hydroplaning

Hydroplaning, also known as aquaplaning, is a loss of traction that occurs when a layer of water builds between a vehicle's tires and the road surface, preventing direct contact and reducing the effectiveness of braking and steering.

The mechanism involves water under the tires as the vehicle moves; if water pressure rises ahead of the tire and the tread cannot channel it away quickly enough, the tire rides on a thin water film. Tire tread depth, inflation, speed, and load affect the likelihood, with worn tires, low pressure, and high speed on wet pavement increasing the risk. Road design and drainage also influence how readily water accumulates on the surface.

Hydroplaning most commonly occurs on wet pavements with standing water, especially at speeds above about 35 mph (56 km/h). It can occur at lower speeds under shallow water or when tires are severely worn, underinflated, or when rainfall is heavy.

The effects include loss of steering, braking, and overall vehicle control, with a sudden reduction in traction that raises the risk of crashes and skidding.

Prevention centers on reducing speed in rain and avoiding standing water when possible. Maintaining tires with adequate tread depth (a minimum of 2/32 inch or 1.6 mm) and proper inflation, rotating tires as recommended, and ensuring the vehicle’s suspension and tires are in good condition all reduce risk. In addition, drivers should exercise caution when driving through water and avoid abrupt steering, acceleration, or braking.

If hydroplaning occurs, avoid hard braking or sharp steering. Ease off the accelerator to slow gradually and allow the tires to recontact the road, then proceed smoothly to regain traction.