Research On The Effects And Improved Methods Of Highway Geometric Design On Driving Comfort

With the improvement of people’s living standard, more and more people pursue high quality life. People are not merely content with "there is a road", but care about "there is a good road". So when driving on the road, people not only care about the security, but also pay more attention to the comfortableness. There are many factors which affect the driving comfort, but the road geometry design is the key factor. But, at present the research of the driving comfort is almost about the evaluation method, and the research of how to improve the co mfortableness of driving is rare. Therefore, in order to catch up with the development of road design, it is necessary to study how to improve the driving comfort of road geometric design.Through the analysis of the definition of driving comfort, form of expression and the influence factors, this article states the influences of road design factors on the driving comfort from the perspective of kinematics and visual analysis. And on the basis of existing research results, the paper put forward the evaluation standard and evaluation method of driving comfort. On this basis, this paper combines qualitative analysis and quantitative calculation to study the relationship between road geometric design and driving comfort. With the target of improving driving comfort, the paper respectively puts forward the concrete measures and suggestions to improve the comfortableness of driving from the horizontal alignment design, the profile path linear design, and the roadbed cross-section and roadside landscape design. In horizontal alignment design, the article first establishes the relationship between the circular curve radius and the easement curve length and the comfort control indicators, and studies the minimum radius of circular curve and minimum length of easement curve; Then the paper proposes Bloss curve or Mcconnell curve as a high- grade highway easement curve, and analyzes the meaning of improving driving comfort and the design requirements; Finally the article proposes to limit the size of the axial acceleration to control the design of model, the s-shaped curve and the oval curve. In terms of the vertical alignment design, the article first establishes the relationship between the vertical curve radius and the vertical acceleration, and contacts the actual situation to study the improved method; Then combining with the existing research results, the paper analysis of the influence of the longitudinal slope design for driving comfort, and gives the suggested value of the longitudinal slope difference before and after. In roadbed cross-section and landscape design, combining with factor of the comfortableness of driving, this article put forward the improvement suggestions of roadbed slope and ditches design; Finally this paper analyzes the landscape design how to affect the comfortableness of driving from the perspective of visual comfort, and puts forward some improving suggestions.This paper respectively put forward the improvement measures and suggestions of driving comfort from the horizontal alignment, vertical alignment, roadbed and landscape design. The research results provide theoretical support for improving the driving comfort. It offers a certain effect and actual reference value to guide the road geometric design and to improve road driving comfort.