Abstract: A typical six axle tractor-semitrailer was selected as the representative model for the expressway. The operating speed of the train with different initial speeds (80, 90, 100 km/h) and different slope gradients (2.2%, 2.9%, 3.5%) were tested on a Chongqing mountainous expressway, and the rear-end characteristics of the car rear-end tractor-semitrailer were analyzed. The results show that the maximum continuous climbing speed remain the same when the tractor-semitrailer enters the same longitudinal slope section at different initial speeds. On different slopes, when the operating speeds of the vehicle decrease differently, the maximum continuous climbing speeds are different. The greater the gradient, the lower the speed and the smaller the maximum continuous climbing speed. The time of the car rear end tractor-semitrailer shortens with the decrease of the initial speed of the tractor-semitrailer entering the slope, and the slope does not much affect the car rear end tractor-semitrailer.

Key words: traffic engineering, uphill section, tractor-semitrailer, operating speed

摘要： 选择高速公路常见的六轴半挂汽车列车为代表车型，在重庆山区高速公路上测试了列车以不同入坡初速度(80、90、100 km/h)驶入不同坡度(2.2%、2.9%、3.5%)路段后的行驶速度，并分析了小轿车追尾半挂汽车列车的追尾特性。结果表明：半挂汽车列车以不同初速度进入同一坡度路段运行时达到最大持续爬坡速度相同；在不同坡度上，车辆的行驶速度下降变化不同，最大持续爬坡速度也不同，坡度越大，速度下降越快，最大持续爬坡速度也越小；小轿车追尾半挂汽车列车的时间随半挂汽车列车入坡初速度的降低而缩短，坡度大小对小轿车追尾半挂汽车列车有影响，但影响较小。

关键词: 交通工程, 上坡路段, 半挂汽车列车, 行驶速度