A directional tread is engineered to roll in a certain direction when the machine or vehicle travels forward. It is usually designed to offer good traction, stability and better comfort in certain applications. Tires with directional tread patterns must be mounted so that the forward direction of rotation matches the directional arrows on the tire sidewall. If mounted improperly, directional tires may also wear irregularly and prematurely, and produce excessive road noise. The opposite of a directional tire is a non-directional tire, which can rotate in either direction with equal performance, regardless of the road conditions.