In case of rain or a wet road surface, most tires have a good grip up to about 55 km / h. If you drive faster, the tires start riding on the water like water skis. We call this "hydroplaning", in dutch water smoothness or aquaplaning. If there is water on the road surface, the tires can completely lose their grip with the road. Bare or worn tires can lose their grip at much lower speeds. The best way to prevent hydroplaning is to reduce the speed in case of rain or a wet road surface.