平纵组合曲线的加减速特征

Acceleration and Deceleration Characteristics of Horizontal and Vertical Combination Curve

平纵组合曲线对驾驶人的加减速行为产生直接影响,不良的线形组合易诱导不利的加减速行为进而导致安全问题。研究了凹、凸两类共6种典型平纵组合曲线上的车辆加减速特征,收集了二广高速公路41条平纵组合曲线的实车运行速度数据。根据组合曲线上最大速度与最小速度的差值定义了5种加减速特征:保持稳定车速、显著加速、显著减速、先加速后减速及先减速后加速。使用多元Logistic回归模型分析了两种组合曲线及其几何特征对车辆加减速特征的影响。结果表明:凸形组合曲线、凹形组合曲线上加减速特征明显不同。对于凹型组合曲线而言,圆曲线长度、进弯缓和曲线长度对加速行为有显著负效应,随着进弯缓和曲线长度的增加,发生显著加速的概率将显著降低。对于凸形组合曲线,组合曲线半径、组合曲线长度对加速行为有显著负效应。

The combination of horizontal and vertical curves has a direct impact on the acceleration and deceleration behavior of drivers,and the poor combination of lines is easy to induce the adverse acceleration and deceleration behavior and then leads to safety problems.The acceleration and deceleration characteristics of vehicles on six typical horizontal and vertical composite curves of concave and convex types have been studied,and the real vehicle running speed data of 41 horizontal and vertical composite curves of Er-Guang Expressway have been collected.According to the difference between the maximum speed and the minimum speed on the combination curve,five acceleration and deceleration characteristics have been defined:maintaining a stable speed,significantly accelerating,significantly decelerating,accelerating before decelerating,and decelerating before accelerating.The influence of two combination curves and their geometric characteristics on vehicle acceleration and deceleration characteristics has been analyzed by using multiple logistic regression model.The results have shown that the acceleration and deceleration characteristics of convex combined curve and concave combined curve are obviously different;for concave composite curve,the length of circular curve and the length of transition curve has significant negative effects on the acceleration behavior.With the increase of transition curve length,the probability of significant acceleration will be significantly reduced.For convex composite curves,the radius and length of composite curves have significant negative effects on acceleration behavior.