A Study On The Safety Of Continuouos Long Downgrade Section Of Highways In Mountainous Areas Based On Driving Behavior

Due to the constraints of mountainous terrain,expressway is often difficult to spread.Continuous long and steep slope sections have large difference,steep longitudinal slope and long,many corners and large corners,and high risk of accidents.From the perspective of driver's vision,the paper analyzes the influence of different road factors on the vision and its behavior,and studies the safety evaluation method of the continuous growing and downhill section of mountain expressway based on driving behavior,which has important guiding significance for improving the safety of the continuous long longitudinal slope section of the mountainous expressway.First of all,through consulting relevant data,combined with the specific road conditions of the continuous long longitudinal slope section and its influence on the driver's vision,the safety factors of the continuous long longitudinal slope section of the mountainous expressway are systematically analyzed.Secondly,combined with the driver's basic visual theory,Smart Eye Pro5.7 non intrusive eye movement apparatus has been used to carry out the pilot eye movement test of the continuous growing downslope section of the mountainous expressway,and collect the driver's visual parameters and the running speed of the test vehicle.Taking the percentage of driver pupil change as the indicator of driver's driving psychological change,through partial correlation analysis,the slope of straight slope section in the long downgrade section has a strong influence on the driver's psychological fluctuation,and the slope is a long time,and the angle change rate of the slope section has a strong influence on the driver's psychological fluctuation,and the slope is the second.By controlling variable method,the influence of single linear change on driver's pupil percentage was analyzed.In order to simplify the complexity of driver's visual behavior analysis,a method of system clustering is used to zoning a single road line index value,and the influence of the change of single road linear index on driver's fixation and saccade behavior is analyzed according to the result of the division.Thirdly,according to the basic law of driver's visual behavior,the concept of horizon space is put forward,and the effective spatial scope calculation model is constructed.In order to quantify the continuity of visual changes in the continuous growing and downhill sections,the index of the average change rate of the effective horizon space is put forward,and the influence of the different road conditions on the index is analyzed.For the straight slope section,when the slope is greater than 4%,the efficiency of the pilot's effective vision space is obviously increased,when the slope is long in the slope.At the time of 300m-500m,the driver's visual continuity is better;for the curved slope combination section,when the slope is more than 3%,the average change rate of the driver's effective vision space is obviously increasing.When the angle change rate is greater than 0.08 degree/m,the driver's visual search frequency is higher,and the natural guidance ability of the road is poor.Then,taking the driver's effective vision space and pupil diameter as the basis of driving behavior,taking the average change rate of the effective vision space and the percentage of driver pupil change as the basis of driving safety of the continuous growing downslope section,the safety evaluation model of the continuous growing downhill section is set up,and the driving safety is put forward.The total threshold is divided into five grades.Finally,with the results of the study,from the two aspects of road safety design and safety facilities setting,the suggestions for improving the safety of continuous long longitudinal slope section of Expressway in mountain areas are proposed.This paper puts forward the safety evaluation method and safety improvement suggestion for the continuous long longitudinal slope section of the mountainous expressway,and the research idea has the reference value.The conclusions and results provide the theoretical basis for improving the safety of the continuous long longitudinal slope section.