Illinois DUI law is constantly changing. Over the last year, Illinois' DUI statute underwent no less than 7 significant changes. Since tough legislation is popular, things get tougher for the average citizen at every turn. There's no waiting to see if the last change had any effect on public safety, it's on to the next thing MADD or AAIM decides is important (note that AAIM's website is funded by IDOT . . . isn't that something).
In this environment, it bears saying the obvious . . . drinking and driving is not illegal. Did you realize that? Truly, the limit of how much one can drink and expect to stay out of handcuffs is ever changing, and every more restrictive. The fact remains that there are no other "crimes" I can think of after ten years of practice as a criminal and DUI defense attorney in Illinois which require an officer to run you through some tests in order to figure out whether what he just saw happen was a crime, all while the "suspect" is under the impression he or she committed no crime and never intended to.
Some of these statements are going to need to be expanded on, and I hope to do so in the near future. Check back when you get a chance. For now, suffice it to say this - if you or someone you love face a charge of DUI in Chicago or the surrounding Illinois counties, do some research, get a lawyer as soon as possible, and be prepared to fight for yourself.