There are still a number of holes in the Government's proposed drug-driving legislation, which could lead to higher Māori incarceration and push some drug users towards more harmful substances.
That's according to the New Zealand Medical Association, which also has concerns about whether the technology for a comprehensive drug-driving regime exists yet.
MPs this morning heard from a number of key submitters on the Land Transport (Drug Driving) Amendment Bill – legislation which would give Police the power to perform random drug tests.
Any driver who fails two consecutive oral fluid tests would incur an infringement penalty, aligned to the drink-driving infringement penalty, according to the legislation.
The bill passed its first reading and is now going through the select committee process, where MPs will refine it before the House votes for it to come into law.
New Zealand Medical Association chief executive Lesley Clarke told the committee this morning that the bill, as it stands, has a number of "flaws and weaknesses".
"Our view is that the science to support roadside oral fluid testing is not quite sufficiently advanced," she said.
Chief among Clark's concerns was that roadside oral fluid drug testing only detects the presence, or the absence, of a small panel of common drugs.
Because of this, Clark said, the bill could encourage people who use cannabis, to switch to more harmful substances such as synthetic cannabinoids to evade detection by roadside oral drug testing.
"[That] defeats the purpose and creates bigger problems."
She said the technology needed to be much further along so it is able to detect all illicit drugs.
As well as this, as the bill stands, drug testing does not detect impairment - rather, just the presence of drugs in someone's system.
That means, according to Clark, people might receive convictions for drug-driving, despite the fact they are not actually impaired.
"We have particular concerns that the bill would exacerbate equities for Māori and the clinical criminal justice system," she said.
That is because there is already a disproportionately high number of Māori in jail for cannabis-related offences, Clark said.
Police Association president Chris Cahill was supportive of the legislation: "We only have to look at the atrocious numbers of deaths on the roads that we can contribute to drug-drivers to know it's time to do something about it."
But he did highlight some areas where the bill can be improved.
For example, he recommended that any driver who returned a positive oral drug test – who has two or more convictions within the previous four years for drug-driving – should have their vehicle impounded immediately.
As the bill currently stands, the vehicle of someone caught twice is seized after 28 days.
During that time, Cahill said, a vehicle could easily be sold – thus defeating the purpose of the impounding.
Meanwhile, Road Transport Forum chief executive Nick Leggett said drug testing should be done on everyone involved in accidents on the road.
"It should be a routine test, like alcohol, given the stats about drivers and fatal accidents as a portion of drugs in the system."