Anti-lock brakes greatly enhance trailer stability while braking. Because a sliding wheel always leads, a brake lockup situation under manual braking can cause loss of control as the trailer slides sideways. Anti-lock brakes provide the electronic and physical control to prevent wheel lockup and the ensuing control problems. Although Anti-lock brakes may not necessarily help your operators stop over shorter distances, they are designed to help keep your operators in control while eliminating excessive tire wear and flat spotting.
Resources:
Anti-lock Brake System Details
Haldex L30030 Installation & Service Manual