior At Signalized Intersection

Signalized intersection traffic safety is one of the relatively weak link in road traffic safety.With the rapid growth of the number of drivers in our country,the different characteristics between the drivers is increasing,and the traffic safety at the signalized intersection is facing new challenges.This challenge is mainly due to the risk caused by the diversity of lane-changing behavior and the dilemma when the drivers at signalized intersections approach.Based on this,we make a quantitative analysis of the different driving tendencies of drivers' lane-changing behavior and the dilemma by collection of vehicle trajectory data in the real road and the dynamic traffic environment in this dissertation.The risk prediction model of lane-changing behavior and the risk prediction model of the dilemma collision are established to analyze the traffic safety risk under different driving tendencies when the drivers at signalized intersections approach.The research of this paper is of great significance to understand the relationship between driver's driving tendency and traffic safety at signalized intersection,and to improve the traffic safety management level of signalized intersection.Firstly,the driving tendency of the driver is summarized,and the questionnaire,simulation test and real vehicle test are designed to collect various characteristic indexes of driving tendency.The questionnaire mainly obtains three factors that affect the experimenters'driving skills,safety awareness and driving tendency.The simulation test collects the experimenters' response time and velocity estimation ability.The real vehicle test collects the experimenters' lane changing frequency,accelerate frequency and braking frequency.On the basis of this,the driving tendencies of the experimenters are divided into three types:aggressive,steady and conservative by using K-means clustering analysis.Secondly,the characteristics of the traditional vehicle trajectory acquisition method(high point recording method,experimental vehicle method and simulated driving method)are analyzed.Aiming at the driver's lane changing behavior,the traditional method of' vehicle trajectory acquisition is improved,and a high-point recording method combined with the experimental vehicle method is used to colect the trajectory data of lane changing vehicles.In view of the driver's dilemma selection behavior,using the traditional video method to collect the trajectory data of the vehicles in the dilemma zone.The Tracker software is used to extract the trajectory data and then the data is converted by the camera imaging theory.The real trajectory data after the conversion is smoothed,and the driving behavior of the driver with different driving tendency is calculated separately.Thirdly,the meaning of driving behavior is sorted and interpreted from both macro and micro levels,and the driving characteristics of driving behavior are determined from the micro level.For the lane changing behavior,the position of the implementation of the lane change,the duration of the lane change,the velocity during the lane change,and the spacing between the vehicles are determined to be the influencing factors.For the dilemma selection behavior,the distance to the stop line,the velocity,the acceleration,the deceleration,the headway are determined to be the influencing factors.On this basis,the lane changing driving behavior and the dilemma selection behavior under the aggressive,steady and conservative driving tendencies are described and analyzed respectively.Then,this dissertation defines the Integrated Conflict Risk Index(ICRI),which takes into account the probability and severity of risk.Using the index as the dependent variable,four risk levels are determined:zero risk level,low risk level,middle risk level and high risk level.Based on this,the risk prediction model of implementing the lane-change process is established.The model results show that the vertical velocity,the spacing between the target vehicle and the vehicle in the target lane and the driving tendency of drivers have a significant effect on the conflict risk caused by the vehicle lane change process.Compared with the zero risk level,when the longitudinal velocity increases,the spacing between the target vehicle and the vehicle in the target lane decreases,the aggressive driving tendency increase,the odds caused by the vehicle lane changing at low risk level,middle risk level and high risk level have different degrees of increase.The model can also be used to predict the probability that the lane changing behavior is at different risk levels under certain conditions.It can provide the calculation method and theoretical basis for the traffic simulation model at the lane changing behavior.Finally,based on the analysis results of the driver's dilemma selection behavior,the model of the driver's binary selection(continued driving or stopping)including the driving tendency factors in the phase transition period is established to determine the boundaries of the dilemma zone under different driving tendencies.On the basis of this,the risk prediction model of rear collision and the risk prediction model of lateral collision are established.Monte Carlo simulation is used to show that the probability of lateral collision is higher than that of rear-end collision in the dilemma.In addition,the risk of collision is different because of the different driver's driving tendency,the degree of impact on the risk of collision from the large to small driving in order:aggressive,conservative,steady.