Question Hydroplaning: Answers Only occurs at extremely high speeds. Can occur at speeds as low as 30 mph. Happens most frequently when tire pressure is too high. Explanation If there is enough water on the road, hydroplaning can occur at speeds as low as 30 mph. It is most likely if the tires' air pressure is too low or if tires' tread is worn. This questions appears in the following tests: Connecticut Double Louisiana Tank Nevada Class A Knowledge Test New Mexico Class B Knowledge Test