Abstract:Improper combination between highway horizontal and vertical alignment is one of the main reasons of dangerous segments, which easily leads to traffic accidents, such as speeding, rear-end collision, rollover, and emotional stress. They often are shown as broken back curve, inadequate sight distance and lack of beauty in drivers' visual. This is mainly due to a large deviation between visual perception and the actual supply from highway horizontal and vertical design, especially horizontal information even more so. In this paper, the index of the visual horizontal component was used to describe the deviation between visual horizontal perception and the actual supply and a new analysis technique to evaluate the coordination between highway horizontal and vertical alignment was studied. Firstly, the model of centerline in highway perspective view was built based on CatMull-Rom spline, the centerlines of actual perception and horizontal datum in highway perspective view were proposed based on the perspective principle. Secondly, based on front study, the method of calculation driver's perception horizontal deviation according visual reconstruction was put forward and the causes of perception deviation was also analyzed simultaneously. Finally, the horizontal and vertical coordination classification thresholds were determined using interval estimation methods based samples in the past used to evaluate the coordination between highway horizontal and vertical design, the results could provide technical support for research on horizontal and vertical coordination assessment.
