National cannabis impairment standard

(a) In general Not later than 3 years after the date of enactment of this Act, and once every 2 years thereafter, the Secretary shall make a determination as to whether or not it is feasible to establish a national standard for determining impairment for cannabis-impaired driving. (b) Rulemaking required If the Secretary determines that establishing a national standard relating to cannabis-impaired driving under subsection (a) is feasible, the Secretary shall, not later than 1 year after that determination, promulgate regulations establishing a model marijuana impairment standard for States.