When lightly loaded, stiff suspension springs and strong brakes give poor traction and make it easy to lock up the wheels. Combination vehicles are longer than bobtails and therefore require more length to stop. Empty trucks are harder to control and the brake connections are more likely to come loose. Bobtails may not be equipped with splash guards or back bumpers. Bobtails stop more smoothly but take longer to stop.
Bobtails can be hard to stop smoothly and take longer to stop than a loaded tractor-semi trailer.
The trailer will immediately stop. The trailer will tend to jackknife or swing around. The trailer will automatically break loose from the fifth wheel assembly. This is the best way to recognize if the trailer has started to skid. To tell if the mirrors are still in adjustment.