信号交叉口左转车辆跟驰行为建模

Modeling on the Car-following Behavior of Left Turn Vehicles at Signalized Intersection

跟驰模型是交通流理论的核心内容之一,但左转车辆在交叉口转弯过程中跟驰行为的特征表现,尚缺少基于实际数据的深入研究。针对这个问题,设计了信号交叉口左转车辆跟驰实验,基于高精度全球定位系统(global positioning system,GPS)和移动地理信息系统采集车辆跟驰行为相关数据,分析了信号交叉口不同转弯半径下左转车辆跟驰速度时变规律及分布本征。在全速度差(full velocity difference,FVD)跟驰模型的基础上,考虑跟驰车驾驶员对前导车加、减速反应的非对称性,构建了改进的全速度差模型,并采用遗传算法对模型进行了参数标定。最后,以跟驰车加速度为检验指标,利用实测数据对改进的全速度差模型加、减速度过程的准确性进行了分析与评价。结果表明:信号交叉口左转跟驰车辆的平均运行速度与转弯半径成正相关;在不同转弯半径下跟驰车速度出现频数最高的数值随着转弯半径的增大而增大;改进的全速度差模型,能更好地描述交叉口左转车辆跟驰过程,驾驶员对前导车减速行为的反应比对加速行为的更强烈。

Although car-following model is one of the core components in traffic flow theory, the characteristics of left turning car-following behavior in turning process at signalized intersections has not been examined with field data yet. Therefore, a left-turn car-following experiment at signalized intersection was designed. Based on high precision global positioning system(GPS) and mobile geospatial information system(GIS), the data of car-following behavior were collected, and the time-varying law and distribution characteristics of left-turn car-following speed at signalized intersections with different turning radius were analyzed. On the basis of full velocity difference(FVD) model, considering the asymmetry of driver’s response to acceleration and deceleration of the leading car, an improved FVD(IFVD) model was developed, and the parameters of the model were calibrated by genetic algorithm. Finally, taking the acceleration of the following car as the test index, the accuracy of the acceleration and deceleration process of the IFVD model were analyzed and evaluated by using the real-world data. In is found that the average speed of the left-turning car-following vehicle increases with the turning radius of signalized intersection;the highest frequency of car-following speed increases with the increase of turning radius;and the IFVD model can better describe the left turn car-following process at signalized intersections, and the driver’s response sensitivity to the deceleration behavior of the front vehicle is stronger than that of the acceleration.