ABS improves driver control and stability by preventing wheel-lock under heavy braking, and it has led to the development of more sophisticated car safety devices including Electronic Stability Program and Traction Control Systems.
The first system to be used by production cars, dubbed ABS 2, was developed by Mercedes-Benz and Bosch. It featured an electronic controller, a speed sensor on each wheel and two or more hydraulic valves on the brake circuit. If the system detects that any number of wheels are rotating considerably slower than the others, it adjusts the braking force and allows the wheels to speed up before applying the braking force again. A typical anti-lock system can apply and release braking pressure up to 20 times a second, helping to maintain stability and reduce stopping distances.