Drugged Driving Per Se Laws
All states have drunk driving laws but cases involving drug impaired driving are more problematic. According to the Governors Highway Safety Association, only 19 states have strict per se laws that prohibit the presence of any amount of a prohibited substance while driving.
At the federal level, marijuana remains classified as a Schedule I substance under the Controlled Substances Act, where Schedule I substances are considered to have a high potential for dependency and no accepted medical use, making distribution of marijuana a federal offense. However several states have passed laws legalizing medicinal and recreational marijuana.