California Vehicle Code, section 670, definition of a vehicle:

670. A "vehicle" is a device by which any person or property may be propelled, moved, or drawn upon a highway, excepting a device moved exclusively by human power or used exclusively upon stationary rails or tracks.

Section 231 defines a bicycle:

231. A bicycle is a device upon which any person may ride, propelled exclusively by human power through a belt, chain, or gears, and having one or more wheels. Persons riding bicycles are subject to the provisions of this code specified in Sections 21200 and 21200.5.

So although in most states a bicycle is a vehicle, in California, it is a device.