What is the term for the tendency of long commercial vehicles to swing wide on turns?

The correct term for the tendency of long commercial vehicles to swing wide on turns is off-tracking. This phenomenon occurs due to the difference in the path traced by the front wheels compared to the rear wheels of the vehicle. When a long vehicle, such as a tractor-trailer, makes a turn, the rear wheels follow a different trajectory than the front wheels. The rear of the vehicle extends outward, often encroaching into adjacent lanes or off the roadway, creating a potential hazard.

Understanding off-tracking is crucial for truck drivers because it affects how they maneuver through turns, navigate intersections, and change lanes. This awareness helps in preventing collisions and ensuring that the vehicle remains within the designated space while turning.

Other terms like oversteering and understeering refer to the behavior of vehicles in response to steering inputs, particularly in passenger vehicles, and are not relevant to the specific behavior of long commercial vehicles during turns. Jackknifing pertains to a situation where the trailer of a tractor-trailer swings out to an extreme angle, which is a different consideration altogether. Identifying off-tracking is essential for safe operation and handling of large trucks on the road.