Yet more than a decade after states began legalizing recreational marijuana, or cannabis, effective policies to counter driving while high on it don’t exist. The first challenge is that when police stop a driver suspected of driving under the influence, they have no equivalent of a roadside breathalyzer test for detecting cannabis intoxication. That can skew testing, producing a positive result in a blood or urine test even though the person who consumed the cannabis is no longer high. How states would detect and deter cannabis-impaired driving is one of many policy problems that did not receive sufficient thought. The penalty is enforced with frequent testing and immediate sanctions after a positive test.

Source: Washington Post December 29, 2025 21:32 UTC