Everything You Should Know About Roadside THC Testing

By Jonathan Blecher on February 6, 2023

What is THC and why is it important?

THC (tetrahydrocannabinol) is the main psychoactive ingredient in cannabis that causes the “high” associated with marijuana use. Unlike alcohol, which leaves the body relatively quickly, THC can remain in a person’s system for days or even weeks after use. As a result, a positive test for THC does not necessarily indicate that a person is currently impaired.

How does roadside THC testing work?

There are a few different methods for detecting THC on the road, but the most common are oral fluid tests and breathalyzer tests. Oral fluid tests are relatively simple and non-invasive. A driver simply has to provide a saliva sample, which is then tested for the presence of THC. The results are usually available within minutes. Breathalyzer tests are similar to those used to detect alcohol. However, instead of measuring the amount of alcohol in a person’s breath, they measure the amount of THC. Like oral fluid tests, the results are available quickly and the process is relatively non-invasive.

What are the limitations of roadside THC testing?

While roadside THC testing can be a useful tool for law enforcement, it does have some limitations. As mentioned earlier, THC can remain in a person’s system for days or even weeks after use, so a positive test does not necessarily indicate that the person is currently impaired. Additionally, different people metabolize THC at different rates, so it can be difficult to determine when a person was last using marijuana based on the test results alone.

Another issue with roadside THC testing is the accuracy of the tests themselves. Some studies have found that oral fluid tests can produce false positives, while others have found that breathalyzer tests can be inaccurate. As a result, it’s important to consider all of the evidence in a case, rather than relying solely on the results of a roadside THC test.

Rroadside THC testing can be a useful tool for law enforcement in detecting impaired drivers. However, it’s important to understand the limitations of these tests and to consider all of the evidence in a case, rather than relying solely on the results of a roadside THC test.