3. Adequate braking is easy to achieve on dry roads with or without antilock brakes. Even if wheels lock, the coefficient of friction between tires and road surface still is relatively high, so a vehicle stops relatively quickly. It is even possible on some surfaces to stop sooner without antilocks than with them, although such instances are
rare. They occur, for example, when loosely packed snow or gravel creates a "dam" effect in front of locked wheels, shortening the stopping distance more than antilocks could.
http://www.iihs.org/research/qanda/antilock.html