The incident is the third to be reported in that same area.
The pumpkin was thrown from the overpass at late Tuesday, hitting a vehicle driving eastbound.
The 64-year-old woman driving crashed into a ditch, police said. She sustained minor injuries.
It was the second report of this type of incident at this location and the third in the area since Nov. 7. All three incidents happened between 8:44 p.m. and midnight.
"It's at least the second one at that location, and we had a third incident but the driver kept driving to a service area, so that driver was unsure of the exact location," said Sgt. Ted Bohner, Indiana State Police.
Police warned that throwing objects from an overpass can cause injuries as well as death and that anyone caught committing this crime can be charged with criminal mischief, a misdemeanor, or overpass mischief, a felony, if the victim sustains injuries.