Why Doesn't A Test To Check For Marijuana Impairment Exist?
Newsy
Though toxicology reports can show THC in a driver's system, no test exists to check if its levels are affecting their ability to drive.
The kind of tests and technology for detecting drunk drivers has long been standardized across the U.S., yet the same kind of widespread roadside test doesn't exist for marijuana impairment, despite 38 states allowing legal weed for recreational use or by prescription.
Typically, if you get pulled over and police suspect you're high, they can do a field sobriety test, use specially trained officers to make that call or run a toxicology exam. Field tests are often subjective, and toxicology reports may show the presence of THC in your system, but not whether you're inebriated.
"The pharmacokinetics of alcohol are relatively unique to alcohol," said Paul Armentano, deputy director of NORML — a non-profit focusing on marijuana law reform. "There's a linear correlation between the more one drinks, the higher their blood alcohol levels, and maximum blood alcohol levels being correlated with maximum impairment of performance. If we had those same linear correlations with cannabis and other substances, arguably we would have per se standard for them too. But we don't."