Reports showing deaths caused by drug driving having overtaken the drink driving toll don't take into account all of the available information, says a drug and alcohol counsellor.
Figures released by the Automobile Association (AA), which included deaths caused by those over the legal limit for alcohol, did not include deaths caused by drivers who'd been drinking but were under the limit.
The AA said in 2017, 79 fatal crashes involved a driver with drugs in their system, compared with 70 involving an intoxicated driver.
Drug and alcohol counsellor Roger Brooking told Morning Report the AA seems to have asked for the wrong information.
"They asked for the number of drivers who caused death under the influence of drugs and the answer was 79, but when they were talking about alcohol, they only asked for the number of deaths that were caused by drivers over the legal limit.
"They completely forgot to ask, or didn't realise that drivers under the legal limit cause just as many deaths as those over the limit, so they missed half the information."
He said the total number of deaths caused by people driving after drinking alcohol was 154.
It's surprising information, he said.
"When the legal limit was changed in 2014 ... the intention of that legislation change was to reduce the road toll but it turns out that it's actually made no difference whatsoever."
"The AA has mistakenly put out information which was picked up by the media, including The Guardian in England, trying to suggest that New Zealand is in the grip of a drug taking whatever and that drugs have overtaken alcohol related deaths on the road, that's simply not true."
"Alcohol is and always has been, the number one drug problem in the country."
However AA spokesperson Dylan Thomsen said there are two different ways to look at the data.
He told Morning Report the approach the AA took was in line with how official statistics on alcohol impaired driving in New Zealand is done.
"When the government reports on how many crashes involve drink driving, the meta for that is how many people were over the limit," he said.
He said in the future the AA should be reporting both figures.
"We were never trying to give any suggestion that alcohol is not a major problem on the roads ... it's not an either or situation here."
The drugs involved in the study included cannabis, methamphetamine as well as medicine that impairs driving ability, Mr Thomsen said.
An increase in the number of people causing death because of driving while drugged could come down to there being more testing done after crashes, he said.
There are not enough police drug checks on drivers and saliva tests should be introduced, he said.