What is the function of the ABS (anti-lock brake system) in a vehicle?
Show the correct answer
Correct answer
B. It allows the driver to control the vehicle at the time of sudden braking.
Explanation
The ABS anti-lock braking system allows you to keep control of the vehicle during sudden braking - answer B. It does not prevent the wheels from spinning when moving off (A) - that is the job of traction control - and it does not always shorten the braking distance (C).
ABS measures the rotational speed of the wheels, and when one of them starts to lock, it reduces the braking force on that wheel for a fraction of a second and then increases it again, a dozen or so times per second. A locked wheel slides and does not transfer side forces, so the car stops responding to the steering wheel; thanks to ABS the wheels keep rolling and you can steer around an obstacle while braking. On loose snow or gravel, the braking distance with ABS can even be longer than with locked wheels. The Road Traffic Act requires you to brake in a way that does not create danger; in a car with ABS, in an emergency you press the brake pedal all the way down, do not release it even though the pedal pulses, and steer.
Legal basis: Art. 19 para. 2 point 2 of the Road Traffic Act (Prawo o ruchu drogowym)