Tests for driver impairment by marijuana flawed: AAA

Driving with "a noisy child in the back of the car" is about as dangerous as using marijuana and driving
CBS News (US)
Tuesday, May 10, 2016

Six states that allow marijuana use employ legal tests to determine whether someone is driving while impaired by the drug that have no scientific basis, according to a study by the nation's largest automobile club that calls for scrapping those laws. The study commissioned by AAA's safety foundation said it's not possible to set a blood-test threshold for THC, the chemical in marijuana that makes people high, that can reliably determine impairment.