Study On Geometry Alignment Safety Of Two-lane Road Based On Natural Guidance Of Driver

Two-lane highway occupies a large proportion in the road network of our country,whose complex alignment and traffic composition increases the amount of information in the road environment and the difficulty of the driver receiving information,increasing the driver's visual load,making a serious impact on traffic safety.From the driver's visual characteristics and psychological needs,analyzing the influence of different road conditions on the driver's vision of two-lane highway,Studying on the laws of different linear design parameters and the driver's visual load,which improves the traffic safety level of two lane highway is of great significance.First,from the geometric alignment characteristics and the driver's visual characteristics of two-lane road,the influence of geometric alignment condition and section layout of two lane highway on the driver's dynamic visual characteristics and traffic safety is analyzed,the driver's eye movement test is designed.Secondly,using the Eye Pro Smart 5.7 eye tracker and GNSS receiver to carry out the driver's eye movement test and recording the driver's eye movement parameters.The sensitivity of the driver's visual load is determined by the percentage of the driver's pupil diameter,the percentage of fixation time and the percentage of scanning time,that analyses the variation characteristics of the driver's pupil diameter,the percentage of fixation time,the discrete factor of the visual angle and the position of the fixation point.Then,the calculation formula of visual load intensity is determined by the principal component analysis method,it analyses on the relationship between the visual load intensity and the parameters of the double lane highway horizontal and vertical section.The value of visual load intensity decreases with the increase of the length of the straight line segment.The F value decreases with the increase of the radius of circular curve.The visual load value of CCR value less than 0.5 °/m is low and tends to be stable.The value of F increases with the increase of the slope,straight and curved slope.The slope of the slope,the length of the transition curve and the length of the slope had no significant influence on the visual effect of the drivers.Combined with the relationship between driver's visual load and road natural guidance.It found that the natural leading index is less than or equal to 3 in the straight line segment and the curved slope section,or less than or equal to 3.5 in the reverse curve between the straight line segments,the linear nature guidance of the front road is great and the driver's physiological comfort is better.The influence of sight distance on the vision of the driver is influenced in the section landscape environment,calculating crossing the horizon and drawing the envelope of horizon rendering,for occlusion horizon should be clearing vegetation to the excavation line height.Third,the choice of load degree to characterize the ability of the driver to accept and deal with road information.It analyzes the influence of road environment complexity on driver's load level and determines the limit value of the load level is 10;Selection of information processing time for the evaluation of the road alignment of natural excellent indicators.It determines the evaluation standard and puts forward the corresponding improvement measures.Finally,Study on geometry alignment and geometry section safety of two-lane road based on natural guidance of driver.When the road changes from one line to another,it is necessary to set the 6S pre judgment distance for the driver to identify and plan the road ahead.The level of light stimulation and the diversity of driving environment should be taken into consideration in the layout of the line section in the geometric section.The inner side of the bend section should ensure enough sight distance and the outer side should be closed to avoid visual mutation.