When is jack-knifing most likely to occur?
- When the trailer springs are over-greased.
- Correct answerWhen trying to reduce speed sharply while travelling downhill.
- When travelling uphill.
- When travelling sideways across a slope.
Explanation
Towing a trailer or caravan dramatically reduces the stability of the towing vehicle. If a driver brakes sharply or slows down quickly, the trailer may pivot around the tow hitch coupling, causing both vehicles to go off course, and possibly overturn.
Read in Chinese
何时最有可能发生折叠（jack-knifing）？
- 当拖车弹簧过度润滑时。
- 在下坡行驶时尝试急剧减速。
- 上坡时。
- 横向穿越斜坡时。
拖曳拖车或大篷车会显著降低牵引车辆的稳定性。如果司机紧急刹车或快速减速，拖车可能会围绕拖钩枢轴旋转，导致两辆车偏离路线，甚至可能翻车。