A national poll from 2017 suggests that half of Americans are unconcerned by the prospect of stoned drivers on the roads, but law enforcement officials in many US states have drug-impaired driving laws that they intend to enforce. So, what tools should they use?
Huestis, who is also a senior investigator at the National Institute on Drug Abuse, does not support a legal driving limit for marijuana. She believes that, currently, well-trained police officers are best-suited for recognizing signs of impairment. Meanwhile, researchers such as herself are working to identify biomarkers that are more representative of the drug's cognitive effects than blood THC. Ideally, these can then be measured using rapid non-invasive tests.
Another interesting prospect: Researchers at University of California San Diego are recruiting participants for a trial to develop an iPad-based cannabis-specialized field sobriety test. Volunteers will randomly receive marijuana joints at various THC concentrations, then complete driving simulations and undergo experimental impairment assessments. You can sign up here.