This is a tricky question and the answer has changed with recent changes in the law concerning cannabis DUI cases. Traditionally, a driver in Illinois had an absolute right under the 4th amendment to refuse all chemical testing and field sobriety testing. That is still true to some extent. However, the Illinois legislature has decided to up the penalties for persons who refuse field sobriety testing as it relates to driving privileges of motorists suspected of driving under the influence of cannabis.
Illinois is considered an implied consent state, which means, if you are on the roadways within the state, you have already given consent to submit to chemical testing. If you chose not to cooperate, the secretary of state will suspend your license, regardless of whether you are eventually found not guilty of the underlying DUI charge. The implied consent statute is listed below.
625 ILCS 5/11-501.1
(a) Any person who drives or is in actual physical control of a motor vehicle upon the public highways of this State shall be deemed to have given consent … to a chemical test or tests of blood, breath, other bodily substance, or urine for the purpose of determining the content of alcohol, other drug or drugs, or intoxicating compound or compounds
While refusing chemical testing is subject to a suspension of driving privileges, it has always been the right of motorists within the state to refuse field sobriety testing. Recent changes in the law, specifically concerning drivers who are suspected of operating their vehicle while under the influence of cannabis, will now have their driving privileges suspended if they refuse to participate in field sobriety testing. The law allows for the suspension of driving privileges when the following conditions are met:
The law concerning DUI cases involving alcohol is still the same and motorists may refuse field sobriety testing without consequence. However, refusal of chemical testing, whether it involves a DUI based on alcohol or cannabis will still lead to a suspension in driving privileges.
Additionally, if a driver refuses chemical testing, the police officer may then seek to obtain a search warrant to allow for blood, urine, or saliva to be collected from the motorist. To do this, the officer must contact a judge, offer all the evidence that has been collected to that point, and if the judge determines that probable cause exists, then the judge will sign the warrant to allow the officer to collect the requested chemical sample. Should the motorist refuse to comply with the search warrant, they could possibly face felony obstruction charges.