- Entry Level Driver Training Skid Control and Recovery Questions and Answers Flashcards

What is a 'jackknife' and what typically causes it?

Answer: When the tractor drive wheels lock up and the tractor swings sideways relative to the trailer

A jackknife occurs when the tractor's drive wheels lose traction (usually from hard braking) and the tractor rotates around the fifth wheel connection point, folding against the trailer like a closing jackknife.

How does trailer swing differ from a tractor jackknife?

Answer: In trailer swing, the trailer wheels lock and the trailer swings outward; in a jackknife, the tractor drive wheels lock

Trailer swing occurs when the trailer's wheels lock up, causing the trailer to swing outward and potentially into adjacent lanes. In a jackknife, it is the tractor drive wheels that lock up.

What is countersteering and when should it be used?

Answer: Steering in the direction the rear of the vehicle is sliding; used during a rear-wheel skid recovery

Countersteering means turning the steering wheel in the direction the rear of the vehicle is sliding. It is used to regain control during a rear-wheel skid by aligning the front wheels with the vehicle's actual direction of travel.

How do road surface conditions affect the type and severity of skids?

Answer: Different surfaces provide different levels of traction, directly affecting when skids begin and how they behave

Different road surfaces dramatically affect traction: dry concrete provides the most grip, wet surfaces reduce traction, ice can reduce it by 80% or more, and gravel or dirt create unpredictable traction.

What is the 'rocking' recovery technique for a vehicle stuck in snow or mud?

Answer: Gently alternating between forward and reverse gear to build momentum

The rocking technique involves gently shifting between forward and reverse to build progressive momentum, allowing the vehicle to work its way out of the stuck position without spinning the wheels.

How do tire chains affect skid prevention and when should they be used?

Answer: Tire chains significantly increase traction on snow and ice but must be used at reduced speeds

Tire chains dig into snow and ice to provide significantly increased traction, but the vehicle must be operated at reduced speed (typically 30 mph or less) to prevent chain breakage and vehicle damage.