When any vehicle is equipped with any solid tire, the solid tire shall have a minimum thickness of resilient rubber as follows:
- (a) If the width of the tire is three inches but less than six inches, one inch thick.
- (b) If the width of the tire is six inches but not more than nine inches, 11/4 inches thick.
- (c) If the width of the tire is more than nine inches, 11/2 inches thick.