If we liberalise cannabis laws is it likely there will be more people driving while impaired? And how and when should we address this when the number of drugged drivers involved in fatal road crashes last year was more than drunk drivers? Northland road safety official John Williamson explains.

One of the more interesting items on the recent Northland Land Transport Committee agenda was "The Request to Endorse and Promote the Petition of Karen Dow" – sent to the committee by MP Dr Nick Smith.

The petition called for the House of Representatives to urgently introduce random roadside drug testing so as to reduce the escalating road toll from drugged drivers of 79 in the last year, which now exceeds those impaired by alcohol.

Green Party MP Chloe Swarbrick. The referendum on recreational cannabis use is separate from medicinal use, for which a regulatory regime is expected to come into force later this year. Photo / File
Green Party MP Chloe Swarbrick. The referendum on recreational cannabis use is separate from medicinal use, for which a regulatory regime is expected to come into force later this year. Photo / File

Karen Dow's son, Matthew, was killed by a methamphetamine impaired driver in December 2017.


There was no great debate on the agenda item but the committee endorsed the intent of the petition and agreed to its display in the council's offices and libraries.

All this came together last week. The petition with about 1900 signatures was presented to Parliament and Nick Smith was subsequently booted out and "named" for raising the integrity of the Government's approach to the issue of drugged drivers.

Also, last week, we had the publication of data indicating that Northlanders as a group were the biggest consumers of methamphetamine in the country, based on a nationwide, wastewater testing regime. And Parliament agreed to a national referendum regarding the legalisation of cannabis.

The question of roadside testing for illegal drugs is not new. The NZ Automobile Association has been advocating for years to give police the technology to test and catch drugged drivers.

The AA's 2017 election calls identified that "Australia has been doing roadside drug testing for more than a decade and the UK introduced it in 2015. It is past time that New Zealand followed suit to fight this hidden killer on our roads."

Currently a driver stopped by police, may pass a breathalyser test but still acts and looks impaired. The driver could then be required to perform a physical impairment test. Failing this, the driver is asked to provide a blood sample to test for drugs. Any sign of illegal drugs in the blood sample is an automatic conviction.

This testing regime is time consuming and cumbersome in a chaotic booze bus environment, so few tests are done.

In Nick Smith's letter to the Regional Transport Committee he identified that:
"Last year there were 79 deaths nationally involving drug drivers, compared to 70 where drink drivers were involved.

"Conversely during that same period there were 16,000 convictions for drink-driving but less the 200 for drugged driving. The current system is simply too difficult for police and too open to interpretation. A test that is quick, easy and objective is essential if we are to reduce our road toll and make our roads safer for all. This issue will become more important in the context of the Government policies to liberalise access to drugs like cannabis," Dr Smith concluded.

The rationale of putting roadside drug-driving testing alongside the well-established drink-driving testing is absolutely compelling. The caveat though, is that police have sufficient resources of people and money to ensure those who choose to drive, either drunk, stoned or both have a very good chance of being caught.

It is troubling therefore, to read recently released statistics which show that, while drink-driving convictions have almost halved to 16,000 over the last 10 years but also that, the number of random breath-tests carried out have dropped by the same proportion, from 3 million to 1.7 million over the same period.

Perhaps we have better targeting by police but it could also reflect a resource priority.

But here's the rub - if we liberalise cannabis laws then it is possible that we may have more people driving while impaired. The police need the resources to deal with that and the ability to be able to randomly roadside test for drugs becomes even more important.

We shouldn't have to wait for the cannabis referendum to act.

* John Williamson is chairman of Roadsafe Northland and Northland Road Safety Trust, a former national councillor for NZ Automobile Association and former Whangārei District Council member.