Gino Vumbaca recommends that Australia learn from New York’s recent legalization effort. Actually, the opposite is true. New York should learn from Australia. New York legislators were intent on lowering the crime category for stoned driving from misdemeanor to petty offense. Only an uprising by safety advocates prevented that disaster.
Sixteen states in the US have zero-tolerance laws for at least some forms of drugged driving, similar to Australia’s laws. It’s the zero tolerance that Vumbaca and others such as Michael White rail against. There is a significant difference in the implementation of those laws between the US and Australia: in the US, a driver must exhibit probable cause of behavioral impairment before a toxicology test can be ordered.
Writers like Vumbaca and White confuse the public by implying that drug per se limits, whether they be zero or some finite number, are selected to define impairment. They aren’t. They are selected as a social and political policy to deter impaired driving. That is why we see different alcohol per se limits in different countries, all based on the same scientific data.
These writers also fail to distinguish between THC’s acute impairment and chronic impairment. It is certainly true that chronic marijuana users can have THC circulating in their blood long after their acute impairment subsides. But we’ve also seen from Gruber and others that chronic users maintain a low level of chronic impairment long after acute impairment has subsided.
Any level of THC in blood may not prove acute impairment, but data still support use of zero tolerance for THC in drivers as a sound social and political policy.
This is why we advocate for Tandem DUI per se which requires not one, but two elements to prove a violation of an impaired driving law: evidence of behavioral impairment and any level of an impairing substance in the driver’s blood or oral fluid.
Ed Wood (Driving Under Influence of Drugs Victim Voices)