Tenn. Code Ann. § 55-4-136: Registration of medium speed vehicles

(a) Any vehicle that is not equipped with a windshield and that otherwise qualifies as a medium speed vehicle as defined in § 55-1-125 may be registered as a medium speed vehicle; provided, that while the vehicle is in operation upon any public road of this state, the operator and each passenger shall wear a helmet in accordance with § 55-9-302 and eye protection, including glasses containing impact resistant lenses, safety goggles, or a face shield.

(b) Any vehicle described in subsection (a) shall be registered as a medium speed vehicle if the operator provides an affidavit, under penalty of perjury, on a form prescribed by the department certifying that the vehicle meets applicable safety standards and that the operator will otherwise comply with subsection (a).