(A) For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
MOTOR VEHICLES. Automobiles, loco- mobiles and all other vehicles propelled otherwise than by a muscular power, except traction engines and road rollers, the cars of electric and steam railways and other motor vehicles running only upon rails or tracks.
(B) Nothing in this chapter shall be construed to apply to or affect bicycles or tricycles or other vehicles as are propelled exclusively by human muscular power.
('73 Code, § 21-261)