The crash happened minutes after 4 p.m. on the eastbound Indiana Toll Road just east of the State Road 39-LaPorte exit.
Police say that their preliminary investigation has found that the truck driver, a 39-year-old Chicago resident, was stopped in the left lane when a Honda CR-V ran into the back of the trailer.
Traffic was reportedly stopped in the area for a semi that had gone into the median nearby and was being towed out.
Police say the driver of the Honda CR-V, Leonard Daniel Ball III, 69, of Granger, Ind., had to be extricated from the CR-V and was pronounced dead at the scene by the La Porte County coroner. The cause of death was massive blunt force trauma.
The driver of the semi trailer was not injured. Eastbound lanes of the Toll Road were closed until about 6 p.m. for reconstruction of the crash, removal of the body and vehicles and to clean up the roadway.
The Sun-Times Media Wire contributed to this report.