605 ILCS 125/10
As used in this Act:
"Department" means the Department of Transportation.
"DUI memorial marker" means a marker on a highway in this State commemorating one or more persons who died as a proximate result of a crash caused by a driver under the influence of alcohol, other drug or drugs, intoxicating compound or compounds, or any combination thereof.
"Qualified relative" means: an immediate relative of the deceased, by marriage, blood, or adoption, such as his or her spouse, son, daughter, mother, father, sister, or brother; a stepmother, stepfather, stepbrother, or stepsister of the deceased; or a person with whom the deceased was in a domestic partnership or civil union as recognized by a State or local law or ordinance.
"Supporting jurisdiction" means the Department or any municipality, township, or county that establishes a Roadside Memorial program within its jurisdictional area.
605 ILCS 125/10