Section 312 Of Division 1. Words And Phrases Defined From California Vehicle Code >> Division 1.

. The term "drug" means any substance or combination of substances, other than alcohol, which could so affect the nervous system, brain, or muscles of a person as to impair, to an appreciable degree, his ability to drive a vehicle in the manner that an ordinarily prudent and cautious man, in full possession of his faculties, using reasonable care, would drive a similar vehicle under like conditions.