3. Visual requirements. A tire is not in safe operating condition if that tire has:

A. A fabric break or a cut in excess of one inch in any direction as measured on the outside of the tire and deep enough to reach the body cords;

B. A temporary repair by the use of blowout patches or boots;

C. A bump, bulge or knot related to separation or partial failure of the tire structure;

D. A portion of the ply or cord structure exposed; or

E. Sidewalls damaged to the extent that the body cords are damaged.

4. Tread depth. A tire is not in safe operating condition if it is worn to the point where less than 2/32 inch of tread design remains at all points at which gauge readings are required. Tread depth must be measured as follows.

A. Tire tread depth must be measured by a tread depth gauge that is calibrated in 1/32 inch.

B. Readings must be taken in 2 adjacent major tread grooves at 2 points in each of the grooves not closer than 15 inches.

C. Readings for a tire that has the tread design running across the tire or for a siped tire must be taken at or near the center of the tire at 2 points of the circumference not closer than 15 inches.

5. Exemptions. A farm vehicle used exclusively for agricultural purposes, including, but not limited to, a self- propelled combine, self-propelled corn and hay harvesting machine or tractor used exclusively for agricultural purposes, is exempt from this section.

6.__Wheels.__If the rim size has been altered, the overall diameter of the wheel with the tire must be within the vehicle manufacturer's specifications.