Avoiding Car Accidents When Your Car Hydroplanes On A Wet Road

Hawaii is famous for good (great!) weather and lots of sun, but a few times a year Hawaii is hit with a storm and the rain is heavy and the visibility reduced. The systems that drain water from road surfaces get overwhelmed in these storms and water sheets the roadways at certain locations where drains are full. This week we are having such conditions and a number of drivers will find their car hydroplaning and some crashes will occur. We hope that no injuries will occur but history tells us that some major injury accidents happen in Hawaii in this situation. So what should a driver do if they find their car sliding on a wet road?

You can start by reading Driver safety: How to drive through a hydroplane at Helium. The author, Kevin Guthrie, explains that tire treads are meant to dissipate water and when they get filled the tire loses its ability to hold the road. This can occur, according to Guthrie, to driving too fast in wet conditions so slow down in these wet Hawaiian conditions!

First rule: don’t do anything much with the brakes or steering wheel. Guthrie explains:

The principle point to remember is that no sudden inputs should be made to any of the car’s controls. Although the driver has no directional control over the car while it is hydroplaning any steering adjustments should be small and gently made. The reason for this is that, when the car eventually does regain grip with the road surface, it is preferable to have the vehicle pointing as straight as possible. Otherwise, oversteer can occur resulting in a slide or spin. Oversteer is when the rear wheels of a car break traction and tends to happen more in rear-wheel drive cars. The opposite effect to this is understeer, when the front wheels are reluctant to turn into a corner.

Second Rule: gently pull your foot off the accelerator. This allows the water filling the reads to go down to a level where the car can get traction again. Like an airplane landing on a runway, the reduced speed lets the car settle back down on the road surface underneath the water.

Third Rule: If it is raining, slow down and keep extra distance between your car and the cars ahead and behind you. If someone is tailgaiting you, get out of their way.

Fishtailing and spinning usually occur when the driver, feeling the car sliding, turns the steering wheel or hits the brakes to try to control the car. Remember that the car will get free of the flooded portion of the roadway and if the car is sliding sideways if the driver is still pushing the accelerator the car will shoot forward in the direction it is pointed. Slowly take your foot off the gas in your car is sliding on a wet road.

Fourth Rule: Good tires. Don’t let the tire tread depth fall below 1/6th-inch (3 millimeters). worn tires and lack of tread depth make the car more susceptible to sliding a wet road. This recommendation comes from the Royal Society for the Prevention of Accidents (RoSPA).

In an article on the safety of worn tires, "How safe are worn tires? Even tires with half their tread intact may be riskier than you think", the well-regarded magazine Consumers Reports points out that tires are considered bald when they have a tread depth of 2/32-inch or less and that a new tire usually has a depth of 10/32-inch. They explain how to spot a bald tire on your car:

Manufacturers have made bald tires easier to spot by placing a series of molded horizontal bars at the base of the grooves. The bars become flush with surrounding tread when wear reduces a groove’s depth to 2/32 of an inch. That’s also the point where tires will flunk a state safety inspection–and where tread must be worn for you to collect on a tire’s tread-wear warranty.

However that may not be adequate on a wet road:

Unfortunately, 2/32 of an inch may be too late if you drive in rain or snow. Based on our tests of new and half-tread-depth tires, you may want to consider replacing the ones on your car or truck closer to the 5/32-inch groove depth that marks the half-tread point on many tires.

The Consumers report article goes on the report on testing of various tires. protect yourself and your passengers by keeping good tires on your car.