Research on Highway Three-Dimensional Dynamic Sight Distance Based on Drivers' Characteristics

Based on the analyses of research findings from both domestic and abroad, Highway Three-Dimensional Dynamic Sight Distance (H3DSD) and methods for calculating it are put forward in this paper. Key techniques and basic characteristics for H3DSD are illustrated in detail. With the characteristics of second-order continuity, localization, flexibility, etc., cubic B-spline curve, as the prerequisite of calculation of H3DSD, is used to represent highway alignment. Meanwhile, the method for calculating highway geometry elements from GPS data is also provided. Using the relation of space geometry and vector, the calculation of H3DSD is done in 3D space. In the calculation, the drivers' dynamic visual angle, the limitation of the vehicle's headlights at nighttime, and the combination of horizontal and vertical alignment, etc. are taken into account. And a new method is provided to evaluate the consistency of highway alignment much more scientifically.