In the wake of surging drug-related traffic fatalities, police departments across the United States find themselves grappling with a critical challenge: how to accurately determine if a driver is impaired by cannabis. This predicament arises from the rapidly expanding legalization of cannabis nationwide, leaving law enforcement without a reliable equivalent to a breathalyzer for marijuana detection. The absence of such a tool leads to inconsistent enforcement and legal challenges, highlighting a pressing need for innovative solutions.
The Elusive Standard:
According to the National Highway Traffic Safety Administration, over half of drivers involved in fatal crashes in 2021 tested positive for drugs. While states are adopting varying standards for cannabis impairment, six have implemented “per se” THC limits, similar to blood alcohol levels. However, research indicates no direct correlation between THC levels in the bloodstream and impairment. This approach, while seemingly straightforward, is scientifically flawed, as Professor William McNichol of Rutgers Law School points out, comparing it to the simplicity of alcohol enforcement but emphasizing its lack of scientific validity.
Studies on THC levels reveal a rapid dissipation of the substance from the bloodstream after inhalation, making it difficult to establish a universal standard for impairment. Furthermore, frequent cannabis users can maintain detectable THC levels long after their impairment has subsided, raising doubts about the reliability of blood tests alone.
Traditional Tactics: Limitations and Challenges:
In the absence of a scientifically validated test, law enforcement has heavily relied on Drug Recognition Experts (DREs), officers trained to identify signs of impairment through a 12-step evaluation process involving assessments of eye movement, balance, and pulse rate. While DREs traditionally held expert witness status in court, a growing number of states are stripping them of this privilege due to concerns over scientific validity. DUI attorney Michael Boyle highlights the inconsistencies inherent in these traditional methods, stating that the limitations of available testing exacerbate the legal and logistical hurdles faced by police.
A Push for Modern Solutions:
In recent years, several states have sought to modernize their approach with new tools. The SoToxa roadside saliva test, which detects drugs like THC, cocaine, and opioids within minutes, has emerged as a potential solution. However, the test has shown inaccuracies, with Michigan’s 2019 pilot program revealing that nearly 24% of positive results were contradicted by blood tests. Another technology, the OcuPro, a VR-based headset designed to measure pupil movement, has undergone trials but is not yet admissible in court.
Research into brain-scan technology offers a glimmer of hope. Boston researchers have successfully demonstrated the ability of portable brain scans to detect THC impairment with greater reliability than DREs. However, this technology remains in its infancy and requires further development.
A Costly and Uncertain Path Forward:
Despite the limitations of current methods, many states, including Alabama, continue to invest in the DRE program, with plans to expand it in the coming years. Alabama’s $1.15 million investment aims to “better detect” cannabis impairment, even though the efficacy of the approach remains under scrutiny. The lack of a reliable, scientifically validated tool for determining cannabis impairment presents a growing concern, particularly as drugged-driving fatalities increase in states where cannabis use is legal.
As the demand for a solution intensifies, so does the debate over whether current efforts represent the optimal use of resources or whether alternative methods should be explored. For now, law enforcement remains stuck with outdated methods that deliver imperfect results, leaving both drivers and police facing an uncertain future on the road.
