Research On Prediction Model Of Operating Speed For Passenger Cars On Expressway Interchange Single-lane Entrance And Exit

In recent years,with the increasing mileage of expressway in China,the number of interchange on the expressway has been increasing,and the traffic safety problem of expressway interchange is becoming more and more serious.There are a lot of security risks on expressway interchange entrance and exit in the design stage and operation period.Existing "Specifications for highway safety audit" in the use of vehicle operating speed to carry out safety evaluation has achieved good results,but this specification does not stipulate the speed of expressway interchange entrance and exit,and it is imperative to carry out research on the operating speed of expressway interchange entrance and exit.Based on the analysis of the traffic accidents in the main line of expressway interchange range in Sichuan Province,this paper draws the conclusion that the number of traffic accidents in the expressway interchange is obviously higher than the basic section of the main line of the expressway and the number of the exit is higher than that of the entrance.Based on the statistical analysis of the types of traffic accidents in expressway interchange entrance and exit,the rear-trailing accident is relatively large.From the view of safety,it is determined that the study area is expressway interchange entrance and exit,taking into account driving characteristics of the main line and speed-change lane to determine the influence factor of speed.The paper mainly analyzes the operating speed and acceleration of expressway interchange single-lane entrance and exit.The speed data of each record point is analyzed and summarized every 10 m by the SPSS from the gradual starting point and the convergence of the nose in expressway interchange entrance and exit,and the vehicle dynamics simulation software CARSIM is used to analyze longitudinal acceleration.It is determined that the expressway interchange is divided into transition segment,deceleration segment and triangular segment,accelerated and changed lane segment.Based on the free flow of passenger cars as the research object,the use of chained radar to obtain real-time driving data of 12 interchange entrances and 12 interchange exits,passenger car speed descriptive statistics,the speed calculation to feature points,Differential test,collinearity analysis,regression coefficient analysis and independent parameter correlation test respectively,the operating speed predict models of expressway interchange single-lane entrance and exit are established,and the mean relative error value of four interchange entrances and four interchange exits is made and the models can meet the requirements.This paper studies the operating speed predict models of expressway interchange single-lane entrance and exit,which can help to improve the operating speed of the existing interchange entrances and exits,and ensure the smooth traffic of the expressway interchange and the driver ’s life and property.