Why must drivers of doubles and triples allow more following distance and avoid quick lane changes?

A doubles or triples combination is long and heavy, so it needs more distance to stop and more room to maneuver than a single trailer. Just as important, abrupt steering inputs are amplified toward the rear and can throw the last trailer out of its lane or tip it over. The driver should keep a large following distance, plan lane changes far ahead with smooth, gradual steering, and avoid sudden swerves or quick corrections. Looking far down the road to anticipate hazards is critical, because the maneuvers needed to avoid a problem must be gentle and made early to keep all the trailers tracking safely.