Driving Under the Influence (DUI)
"Driving Under the Influence" is defined as operating a motor vehicle while impaired by alcohol, other drugs or intoxicating compounds and methamphetamine. In Illinois, a driver is legally considered to be under the influence if he/she has a blood-alcohol concentration (BAC) of .08 or more, 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 with a BAC between .05 and .08 may be convicted of DUI if additional evidence determines that the driver was impaired. In 1997, the Illinois General Assembly passed legislation to lower the illegal BAC limit from .10 to .08. Illinois was the 15th state to impose such a change.
The effect of alcohol on an individual is determined primarily by two factors: the amount of alcohol consumed and the rate at which it is absorbed by the body. Other contributing factors include gender, body weight, alcohol tolerance, mood, environment and the amount of food consumed.
To reach .08, a 170-pound male would have to consume four drinks in a one hour period on an empty stomach. A 137-pound female would have to consume at least three drinks in one hour to reach .08. A drink is considered a 12-ounce beer, a 5-ounce glass of wine or a cocktail containing 1.5 ounces of 80-proof liquor.
During 2009, 372 people in Illinois were killed in alcohol-related crashes, which is 36% of the 1,043 total motor vehicle crash fatalities.