Testing approach will lead to innocent people being charged

Thursday, 13 November 2025

“Someone who used cannabis 72 hours before a roadside drug test could give a positive result, despite not having been impaired for days,” Jack McDonald writes of a new roadside drug-testing regime.

Jack McDonald is a campaigner and political commentator who has worked for Te Pāti Māori and the Green Party and spent a year employed by the Drug Foundation.

OPINION: The Government has announced that roadside drug-testing will begin in Wellington next month and then be rolled across the country by mid-2026.

The regime will test drivers’ saliva using an oral fluid test that will screen for cannabis (THC), cocaine, methamphetamine, and MDMA.

Getting drug-impaired drivers off our roads is a worthy goal. No-one should be driving while under the influence of mind-altering substances.

But the new saliva-testing regime is a flawed approach that will lead to innocent people getting charged. Unlike alcohol, where its presence in your blood or breath directly correlates to impairment, a medicine or drug can be detected in your saliva long after you stop being impaired.

For example, someone who used cannabis 72 hours before a test could give a positive result, despite not having been impaired for days.

If there was a method as accurate as breathalysing for detecting impairment of drugs, then this would not be controversial. However, such a method doesn’t exist yet.

The previous Government introduced legislation allowing for a random roadside drug-testing regime, but no oral fluid testing devices were found that met the specified evidentiary standards.

That led the current Government to pass the law with a weakened standard, despite opposition from drug policy experts. The attorney-general advised that elements of the law are inconsistent with the Bill of Rights.

Police roadside testing is set to target four drugs, but Jack McDonald says the new regime is problematic. (File photo)

The law will likely be applied in discriminatory ways. The most common penalty for a positive test will be a civil infringement, however if the Police decide to undertake a compulsory impairment test or require a blood test, then criminal charges can be brought.

Given institutional police bias it is inevitable that Māori, Pasifika and other marginalised groups will be targeted and criminalised at disproportionate rates.

The new roadside testing regime is yet another example of our country failing to implement evidenced-based drug policy. For far too long we have had an irrational approach to substance use.

Last month the New Zealand Drug Foundation (NZDF) released a major new report highlighting the devastating impacts that the Misuse of Drugs Act 1975 has had on communities in Aotearoa. In the words of its executive director, Sarah Helm, “the evidence shows that our drug laws have exacerbated addiction, overdose, deaths and criminalisation”.

The situation is only getting worse. The report found that substance use disorders and drug-related deaths are increasing, with nearly three fatal overdoses every week in 2024.

In recent years methamphetamine and cocaine use have doubled, new potent substances have entered the drug supply chain, and 3000 New Zealanders have been criminalised for cannabis consumption.

Māori have faced disproportionately severe impacts, accounting for more than half of those imprisoned for drug offences in 2023 and suffering a fatal overdose rate twice that of non-Māori.

Our drug laws are a relic of a bygone era that has caused untold harm.

Not only has the war on drugs failed, but the reason it was waged in the first place was to criminalise racialised communities and protect commercial interests, not reduce drug-related harm.

As a society we need to recognise that we have made arbitrary decisions to criminalise certain substances, while regulating and controlling other substances. This makes no sense.

The starting point must be that people who suffer from addiction need support and care, not punishment and stigma.

Nothing will change if we keep doing what we’ve been doing. We spend 3.5 times more on drug-related enforcement than we do on health interventions.

Shifting resources away from police, corrections and the courts and into treatment, prevention and education is the single best thing we can do to reduce drug harm.

That requires overhauling the law to decriminalise drug use and regulate low-harm substances such as cannabis. Changing the law will help many people suffering from addiction to get the help they need by enabling life-saving overdose and harm reduction measures and reducing stigma.

The NZDF report recommends a new regulatory framework to approve and licence evidence-based measures such as overdose prevention centres, safer-use equipment, and flexible drug-checking.

The international evidence from countries such as Portugal is clear, that decriminalisation alongside well-resourced health interventions works in reducing drug-related harm, including overdose deaths and HIV transmission. Portugal has not seen an increase in drug use.

Yet in Aotearoa we continue to let addiction ruin lives, tear apart families, and devastate communities. Instead of responding with care and compassion, we are vilifying people who are sick.

Politicians continue to ignore the evidence and bury their heads in the sand. We must demand better.