Roadside drug testing is about to begin: here’s how it will work
Photo: RNZ / Alexander Robertson
Even if you have a prescription or a medical note, refusing a roadside drug test could bring hefty fines, police officials warn, just days before the program launches.
In Wellington, drivers will be asked to take a drug test starting Monday, marking the first step of a rollout that will extend to the rest of the country next year.
Selected drivers will be directed to swipe their tongue on an oral-fluid screening device to check for four drugs: THC (cannabis), methamphetamine, MDMA (ecstasy/molly), and cocaine.
According to Superintendent Steve Greally, a prescription or medical note cannot be used to avoid testing. Refusal to take the roadside test may result in an infringement notice, carrying a $400 fine, 75 licence demerit points, and a 12-hour driving stand-down.
The initial test is expected to take roughly 10 minutes. If the first result comes back positive, any additional roadside testing will be conducted.
Officers will also continue to use the Compulsory Impairment Test (CIT) to gauge impairment if they suspect a driver is under the influence of drugs.
Once a saliva sample is collected, prescriptions or medical notes cannot be used to challenge a positive result. Anyone with a prescription who tests positive must still undergo the testing process and will be barred from driving for 12 hours. A dispute of the result can only be made after the laboratory results from the third test are received.
Details on how to seek a medical defence after a positive result were not yet provided, but Greally said information would be available on the police website from Monday.
What happens when you’re selected for testing?
First test
Drivers will be instructed to wipe the screening device pads across their tongue. The process takes about 10 minutes. If no drugs are detected, the driver is free to go.
Second and third tests
If the first test is positive for drugs, two additional tests are conducted.
A second test, identical to the first, is performed. If this second test is also positive, the driver is prohibited from driving for 12 hours.
If the second test is negative, the driver may leave after the third sample is collected.
The third test requires the driver to provide a saliva sample by holding an absorbent pad under the tongue. This sample is sent to a laboratory for analysis.
Laboratory testing
The third sample is analyzed in a lab to check for 25 different drugs.
An infringement notice is issued if the laboratory result tests positive for any of these substances.
The police could not immediately specify how long the final lab result would take.
Medical defence option
If an infringement is issued after laboratory testing, drivers will have the option to apply for medical defence if the drug detected was prescribed to them.
Concerns and reactions to roadside drug tests
Officials emphasize that the four targeted substances are impairing drugs, and the new tests are intended to deter drug-driving and help officers identify impaired drivers.
Critics have raised concerns ranging from potential clashes with the Bill of Rights Act, the possibility of detecting prescribed medications, and worries that the testing could cast too wide a net—potentially catching impairment long after actual driving ability has been affected. Some argue the testing process could yield positive results even when drugs are not impairing driving, or when medicines are taken as prescribed.
Others worry about the time required to complete tests and the waiting period for results, which could disrupt drivers who face multiple test stages and a 12-hour stand-down after positive findings. Research from other countries has highlighted concerns that roadside testing might discourage people from continuing prescribed therapies.
Greally advised drivers who use prescription medications to follow their healthcare provider’s instructions and to consider any possible impairing effects. If there are impairing side effects, drivers should not operate a vehicle.
Like alcohol testing, there are impairment thresholds for each drug designed to indicate recent use rather than historical use, passive exposure, or accidental ingestion, which is unlikely to cause impairment.
Minister of Transport Chris Bishop has noted that roughly 30 percent of road fatalities involve impairing drugs.
Greally summarized the public safety aim: police have worked closely with agencies to address the significant changes this brings for road users. The introduction of roadside drug-driving testing is a step toward reducing harm from drug-impaired driving. The core message remains clear: if you plan to drive after using impairing drugs, you will be caught.
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