Ending cannabis prohibition is a topic currently being debated in many countries across the world, Thailand and Malta are two countries that have recently legalised the plant, and many others are putting similar plans into place.
During these discussions, the issue of driving under the influence of cannabis will always arise. There are those who are often opposed to loosening cannabis laws who will frequently cite the dangers of driving while having cannabis in one’s system as a reason not to legalise the plant, and there are those who feel current laws are not based on scientific evidence, which unfairly penalises cannabis-using drivers.
In an attempt to aid legislators in making decisions based on science and not opinion, scientists from the University of San Diego in California have published a study that found being under the influence of cannabis is not associated with poor driving performance.
Published on May 26th, the study was funded by the State of California and involved the use of specially trained law enforcement officers.
After being given cannabis via a ‘cannabis cigarette’ containing 5.9% THC or 13.4% THC, or a placebo, the 191 participants were assessed on their use of a driving simulator, a real car, and were also put through standardised Field Sobriety Tests (FSTs) by the specially trained police officers.
Although FSTs did correctly identify participants in the cannabis control group 81% of the time, they also incorrectly identified 49% of the placebo group to be intoxicated, suggesting unreliably in the police-performed tests.
Analysis carried out by the researchers on participants’ oral swabs, blood samples and breath after using the car and the simulator found no relationship between a sub-standard driving level and cannabis use.
Researchers said in their study, “In the largest trial to date involving experienced users smoking cannabis, there was no correlation between THC (and related metabolites/cannabinoids) in blood, oral fluid, or breath and driving performance. The complete lack of a relationship between the concentration of the centrally active component of cannabis in blood, OF, and breath is strong evidence against the use of per se laws for cannabis.”
In the UK there were over 20,000 convictions for drug driving in the year ending March 2022, all convictions carry a minimum punishment of disqualification from driving for a certain period of time and can rise to life in prison if a person is killed or seriously injured in an accident caused by somebody who is under the influence of drugs or alcohol.
Those driving while using cannabis that has been prescribed legally in the UK are subject to different laws. You can read more about driving with a legal cannabis prescription here.