Dual Two-lane Road Horizontal Curve Elements And The Relationship Between Traffic Safety Research

In our country second two-lane highway, curve highway sections have a lot of traffic accidents, because of the flat curve is designed improperly. It is important meanings for design safely to flat curve and existing curve security renovation of highway section to finding the key element of curve and inherent relation of the traffic safety. This text is from the domestic and international research about the curve key element and security relation, have analyzed the straight line near the curve, degree of curve, radius of curve , central angle of curve, CCRs, length of curve, rate of curve, etc. curve key element, find out these curve key element and inner link of traffic safety, confirm the goal in research, lay the foundation for the follow-up work.This text has analyzed a great deal of methods to study the line shape and traffic safety both at home and abroad systematically, to having deficiency of the method, the paper has put forward a practical, convenient, research approach apt to walk of science, taken the operating speed, side friction fator coefficient and CCRs as the carrier to study and appraise curve security using the curve fitting. Paper adopted Shandong Province kengshou road, dongxiao road, boyi road, Yunnan Province anchun road, dali road, Qinghai Province huanggui road,etc. operation speed that carry on at the highway observe the materials, analyze and summarize the operating speeds of vehicle in the little radius, and has proposed and set up the model of speed and radius, model of speed and CCRs. In studying the foreign materials, this text has analysised side friction fator coefficient abroad, utilized these data to set up the model of designing speed and side friction fator coefficient, the model CCRs and side friction fator coefficient. The foundation of the model has offered the effective calculation basis for the security of improving the design of highway.In safe evaluation criterion of flat curve of the highway, the paper is on the basis of comparing and absorbing some foreign evaluation criteria, according to the actual conditions of second pair of traffic accidents of lane of our country, have proposed the operating speed, the side friction factor coefficient and CCRs safe evaluation criterion. The application of these models and evaluation criteria, can offer a kind of new means for designing and verifying in road safety.