The shooting took place about 5:30 p.m. at the westbound I-80 entrance to Interstate 355, state police said.
One person was taken to a local hospital with life-threatening injuries, police said. The victim later died, police said.
A person of interest was taken into custody, police said. Parts of the expressway were shut down as police investigated the shooting.
SEE ALSO: Multiple injured in crash on Dan Ryan Expy. on South Side
New Lenox police said there was a large police presence around Liberty Junior High School, which had parent-teacher conferences Monday night, and near Francis and Marley roads.
New Lenox police helped Illinois State Police take a suspect into custody without incident.