What constitutes a DUI in Illinois?
“Driving Under the Influence” is defined as operating a motor vehicle while impaired by alcohol, other drugs or intoxicating compounds. In Illinois, a driver is legally considered to be under the influence if he/she has a blood-alcohol concentration (BAC) of .08 percent or greater, has used any illegal substance, or is impaired by medication. A driver’s BAC is based on the ratio of alcohol to blood or breath. However, an individual showing alcohol levels between .05 and .08 percent may be convicted of DUI if additional evidence determines that the driver was impaired.