By Paul Gregoire and Ugur Nedim
A system of legalised medical marijuana is slowly being established in Australia. Federal government legislation came into effect in October last year, allowing those with licences to cultivate, manufacture and distribute the medicine under strict regulations.
Both the NSW and Victorian state governments are now growing crops of cannabis for medicinal purposes. And Queensland passed legislation last October that will allow doctors to prescribe medicinal cannabis to patients as of next month.
However, as people begin to legally use marijuana for medicinal purposes, they’ll find themselves in a predicament when it comes to driving, as all Australian states and territories run roadside drug testing programs that test drivers for traces of THC: the psychoactive ingredient of the plant.
A zero tolerance approach
Roadside drug testing programs have been implemented throughout the country on the pretext of road safety, the claim being that it will lead to a reduction in the number of car accidents caused by drivers under the influence of drugs.
But the reality is this type of testing has more to do with a zero tolerance approach to illicit substances, as the regime focuses on cracking down on people for using certain drugs, rather than representing an evidence-based approach to halting road fatalities.
Random breath testing for alcohol tests for driver impairment; it is a regime based on extensive evidence that certain concentrations of alcohol in the blood system lead to an increased danger. Indeed, this is why there are different gradients of prescribed concentration of alcohol (PCA) charges – low range, mid range and high range.
But roadside drug testing is not an evidence-based approach – a driver can be charged even if they have minute traces of residual drugs in their system, amounts so small they could not possibly impair driving.
Along with THC, police test drivers for MDMA and amphetamines, via a saliva test. And the devices they use don’t gauge drug concentrations, which means a driver could have taken the drugs days before.
The trouble in NSW
The Northern Rivers region has been the flashpoint of the NSW police blitz on roadside drug testing for years now. This is having an adverse effect on the local court system. Lismore Court is overwhelmed with cases of people who’ve been charged for driving with cannabis in their system.
In February last year, Lismore magistrate David Heilpern found Joseph Carrall not guilty of drug driving, when he accepted testimony that he hadn’t smoked any pot for nine days prior to being tested, which meant he could rely on the defence of ‘honest and reasonable mistake’.
Australia flies in the face of the evidence
Australia is the only country in the world to have implemented a large-scale roadside drug testing program of this kind. In NSW, it began in 2007, while the first jurisdiction to introduce the program was Victoria in December 2004. In England for example, drivers are not charged unless they have a certain concentration of drugs in their system.
At the same time as Victoria was implementing the zero tolerance program, the world-renowned National Institute for Road Safety Research in the Netherlands was recommending against this type of testing.
The institute found that zero tolerance legislation for illegal drugs – with the exception of heroin – would “produce a massive overkill… resulting in very high cost and hardly any road safety benefits.”
It illustrated this in a case-controlled study in the Tilburg police district, where was shown that 87 percent of all cannabis users did not have a concentration sufficient to significantly increase the risk of injury.
The institute concluded that this did not mean cannabis use does not have an impact on road safety, as the remaining 13 percent used more than one drug at a time, and cannabis users constituted 70 percent of this high-risk group.
The research of professor Ross Homel of Griffith University was instrumental in the introduction of random breath testing in Australia. He has expressed the view that the inclusion of cannabis in roadside drug testing is more about the “enforcement of drug laws,” than an attempt to achieve “road safety benefits.”
Cannabis impairment: a contentious issue
The impact of cannabis use on driving ability is a controversial subject. There’s much debate as to whether it poses a significant risk. There’s also contention over the amount of the substance that needs to be taken in order to constitute a threat to road safety.
Professor Homel wrote in his paper that there’s increasing evidence that people who drive under the influence of cannabis do place themselves and others at an increased risk. But he also states that cannabis use seems to increase that risk by two to three times, compared to alcohol, which increases the risk by six to fifteen times or more.
A 2002 paper titled Cannabis and Alcohol in Motor Vehicle Accidents found that “crash culpability studies have failed to demonstrate that drivers” with cannabis in their systems “are significantly more likely than drug-free drivers to be culpable in road crashes.”
A Canadian Senate Special Committee on Illegal Drugs report, found that “cannabis leads to a more cautious style of driving.” And while it found that its use does have “a negative impact on decision time,” it also concluded that this doesn’t mean that drivers under the influence of marijuana posed a traffic safety risk.
The committee remarked that “cannabis alone, particularly in low doses, has little effect on the skills involved in automobile driving.”
In 2015, the US National Institute on Drug Abuse conducted a driving simulator test at the University of Iowa on the effects of cannabis and alcohol on driving ability.
Researchers found that while alcohol had an effect on the number of times a car left a lane it was driving in and the speed of weaving, marijuana did not. But they did find that cannabis increased weaving, and the higher the concentration of THC in a driver’s blood, the worse this became.
Police should stop testing for cannabis
However, Australian police aren’t testing for the level of THC in a driver’s blood.
They’re often pulling people over and charging them for traces of a substance that may have been consumed days before.
Cannabis is now understood to be at the low level of the harm scale, and its medicinal benefits are acknowledged globally. And as legal medicinal use of the drug becomes a reality, the roadside drug testing regime is going to impact sick people who should not be criminalised.
Until there’s conclusive evidence that the use of cannabis is detrimental to road safety, and an evidence-based approach similar to the drink driving regime is introduced, many believe marijuana should be removed from roadside drug testing in all jurisdictions across the country.