高速公路互通立交小半径匝道车辆行驶轨迹特征分析

Analysis of vehicle trajectory characteristics on small radius ramps of freeway interchanges

为明确高速公路互通立交小半径匝道的车辆行驶轨迹特征和驾驶模式,使用无人机在四川省2处高速公路互通立交上空进行高空拍摄,利用视频分析方法采集了小半径匝道上汽车行驶的轨迹数据、速度及行驶轨迹坐标等。通过分析行驶轨迹与车道线的占用关系,得到了不同车型轨迹与不同行驶阶段之间的关系,明确了不同小半径匝道下的行驶轨迹偏好,并分析了运行速度对不同类型车辆行驶轨迹的影响。采用三点定位法计算得到轨迹曲率,分析了小半径匝道的曲率特征,确定了轨迹曲率与匝道曲率之间的差异及其轨迹横摆特点。结果表明:匝道行驶的车辆中,小客车在小半径匝道缓和曲线段的轨迹线束宽幅宽于重型汽车,在圆曲线段对车道线的侵占较为明显;将行驶过程中车辆的驾驶偏好分为3类,A型喇叭口外环匝道上外侧压弯的小客车和重型汽车运行速度较高,对角象限双环式匝道上内侧切弯的小客车和正常行驶的重型汽车运行速度较高;小客车和重型货车在2种小半径匝道上的轨迹曲率整体大于道路设计曲率,对角象限双环式匝道上车辆轨迹改变的幅度和频率较高。

Unmanned aerial vehicles were used to take high-altitude photographs over two highway interchanges in Sichuan province to clarify the vehicle trajectory characteristics and driving modes on small radius ramps of highway interchanges via collecting trajec⁃tory data,speed,and trajectory coordinates of vehicles traveling on small radius ramps by video analysis method.By analyzing the relationship between driving trajectory and lane occupancy,the relationship between the trajectories of different vehicle models and different driving stages was obtained.The different driving trajectory preferences under different small radius ramps were clarified,and the effect of operating speed on the driving trajectories of different types of vehicles was analyzed.Additionally,the trajectory curvature was calculated using the three-point positioning method,and the curvature characteristics of small radius ramps were ana⁃lyzed.The difference between trajectory curvature and ramp curvature,as well as the trajectory lateral characteristics,was deter⁃mined.The research results indicate that among vehicles traveling on ramps,small and medium-sized buses have wider trajectory harnesses on the gentle curve section of small radius ramps compared to heavy vehicles,and their encroachment on lane markings is more pronounced on the circular curve section.The driving preferences of vehicles during the driving process are divided into three categories.It is found that on the A-type horn ramp,small buses and heavy vehicles with outer bends run at higher speeds,while on the diagonal quadrant double loop ramp,small buses with inner bends and normal heavy vehicles run at higher speeds.The overall curvature of the trajectory of small buses and heavy trucks on two small radius ramps is greater than the design curvature of the road.Both the amplitude and frequency of vehicle trajectory changes on diagonal quadrant double loop ramps are higher.