Indiana State Route 39 is a north-south highway in a north-south highway in Carroll County. It runs from the White/Carroll County Line, south of Monticello, to the Carroll/Clinton County Line, near Rossville. It runs in the western part of the county. U.S. Rt. 421 passes through the following towns in Carroll County. Patton Yeoman Delphi
Radnor Ockley Owasco U.S. Rt. 421 is multi-plexed in Carroll County. U.S. Rt. 421, throughout Carroll County. Indiana State Route 18, from near Springboro to near Delphi.