New research has reinforced concerns that the use of illicit drugs is contributing to the death of drivers and motorcycle riders on Western Australia roads.
Using WA Police and ChemCentre data, the Curtin-Monash Accident Research Centre (C-MARC) found that 23 per cent of the 1,375 drivers and motorcycle riders fatally injured during the 2000-2012 period on WA roads tested positive to one or more illicit drugs.
C-MARC Research Fellow and project leader, Mr Peter Palamara said the study revealed that nearly two thirds of positive results were for cannabis, followed by methamphetamine or ecstasy.
“Of the 312 drivers and riders killed who tested positive, 20 per cent tested for two or more illicit drugs, most commonly cannabis in conjunction with methylamphetamine,” Mr Palamara said.
“Alcohol also featured very strongly in the study findings with 34 per cent of drivers and riders fatally injured during the period showing a Blood Alcohol Concentration level of 0.05gm per cent or higher.
“The findings of the study demonstrated that the risk of driver impairment due either to alcohol or illicit drugs, or a combination of the two, was substantial – around one in two fatally injured drivers and riders. Of the drivers and riders who tested positive for an illicit drug, 45 per cent had a Blood Alcohol Concentration level of 0.05g per cent or higher.”
“The results were disturbing as evidence continues to accumulate of the impairing nature of illicit drugs and alcohol, alone and in combination, on driving and the prevalence of their use among crash and non-crash involved drivers.”
Mr Palamara said the likelihood of a fatally injured driver or rider testing positive for an illicit substance was significantly higher if the driver/rider were male, under 40 years of age, driving without authority to drive; had a Blood Alcohol Concentration level in the 0.05 to 0.149gm per cent range, and tested positive for benzodiazepine use alone or in combination with opioids.
“It is quite clear that more must be done to detect and deter the combined use of alcohol and illicit drugs and even other legal impairing drugs,” Mr Palamara said.
Proposed recommendations in the report include ways to improve WA’s enforcement of illicit drug driving in combination with alcohol breath testing, and opportunities for further research using linked data to better understand and manage those at risk of drug driving.
The full report, Illicit drugs in driving: An investigation of fatalities and traffic offences in Western Australia is available at: www.c-marc.curtin.edu.au.