UK Driving Theory Practice Exam

Under which conditions might ABS fail to operate effectively?

1. On loose road conditions

2. When driving on smooth tarmac

3. During heavy rain

4. In foggy weather

The correct answer is: On loose road conditions

Anti-lock Braking System (ABS) is designed to prevent the wheels from locking up during braking, allowing the driver to maintain steering control. However, on loose road conditions such as gravel, mud, or snow, the effectiveness of ABS can be compromised. This is because ABS relies on the friction between the tires and the road surface to function properly. When the surface is loose, the tire can more easily slip and slide, resulting in reduced braking efficiency even when ABS is engaged. In contrast, conditions like smooth tarmac, heavy rain, or fog may pose challenges for other aspects of driving but do not typically compromise the fundamental operation of ABS itself. Smooth tarmac often provides good traction; heavy rain, while it can create issues with hydroplaning, typically does not prevent ABS from functioning; and fog impacts visibility but not the braking mechanism. Thus, loose road surfaces represent a scenario where ABS may fail to operate effectively due to a lack of adequate traction and control.