Nearly half of Kiwi cannabis users don't think twice about driving after smoking, a new study has found.
Researchers at the University of Waikato surveyed hundreds of legal and illegal drug users, including cannabis, alcohol, anti-depressants, hallucinogens and painkillers.
They found while nearly three-quarters (73.6 percent) of drinkers had made a decision not to drive after drinking, only 57 percent of cannabis smokers had made the same call.
Those who admitted drink driving were more than three times likely to also have driven after taking other drugs.
Hallucinogens and opiates were ranked the worst drugs to use before driving, and cannabis the safest.
Only 10 percent of people taking anti-depressants made a call not to drive afterwards.
"Drivers in this sample were less aware of the potential negative effects of legal drugs on driving compared to illegal drugs," the study notes.
"More than half the respondents from this study acknowledged drug driving as a road safety issue which needs more resources dedicated to it."
The findings have been published in journal Accident Analysis & Prevention.