hump speed

例句：

1. 1. The car was traveling at a bump speed when it hit the pothole.
   汽车在碰到坑洼时以颠簸速度行驶。
2. 2. The train's bump speed caused the passengers to feel uncomfortable.
   火车的颠簸速度让乘客感到不舒服。
3. 3.The driver had to slow down to maintain a safe bump speed on the icy road.
   司机不得不减速，以保证在结冰的道路上保持安全、稳定的颠簸速度。