PLANS to triple the number of roadside drug tests in New South Wales by 2017 are short-sighted and rely on bad science, according to Southern Cross University law lecturer Aidan Ricketts.
The 2016-17 NSW Budget included $309 million to decrease the road toll, with police setting the target of carrying out 97,400 drug tests next year.
But magistrates on the North Coast are increasingly allowing drivers caught with marijuana in their system to go unconvicted, or even dismissing their cases entirely.
In February, Lismore Magistrate David Heilpern acquitted Joseph Ross Carrall, who tested positive for cannabis he had smoked nine days earlier, because Transport NSW's guidelines said the drug left the system after 12 hours.
Prosecutors chose not to appeal the decision, and the timeframe for appeals has now expired.
"Not once has any scientific evidence been produced to this court that supports the contention that the final or any other test only works for 12 hours," Mr Heilpern later said.
Grafton Magistrate R. Denes this week opted not to penalise a man who pleaded guilty to driving with marijuana in his system, other than to place him on a good behaviour bond.
"The test is not perfect, I accept that... and that's why there's a lot of discussion around this at the moment," Ms Denes noted.
The budget makes it clear the Baird Government has no plans to cut back on drug testing.
Quite the opposite, in fact.
"It's pretty sad to see them tripling their expenditure before getting the science right," Mr Ricketts said.
"The government hasn't come up with a testing regime that tests impairment - instead it tests historical use."
Mr Ricketts suggested the NSW Government follow the recommendations of the United Kingdom's Wolff report that devised a system of testing actual impairment.
The UK's drug-driving policing is based on those recommendations.
"I would support an evidence-based regime that tested for actual impairment across the whole range of drugs, recreational, prescribed or otherwise, but was based on actual clinical impairment, not simply on historical use," Mr Ricketts said.
NSW Centre for Road Safety executive director Bernard Carlon said 21% (72 deaths) of the 2015 road toll were from crashes where the driver had illicit drugs in their system.
"In 2015, almost two thirds of the drivers involved in fatal crashes where illicit drugs were detected involved the presence of cannabis," he said.
"Through the community road safety fund we have continued to increase mobile drug testing across the state and our education campaign to tackle this significant road safety risk.
"We know that sanctions such as fines, demerit points and even attendance at court can have a significant impact on reducing this dangerous behaviour." -ARM NEWSDESK