A recent decision by the Arizona Court of Appeals has sparked both support and concern regarding marijuana use and driving safety. While the court’s ruling acknowledges that THC can remain in the bloodstream long after impairment fades, it risks sending the wrong message: that it’s safe to drive after using cannabis.
The ruling stems from a shift in Arizona’s legal landscape. Before the 2020 passage of Proposition 207, which legalized recreational marijuana, finding THC metabolites in a driver’s blood could lead to a DUI conviction. However, with the new law in place, drivers can only be penalized if they are “impaired to the slightest degree” by marijuana. The court’s decision now clarifies that the presence of THC alone is no longer sufficient for a DUI charge—there must be additional evidence that the driver was actually impaired at the time.
This ruling stands in contrast to Arizona’s alcohol DUI laws, where a blood alcohol concentration (BAC) of 0.08% is an automatic indicator of impairment. No such concrete threshold currently exists for marijuana, leaving law enforcement with a more subjective and potentially inconsistent method of determining impairment on the road.
While there is progress toward developing a THC breathalyzer, no reliable tool has yet been approved for use. This gap leaves both law enforcement and lawmakers with the task of finding a solution to address marijuana impairment standards—just as the 0.08% BAC serves as a benchmark for alcohol.
The concern is that this legal gray area could lead to risky behavior, with some individuals mistakenly believing they are safe to drive after consuming marijuana. As Arizona works toward more precise tools for measuring THC impairment, it’s crucial to remember that driving under the influence—whether from alcohol or cannabis—remains a significant public safety issue.
Until new standards and technology are in place, Arizona drivers should avoid the misconception that they can safely drive after using marijuana. Road safety must remain a priority, and until clear guidelines are developed, it’s better to err on the side of caution to prevent accidents, injuries, or worse.