Illinois CDL Practice Exam

What does 'jackknifing' refer to in trucking terminology?

1. A sudden loss of control

2. When a trailer swings out and forms an angle with the towing vehicle

3. Driving at high speeds while cornering

4. A type of truck accident involving multiple vehicles

The correct answer is: When a trailer swings out and forms an angle with the towing vehicle

In trucking terminology, jackknifing refers to a situation where a trailer swings out and creates an acute angle with the towing vehicle, resembling the shape of a folding knife. This typically occurs when the trailer's wheels lose traction, often due to slippery road conditions, sudden braking, or sharp turns. When jackknifing happens, the trailer can slide sideways, leading to a loss of control for the driver and potentially resulting in a collision or further accidents. Understanding this phenomenon is crucial for drivers, as it highlights the importance of maintaining control of the vehicle, especially under adverse conditions. Proper speed management, anticipatory driving, and awareness of the trailer's handling characteristics are essential in preventing jackknifing scenarios. Recognizing the signs that may precede such an incident can help drivers take corrective actions before the situation escalates.