It has long been Illinois policy that any amount of cannabis in the blood or urine of a driver can be the basis for a DUI charge. As of January 2014, Illinois updated the DUI laws in response to its new medical marijuana law. Under the new law, a qualifying patient under the Medical Cannabis Pilot Program Act can legally use marijuana and operate a motor vehicle unless they are impaired while driving:
Sec. 11-501. Driving while under the influence of alcohol, other drug or drugs, intoxicating compound or compounds or any combination thereof.
(6) there is any amount of a drug, substance, or compound in the person’s breath, blood, or urine resulting from the unlawful use or consumption of cannabis listed in the Cannabis Control Act, a controlled substance listed in the Illinois Controlled Substances Act, an intoxicating compound listed in the Use of Intoxicating Compounds Act, or methamphetamine as listed in the Methamphetamine Control and Community Protection Act. Subject to all other requirements and provisions under this Section, this paragraph (6) does not apply to the lawful consumption of cannabis by a qualifying patient licensed under the Compassionate Use of Medical Cannabis Pilot Program Act who is in possession of a valid registry card issued under that Act, unless that person is impaired by the use of cannabis.
Pursuant to the statute, a licensed cannabis user cannot get arrested for a DUI unless their driving is actually impaired. However, there is a tradeoff. Normally, a driver is not required to submit to standard field sobriety tests and there is no penalty for refusing to take or failing the tests. Under the new law, any person issued a registry card under the Compassionate Use of Medical Cannabis Pilot Program Act who drives or is in actual physical control of a motor vehicle shall be deemed to have given consent to perform standardized field sobriety tests. However, the officer must have an independent cannabis-related factual basis giving reasonable suspicion that the person is driving under the influence of cannabis for conducting standardized field sobriety tests. If the driver fails or refuses testing, he is subject to suspension or revocation of his driving privileges. It is pertinent that drivers are aware of potential charges, despite having the proper medical marijuana licensure.