New Zealand / Politics

Legal cannabis cards highlights flaws of roadside testing, critics say

08:09 am on 11 October 2024

Photo: RNZ / Alex Perrotet

  • Roadside Drug testing scheme "broken' - Council for Civil Liberties
  • The head of the Cannabis Clinic says up to 100,000 people using medicinal cannabis could be unfairly barred for twelve hours from driving by the government's roadside drug testing scheme
  • Dr Waseem Alzahar says saliva tests will detect the drug days beyond any window of impairment
  • The Cannabis prescriber will produce a Canna-card ID in the hope it will allow patients to prove their legal use and avoid being stood down from driving
  • The Council for Civil Liberties says need for the card shows the government's proposed drug testing scheme is "fundamentally flawed"

The head of a medicinal Cannabis prescribing and supply service says its developing a "Canna-card" ID people can present if stopped by police to show they are legally using the drug.

But the Council for Civil Liberties said the need for the card only served to illustrate flaws in the government's plan to introduce the testing regime.

They said the government was trying to gloss over the limitations of saliva drug testing systems to plow ahead with the bill.

In July Transport Minister Simeon Brown signaled the government's intention to have police conduct up to 50,000 random roadside drug tests a year.

Under the proposed scheme, motorists who tested positive in two saliva tests would be immediately banned from driving for 12 hours.

A Wellington man - who did not want to be named - said he had been prescribed cannabis after an assault left him with Post Traumatic Stress Disorder resulting in anxiety and problems sleeping.

He said it was "ridiculous" that people using the drug medicinally - within the guidelines of their prescription - could have their lives disrupted by the twelve hour ban.

"It could totally throw your throw your day-to-day. I feel that's really incredibly unjust," he said.

He said he would proudly carry a Canna-card if he felt it would be recognised by police when the law came into effect.

"I think it is a legitimate substance which is far healthier for you than a lot of prescription drugs and self medication people take. I think [its] a lot safer and proven to be more effective," he said.

The card was being proposed for use by patients of Cannabis Clinic a medicinal cannabis prescriber and provider.

Head of the clinic Dr Waseem Alzahar said they prescribed cannabis in a variety of forms to more than 35,000 patients "from all walks of life".

Alzahar estimated up to 100,000 New Zealanders were currently taking cannabis for medicinal use.

The clinic typically recommended patients wait eight hours after a dose of tetrahydrocannabinol (THC) - the psychoactive ingredient in Cannabis - before driving or operating heavy machinery.

But Alzahar said cannabis could be detected in the body long after any driving impairment had passed meaning tens of thousands of people could be unfairly barred from driving.

"In chronic users, which is people using cannabis at least three times a week - whether they are consuming THC orally or via inhalation, they could be testing positive through the salivary test up to three days post use and that is outside the window or period of impairment. So you can be unimpaired and remain positive," Alzahar said.

He said the drug's effect varied widely among patients to the extent where it was practically impossible to infer a person was impaired from levels of the substance detected.

"Unlike alcohol where a specific level correlates really strongly with impairment and judgement. With cannabis that doesn't exist. Someone might be very sensitive to cannabis and for someone else they might not even feel that impact. So it's a very personalised type of medicine and it's very difficult to then say 'OK, well, if you've had this much THC or this much cannabis then you're going to be impaired. How do you test for it?," Alzahar said.

Transport Minister Simeon Brown said in the previous three years an average of a 108 people a year were killed in crashes after drivers took "impairing drugs".

He aknowledged the saliva tests proposed for use in the scheme were "prone to false postives" and said infringement notices would only be issued after positive saliva tests were confirmed by a laboratory test.

He said the 12 hour stand down period was neccesary to "address road safety risks" if drugs were detected by saliva tests on the roadside.

"Rather than using the test results at the roadside as the basis of issuing an infringement notice, the oral fluid testing devices will be used to screen drivers for qualifying drugs. A positive result from a lab test will be required before an infringement notice is issued.

"To address road safety risks, people who return two positive roadside oral fluid tests will be prohibited from driving for 12 hours. The requirement for two positive tests is intended to reduce the possibility of a person being prevented from driving based on false positive results," Brown said.

Council for Civil Liberties chair Thomas Beagle said without the research and technology to reliably indicate impairment the Land Transport (Drug Driving) Amendment Bill would remain "fundamentally flawed".

"The technology to do what they want to do does not exist and rather than admitting that we seem to decide that 'well, because we can't measure impairment, we're just going to measure what we can measure and then make laws against that' and that just doesn't make sense," Beagle said.

An explanatory note within the Bill said saliva tests proposed for use in roadside testing "can produce false positive and false negative results".

Beagle said Official Information Act requests into redacted parts of the regulatory statements and supporting information alongside the bill showed some of those redactions related to the accuracy of the tests.

"They're actually hiding some of the shortcomings with the tech use that the bill relies on and we thought that was pretty disturbing.

"The idea that they actually know that the technology is weak and they were trying to suppress it - even for the information we we're trying to use to consider the bill and make [ https://nzccl.org.nz/submission-land-transport-drug-driving-amendment-bill/submissions] on it - I really do think it's a concern. The idea that the government knows the bill's not any good and it's trying to hide that information and push it through anyway," Beagle said.

Thomas Beagle said the need for the Canna-card to identify people legally using the drug was evidence that the roadside drug testing scheme was "broken".

"If this whole roadside testing scheme was actually measuring impairment, of course you wouldn't let people drive under the influence of medicinal cannabis as well, would you?

"So what it's really saying is it's acknowledging that they're not measuring impairment. It's actually saying that this is not a road safety measure. This is actually a measure to try and catch people who have smoked cannabis and punish them for that," Beagle said.

The Land Transport (Drug Driving) Amendment Bill is currently before a select commitee which will report to Parliament in December.