Elements of a DUI: A motor vehicle
A motor vehicle

SECTION 56-5-130. Motor vehicle defined.
Every vehicle which is self-propelled, except mopeds, and every vehicle which is propelled by electric power obtained from overhead trolley wires, but not operated upon rails, is a "motor vehicle".[4]
SECTION 56-5-165. Moped defined.
Notwithstanding the provisions of Section 56-5-160, every cycle with pedals to permit propulsion by human power or without pedals and with a motor of not more than fifty cubic centimeters which produces not to exceed two brake horsepower and which is not capable of propelling the vehicle at a speed in excess of thirty miles an hour on level ground is a moped. If an internal combustion engine is used, the moped must have a power drive system that functions directly or automatically without clutching or shifting by the operator after the drive system is engaged.[5]