What is Hydroplaning? Hydroplaning is the loss of contact between your tires and the road because of water buildup. When your car hydroplanes, it essentially turns into an unsteerable sled, which is especially dangerous if there are people or vehicles in front of you on the road.
Rain means high danger for hydroplaning. Older highways with ruts and non-porous surfaces have a higher occurrence of Water puddles ... and thus an increased danger of hydroplaning.