Xiaomeng Wang, Rongjie YU, Xuesong Wang
Abstract:Vehicle speed has a complex relationship with driving safety. Numerous factors affect the vehicle speed; among these factors, the geometric design has an extreme influence on the vehicle speed, especially in the segments with a combination of horizontal and vertical. This study attempts to analyze the speed in combined segments. The combination of horizontal curve and downslope segment was selected as the research object. Furthermore, this type of segment was divided into three parts, the approach transition curve, circle curve and departure transition curve, while this study only focused on the circle curve part. The Tongji 8DOF Driving Simulator was used for data collection. In this study, linear regression models were established for speed consistency of circle curve sections. The influence of adjacent segments was considered simultaneously. The models showed that the slope, curvature, radius and length had a significant influence on vehicle speed.