Hydroplaning is the loss of traction that occurs when a layer of water builds up between your car’s tires and the road surface, causing the vehicle to ride on a film of water. This separation from the pavement results in a sudden loss of steering and braking control. Knowing the immediate actions to take and preventative measures is important for safely navigating wet road conditions.
Regaining Control During a Slide
The moment a car begins to hydroplane, the driver will feel a sudden lightness in the steering wheel and a lack of response. The immediate action is to remain calm and avoid sudden movements. Gently ease your foot off the accelerator pedal to allow the vehicle to slow down naturally.
Resist the urge to slam on the brakes, as this can cause the wheels to lock up and lead to a severe skid, especially without an Anti-lock Braking System (ABS). If your car has ABS, apply light, steady pressure to the brake pedal only after the tires begin to regain contact with the road. If your car lacks ABS, gently pumping the brakes can help slow the wheels without causing a lock-up.
While sliding, keep the steering wheel pointed straight or steer gently in the desired direction. Avoid sharp turns, as the tires will not respond until traction is restored. Once you feel resistance, indicating the tires are reconnecting, make small, controlled steering adjustments to correct the vehicle’s path and proceed with caution.
How to Prevent Hydroplaning
Preventing hydroplaning begins with proper vehicle maintenance. Adequate tire tread depth is a factor, as the grooves channel water away from the contact patch. Tires should be replaced when the tread depth reaches 2/32 of an inch or less, a measurement often checked using the head of a penny.
Maintaining correct tire inflation pressure is necessary, as improperly inflated tires reduce the ability to disperse water effectively. The most effective preventative measure is to significantly reduce speed in wet conditions, as hydroplaning can occur at speeds as low as 35 miles per hour. Reducing speed gives the tire tread more time to displace water and maintain contact with the road surface.
Drivers should avoid large puddles or areas of standing water, which increase the risk of the tires being lifted off the road. If possible, driving in the tracks left by the vehicle ahead can be beneficial, as that car has already dispersed some water. Avoid using cruise control in wet weather, as it can maintain speed even when traction is lost, hindering quick driver reaction.
The Science Behind Hydroplaning
Hydroplaning occurs because water is incompressible, meaning the tire cannot push it out of the way fast enough to maintain contact with the road. As the tire rolls over a wet surface, water pressure builds up in front of the contact patch. This pressure forces a wedge of water underneath the leading edge of the tire.
When the upward force created by this water wedge equals the downward force of the vehicle’s weight, the tire is lifted completely off the road surface. The vehicle rides on a thin sheet of water, eliminating the friction needed for steering, braking, and acceleration. The primary factors influencing this phenomenon are the vehicle’s speed and the depth of the water on the road.
The tire’s tread pattern and depth are designed to create channels that allow water to escape from beneath the tire. If the water is too deep, the speed is too high, or the tread is too worn, the water cannot be evacuated quickly enough. This failure to displace the water causes the loss of traction and control.