What is the primary function of anti-lock brakes (ABS) in emergency braking?

• A. They automatically steer the vehicle to the side of the road.
• B. They release brake pressure to allow wheel spin.
• C. They prevent wheel lockup while maintaining steering control; apply firm, continuous brake pressure.
• D. They increase braking force to the wheels beyond pedal input.

Answer: (C)

The primary function of ABS in emergency braking is to prevent the wheels from locking up while you brake, so you can keep steering control. It does this by monitoring each wheel and rapidly adjusting brake pressure to avoid a skid. When a wheel starts to lock, the system releases and then re-applies pressure many times per second, which you may feel as a pulsing or vibration in the brake pedal. You should keep your foot firmly on the brake and hold it there; the system will do the modulation for you. This keeps you in control to steer around hazards, rather than the braking force automatically increasing beyond what you apply or the car steering itself.