Although driving under the influence of marijuana could cause accidents, it’s been hard for police officers to find a test that accurately measures how much THC in a driver’s system causes impairment and how to connect the timeline between marijuana use and drugged driving. Since THC can show up in a person’s system for days after usage, this often presents a challenge in determining whether or not the driver was still under the influence of marijuana at the time of the traffic stop. As part of an ongoing effort to better understand the influence of drugged driving, researchers in San Diego are conducting a study.
Research shared by the National Highway Traffic Safety Administration indicates that one out of five drivers has had a drug beyond alcohol in their system on Friday and Saturday nights. The drug with the greatest increase between 2007 and 2014 was marijuana, prompting San Diego researchers to attempt to discover whether there is a DUI limit for marijuana.
UC San Diego Medical Center in Hillcrest is home to a driving simulator. Individuals participating in the study are given varying amounts of marijuana based on different types of strengths and then are asked to take a run through the simulator. This double-blind study is testing participants immediately after they smoke marijuana and then several hours later to determine how their impairment changes over time. Researchers are looking at saliva levels, blood levels, expired breath and more.
Cognitive tests are also helping to determine how impaired a person truly is. Although the study is just beginning, it could have important implications as many accidents have already been tied to driving under the influence of alcohol. But the emergence of marijuana as a common drug in people’s systems can also raise critical questions.