Study On The Influence Of Long Straight Lines Of Semi-desert Grassland Highway On Driving Safety Under The Time Accumulation Effect

The long straight line is not only simple and easy to measure,but also has a wide driving field of vision,which is the first choice for linear design in semi-desert grassland area.However,most of the accidents occur on long straight lines.According to the statistics of traffic accidents in recent years,most of the traffic accidents are related to drivers.Therefore,it is urgent to study the driving safety in the semi-desert steppe region from the driver’s physiological information.In this paper,the driver’s pupil diameter,fixation point variance,heart rate are as research indicators,through the SPSS and Excel modeling and the model using the extreme theorem method to obtain the maximum length of straight line segment and the minimum radius of straight line segment followed by curve segment under time accumulation.Firstly,the qualitative analysis of the driver pupil diameter and heart rate changes under different speeds,different road sections,different lengths of straight line,different road environment and different driving time accumulation.The results show that the more monotonous the of environment,the faster the driver’s fatigue accumulates;at a normal driving speed,the faster the speed,the slower the driver enters fatigue;the change of the linear index has a certain relief effect on the driver’s fatigue.Secondly,the model of the relationship between the pupil diameter,the variance of fixation point and the straight line length is established under different time accumulation effects.The results show that the longest straight line length of the semi-desert steppe highway is 4710m and 4070m,which meet the driver’s pupil diameter and fixation point variance under the condition of 240min driving.Furthermore,the change model of the driver’s pupil diameter and heart rate is established when the driver enters different curve sections from different straight sections under the effect of time accumulation.It is found that when the length of the straight line segment L≤1000m,1000<L<4070m,the minimum curve radius satisfying the driver’s pupil diameter and heart rate changes is 719m and 2113m.Finally,according to the experimental analysis and the establishment of the model,the long straight line index optimization and security measures based on driving fatigue in semi-desert grassland area are put forward.