"Tread depth" shall mean the amount of tread design on the tire. Tread depth includes both original, retread and recap tread design; and, in respect to special mileage commercial tires, recut, re-grooved and siped tread design.
Source. RSA 263:85, I. 1965, 299:1. 1981, 146:1, eff. Jan. 1, 1982.