As of January of 2020, recreational marijuana use will be legal in Illinois, with certain restrictions. One of those restrictions is that it is illegal for someone to drive will under the influence of marijuana, just like the laws regarding alcohol.
It's not hard to prove that a driver is under the influence of alcohol. A breathalyzer can detect it, and the law can set a hard and fast limit (0.08). However, what can the police do about marijuana?
Back in 2016, Illinois set a marijuana DUI limit, five or more nanograms of THC in the blood or ten or more in the saliva.
The law is good news for legal smokers. Until the change, any trace of THC in your blood or saliva meant an automatic DUI. Now, you can theoretically smoke and then get behind the wheel after a few hours pass. (Though, it's not a guaranteed way of avoiding the charge.)
At the same time, the state still has a problem…there's no way to test for THC in the field.
Can Police Test THC Sobriety?
Setting a marijuana DUI limit was an essential first step for protecting recreational users, but there's a problem for the state. They can't prove that a driver is under the influence at the time that they are driving.
You can test alcohol with a breathalyzer, but there's no equivalent for marijuana. There are portable saliva tests, but it's unclear whether they do much good. The tests are so unreliable that they are constantly challenged in court when used to prosecute and convict a marijuana DUI.
When a person smokes marijuana, the molecule present is Δ9-THC. However, the saliva tests look for THC-COOH. As a result, they do not detect the substance that they need to. They also don't have FDA 501k approval, which is a designation that suggests the device is both safe and effective, and that it's as good as other devices on the market.
When it comes to marijuana, blood and urine testing are the most effective ways of measurement. Neither of those is helpful field tests when it comes to a DUI however, because if you use marijuana regularly, then it can be detected for up to 100 days in your urine, and seven days in your blood. That means you could have smoked a week ago, but it could turn up in a sobriety test. What it doesn't mean is that you're under the influence at the time you get pulled over.
What Does that Mean for Marijuana DUIs?
Legal experts in private practice and who cooperate with the state and district attorneys are in agreement that a lack of field testing is bad news for marijuana DUI enforcement, even with the new limits.
A DUI requires proof that a person is under the influence. If the state can't prove it, it's difficult to prosecute.
There is a second issue for drivers in Illinois. Marijuana tests are more invasive than breathalyzers, because they require saliva or blood. As a result, more people are likely to refuse them. Refusing a test also comes with a license suspension.
As a result, drivers aren't off the hook even though it is reasonable to not want to submit to a saliva or blood test.
Why Doesn't a Breathalyzer Work?
Saliva is unstable, no matter if you use it in a lab or on the side of the road. However, why isn't there a breathalyzer?
To use a breathalyzer, you need it to be powerful, because THC shows up in the breath in parts per trillion. Compared to alcohol, it's a billion times less concentrated.
Experts in the field say finding THC in the breath is "kind of like putting together more than a dozen Olympic size swimming pools and saying, ‘Hey, go find those 10 specific drops of water in those 10 pools put together.’"
There Are Pot Breathalyzer Prototypes
Even though there's not currently a product that can reliably test for THC, people across the country are hard at work to fix that.
Hound Labs, a California company, told the press in 2018 that it was on the edge of a breakthrough. Started by a practicing ER trauma physician, the company created a device that should be able to identify whether the user smoked in the previous few hours.
How? It detects THC in the breath. It also doubles as a breathalyzer for alcohol.
Plus, unlike other options, it produces a result in four minutes. There's no need to send it to a lab or wait hours or days for the result.
Hound Labs says it shouldn't impact people who don't smoke and drive. It shouldn't (or can't) tell if you smoked earlier in the day or the week. They aim to put out a product that demonstrates whether a person imbibed and then started to drive, not to penalize legal smokers generally.
The California company isn't the only one on the case. A Canadian firm, Cannabix Technologies, is also attempting to develop THC tools for law enforcement.
However, it is likely to be several years before these products have enough consensus to put them in the hands of police officers.
Marijuana DUIs Are Still a Struggle for Police and Courts
Illinois now has new laws governing a marijuana DUI to cope with decriminalization and legalization. However, proving impairment will still be a challenge for the state. Unless an officer catches you behind the wheel with marijuana, they don't have any way to measure how much THC is in your system officially. As a result, they can't prove whether you are above or below the limit.
However, drivers shouldn't take these problems for granted. You can still find yourself convicted of both a marijuana DUI and a possession charge. The penalties for a DUI in Illinois are severe.
Were you pulled over and charged with a DUI of any type? You'll need a lawyer. Click here for a free consultation to learn when and how you can get back on the road.