Research Of Limited Slope Grade And Length Of Rur Road Based On Driver's Psychological And Physiological Reflection

Traffic accident is the focus of the whole world. China has become one of the highest traffic accidents countries. Traffic accident is the result of disharmony of human, vehicle, road and environment. The traditional theories was based on vehicle dynamics, it did not take account the factor of human. This paper used psychological and physiological theories and research method, carried a large mount of tests to find the relationship and rules between human's psychological and physiological demand and road geometric design. The heart beat can be seen as a reflection of psychological and physiological demand. This research object of this paper was rural 3th class road. The relativity between road vertical geometric alignment and heart beat change rate of drivers was assured by partial relative analysis. This paper used the method of regression to establish a model about road vertical geometric alignment and drivers'heart beat change rate based on the large amount of operating data. And the geometric alignment which can satisfy the driver's psychological and physiological demand. was discussed on the base of the established model. Based on the analysis,the following conclusion can be made: 1)The change rate of heart beat is related with slope grade, slope length and vehicle performance velocity, and the velocity has the biggest influence to the change rate; 2)For the same slope grade, the change rate of heart beat increases with the vehicle speed increases; for the same speed, the change rate of heart beat increases with the slope grade increases; 3)In the upgrade, the heart beat change rate has little relationship with the slope length, the major factors are slope grade and operating speed. In the downgrade, the slope grade, length and operating speed all have influence to the heart beat change rate; 4)From the data analysis it can be seen that the combination of steep downgrade, long distance and high speed will lead to the biggest change rate of driver's heart beat. This paper established a model about driver's heart beat change rate and slope grade and length. This paper compared the field heart beat change rate data and model forecasting data. for the upgrade data, the relative mean difference was 7.01%, for the downgrade, the relative mean difference was 8.53%. In the final this paper made a suggestion that the limited slope grade should not bigger than 7% based on the heart beat change rate of 40%.from the perspective of driver's feeling. For the grade of 3%, 4%, 5%, 6% and 7%, the suggested limited length are 700m, 550m, 450, 400m and 400m based on the analysis of traffic safety of downgrade road.