Like many states, Illinois has legalized (with certain restrictions) the medical and recreational use of marijuana. However, driving after using marijuana or other intoxicating substances can still result in a driving under the influence (DUI) charge. This article explains when the use of drugs and other substances—legal or otherwise—can result in a drugged driving conviction.
In Illinois, you can be convicted of a drug DUI for driving:
In other words, a drug DUI conviction can be based on actual drug impairment or a blood test showing you have a controlled substance or prohibited concentration of THC in your system.
Driving under the influence. A driver is considered "under the influence" if an intoxicating compound has rendered him or her incapable of driving safely. Prosecutors might use evidence like blood test results, expert testimony, and the officer's investigation report to prove this type of DUI charge. The fact that the driver was legally permitted to use the drug—due to a prescription or otherwise—is not a legal defense to impaired driving.
THC per se DUI. Drivers with a THC concentration of 5ng/ml or more in their blood can be convicted of a THC per se DUI. However, an exemption exists for medical marijuana patients. A patient with a valid Compassionate Use of Medical Cannabis Program registry card has a complete defense to a THC per se charge. (But, note, a medical marijuana patient can still be convicted of an impairment DUI.)
Controlled substances. Having any amount of unlawfully consumed controlled substances in your system can lead to a DUI conviction. Illinois' list of prohibited drugs includes street drugs like methamphetamines and cocaine, but also prescription drugs like opioids. The controlled substance ban applies only to unlawful consumption, so drivers with valid prescriptions might have a legal defense to this type of DUI charge (though an impairment DUI conviction is still possible).
The penalties for drugged driving are nearly identical to those for drunk driving.
Second offense. A second DUI conviction is still a misdemeanor but carries a mandatory five days in jail or 240 hours of community service. The offender will still be required to complete the substance abuse evaluation and complete the recommended treatment.
Third and subsequent offenses. A third or subsequent DUI conviction is a felony and carries more severe penalties than a first or second offense.
A drugged driving incident can also result in multiple driver's license penalties.
Administrative revocations. Generally, Illinois' implied consent law requires all drivers to take a blood, breath, or urine test if requested to do so by an officer. Failing one of these tests will generally lead to a six-month administrative license revocation. But drivers who refuse to take a test are looking at a one-year administrative license revocation. Administrative revocations are triggered by the driver failing or refusing a test and don't require a criminal conviction.
Conviction revocations. A DUI conviction will also result in a six-month license suspension (or one year for a second offense). However, the administrative and conviction suspension periods for a single DUI incident generally run together.
Restricted licenses. A restricted license may be available to a driver during the revocation period, but generally not if the offender refused the chemical test. The restricted license requires the use of an ignition interlock device and may restrict the driver to certain destinations.