Ask a Trooper: Be careful of hydroplaning

Q: With all the rain we’ve been having lately, can you talk about hydroplaning?

A: At speeds of 35 mph or less, most tires will “wipe” water off the road surface to keep tires in contact with the road. At higher speeds, water can collect under tires and lift them off the surface of the road — this is called “hydroplaning.”

When your tires hydroplane, they lose all contact with the road. If this occurs, you will be unable to brake, accelerate, or change direction. If your tires begin to hydroplane, take your foot off the gas pedal.

Hydroplaning is less likely to occur at normal highway speeds if your vehicle is equipped with good tires that have deep treads, which will allow water to escape. But hydroplaning can occur at any speed if the depth of the water on the road is greater than the depth of the tire treads. In heavy rain, standard cars may begin to hydroplane at 35 mph.

To prevent hydroplaning, keep your tires in good condition and reduce speed when driving on wet roads.

Q: Can you talk about drug use and impaired driving. It seems like I am seeing more and more of this.

A: Drug-impaired driving is as dangerous as alcohol-impaired driving. Minnesota law prohibits driving while impaired by controlled or intoxicating substances. These substances include illegal drugs, prescription drugs, and over the counter drugs (cold medicines), as well as household products. These substances can cause drowsiness and impair a driver’s mental and physical ability to safely operate a vehicle and to respond to driving conditions.

Legal drugs that may not cause impairment alone can produce powerful intoxicating effects when mixed with alcohol. The safest rule is do not mix drugs with driving at all. Use of drugs can lead to traffic crashes resulting in death, injury and property damage. It can lead to arrest, fines and jail sentences.

Pay attention to warning labels for legitimate drugs and medicines and to doctor’s orders regarding possible effects. Stay away from illegal drugs. Don’t use any drug that hides fatigue — the only cure for fatigue is rest.

If you have any questions concerning traffic related laws or issues in Minnesota, send your questions to Trp. Jesse Grabow – Minnesota State Patrol at 1000 Highway 10 West, Detroit Lakes, MN 56501-2205. You can follow him on Twitter @MSPPIO_NW or reach him at, jesse.grabow@state.mn.us.