To prevent hydroplaning, in which a water film is formed on a tire during high speed travel in a heavy rain and brake cannot work, by fixing a rubber plate with a specific thickness and a mudguard integrally and preventing water from moving onto the tire.

A rubber plate with a thickness of 1.5m/m is matched with the width of a tire with its both ends slightly bent into arches so as to be fixed integrally with a mudguard, and the rubber plate is brought into contact with a tire if necessary. In this process, the rubber plate is installed in a vehicle provided with no mudguard, while a mudguard is installed integrally with the rubber plate in a vehicle provided with a mudguard. However, an arch shaped rubber plate causes a disturbance if it is installed in a front wheel. Even if a tire and a rubber plate are brought into mutual contact for a long time without any water, grooves in the tire radiates heat, and when the tip of the rubber plate is formed into a round shape, inconvenience in backing can be eliminated. In this way, water can be prevented from moving onto a tire, and at the same time, danger due to a failure in braking can be prevented.