The Difficulty of Testing Drivers For Cannabis

The increasing acceptance of cannabis use in states across the U.S. is creating a headache for law enforcement officials – especially when it comes to testing drivers who might be suffering from impairment due to their use of either cannabis itself – or products containing tetrahydrocannabinol (THC) extract. THC is the active ingredient that causes the euphoria associated with the use of marijuana and other retail products containing the compound. The recreational use of marijuana is now legal in 11 states – it is also legal for medical use in 33 States – and with the increasing number of consumers using THC or marijuana, there are worries that driving impairment from that use is on the increase.

The question is – why is roadside testing for impairment caused by marijuana so challenging, after all, breathalyzers for testing blood alcohol levels have been around since 1954. Those devices return results quickly, they are portable and relatively inexpensive. Although some researchers claim to be close to perfecting a similar device for analyzing THC concentrations in the human body some experts say that there is still some way to go. The challenge of finding a portable machine to perform checks on drivers who may be intoxicated through the use of marijuana is much more complicated than that faced by those who developed the alcohol breathalyzer.

Firstly, there is the fact that alcohol tends to metabolize fairly quickly in the human body. Chances are that if you fail a breathalyzer test for alcohol you will be impaired to a certain extent. A cannabis impairment analyzer of some type must be able to tell if the user has been using the drug recently – that the use is impairing their ability to drive safely. Finding a solution that can combine these two tests is proving problematic. One of the reasons is that cannabis tends to linger in the human body. An analyzer that spots cannabis use may not necessarily indicate that the driver is impaired – just that they have used the drug sometime in the medium term. A result like that would almost certainly be challenged in a court of law.

Another problem is that there has been insufficient research done on levels of impairment. There is broad consensus that the use of cannabis does affect motor skills and judgement, but far more research is required as to just how impairment can be classified. There is also a lack of research into just how exactly cannabis affects driving. The old adage of ‘if you can’t measure it, you can’t manage it’ applies.

But many researchers believe they are close to meeting the challenge. For example, researchers at the University of California-San Francisco believe they are close to perfecting a device that can measure THC concentrations in breath up to three hours after it was used. They also believe that the device could combine an alcohol and THC analyzer.

In essence, law enforcement is faced with a problem. If you cannot define impairment – you cannot take action against those who are suspected of being impaired. The fact that people have different reactions to the use of cannabis further complicates matters. For the time being it seems that law enforcement is relatively powerless – but that could change very quickly if current research bears fruit. In the meantime, cannabis users need to exercise self-restraint when it comes to using the drug and driving.