Roadside drug testing in NZ: what changes for everyday drivers

27 September 2026

For years, most New Zealand drivers only thought about one test at the roadside: the breath test. That has changed. Police now carry saliva screening devices that check for recent drug use, and they can ask any driver to take one ^[1][12].

If you drive to work, do the school run, or take medication every day, here is what the new rules actually mean for you.

What the law now says

Drug driving rules sit inside the Land Transport Act 1998. They were updated by the Land Transport (Drug Driving) Amendment Act 2022 and the Land Transport (Drug Driving) Amendment Act 2025 ^[3].

The 2025 Act received Royal assent on 29 March 2025. It was set to come into force on a date chosen by Order in Council, and that date was 15 December 2025 ^[2]. The 2025 Act is what switched roadside saliva screening on.

The law covers driving with evidence of one qualifying drug, driving with two or more qualifying drugs, and driving with alcohol and a qualifying drug together ^[2].

When testing started, and where it is now

• 15 December 2025: roadside drug testing began in Wellington ^[1].
• By 18 February 2026: Police said more than 300 screening tests had been done in Wellington and seven infringements issued ^[9].
• From April 2026: Police said testing would scale up nationally, with testing operating across New Zealand by mid-2026 ^[8][9].

Police's current guidance says it can test drivers for drugs at the roadside "anytime, anywhere" ^[12]. We could not find a Police notice confirming the exact date the national rollout was finished, so if you want to know about your own region, check the Police website or ask your local station.

Which drugs are tested for

There are two stages, and they test for different things.

At the roadside, the screening device checks your saliva for four drugs ^[3]:

• THC (cannabis)
• methamphetamine
• MDMA (ecstasy)
• cocaine

In the laboratory, a separate saliva sample is tested for 25 drugs listed in the Land Transport Act 1998. Police describe these as the drugs with the highest risk to road safety, made up of four illicit drugs and 21 prescription medicines ^[4]. They include cannabis, methamphetamine, cocaine and MDMA, plus medicines such as codeine, diazepam, fentanyl, methadone, morphine, oxycodone, tramadol and zopiclone ^[4].

The lab limits are designed to leave out past use and passive or accidental exposure ^[4].

What happens at the roadside

You will usually be breath tested for alcohol first ^[3]. Then:

1. You wipe the device along your tongue. This takes about 7 to 10 minutes ^[3].
2. If the result is negative, the testing is over and you can go ^[3].
3. If it is positive, you give a saliva sample for the laboratory. You can choose to give a separate sample for your own independent testing, at your own cost ^[3].
4. You take a second roadside screening test ^[3].
5. If the second test is also positive, you cannot drive for 12 hours ^[3].

A 12-hour ban is not a licence suspension. It is there to deal with the immediate risk. Police say that in most cases you can arrange for someone else to collect you and your car, and vehicles are not automatically impounded. If your car cannot be safely left and is towed, the owner pays the towing and storage costs ^[5].

What happens if you test positive

This is the part that matters most for everyday drivers, because a positive roadside result does not by itself mean a fine.

The infringement route

You only get an infringement notice if the laboratory test comes back positive for one or more of the 25 drugs ^[5][12]. The penalties are ^[5]:

Those demerit points are the real sting. Your licence is suspended for three months if you reach 100 demerit points within two years ^[5]. Points from other offences count towards the same total, so a single drug infringement can be enough to tip a driver who already has points over the line.

Blood tests and criminal charges

Police may require a blood test instead of relying on saliva, for example if you cannot give enough saliva, or if you were in a crash causing injury or death and had two positive screening tests ^[5].

What happens next depends on the level of drug in your blood. Within the tolerance range it is an infringement offence. At a high-risk level it is a criminal offence ^[5]. A criminal offence goes through the court, not the infringement system.

The impairment test

Police can also skip the saliva test altogether. If you show signs of being under the influence, an officer may require a Compulsory Impairment Test instead ^[7]. This is a behavioural check done by a specially trained officer, covering the eyes, a walk and turn, and standing on one leg. If you fail it, you may be required to give a blood test for laboratory analysis, which carries different enforcement outcomes from a roadside saliva test ^[7].

What about prescription medicine?

This is the question most people ask, and the honest answer has two sides.

The law protects drivers who have taken medicine in line with a current and valid prescription, and those with only low leftover levels below the legal threshold ^[6]. But Police are clear: "Having a prescription does not allow you to drive while impaired" ^[6].

