Just prior to Christmas last year, coroner David Robinson found that cannabis was implicated in six of the nine fatalities he was required to examine.
Drugged driving has been the hidden killer on our roads for many years and it now exceeds drink driving as a cause of road fatalities.
The AA has regularly surveyed its members about attitudes to drugged driving. Ninety five per cent support introducing saliva-based roadside testing for the presence of illegal drugs while driving.
Currently, police use the Compulsory Impairment Test if the officer has good cause to suspect the presence of drugs and the driver has passed the breath alcohol test.
This test involves various physical tests like walking a straight line, standing on one leg and following a finger with the eyes.
The physical factors about the driver and their car usually give "cause to suspect".
Drivers are prosecuted only if a follow-up blood test detects drugs and this two-test system has a 92 per cent hit rate.
This whole process, though, is time-consuming and expensive in a chaotic roadside environment.
Saliva-based testing is relatively quick and cost-effective, with the initial indicative saliva test needing to have lab test confirmation of illegal drugs in the system before prosecution happens.
This regime will require a significant commitment of money and human resources in order to assure the necessary exposure to drug driving testing activities so that we have a strong general deterrent effect.
We need to know that there is a real chance of being caught if we choose to drive while drugged.
What is proposed is a two-step penalty regime. Drivers who test positive for the presence of drugs will be fined, immediately suspended from driving for 12 hours and lose half of their demerit points.
Drivers will also face harsher criminal penalties where blood tests confirm drug impairment or drugs combined with alcohol.
Specific details are still being worked through. The principal argument that drug users promote is the question of impairment - at what level of a specific drug in your saliva is your driving impaired?
That issue is not settled, but for now cannabis, methamphetamine and MDMA (ecstasy) are illegal drugs, any level in the body is illegal and doing nothing about drugged driving is not an option.
You've got to start somewhere, and the vast experience of the Australian jurisdiction has pretty much sorted the issues.
It is fully acknowledged that drugged driving is much more complex than drink driving. There is an established relationship between blood alcohol levels and impairment which is not the case with drugs.
Testing for drugged driving is much more expensive in terms of time and money. Each test will cost around $200 and the State of Victoria is expecting to carry out 400,000 tests per year in the near future.
That's a big commitment to dealing with an increasingly vexed road safety and social issue.
The Australians, though, can demonstrate strong community support for their present testing programme and a community expectation that police should be out there testing. It's time we copied the Aussies.
• 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.