Police will soon have the right to conduct random roadside drug testing on drivers, Associate Transport Minister Julie Anne Genter announced on Wednesday.
The new laws will come into effect in 2021.
Police will be able to test drivers for drugs and impairing medication "anywhere, anytime", just as they currently do for alcohol, Genter said.
"The new powers will send a clear message that if you take drugs and drive, you will be caught."
Anyone testing positive will receive a fine and be immediately suspended from driving for a minimum of 12 hours.
Criminal penalties may also possible, depending on further blood tests, Genter said.
"The threshold for a criminal offence will be aligned with that for alcohol. This means a blood test that identifies impairing medication or drugs at or above an amount equivalent to the criminal drink driving limit (80mg of alcohol to 100ml of blood) will result in a criminal offence."
Roadside testing will use oral fluid devices to test for THC, methamphetamine, opiates, cocaine, MDMA (ecstasy), and benzodiazepines.
Genter said the Government will work with health professionals to make sure patients are warned whether they should be driving after taking prescription drugs.
The announcement comes ahead of a planned referendum next year where New Zealanders will vote on whether to legalise the personal use of cannabis.