Lines are grouped into historic operating divisions. As passenger service declined during the 1950's, many divisions were consolidated.
Main Line (Logansport-Frankfort-Indianapolis)
Main Line (Indianapolis-Louisville)
Vincennes Branch (Indianapolis-Vincennes)
Main Line (Indianapolis-Terre Haute)
Main Line (Terre Haute-East St. Louis)
Peoria Branch (Terre Haute-Peoria)
Crawfordsville Branch (Terre Haute-Frankfort IN)
Toledo Branch (Ecorse-Carleton)
Toledo Branch (Toledo-Mansfield)