Many Illinois drivers assume that they can only get charged with a DUI if their blood alcohol content level is .08 or higher. However, according to 625 ILCS 6/11-501, it is also against the law for a person to drive a vehicle if they are under the influence of alcohol to a degree that prevents them from driving safely or are under the influence of drugs.
In other words, you can be charged with a DUI with a BAC level under .08 if the officer at the scene finds that your driving ability is impaired. Merely having a BAC level of less than .08 is typically not enough for a solid DUI defense. Even a small amount of alcohol can affect your vision, slow your reaction times and affect your decision-making abilities. Also, keep in mind that many things can affect how your body is affected by alcohol on any given day, including your size and weight, the amount you drink, the food you have eaten and your tolerance levels.
Generally, if an officer thinks that you have been drinking, they may ask you to submit to a breathalyzer to determine your BAC level. They may also ask you to perform field sobriety tests to test your balance and motor functions. If you show signs of intoxication (e.g. slurred speech, smell of alcohol) or you fail any of these tests and your BAC level is between a .05 and .08, you may be charged with a DUI. If your BAC level is less than .05, there is generally a legal presumption that the driver is not impaired.
Cases involving DUI charges against drivers with a BAC level of less than .08 are harder to prosecute but can still result in a DUI conviction. Any driver facing DUI charges may benefit from speaking with a criminal defense attorney.