Papers by Keyword: Highway Alignment Design

Abstract: Existing highway vertical curves may be grouped into two categories: symmetrical vertical curves and unsymmetrical vertical curves. In the past vertical curves design, parabolic arc was used as the vertical curve. This paper presents the new single-arc unsymmetrical vertical curve which is include only one cubic parabola. This curve has the gradual change of the rates of change in grade so that it can provide more comfort to the driver. This paper mainly presents the method by which to find the minimum length for a new single-arc unsymmetrical crest vertical curve based on the minimum sight distance . The discussion will be divided into two situations: the sight distance is longer than the curve length and the sight distance is not longer than the curve length.

Abstract: In order to ensure quality of highway alignment design, and reasonably evaluate the design proposal, the main factors which affect the highway alignment design, including horizontal alignment design, vertical section design and combination of horizontal and vertical design, are analyzed. Based on these key factors, a system of evaluation based on game theory is constructed and the evaluation index is normalized from both qualitative and quantitative view. So an evaluation model of highway alignment design is established. Under the situation of highway alignment designs, the model and fuzzy comprehensive evaluation method are applied to determine the most suitable alignment design for that city. The best choice, design 3rd, is identical, but the sort of design 2nd and design 4th is not consistent with each other for the reason of large deviation of weight of the fuzzy comprehensive evaluation method. Because the evaluation model based on game theory can better determine the optimal weight, the evaluation is more reliable and it meets the practice. The results show that the model is effective and reliable.

Abstract: This text applies grey target theory to evaluate the safety of highway alignment design. According to grey target theory, many factors which affect the safety were selected. The model of the safety evaluation of highway alignment design model was put forward based on grey target theory. After we apply this method in the practice, this method of the safety evaluation of highway alignment design is proved to be effective in course of the accuracy of the safety evaluation. Investigative results indicate that some subjective factors can be eliminated to a certain extent based on evaluation model of grey target theory in the course of alignment scheme choice，which make the choice result more objective. And it is a certain application value for the safety evaluation of highway alignment design.