A 2017 survey by the Colorado Department of Transportation (CDOT) found that almost 70 percent of cannabis consumers drove high at least once in the past year. Twenty-seven percent said they drive high almost every day.
Currently, officers who suspect a driver is impaired can only test the hunch with field sobriety tests. Blood, breath or urine samples could be taken to determine if a driver is high, but such tests can be inaccurate. Those tests also detect if the driver was high that day or week, rather than if they were high while operating the vehicle in that instance.
Tools such as Hound Labs’ alcohol-and-marijuana breathalyzer or Canadian company Cannabix Technologies Inc.’s THC breathalyzer aim to present an objective determination of recent marijuana use rather than one based on an officers’ judgement or an intrusive test. Drivers with a blood alcohol concentration above .08 percent are considered under the influence of alcohol or driving while impaired. But what exactly qualifies a driver under the influence of marijuana as “impaired” is up for debate in the science community.