With dagga now legal for recreational use in parts of America, a Washington television station decided to put a few "stoned" motorists behind the wheel for testing.
Colorado and Washington State now allow limited use of marijuana. TV station KIRO used three people in the study, and had a driving instructor in the car as well as a "Drug Recognition Expert" from the police force on hand for the test.
Picking up on drug-impaired driving is far more difficult for officers than recognising alcohol-impaired driving, the video reveals.
Each of the three participants was well over the legal limit while navigating the course, according to tests measuring the amount of marijuana in their blood.
But both the officer and instructor said all three did rather well initially (don't for a minute think we're endorsing "drug-driving". We're not). However, as they got "higher", they slowly started showing signs of impairment.
Check out the video below...