A petition has been launched in Nelson today that seeks the urgent introduction of roadside drug testing of drivers.
Peter and Karen Dow's son was killed last New Year's Eve by a driver found to have been high on methamphetamine.
The couple say police need better tools to get drivers influenced by drugs off the road.
Matthew Dow of Christchurch, who was 23, was killed while driving that night to join his family on holiday in Nelson.
The crash, between Richmond and Motueka was caused by a Takaka woman, Alicia Fulcher-Poole who was travelling in the opposite direction. She was driving a ute with four passengers, including her partner and her two children.
She has been convicted on charges including driving while under the influence of drugs, and is now serving a three-and-a-half year jail term.
Mr Dow hopes the petition will save another from enduring what they have.
"At the very least it might save another family going through what we've endured this last 12 months. It's been an horrific time in all our lives - we've lost a son and our two other boys have lost a brother, and it was such a tragic waste - it didn't need to happen.
"It wasn't an accident in the true sense of the word. The girl that ran into Matthew had been using meth the night before - she was tested positive after the event.
"It's just... a horrific waste of life."
Mr Dow is hoping the petition will trigger a change in the law that would allow police to carry out random, roadside drug testing.
He said the statistics showed the road deaths attributed to drugs exceeded those attributed to alcohol.
Nelson MP Nick Smith, who is backing the petition, said Matthew was among the 79 killed on the road last year in accidents caused by drivers under the influence of drugs.
He said police needed the tools to help get such drivers off the road.
"And that is why this petition is calling for the introduction of roadside drug testing as occurs in Australia, Canada and the UK. It's an essential tool for the police if we're going to be able to avoid the sort of tragedy that occurred with Matthew Dow last New Year's Eve."
Dr Smith said he had been hearing from police officers, both retired and current, who were "extremely worried" about the growth in the number of road fatalities occurring as a result of drugs.
"In our own region last year [Nelson], a third of the 15 fatalities were drug-related."
Dr Smith said he predicted the problem would become worse with the government's plan to liberalise access to drugs like cannabis.
The government recently announced a binding referendum on legalising cannabis for personal use will be held at the 2020 general election.
"We know in other jurisdictions that roadside drug testing raises the profile and gets drugged drivers off the road. This [petition] is an essential step if New Zealand is going to reverse the dangerous trend of an increasing road toll," Dr Smith said.
He said the technology was simply a saliva-based test and was well developed overseas.
"It's done randomly, the same way as breath testing is done for alcohol, and it can pick up drugs like P and cannabis that are both predominant in the recent road stats.
"We want to get as many signatures for the petition over the next four months."
Dr Smith says the petition closes in May on what would have been Matthew Dow's 25th birthday.
"We then want to put maximum pressure on the government to get on, and utilise this technology to ensure we get those drug users off the road."
Mr Dow said the message on the drink-driving had got through but the message around the dangers of driving while under the influence of drugs was "far from it".
Dr Smith said the Clerk's office has advised the petition might go live on the Parliamentary site later today.