CDL Class A Practice Test

The term describing a wobble or roll in a truck is known as “jackknifing.” This occurs when the trailer swings out to one side, creating an angle between the cab and the trailer that resembles a folding knife. Jackknifing can happen due to sudden braking, loss of traction, or sharp turns, and is particularly dangerous because it can lead to the trailer rotating and potentially causing a collision. In the context of vehicle dynamics, tipping refers to a vehicle losing its balance and potentially overturning, which is different from the wobble or roll associated with jackknifing. Spinning typically describes a vehicle losing control and rotating around its vertical axis, often resulting in a complete 360-degree turn. Rolling refers to the side-to-side motion or swaying that can occur but does not specifically denote the severe angle created in a jackknife scenario. Each of these terms describes different types of loss of control in heavy vehicles, highlighting the unique nature of jackknifing in the context of truck operations.