The government on Tuesday announced roadside testing for four types of drugs will begin next month in Wellington, spreading nationwide by mid-2026.
It said there would be "fewer tragedies" as a result.
An oral-fluid testing device would be able to detect cannabis, cocaine, ecstasy or meth.
If a tongue-swipe test taking a few minutes was positive, a second roadside test would follow.
If that was positive too, then the driver would be prohibited from driving for 12 hours.
In addition, police will take a saliva sample for analysis in a lab that can test for 25 types of drug, and any infringement notice will follow from that.
"Most drivers will be free to go within about five minutes once they have a negative test result," the government announcement said.
"Around 30 percent of all road deaths now involve an impairing drug," Transport Minister Chris Bishop said in a statement.
"If you take drugs and drive, you're putting innocent lives at risk - and we will not tolerate it."
