Researches On Operating Speed And Continuity Of Highway Alignment

Highway alignment is one of the main factors affecting road safety. The paper, in the aspect of the consistency of operating speed, analyses the highway linear continuity. The actual speed the driver selects when driving is a performance of judging the linear three-dimensional forms. Therefore, the key indicators which reflect the continuity of the highway alignment good or bad is the continuity of operating speed. If the speed change between sections is limited in a certain extent to ensure the continuity of speed, then the highway alignment continuity will be ensured, and the traffic accident will be reduced.Firstly, the paper introduces the development process of the study on the road line and speed, and put forward to operating speed to evaluate the highway alignment continuity, and then lodges the main content, the study approach, and the technical routes.Secondly, this paper analyzes the factors of driver, car, environment, road alignment and other factors in detail impacting the operating speed, and educes that the highway alignment is a major factor by the AHP method.Thirdly, the paper derives the velocity formula model which bases on car in a . straight line, Profile, flat curve, and combined with flat vertical speed through the car dynamic performance and the linear elements in the beginning. And then derives the actual operating velocity formula model through correcting the factors of the traffic volume, climatic conditions, the rate of car intersection, the carriage way, flat horizon and other factors. At last, the paper analyses the relationship between the operating speed and the continuity of highway alignment.Finally, this paper calculates the actual operating speed through the velocity formula model, analyses the highway linear continuity, and proposes the amending scheme by the use of an example in order to provide an important gist for rebuilding or building highway.