What is Tail Swing?
Tail swing is the rear-end movement of a large vehicle, typically a truck, bus, or trailer, which swings out in the opposite direction of the front of the vehicle during a turn.
This creates a wide arc at the rear, which can lead to damage to nearby vehicles, roadside infrastructure, or pedestrians if sufficient space is not allowed.
The extent of tail swing depends on:
- The distance between the rear axle and the end of the vehicle or trailer
- The angle and tightness of the turn
As vehicle lengths increase, particularly with the use of Longer Semi-Trailers (LSTs), and with the introduction of rear-steer axles on trailers and buses, tail swing has become a more significant and visible risk in day-to-day operations.
How Can Tail Swing be Managed?
Tail swing cannot be eliminated, as it is a natural result of vehicle geometry. However, the risk can be reduced by improving driver awareness at the point of manoeuvre.
SCC’s approach is to provide an early warning to the driver when an object is at risk of being struck.
Sensors are positioned at the rear of the vehicle or trailer, at the point where tail swing is most pronounced. When an object is detected within a defined range, both audible and visual warnings are provided to the driver in the cab, indicating the side of the potential hazard.
As the vehicle moves closer to the object, the warning escalates, allowing the driver to adjust their manoeuvre and avoid a collision.
