A study to examine the effects of kava on driving ability is being commissioned by New Zealand's Health Research Council.
The study, which is the first of its kind, will use cognitive and driving simulation tests to assess driver fitness immediately after consuming significant amounts of kava.
Apo Aporosa, who will begin the study in March, says it is estimated there are more than 20,000 kava users on an average Friday or Saturday night in New Zealand.
Dr Aporosa says most of them are consuming kava at volumes 32 times greater than pharmacologically recommended doses, with many then driving home.
He says there's no technology to measure the consumption of kava but he hopes to raise awareness around the possible dangers of its consumption.
"Kava doesn't metabolise on the breath like alcohol so you know, you drive in to a checkpoint, you blow into the bag, there's nothing at this stage that can actually measure it. But right at this stage, I think until science can catch up, I think it comes down to a conscience thing."