Indiana County – Back Road Numbering System

[caption id="attachment_3624" align="alignleft" width="300" caption="Indiana County – Back Road Numbering System"]Indiana County – Back Road Numbering System[/caption]

Indiana County – Back Road Numbering System

Indiana uses a system of numbering its back roads which on the surface appears confusing, but is really quite logical, once you understand the basics of how it works. Most, but not all, counties use the same basic road numbering system. Most of the counties which do not use it have very hilly terrain which renders the grid system useless for their needs. Most of these counties utilize a naming system which has no basis in geographic placement, as the grid system used by most other counties.

Think of the county road system as a grid, as pictured in the drawing. The center of this system is usually the county seat, which in most, but not all, counties is close to the geographic center of the county. Notice the two black lines. The north/south axis is called the base and the east/west axis is called the baseline. Thus any point on the road called Base Road is going to be either directly north, or south, of the geographic center located in the county seat. This is usually the court house. Any location on Baseline Road is going to be directly east or west of the county seat.

Miles are divided into hundreds. N and S roads are indicated by the red lines. 100 N means the road is one mile north of the baseline. 200 N is two miles north of the baseline. Similarly, 100 S would be one mile south of the baseline, and 200 S two miles south. 1200 S would be twelve miles south of the baseline. 750 N would be seven and one half miles north of the baseline and 725 N would be seven and a quarter north of the baseline.

The East and West roads, indicated by the blue lines are exactly the same as the red lined North and South roads, with each division of 100 equaling one mile.

It is important to remember that the designation N, E, S, or W does not indicate which direction the road travels. It designates the direction that the road lies in relation to either the Base or Baseline roads. Thus an E or W road always travels with a north/south orientation, and N and S roads always have an east/west orientation. Since counties all use their own numbering system, a road will almost always change numbers when you cross a county line. Thus 500 N in one county may become 1200 N in the next one over.

Addresses of homes and businesses may be located using this system, as the home numbering system corresponds to the county road numbers. A home address of 1055 N County Road 500E would be located .055 mile north of County Road 100 N on County Road 500 E. 12355 E County Road 700 N would be .355 miles east of County Road 1200 E.

Using the road grid numbering system you can navigate around the county and find home and business addresses quickly and easily on a map once you understand the system.

Back to Indiana State Highways