What should you do if a trailer begins to sway significantly?

When a trailer begins to sway significantly, the most effective response is to gradually reduce speed and avoid sudden steering movements. This approach is essential because swaying, often referred to as "fishtailing," can be exacerbated by sudden changes in direction or speed. By gently decelerating, you allow the system to stabilize without introducing additional dynamics that could worsen the sway.

Reducing speed helps decrease the momentum of the trailer, making it easier to regain control. It is critical to maintain a steady and controlled steering input; sudden maneuvers could lead to loss of control or even cause the trailer to flip over. Therefore, prioritizing a smooth reduction in speed while maintaining a straight path provides the best chance of regaining stability and controlling the situation effectively.