CDL Vehicle Combination Practice Test

What does "off-tracking" refer to when making a turn?

1. The front and rear wheels follow different paths

2. The load shifts inside the trailer

3. The trailer detaches from the tractor

4. The brakes apply unevenly

The correct answer is: The front and rear wheels follow different paths

Off-tracking refers to the phenomenon that occurs when the front and rear wheels of a vehicle follow different paths during a turn, particularly in vehicle combinations like tractor-trailers. This situation arises because the pivot point of the trailer—where it connects to the tractor—causes the rear wheels of the trailer to follow a wider arc than the front wheels of the tractor. Consequently, the rear wheels of the trailer will track inside the path taken by the front wheels of the tractor, which can lead to the rear wheels potentially hitting obstacles or corners that the front wheels have successfully cleared. Understanding off-tracking is crucial for operators of combination vehicles, as it can significantly affect maneuverability and safety during turning situations. The other options describe different issues or events that can occur with combination vehicles but do not define off-tracking. For instance, the load shifting inside the trailer is related to cargo stability rather than the turning dynamics of the vehicle. Trailer detachment concerns the integrity of the connection between the tractor and trailer, which is a separate mechanical aspect. Uneven brake application deals with braking systems rather than the turning paths of the vehicle. Each of these scenarios is important in the context of vehicle operation and safety, but only the first option accurately captures the essence