The Research On Operating Speed Modeling And Application Of Mountainous Roads

Too high operating speed is one of mainly inducement of road traffic accidents, and the formation mechanism of the operating speed is so complex. Through analysis of ergonomics theory, the paper has explained the formation mechanism of road operating speed. Furthermore, using the operating speed as the road safety evaluation index, carried out research on the method of road safety evaluation.The mountainous road's terrible conditions and transportation environment have the enormous influence to the road safety, and the operating speed is the reflection of traffic condition. Firstly, through concluding sufficient research on the achievement of the domestic and external,which is mainly about operating speed modeling and application, provides a theoretical basis for the research on operating speed.Secondly, it has analyzed the operating speed, the design speed and the expectation speed's relations, and has analyzed the formation mechanism of the operating speed from the angel of the ergonomics theory. It also revealed the driver's psychology, the vehicle's characteristic and the road traffic environment as well as the traffic control and so on is the primary factor which affects the formation of the operating speed.Thirdly, the paper has carried out the research on the operating speed distributed characteristic of the typical sections of the mountainous road. The case of research on the operating is selected with great deals of data, which were investigated to analyze the relationship between the alignment elements and operating speed. Prediction models of the operating speed and speed difference which are based on the typical road sections of the mountainous area road are set up by means of regression analysis. The operating speed and the speed difference prediction model may be the basis of the speed control of the mountainous road.Finally, through comparing the relationship of |ΔV₈₅| and |Δ₈₅V| , it has analyzed the applicability of |Δ₈₅V| as the road safety evaluation index. The paper researches on road safety evaluation from the angel of operating speed, through gathering speed of each individual vehicle on cross sections, and using the 85th percentile value of speed differentials of individual drivers on successive sections as evaluation index. The method of highway safety evaluation introduces degree of membership in fuzzy mathematics to establish safety evaluation membership function based on speed differential, then assesses road safety level. Take gathering data of some mountainous highway as example, it has carried on the confirmation to this evaluation method.