In 2017, cannabis is now more legal and accessible than ever. And its growing use is presenting new problems for law enforcement. Chief among those issues is how to handle folks who chief and drive. This issue is this: there is no reliable way to test how cannabis use influences driving. And in fact, several studies show that marijuana use does not impact driving ability very much. In light of this, an Arizona court ruled last week that legal medical cannabis patients can fight their DUI charges.
Following Arizona’s Court of Appeals ruling, the burden of proof for charging cannabis users with a DUI is now on the police, not patients. Medical marijuana patients charged with a DUI can fight it in court. Importantly, this means that it’s now up to the arresting officer to prove that the THC impaired the driver.
And police are going to have a hard time doing so, because of two factors. Firstly, how impaired a driver is, has little to do with the amount of THC in their bloodstream. And secondly, people respond to THC very differently. So there’s no concrete basis for setting a legal limit on THC, unlike alcohol. What gets one person too high to drive might not affect another person very much.
Even the National Highway Traffic Safety Administration admits that it’s impossible to tell intoxication based on THC levels. Their website states that it is “difficult to establish a relationship” between THC in the blood and impairment.
It also says that it is “inadvisable” and “impossible” to predict any specific impacts based on THC concentration. Put simply, just because you have cannabis in your system doesn’t mean your driving will suck.