山地城市长上坡路段大型车行驶速度的模式特征

Pattern Characteristics of Large Vehicle Speed on Uphill Section of Mountainous City Road

在重庆市主城区内选择多条具有代表性的上坡路段为对象并划分测试断面,采集了行驶速度值,结果表明：（1）大型车在上坡路段的速度变化有4种模式,上坡时的速度在总体上是下降的,但在一些驾驶模式中出现了坡底和坡顶的冲坡加速行为;（2）公交车在上坡路段的速度均值最低、货车居中,大客车最高,三种车型的稳定爬坡速度为25-35km/h;（3）在直坡路段,大型车和小客车的夜间行驶速度高于日间,并且速度在各观测断面的分布比较离散,而弯坡组合路段各断面的速度观测值更集中,并且维持在一个较低的幅值;（4）不管是日间还是夜间,小客车在上坡路段的行驶速度明显高于大型车,两者之间的平均速度差值约为12km/h,夜间大型车和小客车的速度差与日间相比并未见明显不同。

In this study a number of representative uphill road sections in Chongqing main urban area are selected, driving speed is collected on the chosen cross-sections. The results show that. （1） change of large vehicle speed on the uphill section has four modes, the speed generally decreases on uphill, but there exists acceleration behavior on the bottom and top of a slope for several driving modes; （2） on uphillsection, bus has the lowest average speed, then heavy trucks, coaches have the highest speed; the stable climbing speed on uphill is about from 25 km/h to 35 km/h; （3） on slope of straight sections, passenger car and large vehicles driving at night are faster than during the day and speed distribution is more discrete on each observation point; but for curved slopes, speed distribution is more concentrated on each observation point, and the velocity amplitude is lower than during the day; and （4） no matter in day or at night, speed of passenger cars on uphill is significantly higher than large vehicles, and the difference of average speed between the two vehicle types is about 12 km/h.