Rain reduces visibility, increases stopping distances, and creates aquaplaning risk. Adapting to wet conditions is not optional — it is a legal requirement to drive at a speed appropriate for conditions.
Reduced Grip
A wet road has significantly less friction than a dry road. On a damp road, braking distances are approximately double those in dry conditions. On a road with standing water, grip can disappear entirely — aquaplaning.
Visibility
Rain reduces visibility for you and for other drivers seeing your vehicle. Use dipped headlights in heavy rain even during daylight hours — this is legally required when visibility is significantly reduced. Ensure windscreen wipers are in good condition and washer fluid is filled.
Following Distance
Double your following distance in rain. Light rain can be as hazardous as heavy rain immediately after a dry period — oil and rubber deposits on the road surface form a slippery emulsion when first wetted.
Puddles and Flooding
Never drive through standing water at speed — aquaplaning is almost guaranteed. Slow to a walking pace before any flood. After driving through deep water, test your brakes gently to ensure they are still working — water in drum brakes reduces their effectiveness.
Exam tip: The first minutes after rain begins are often the most slippery, because dry-deposited oil and rubber lift off before being washed away.