The state of Illinois has a law that makes it illegal to drive under the influence (“DUI”). 625 ILCS 5/11-501. According to the Illinois Secretary of State, his office received reports of 49,100 DUI arrests in Illinois for the year 2010.
In the early days of the DUI laws, the only prohibition was driving under the influence of alcohol. The state was required to prove that alcohol affected your ability to drive safely.
In fact, the short cut name for DUI was “drunk driving” and the legal name was “driving while intoxicated”. This wording led the general public, including jurors, to infer that in order to be guilty of DUI, you had to be “stumbling drunk”.
The legal limit was a very high .15 blood alcohol content, which was later lowered to .10 and finally, in July 1997, it was reduced to the current .08. 625 ILCS 5/11-501(a)(1) The name was changed to “driving under the influence”.
The police had always had the right to ask you to take a blood or breath test. However, there was no driver’s license penalty for refusing, and the jury was not told that you had refused.
There were no established standards for performing standardized field sobriety tests (SFTS), including the officer waving the pen back and forth, walking a straight line and the one-legged stand, or for explaining the results to the jury.
All of that has changed under today’s DUI laws. If you take a test and you register .08 or higher, your driver’s license is subject to a suspension. If you do not take a test, the suspension is twice as long and the state is allowed to argue to the jury that you did not take the test because you knew you were drunk. The suspension applies even if the DUI is thrown out.
There are also products other than alcohol that can lead to a DUI arrest. It is illegal to drive under the influence of a drug or combination of drugs other than alcohol (alcohol itself is a drug). Thus, it’s DUI to drive high on cocaine for instance.
It is a violation of Illinois DUI laws to drive while under the influence of “intoxicating compounds” (sniffing glue, “huffing” etc). It is also illegal to drive under the influence of a combination of alcohol, other drugs or intoxicating compounds. 625 ILCS 5/11-501(a)(5) It is not a defense to any of these charges that you had a prescription to use the product, if in fact that prescription caused impairment.
But the per se Illinois DUI law also makes it illegal to be operating a motor vehicle with any amount of a drug, substance, or compound in your breath, blood, or urine resulting from the unlawful use or consumption of a controlled substance, an intoxicating compound or methamphetamine. Thus, with regard to marijuana, the state does not have to prove your impairment.
Unlike states such as Colorado, which requires 5 nanograms of THC (the active ingredient in marijuana), in Illinois, if there is even residual marijuana from something you smoked 10 or 20 days earlier, you are considered to be driving under the influence.