At what depth of rainwater on the road can Hydroplaning begin?

Hydroplaning can begin when there is as little as 1/8 of an inch of rainwater on the road. This phenomenon occurs when a layer of water builds up between the tires of a vehicle and the road surface, causing the tires to lose direct contact with the road. At this minimal depth, tires can struggle to disperse the water effectively, leading to a loss of control as the vehicle begins to glide over the water rather than gripping the surface. Understanding this threshold emphasizes the importance of cautious driving in wet conditions, as even a small amount of water can significantly affect traction and handling.