| With the rapid development of transportation,the traffic safety problem is becoming increasingly prominent.In the road linear design,straight line is the most commonly used flat curve linear.The advantage of straight line is to shorten the distance of the road,reduce the cost and beautify the route.Therefore,in the dense highway network in our country,the linear line type is widely used.However,the long line section has a serious traffic safety hazard,it is a multiple traffic accident,especially in the northwest area with less population density,not only the long linear use frequency is high,but also the typical desert grassland special road environment is also an important factor affecting traffic accidents.Therefore,the analysis of the heart and physiological changes of drivers in the long straight line of desert steppe can provide practical guidance for reducing traffic accident rate.In the dynamic traffic system composed of "man-car-Road-environment",people are the main body of perception and the most active factor in the system,and are easily influenced by the driving environment and the linear road.In the dynamic driving process,the driver's heart and physiological changes are often dynamic and instantaneous.Therefore,this paper introduces two physiological signals of heart rate and eye movement to detect the internal relationship between the driver's instantaneous heart,physiological fluctuation and the linear change of the road,and explore the driver under the radius of the uneven curve and the long line running condition.The change of heart and physiology.The horizontal curve is the most important part of the road alignment design.The focus of this paper is on the characteristics of the driver's gaze distribution,the rhythm of heart rate and the pupil diameter.The study shows that,from the point of line cumulative effect,there is a certain threshold in the concentration state of the driver in long line section.When L>15.8km,the variance of the fixation point drops sharply and the attention is in a slow concentration.When L0>16.8km,the driver's heart rate and pupil diameter drop sharply and enter the deep fatigue driving.Vehicle status;from the time cumulative effect,the formation of driving fatigue is not linearly increased,but is gradually rising in the form of "fatigue cumulative fatigue relief".According to the characteristics of fatigue accumulation,it is proposed that the measures should be set up on both sides of the grasslands road to stimulate the driver,alleviate the cumulative fatigue and prolong the cumulative time of the limit fatigue.When driving from the long straight line to the entrance of the transition curve,the heart rate and the pupil diameter show a sudden increasing trend of different magnitudes.It is found that the degree of heart and physical change caused by the different radius of the straight line is also different.The smaller the radius of the curve affects the rate of heart rate and the change rate of pupil diameter,the sudden sudden change of heart physiology is not conducive to safe driving.On the contrary,with the increase of the radius of the curve,the change rate of driver's heart rate and pupil diameter is smaller and more stable.It is also found that the existence of a certain critical radius RO is a long straight line connecting curve suitable for the driver's continuous stable driving and the stable physiological comfort of the heart,and the critical radius RO corresponding to the different physiological indexes is roughly phase.And so on,the critical radius R0?420m of heart rate and the critical radius R0=380m of pupil diameter.That is,when the radius of curve is in the range of 380m-420m,it has the greatest influence on the driver's heart and physiology.The relationship model of the front line,the ratio of the back radius ratio L/R and the velocity difference Delta V is established,and the critical ratio L/R=2.4 of the velocity difference is obtained by Lagrange's mean value theorem,and the expression of the front line length L and the velocity difference Delta V and the post radius R are obtained.The ratio of the line L to the radius R of the desert steppe road can be used as 3.5-.4 range.These conclusions can provide some theoretical references for road alignment design and highway safety management. |
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