A new tool called the Dräger DrugTest 5000 is available to police, using a mouth swab to determine whether a driver is high on weed.
The device can also detect the presence of cocaine, opiates, methamphetamine, amphetamine, methadone, and benzodiazepines in the bloodstream, though it can’t detect the amount.
This may not always matter, as some 16 states have zero-tolerance laws making it a crime to drive with any measurable drug presence in the body, marijuana or otherwise
Read the article at USA Today.