Evaluating the Validity of Cannabis Impairment Tests


With the proliferation of cannabis use across the globe, many states have taken the step to legalize it for both medical and recreational use. However, cannabis use is still illegal in many states and countries, and its usage can lead to impairment, which can be detrimental, especially if the user operates a vehicle or machinery. To combat this, cannabis impairment tests have been introduced to determine if a person is too impaired to drive. In this article, we will be discussing everything you need to know about cannabis impairment test, including what they are, how they work, and their effectiveness.

What are Cannabis Impairment Tests?

Cannabis Impairment Tests are a set of assessments used to determine if a person is too impaired to drive a vehicle or operate machinery. These tests are similar to the standardized field sobriety tests that police officers use in cases involving alcohol-impaired driving. However, unlike alcohol-impaired driving, there is no set limit on how much cannabis a person can consume before being deemed impaired, as the effects of cannabis can vary based on the individual’s tolerance level and the type of cannabis consumed.

How do Cannabis Impairment Tests Work?

There are two main types of Cannabis Impairment Tests: subjective tests and objective tests. Subjective tests rely on the officer’s observation of the driver’s behavior and performance to determine if there is probable cause for an arrest. These tests include the drug recognition evaluation (DRE) and the modified Romberg balance test.

On the other hand, objective tests use technology to determine if there is THC, the psychoactive component of cannabis, in the driver’s system. These tests include the breathalyzer and oral fluid tests. However, these tests are not well established, and their effectiveness is still being researched.

Effectiveness of Cannabis Impairment Tests

While cannabis impairment tests are meant to ensure public safety by keeping impaired drivers off the roads, their effectiveness is still up for debate. While some studies indicate that they can be effective in detecting cannabis impairment, others suggest that they are not the best way to determine cannabis impairment.

In many instances, cannabis impairment tests have been found to overestimate the level of impairment and detect inactive metabolites of THC in the body, which means that they cannot tell when the person used the cannabis. Additionally, many stressors, including anxiety, fatigue, and poor lighting, can also impact the results of these tests.


In conclusion, cannabis impairment tests are an essential tool used to ensure that impaired drivers stay off the roads, and the public is kept safe. However, their effectiveness is still being researched, and their use is heavily debated in states that allow cannabis use. In any case, it is vital to understand the effects of cannabis use and to use it responsibly. If you are in a state where cannabis is legal, make sure to follow the laws and regulations regarding its usage, and never operate a vehicle or machinery while impaired. Remember that public safety is everyone’s responsibility, and we must all do our part to ensure that no one needlessly loses their life due to impaired driving.