Aquaplaning (hydroplaning) occurs when a tyre cannot clear water from the road surface fast enough and rides on a layer of water, losing all contact with the road. Steering and braking become ineffective.
What Causes Aquaplaning
Three factors combine: vehicle speed, water depth on the road surface, and tyre condition. Higher speed, deeper water, and worn tyres all increase the risk. A tyre with 1.6 mm tread depth is highly prone to aquaplaning at motorway speeds. At 90 km/h with worn tyres on a flooded road, complete aquaplaning can occur.
Warning Signs
The steering suddenly feels light and unresponsive. Engine revs may increase if drive wheels are affected. The vehicle may drift from its lane without response to steering input.
How to Respond
Do not brake hard — there is no road contact to brake against, and sudden braking when grip returns can cause a violent skid. Do not steer sharply. Ease off the accelerator gently to reduce speed. Hold the steering wheel straight. As speed drops, the tyres will regain contact with the road surface.
Prevention
Maintain adequate tyre tread depth, reduce speed when roads are flooded, and avoid standing water where possible. Good-quality tyres with 4+ mm of tread are highly resistant to aquaplaning at normal road speeds.
Exam tip: The correct response to aquaplaning is to ease off the accelerator and hold the wheel straight — not to brake or steer aggressively.