平纵组合线形几何特征对车速变化的影响

利用同济大学高仿真驾驶模拟器,采集山区高速公路连续车速数据,将车速变化划分为减速、稳定车速及提速3个区间.通过多项Logistic回归模型建立组合线形及相邻路段几何特征与车速变化的定量关系.结果表明:组合线形中,坡长越长,平均坡度越大,越不易维持稳定车速;下坡时,提速通过平纵组合线形路段的可能性大;向左转弯,维持稳定车速的可能性大;上游和平纵组合线形的坡度差越大,越不易维持稳定车速;下游路段的曲率越大,减速通过平纵组合线形路段的可能性越大.

Effect of Combined Horizontal and Vertical Curve on Speed Change

The Tongji University Driving Simulator was used to conduct experiment and collect speed data. Speed change was divided into three intervals: substantial speed decrease, steady speed (minimal change) and substantial speed increase. Multinomial Logistic models were used to investigate the relationships between geometric design characteristics of combined curves and adjacent segments and speed changes. The results show that: for combined curves, it is more difficult to maintain speed as the lengths of combined curves and the mean grades of combined curves increase; the probability to increase speed is higher when combined curves are down slopes; the probability to maintain speed is higher when combined curves turn left; it is more difficult to maintain speed as the grade changes between the preceding segments and the combined curves increase; the probability to decrease speed is higher when the curvatures of the following segments increase.