1. A method for estimating the wear state of a tire supported by a wheel and supporting a vehicle, the method comprising: providing a vehicle-based sensor; measuring a wheel speed of the wheel supporting the tire with the vehicle-based sensor; generating a wheel speed signal from the measured wheel speed; communicating the measured wheel speed to a processor; extracting a median slip-ratio of the tire from the wheel speed signal with a processor, the median slip-ratio operably changing with a change in the tire state; extracting a slip-ratio rate of the tire from the wheel speed signal with a processor, the slip-ratio rate operably changing with a change in the tire state; classifying data from the median slip-ratio and data from the slip-ratio rate with a data classifier that includes a support vector data classification algorithm; indirectly estimating the tire wear state by applying the algorithm; and outputting the estimated tire wear state to a vehicle operating system.