ABS is intended to enable steering by increasing static road friction. It is not intended to decrease stopping distance, and in many cases increases stopping distance by keeping the negative G's away from the hard limit in anticipation of lateral G's due to steering.

Older dumb ABS systems would simply "pump the pedal" for the driver, and would increase stopping distance in almost all conditions, especially single-channel systems. Newer systems determine breaking performance via the conventional ABS sensors and additionally accelerometers. These systems will back off N G's, then increase the G's bisecting the known-locked and known-unlocked condition, trying to find the optimum. These systems _will_ stop the car in the minimum distance possible, but very few cars use it.