Research On The Characteristics Of Vehicle Operating Speed And Trajectory In Highway Work Zone

At present,the highways built in the early stage of our country have entered the stage of large and medium-sized road repair,reconstruction and expansion.Compared with other normal road sections,highway sections have problems such as low speed limit and narrow passages.When driving through this area,the driver’s driving behavior is likely to be distorted and cause traffic accidents.Therefore,this paper takes the running speed and driving trajectory of vehicles in the highway work zone as the research object,reveals the influence of the changes in the layout parameters of the work zone on the driving behavior,establishes the driving behavior model of the work zone of the expressway,and formulates Optimization.Firstly,on the basis of studying the domestic and foreign road maintenance operation specifications,determines the type of operation area referenced by the actual vehicle test,selects the operation area layout and sets key parameters for research.Combined with the actual conditions of the operating area of the highway,design an experimental plan,and recruit drivers to carry out real-vehicle tests in an enclosed area to collect key driving behavior indicators such as speed,acceleration and lateral spacing to characterize the driver’s speed selection and direction control behavior.Furthermore,with the help of statistical methods such as analysis of variance and regression analysis,the driving behaviors under different layouts in the work area are analyzed,and the influence of the layout setting parameters on the driving behavior is studied,which provides a theoretical basis for the optimization of the layout parameters of the work area.The main conclusions of this study are as follows:(1)In the study of the operating speed characteristics of vehicles in the work zone,it was found that when the vehicle is traveling in the upstream transition area,the instantaneous speed of the vehicle entering the upstream transition area,the acceleration peak during the acceleration process,and the average vehicle speed would be affected by the speed limit condition.During driving in the activity area,the maximum driving speed of the driver,the starting point of deceleration,the speed of the vehicle leaving the working area,the peak deceleration and the average speed of the deceleration process are mainly affected by the reserved driving width.Drivers of different proficiency levels have different speed control behaviors,and driving experience has a significant impact on various driving behavior indicators.(2)The driving process of the vehicle in the working area is mainly divided into three stages: acceleration,stability and deceleration.The length of the skilled driver in the acceleration and deceleration phase is longer than that of the unskilled driver,and the length of the constant speed phase is shorter than that of the unskilled driver.As the length of the working area is extended,the length of the deceleration phase is shortened,and the length of the uniform speed phase is increased;as the width of the working area channel is narrowed,the length of the deceleration phase is gradually increased.By calculating the distribution characteristics of the variable speed length,it is found that most drivers can complete the deceleration operation within a length of 100 m and the acceleration operation within 120 m.Based on the analysis of the correlation between shift length and shift amplitude,a mathematical model of the driver’s shift length and shift amplitude is established.(3)When studying the characteristics of the vehicle’s driving trajectory in the work zone,it was found that the change of the vehicle’s driving trajectory can be divided into three stages: adjustment,mutation,and stability.By comparing the changes in the speed and trajectory of the road sections in the work area,it is found that the speed and trajectory of the vehicle have a high similarity.Unskilled drivers drive closer to the left than skilled drivers,and the trajectory fluctuates more.As the working area channel width becomes narrower,the vehicle’s driving trajectory further shifts to the left;with the extension of the working area,the unskilled driver’s driving trajectory is more to the left,and the skilled driver is more to the right.(4)On the basis of analyzing the characteristics of vehicle speed and trajectory changes,a safety evaluation method for the working area based on the minimum lateral spacing is proposed.By evaluating the risk of side collision accidents under different combinations of speed limits and widths,in order to ensure driving safety in the working area When the width is 3.5 m,the speed limit is set to 60 km/h;when the width is 3.25 m,the speed limit is set to 50 km/h;when the width is 3 m,the speed limit is set to 40 km/h.