A new law has been proposed to give the police powers to conduct random roadside drug testing of drivers.
The Land Transport (Drug Driving) Amendment Bill was introduced to Parliament today and is intended to have its first reading next week.
Police Minister Stuart Nash said the new law would allow officers to test whether drivers are under the influence of drugs - similar to testing suspected drink-drivers.
Under the new law, officers will be able to saliva-test drivers for commonly used drugs such as cannabis, methamphetamine, cocaine, ecstasy, opiates and benzodiazepines.
Proposed penalties include on-the-spot fines, licence suspension and demerit points - or harsher penalties.
"Under this law, drivers who test positive for the presence of drugs will be fined, immediately suspended from driving for 12 hours, and lose half their demerit points," Nash said.
"Drivers would also face harsher criminal penalties where blood tests confirm impairing levels of drugs in their system, or drugs combined with alcohol."
A statement said specific criminal limits for drugs would be added to the Bill by Supplementary Order Paper and provided to the select committee for scrutiny, allowing the independent expert panel sufficient time to provide advice on the setting of these limits.
Meanwhile, police have unveiled a new testing device to screen drugs in the field for the first time on a mobile app.
The Lumi Drug Scan is a joint effort between the police and the government's science research organisation ESR.
It screens through the packaging and sends results to an app used exclusively by the police after connecting to an ESR drug database, and can test for the three most commonly used hard drugs in New Zealand - methamphetamine, MDMA and cocaine.
ESR forensic research and development project manager Dion Sheppard said leading-edge and reliable science is critical in giving frontline police new tools to carry out their job safely and efficiently.
"A sample can be placed on the device. The scan recorded by the device is then analysed by ESR's drug protection algorithms. The result returns to the officer's phone in the Lumi scan app almost instantly," he said.
"The exciting part for us really is the opportunity to make our science accessible to take it from the lab, which is where you traditionally think forensic science is, and present it in a way police can access it in real time out in the field when they're confronted with substances that are potentially controlled drugs."
Assistant commissioner Superintendent Mike Johnson said the results were not evidential and lab analysis would be required for court.
"One of the biggest advantages of the Lumi Drug Scan service is that, unlike the current field testing kit, the device can screen through packaging, meaning that our officers will not have to open the bags of drugs they seize to test them and won't be at risk of being exposed to the substances inside the package," he said.
"Know what you're dealing with so you can make really good decisions and that's the, really, advantage that the portability, cost and the fact that we can make those informed decisions as we ask our officers to do every day."
Constable Wepiha Te Kanawa from Counties Manukau said it would make the police's work easier and save some time.
"It will be great tool to have out in the streets. We'll be able to make better decision in terms of charging and health referrals as well, so, great across the board."
A six-month trial starts today in Auckland, and Central and Canterbury police districts and the 15 devices available will be shared across those places.