Some practical points from Police guidance ^[6]:

• Showing your prescription at the roadside will not stop the test. Officers cannot check prescriptions on the spot.
• The medical defence comes later. If you get an infringement notice for a medicine you were prescribed and took as directed, you can apply for a medical defence after the notice is issued.
• ADHD medicine: Police say you will not test positive for prescription ADHD medicines on the roadside screening test.
• Medicinal cannabis: even with a prescription, you can still test positive for THC.
• Take your medicine exactly as prescribed, read the label for driving warnings, and ask your doctor or pharmacist whether it is safe for you to drive.

What this means day to day

For most drivers, very little changes in practice. If you have not used cannabis, meth, MDMA or cocaine recently, the roadside test should be a short stop. If you take a listed prescription medicine, keep taking it as directed, keep your prescription details handy for later, and talk to your prescriber about driving.

The bigger risk is the demerit points. Because a lab-confirmed result adds 50 or 75 points, a drug infringement can push a driver who already has points over the 100-point line and into a three-month suspension ^[5].

If that happens, a limited licence may be an option for some drivers. The Ministry of Justice says people suspended for too many demerit points can apply, with no stand-down period, but you must show the court that not being able to drive would cause extreme hardship to you or undue hardship to someone else ^[11]. It is not available to everyone. For example, people disqualified for repeat offending involving alcohol or drugs, or who must use an alcohol interlock, cannot apply ^[11]. NZ Limited Licence prepares limited licence application documents for suspended drivers who need to keep driving for work; call 0800 437 005. We are not a law firm and cannot guarantee any outcome.

Sources

1. Police rolls-out roadside drug driver testing, New Zealand Police, https://www.police.govt.nz/news/release/police-rolls-out-roadside-drug-driver-testing (accessed 27 September 2026)
2. Land Transport (Drug Driving) Amendment Act 2025, New Zealand Legislation, https://www.legislation.govt.nz/act/public/2025/12/en/latest/ (accessed 27 September 2026)
3. About roadside drug driving testing, New Zealand Police, https://www.police.govt.nz/advice-services/drugs-and-alcohol/roadside-drug-driving-testing/about-roadside-drug-driving-testing (accessed 27 September 2026)
4. Drugs and drug limits, New Zealand Police, https://www.police.govt.nz/advice-services/drugs-and-alcohol/roadside-drug-driving-testing/drugs-and-drug-limits (accessed 27 September 2026)
5. Penalties and outcomes, New Zealand Police, https://www.police.govt.nz/advice-services/drugs-and-alcohol/roadside-drug-driving-testing/penalties-and-outcomes (accessed 27 September 2026)
6. Prescription medicines and medical defence, New Zealand Police, https://www.police.govt.nz/advice-services/drugs-and-alcohol/roadside-drug-driving-testing/prescription-medicines-and-medical (accessed 27 September 2026)
7. Testing impairment, New Zealand Police, https://www.police.govt.nz/advice-services/drugs-and-alcohol/roadside-drug-driving-testing/testing-impairment (accessed 27 September 2026)
8. Detection device selected for drug-impaired driver screening, New Zealand Police, https://www.police.govt.nz/news/release/detection-device-selected-drug-impaired-driver-screening (accessed 27 September 2026)
9. Roadside drug testing continues to boost road safety efforts, New Zealand Police, https://www.police.govt.nz/news/release/roadside-drug-testing-continues-boost-road-safety-efforts (accessed 27 September 2026)
10. What happens if I refuse a test?, New Zealand Police, https://www.police.govt.nz/faq/what-happens-if-i-refuse-test (accessed 27 September 2026)
11. Get a limited licence, Ministry of Justice, https://www.justice.govt.nz/courts/criminal/get-a-limited-licence/ (accessed 27 September 2026)
12. Roadside drug driving testing, New Zealand Police, https://www.police.govt.nz/advice-services/drugs-and-alcohol/roadside-drug-driving-testing (accessed 27 September 2026)

Frequently asked questions

Can I refuse a roadside drug test?

You can, but refusing to comply means an infringement notice at the roadside with a $400 fine, 75 demerit points, and a ban on driving for 12 hours.

Will I be fined straight away if the roadside test is positive?

No. You can be stopped from driving for 12 hours after two positive screening tests, but an infringement notice is only issued after a positive laboratory result.

Do I need to carry my prescription in the car?

It will not stop the roadside test, because officers cannot verify prescriptions on the spot. A medical defence is applied for after an infringement notice is issued.

Can a drug driving infringement lead to a suspension?

Yes. A lab-confirmed result adds 50 or 75 demerit points, and reaching 100 points within two years means a three-month suspension.