The trooper was struck Saturday night while conducting a traffic stop on the Dan Ryan Expressway near 63rd Street.
Kimisha Moore, 19, of Chicago told authorities she was looking at her cell phone when she hit the trooper despite warnings from her passenger that she was getting close to the officer.
The female trooper's name has not been released. She remains hospitalized in stable condition with injuries to both of her legs, a shattered pelvis and a head injury.
Moore is charged with aggravated reckless conduct and has been issued several traffic citations. She's being held on $50,000 bond.
"The Illinois State Police is pleading with the motoring public to please try to eliminate all the distractions in your vehicle, including electronic devices," said Lt. Louis Gutierrez, Illinois State Police. "We're also asking the motoring public to please slow down, move over or change lanes when you're approaching emergency vehicles because this could save our life."