English: number of ribs and groove spacing affect the way water is eliminated to avoid hydroplaning (refer to section 3.1). See thru, percent void, shoulder slot size and orientation can all affect traction, handling and water exit paths. The number of pitches and pitch sequence as well as the placement of tie-bars and sipes can affect traction, noise, wear, and the tendency to wear non-uniformly. Figure illustrates a noise treatment using different pitch lengths around the tire circumference to limit tone generation as the tire rotates. Additionally, tread designs need to be acceptable aesthetically and to match the customer’s perception of product performance.