In which conditions might ABS be ineffective?

Explanation: In very wet weather, water can build up between the tyre and the road surface. As a result, your vehicle rides on a thin film of water and your tyres won't grip the road. Gravel or shingle surfaces also offer less grip and can cause problems when braking. An anti-lock braking system may be ineffective in these conditions.

Category: Band 2 traffic signs and signals (2021)

References: The Official DVSA Guide to Driving: Section 5, Highway Code: Rule 120