Research On Highway Safety Design Theory Based On Alignments Design Consistency

Highway traffic accidents and highway conditions, especially liner condition are closely linked.Graceful and smooth linear, clear and eye-catching driving direction, the drivers' sight of full assurance and the linear of meeting drivers' expectation are the basic guarantee of traffic safety. Therefore, road safety is evaluated from highway design consistency, which is important to theoretical development and practice.In this paper, based on a large number of field dynamic measured data, combined with the dynamic performance of our country vehicles, vehicle is classed multi-lane and two-lane highway is divided into section. And the Vgs calculation of the typical section and the relationship of the highway linear, speed and traffic safety are got.In this paper, analysing impact of vertical, horizontal as well as cross-sectional indicators of highway on road safety, a dimensional composite indicator of highway alignment has been achieved; a highway alignment dimensional function has been established by adopting systematical modeling method, and the composite indicator can be reached based on the analyses of sensitivity of alignment composite indicator; according to the three-dimensional characteristics of the highway linear, dimensional curvature indicator can be identified. Aiming at features of tunnel entance/eixt transitional area, alignment transitional indicators of tunnel entrance and exit can be built.Based on operating speed as road safety audit indicator, it proposes discrete indicators of large and small vehicle speed, variation indicators of cross section speed and composite speed indicator. Adopting non-linear regression method, a series of consistency models of discrete indicators of large and small vehicle speed of vehicle speed, the consistency model of variation indicators of cross section speed, and the consistency model of composite speed indicator have been established. According to road safety level of multi-lane highway, the consistency standard of multi-lane highway safety has been proposed.Based on analysing the operating environment of two-lane highway, the traffic safety influencing factors, covering road alignment, ADT, cross-section width, shoulder width, access density, truck percentage as well as roadside hazardous, were analyzed by statistical random theory, the accident prediction model of two-lane highway has been built, and consistency standard of two-lane highway has been proposed.