The friction between a tire and the road is primarily due to the interaction between the rubber of the tire and the surface of the road. This type of friction is called rolling friction.
The magnitude of rolling friction depends on various factors, including:
Nature of the surfaces: The coefficient of rolling friction is influenced by the materials involved. Different types of tires and road surfaces can exhibit varying coefficients of rolling friction.
Texture and condition of the road: The roughness, smoothness, and condition of the road surface can affect the friction between the tire and the road. A rougher surface typically provides more grip and thus higher rolling friction.
Tire design and inflation: The design of the tire, including the tread pattern, compound, and inflation pressure, can influence the amount of friction generated. Tires with deeper treads and appropriate inflation tend to provide better traction and higher rolling friction.
Weight and load distribution: The weight of the vehicle and the distribution of that weight among the tires play a role in determining the friction. Increased weight or uneven load distribution can affect the tire's contact with the road and impact the rolling friction.
It's important to note that the coefficient of rolling friction is typically lower than the coefficient of static friction (friction when the tire is not rolling). This allows the tire to roll more smoothly and efficiently without excessive resistance while maintaining sufficient grip for safe driving.