Hydroplaning

Hydroplaning is known to be a major cause of wet weather road accidents. Hydroplaning occurs when water on the road can not be moved out from underneath your tires, causing your vehicle to no longer respond to the steering wheel and to ride on a layer of water instead of the pavement. A graphic of a tire and its contact with the road during hydroplaning can be seen to the right. When you hydroplane, your steering wheel will either jerk or suddenly feel loose and a little easy to move. In addition, the rear end of your vehicle may feel as though it's moving from side-to-side.

Three main factors contribute to hydroplaning: vehicle speed, tire tread depth, and water depth. These three factors are complicated, and the exact point in which your vehicle will hydroplane takes in many other variables: tire size, tire tread pattern, tire tread depth, tire pressure, water depth, water composition (oil, dirt, and salt can change its density), vehicle speed, vehicle weight, vehicle drive-train (two-wheel-drive vehicles are less likely to hydroplane than all-wheel-drive vehicles), and road surface type.

Almost half of the factors directly contributing to hydroplaning are related to your tires. The tire tread depth is one of the main reasons, because as your tires are worn down, they significantly lose their ability to resist hydroplaning. In fact, if tire treads are too low, hydroplaning can occur at speeds as low as 35 miles-per-hour. Tire tread pattern plays a large role in moving water from underneath your tires, and many tire manufacturers have taken that into consideration in their designs. For example, Bridgestone developed UNI-T AQ II technology specifically to improve wet-weather tire performance by aiding in water evacuation. Tire size and pressure are also important, because the wider the tire's contact patch, the more contact it has with the road, meaning the less likely it is to hydroplane.

While on the road, there are few things you can do to prevent hydroplaning besides lowering your speed and being observant. Look for large puddles in the road ahead of you or pay attention to the car in front of you. If the water being kicked up by the vehicle suddenly increases, or if the vehicle jerks unexpectedly, you may be preparing to enter a large puddle of water with a high risk of hydroplaning. Another option is to look at your tire tracks in the rear-view mirror. If you can not see them, then it is very likely that water is rapidly accumulating on the road.

If you do hydroplane, there are two absolute 'DO NOTs':

You should gently lift your foot from the accelerator and hold the steering wheel firmly and straight ahead. If necessary, you can lightly tap your brakes as you would on ice or snow, because if your tires still have partial contact with the road, you should be able to easily regain control of your vehicle.

While it is almost impossible to prevent hydroplaning, you can control many of its factors with one simple action: keeping good tires on your vehicle.