DUI Enforcement under the Illinois Recreational Cannabis Law

Gov. J.B. Pritzker signed a new law today which will legalize the recreational use of cannabis beginning January 1, 2020. Many of our clients have asked if it will now be legal to smoke cannabis and drive.

What does the current DUI law say?

In Illinois, it is illegal to drive or be in physical control of a vehicle while under the influence of cannabis or with a THC concentration of 5 nanograms or more within 2 hours of driving. THC is the active metabolite of cannabis. It is the ingredient in cannabis that produces the hallucinogenic effects of the drug. The new recreational use law does not change existing Illinois DUI law. This means that, just as in the case of alcohol, the use of cannabis which causes impairment or its presence in a person’s blood above the legal limit within 2 hours of driving or being in physical control of a vehicle is still illegal, and can result in a DUI arrest.

Drivers who are registered as medical cannabis users are exempt from the 5 nanogram limit, but are still prohibited from driving while under the influence of cannabis, regardless of their nanogram level.

Law Enforcement Issues

Enforcement of the cannabis DUI law creates multiple problems for law enforcement. For example, in order to arrest a person for DUI, the officer must have probable cause to believe that the driver is under the influence. Most DUI arrests for alcohol are made using field sobriety tests. These are physical performance tests which have been developed by the National Highway Traffic Safety Administration (NHTSA) and include the walk and turn test; one leg stand test; and the horizontal gaze nystagmus test. However, these tests are specific to alcohol and are not valid in order to determine cannabis (or other drug) impairment.

There are other tests that have been developed by NHTSA which are designed to detect drug impairment, but most law enforcement offices have not been trained in the administration of these tests. Therefore, most officers are not qualified to administer these tests. While recent Illinois cases have stated that an officer may have other means to determine non-alcohol (drug) impairment, these are generally not as effective as the tests administered by a properly trained drug recognition officer.

Additionally, most police departments now equip their officers with a preliminary breath test device (PBT), which is often used for probable cause to determine the driver’s blood alcohol concentration (BAC). However, the use of a PBT is completely ineffective as a means of determining a driver’s nanogram level for a cannabis-related DUI. Currently, the only way to determine a person’s nanogram level is through blood testing, which cannot be performed in a roadside situation prior to arrest. Therefore, blood testing is worthless as a way of giving an officer probable cause to arrest for DUI.

Various companies are working to develop chemical tests based on saliva which can be performed roadside. Before being made available, their accuracy will have to be scientifically verified.

Most law enforcement agencies have opposed the new recreational cannabis law because of the problems that will arise for DUI enforcement. Regardless, it can be expected that once the new law becomes effective in January, law enforcement across the state will be aggressively looking to prosecute offenders.

Contact our DUI Defense Attorneys

The answers to many frequently asked Illinois DUI questions can be found here. If you are charged with DUI, contact the DUI defense attorney at The Davis Law Group, P.C. today. We have decades of experience defending clients throughout Illinois including Cook County, Lake County and DuPage County.

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