The Royal Automobile Club of Queensland (RACQ) has indicated that a medical defence for drivers who return a positive THC result could be worth exploring.
In its response to a government consultation paper on the state's drug-driving laws, the RACQ suggested that drivers who fail a roadside drug test but hold a valid medicinal cannabis prescription could potentially be shielded from prosecution.
The organisation was clear, however, that any driver found to be actually impaired by THC should face charges regardless of whether they carry a prescription.
Pointing to the absence of scientific agreement on blood THC impairment thresholds, and no established connection between saliva THC levels and impairment, the RACQ said a medical defence "could be introduced while further research on the impairment issue is conducted".
"This defence, if considered further, should only apply provided that the driver is using the prescribed medicines as directed," RACQ said in its submission. "[We] agree that this…should only apply to the presence-based offence, and that even with a prescription, a driver who tested positive and is adversely affected by cannabis containing THC, or where there is evidence of impairment or unsafe driving, should be charged with driving under the influence of the drug."
The RACQ also urged the state government to look into making roadside saliva drug testing mandatory following any crash, citing the high rate of positive THC detections as justification for such a policy.
"It is important that Queensland increases the amount of roadside drug tests undertaken and that we can more accurately measure the involvement of the drug [cannabis] in crashes of severities other than fatalities," it said in its submission.
According to the consultation paper, approximately one in five of the 52,000 roadside drug tests carried out annually since 2015 returned a positive result, with 60% of those positives attributable to THC.
Figures from the government also showed that of 62 drug-driving fatalities recorded in 2022, 83% of the drivers involved in fatal crashes tested positive for THC.
The Queensland Government is expected to deliver its findings from the drug-driving review before the end of the year.
