The semantics of "drive" and a useful definition of a non-motorised vehicle: Kentucky law (KRS 189.520) prohibits the operation of a non-motorized vehicle (a vehicle that is not a motor vehicle) while under the influence of intoxicants or substance which may impair a person’s driving ability. That includes, those who are riding horses, bicycles, skateboards, etc.
 (http://www.wkyt.com/news/headlines/Man-on-horse-arrested-for-DUI-170100436.html)