The offense of Driving Under the Influence (DUI, which is the same as DWI or Drunk Driving but the legal term is DUI) most often involves alcohol. However, under Illinois DUI law, it also covers other offenses.
The standard and classic DUI involves being in actual physical control of a motor vehicle while under the influence of alcohol. Grounds for an arrest may include evidence of bad driving, poor balance and coordination, substandard performance on standardized field sobriety tests and other general observations of the police officer, such as slurred speech and bloodshot eyes.
A second type of alcohol-related DUI offense involves what are known as “per se” charges. This is a Latin phrase that essential means “automatic”.
The prosecutor may lack the evidence needed to convict you of DUI under the situations described above. However, the per se law says it is also DUI for you to drive with a blood alcohol level (BAL) of 08% or more. This charge can be proven by blood or breath tests, both of which are known as “chemical tests”.
Chemical tests are different from the preliminary breath test (PBT) . The PTB is administered in connection with the process that involves determining whether or not you are going to be arrested for DUI.
The PBT represents an extension of the field sobriety tests, whose purpose is also to determine if there exists probable cause for a DUI arrest. The results of the PBT are not admissible to determine if your BAL is .08 or higher. In other words, the PBT cannot be used to convict you of DUI but it is a law enforcement tool for making an arrest decision.
The third means of being charged with DUI is to be driving while under the influence of any intoxicating compound or compounds that make it unsafe to drive. This provision is aimed at sniffing glue, huffing and other non standard use of foreign materials to create a mind altering effect.
The fourth type of DUI involves DUI “drugs”. This includes street drugs such as marijuana and cocaine. However, it also covers prescription drugs. That does not mean you cannot drive if you are using prescription drugs in the dosage allowed. But it does mean that you cannot be driving around with prescribed drugs in your system if those drugs are causing driver impairment.
Number 5 in the DUI list is driving under the influence of alcohol, or other drugs, or intoxicating compounds or any combination of the three. This catchall provision is rarely used.
The last DUI category is the “any amount” one. It is illegal to drive with any amount of drugs, including marijuana, in your blood, breath or urine. Proof that you are under the influence of them is not required.
Because this can lead to harsh results, since some drugs stay in your system for weeks after you last used them, there are discussions about changing that aspect of the law. In addition, with medical marijuana being legal in Illinois, further complications arise.
Illinois Driving Under the Influence (DUI) and standardized field sobriety tests Illinois DUI Lawyer Blawg, February 11, 2010
What tools are available to the police in Illinois for proving a DUI charge? Illinois DUI Lawyer Blawg, January 11, 2013