BY C.M. WATTS \n Just because marijuana is recreationally legal in states like Oregon and Colorado, it doesn’t mean that you can now get high and do whatever you want. \n One argument that continually comes to the head when people are discussing marijuana legalization is “what about driving after smoking?” After all, driving under the influence is still an offense and not a typically recommended activity. \n However, issuing someone a DUI due from marijuana use can be a difficult task for the police. The main problem lies in the fact that there isn’t a clear way to test for intoxication on site. Unlike alcohol, there is not a magic number, like a .08 BAC, that signals you’ve enjoyed too much marijuana before driving. \n This problem is only compounded by the fact that marijuana can stay in your system for up to 30 days, so a even an on-site drug test could give police officers incorrect information about the levels of cannabis in your system. \n In a post by Michael Romano, a Portland Oregon DUI attorney , he lays out how Oregon police handle situations where they think a drive is under the influence of cannabis. \n \n Oregon uses Drug Recognition Experts or Drug Recognition Evaluators (DREs) to evaluate whether a given driver or test subject is under the influence of drugs. According to the Drug Symptom Matrix (or chart) relied upon by DREs, “general indicators” of marijuana/cannabis use include: \nVery red eyes, \nOdor of marijuana, \nBody tremors, \nEyelid tremors, \nRelaxed inhibitions, \nIncreased appetite, \nImpaired perception of time and distance, \nPossible paranoia, and \nDisorientation.The duration of effects will be assumed to be 2-3 hours. \nIf a DRE examination is requested by an officer– and if the driver participates in the examination– the evaluator would expect to see (or would say that they saw) some or all of the following indicators of cannabis use: \nNo Horizontal Gaze Nystagmus (HGN) (an involuntary jerking of the eye balls when tracking an object moving horizontally in front of the eyes), \nNo Vertical Gaze Nystagmus (VGN) (an involuntary jerking of the eye balls when tracking an object moving vertically in front of the eyes), \nLack of convergence (an inability to cross the eyes), \n“Normal” pupil size or dilated (larger than normal) pupil size, \n“Normal” reaction of the pupils to light (the pupils become larger in darkness, then quickly become smaller when exposed to light), \nElevated pulse rate (higher than normal pulse rate), \nElevated blood pressure (higher than normal blood pressure), and \nElevated body temperature (higher than normal body temperature). \nOverdose signs will be assumed to be fatigue or paranoia.” \n \n His post even outlines a couple of scenarios where a drive could be accused (even falsely) of driving under the influence. He also lays out what to do if you don’t want to be falsely accused of driving on marijuana. Click here to learn more from Romano on driving under the influence of cannabis .