Slipping, Sliding and Hydroplaning

One of the most frightening things that can happen while driving is to realize that you’ve lost control of your vehicle. But that’s exactly what happens when you hydroplane. Hydroplaning happens on wet highways; it’s caused by your tires losing contact with the road and sliding across the film of water, much like water skis. The faster you drive on wet roads, the more likely you are to hydroplane, because it becomes more difficult for the tire tread to channel water out and away. Worn tires will be even more likely to hydroplane. But hydroplaning can actually happen at low speeds too – in water as little as 1/10” deep, you can hydroplane at only 35 mph.

HYDROPLANING

When you find yourself traveling on wet roadways, the best thing to do is reduce your speed so as to lower your risk of hydroplaning.  If your tires lose traction and your car begins to hydroplane, follow these steps to regain control:

  • Maintain control of the steering wheel with both hands
  • Ease up slowly on the gas pedal to reduce your speed.  Don’t hit the brakes or try to turn; it can cause you to skid sideways. As your speed reduces, your tire tread will be able to funnel water away and regain its grip on the road, putting you back in control.
  • Steer gently and only as you need to maintain your car on the road.
  • If you must brake, use a gentle touch. (See the section “If you have to brake suddenly” for tips on the differences of conventional and anti-lock brakes in an emergency stop.)

DRIVING ON SNOW AND ICE

When the road conditions include snow or ice, you’ll have to make some adjustments to your driving style. Tire traction is compromised, which has a big effect on your ability to steer or brake. If the temperature is around 32F degrees, snow can turn to sleet or rain, creating a layer of water over ice which is more slippery and more dangerous than just ice.

Be extremely careful with a condition called “black ice”, which happens on wet roadways when the temperature drops and thin layer of ice forms. If the road ahead of you appears wet, but there is no “spray” of water behind other cars, you may be seeing black ice.

When driving on slick roads, remember these tips:

  • On wet roads, you should drive 5-10mph below posted speed limits, and lengthen your following distance to 5-6 seconds.
  • On roads with ice or snow, reduce speed even further.  If the road is covered with packed snow, you should reduce your speed to half the posted limit; on ice, no more than a crawl.  You should leave plenty of space between you and the car in front of you – at least ten car lengths.
  • Avoid sudden braking. When braking, do so gently and let up if you begin to skid; reapply brakes once you regain control. (See the section “If you have to brake suddenly” for tips on the differences of conventional and anti-lock brakes in an emergency stop.)
  • Never use cruise-control when driving on slick roadways. It’s easy to lose control of a vehicle when driving in slippery conditions like ice or rain; reducing acceleration is the only method of regaining control and stopping wheel-spin. If you’re cruise-control is activated, it will continue applying power, making wheel-spin worse.
  • Slow down if necessary to avoid driving across slippery areas (like found on shady spots or on bridges) at the same time as other vehicles. It will lessen the risk of collision if one car loses control.
  • Slow down when you see red lights ahead of you, so that you can coast up to the intersection and any other cars stopped – it allows you to avoid braking. Acceleration is also much easier if you haven’t completely stopped.
  • When going uphill, allow plenty of space between you and vehicles you’re following so that you don’t need to step on the brakes. When going downhill, shift into a lower gear instead of using the brakes to reduce speed.