Walters was arrested for driving under the influence, and arresting officers seized two bags of methamphetamine from his pocket. On appeal, Walters challenged the trial court’s finding that the driving under the influence charge rendered him ineligible to participate in treatment under Proposition 36. The appellate court affirmed. The misdemeanor offense of driving under the influence of drugs involves more than the “simple possession or use of drugs” as defined by Penal Code section 1210.1, subdivision (b)(4). It requires the additional element of impaired driving , and therefore disqualified Walters from participation in Proposition 36 treatment.