New Changes to Illinois DUI-Cannabis Law

Governor Rauner has signed into law a change to the Illinois DUI law involving driving while under the influence of cannabis (marijuana).

Until this change, it was illegal to drive with any amount of cannabis in a person’s system. It did not make any difference if the person was under the influence or impaired by the drug. Additionally, the law did not distinguish between the active ingredient in cannabis (THC) and the inactive ingredient (THC-COOH). It is only the active ingredient that causes impairment. This law was commonly referred to as a ‘zero-tolerance’ DUI law.

Under the new law, it is no longer illegal to drive with cannabis in your system unless you are impaired (under the influence) by the substance. Basically, there are two ways a person can be found guilty under the new law:

  1. Chemical testing (blood, urine or saliva) indicates a concentration of 5 nanograms per milliliter or more of the active ingredient of cannabis (THC) in the person’s system within 2 hours of driving or being in physical control of a vehicle;
  1. The police officer makes observations that, in his or her opinion, indicate that the person is under the influence of cannabis.

The new law eliminates the unfair situation where a person may have used marijuana days (or weeks) earlier and it is still present in his or her system and the person ends up charged with DUI.

The law became effective July 29, 2016. Attorney Larry A. Davis of the The Davis Law Group, P.C., was a co-drafter of the new legislation.