When you make a quick lane change or sudden movement of your steering wheel, the rear trailer tends to swing out. The force of the rear trailer becomes amplified, causing it to roll over.
A sudden maneuver by the tractor may cause the rearmost (last) trailer to swing violently and possibly roll over. This is known as the crack-the-whip effect. It is caused by rearward amplification: The farther a trailer is from the tractor, the more likely it is to start swinging dangerously out of control.
B When you make a quick lane change or sudden movement of your steering wheel, the tractor tends to rock and sway. The velocity of the rearmost trailer forces the tractor to roll over before the trailer.
C Your trailer is half full, and the cargo is loaded in the front of the trailer. When you make a sudden movement of your steering wheel, cargo will tend to forcefully slide to the back of the trailer, forcing the trailer to roll over.