Showcase of THC Measuring Devices in Las Vegas

“What police have really needed is a simple roadside sobriety test. Scientists at IBM & UCSD are among researchers who may just have the solution”

The story begins with a resident from the Denver suburbs.

Her name is Amy. She’s 30 and lives in Denver where cannabis is recreationally legal. While driving home from a late dinner with a friend two years ago when she was stopped at a DUI roadside checkpoint.

“I hadn’t drank or smoked anything, so I was like, ‘Let’s go through the checkpoint,’ ” Amy recalled.

Amy is a regular Cannabis user but insists she never drives while high.

Nonetheless, the Police at the checkpoint explained he smelled marijuana and that her eyes are bloodshot. Eventually he whips out handcuffs and Amy freaks.

“Like, massive panic attack. And, ‘Oh, my God, I have babies at home. I need to get home. I can’t go to jail!’ ”

She didn’t go to jail that night, but she did get home several hours later. A blood test later revealed McClean had 5 times the legal limit of Delta 9, the mind-altering compound found in THC.

Colorado’s marijuana DUI law is modeled on the one for alcohol, which sets a number to determine when someone is too intoxicated to drive. For pot, that number is five nanograms of Delta 9 (THC) per milliliter of blood. Anything above that and the law says you shouldn’t be driving.

It may sound like an open and shut case that could have resulted in any number of penalties. But Amy’s attorney,  had a field day in court with Colorado’s marijuana intoxication limit.

“Even the state’s experts will say that number alone is something, but generally not enough, and we really hammered that home,” he says.

After a hung jury and Amy pleaded to a lesser offense.

Still, her trip through the criminal justice system is emblematic of numbers that suggest a sharp increase in marijuana DUI arrests in Colorado. So far this year, Patrol data show that total DUI citations this year rose to 398 through early July, compared with 316 in for the same period 2015.

More states may come up with their own cannabis DUI guidelines. Five other states from California to Maine are deciding this November whether to legalize recreational marijuana. Weighing the good, the bad and the still unknown. Issues like driving while impaired are still in the “unknown” category.

It turns out, measuring a person’s broad THC level is actually a method of assessing intoxication. What is needed is a focus on Delta 9 levels which, Unlike alcohol, Delta 9 gets stored in your fat cells, and isn’t water-soluble like alcohol therefore is not able to be tested by any breath analysis says Thomas Marcotte, co-director of The Center for Medicinal Cannabis Research at the University of California.  You need to get specific. What you are really looking for, the only thing to be looked for is Delta 9, the psychotropic element in THC that causes the impairment.  This is what is used to measure against the prescription of law. This has required detaining the accused for long periods of time for expensive hospital visits to draw blood. What police have really needed is a simple roadside sobriety test.

“Unlike alcohol, which has a generally linear relationship between the amount of alcohol you consume, your breath alcohol content and driving performance, the THC route of metabolism is very different,” he explains.

That’s why adapting drunk driving laws to marijuana makes for bad policy, says Mark Kleiman, a professor of public policy at New York University. “You can be positive for THC a week after the last time you used it,” he says. “Not subjectively impaired at all, not impaired at all by any objective measure, but still positive.”

Still, Colorado and five other states have such laws on the books because pretty much everyone agrees that driving stoned can be dangerous, especially when combined with alcohol.

Scientists at IBM and UCSD are among researchers who may just have the solution that could measure how impaired one is behind the wheel. One device uses a reportedly portable rapid blood sample device described as the “Delta 9 Meter” and is said to be unveiled next month at a marijuana trade show in Las Vegas. Another has a person follow a square moving around a tablet screen with a finger, which measures something called “critical tracking.” One app measures time distortion, because things can slow way down when a person is high.

What the law looks for is content in the users blood system so this may be the year we see the safety of our roads where marijuana impairment is legally monitored less expensively, more quickly and accurately.