Guide to Illinois DUI Laws Being convicted of a drunk driving offense according to IL DUI laws can make your entire life more difficult, including finding employment. Understanding Illinois DUI laws can prevent you from making a costly and life-changing mistake, or may be helpful in understanding why you may need an attorney to represent you. If you need more information than is available in this guide about IL DUI laws, you may want to consider talking to a criminal defense attorney who specializes in representing those being charged with violations of Illinois DUI laws. Blood Alcohol Content Limits While for many years, IL DUI laws only applied to drivers with a blood alcohol content (BAC) of .10 or more, it has joined many other states in adopting more strict DUI standards. Today, any driver over 21 years of age who is caught with a BAC of .08 or higher will be punished according to Illinois DUI laws. For drivers under 21, even the smallest amount of alcohol on your breath will push you over the state's limit—IL DUI laws mandate a zero tolerance policy for people below legal drinking age. Because people with commercial driver's licenses are typically driving much larger and more dangerous vehicles than their non-commercially licensed counterparts on the road, these drivers are held to higher standards according to Illinois DUI laws. Any commercial driver operating a commercial vehicle with a BAC of over .04 can be prosecuted according to IL DUI laws. Refusal to Test If you refuse to submit to a chemical test for alcohol, Illinois DUI laws will still result in you being punished—in some cases, as badly as if you'd tested positive. The first time a driver refuses a chemical test, the state will automatically suspend their driver's license for one year. If the driver is stopped again and refuses to take the test again, he or she can expect a 3 year license suspension and a minimum of 5 days in jail or 240 hours of community service according to IL DUI laws. The third refusal results in even stiffer punishments. Illinois DUI laws specify that anyone refusing a chemical test for the third time should be sentenced according to sentencing guidelines for an aggravated DUI. DUI Penalties Even if you are being charged with drunk driving for the first time, IL DUI laws carry stiff penalties. You can expect to spend up to a year in jail for a first offense under Illinois DUI laws, and you may have to pay a fine of up to $3500 depending on the circumstances of the offense. Your driver's license will be suspended for a minimum of 1 year if you are caught violating IL DUI laws, and you can expect to spend at least 100 hours doing community service. In some situations, you may also have to have an ignition interlock installed on your car that will physically prevent the car from starting unless you blow a clean breath test.