The Australasian College of Road Safety (ACRS) is urging governments to pursue evidence-based drug driving laws, advocating that reforms should focus on the core road safety issue: driver impairment.
While cannabis is currently the focus of policy debate, ACRS emphasises that any substances that impair driving, including illicit drugs, prescribed medicines and alcohol, must be subject to clear, evidence-based and enforceable road safety laws.
Impairment Is the Risk-Not the Drug Alone
Cannabis, like many psychoactive substances, can impair functions essential for safe driving: reaction time, coordination, attention and decision making. While some evidence suggests that cannabis tolerance may reduce impairment in regular users, currently the level of impairment cannot be reliably tested at the roadside.
ACRS warns that road safety policy must focus on impairment as the primary risk.
No Reliable Way to Define a “Safe Level”
Current scientific evidence is unable to provide a reliable THC presence threshold that can consistently distinguish safe from unsafe driving.
A Stronger, Smarter Path Forward
Rather than weakening existing road safety protections, ACRS calls for a renewed focus on improving how impairment is identified and managed.
This includes investment in:
- Developing roadside tools capable of assessing actual impairment, not just substance presence, to better identify unsafe drivers in real time
- Expanding research into the relationship between different substances and crash risk
- Understanding the effects of combined substance use
Safety Must Remain the Priority
ACRS cautions that any reforms must strengthen, not weaken, road safety and:
- Be grounded in robust scientific evidence
- Maintain strong enforcement capability
- Avoid creating loopholes or ambiguity
Road safety must remain the overriding priority, and the road network should not be used to trial policies when significant research questions are still to be answered.
Quote Attributable to Teresa Williams, ACRS President
“Road safety laws must be clear and grounded in evidence. Until we have reliable ways to measure impairment at the roadside, weakening our current protections is not the answer.
The priority should be investing in the science and technology needed to accurately identify impaired drivers; because ultimately, impairment is what puts lives at risk.