Traffic Safety - As enacted, defines "fully enclosed" as having side panels, a roll bar or roof, and a windshield with regard to crash helmet requirements not applying to autocycles that are fully enclosed. - Amends TCA Title 55.

HB 859 changes the effective date for a helmet exemption for certain autocycles in Tennessee. It amends Tennessee Code Annotated, Section 55-10-428(c), by shifting the date when the exemption takes effect from December 1, 2025, to February 1, 2026. The exemption applies specifically to autocycles that meet the definition of "fully enclosed" (having side panels, a roll bar or roof, and a windshield). This affects autocycle operators in Tennessee who use vehicles meeting this definition, as they will no longer be required to wear helmets under the updated timeline.