Image of Pittsboro's historic courthouse and text

John’s O&M Lesson 6: Road Numbering Systems

What do highway numbers mean?

Now that John has knowledge about the nearby small towns and cities, let’s take a moment to learn more about the roads that connect these towns and cities and what the road numbers mean.

United States Numbered Highway System

Note: This lesson can be simplified or expanded depending on your student’s level. The most basic lesson may include numbering systems with even and odd numbers and the different road sizes of local roads he/she might be familiar with. In John’s case, he is familiar with the highway numbers that intersect Pittsboro or are nearby, along with Interstate 40 and Interstate 95. His initial numbering lesson will be narrowed to these local roads. The more advanced student may learn about the four types of highways, spurs, and loops and applying the numbering system to highways around the U.S.

Highways in the United States are split into four main systems: Interstate Highways, U.S. Highways, state highways and county highways. Highways are organized by numbers and each highway system has a designated visual symbol that signifies which system the highway belongs to.

Interstate Highways

Interstate highways are a nationwide network of roads are designed for long-distance travel and are freight routes. The highway numbering system is basically a grid pattern. 

Generally, most north-to-south highways are odd numbered with the lowest numbers along the east coast and the highest numbers along the west coast. Major north-to-south highways ends in “1” or “5”, such as Interstate 95 which is the major interstate that runs from Maine to Florida.

Most east-to-west highways are even numbered with the lowest numbers in northern part of the US and the highest numbers in the southern part. Major east-west roads end in “0”. Example: Interstate 40 is a major interstate that runs east-to-west, starting on the east coast in North Carolina and ending in California. 

These highways have two-digit numbers with auxillary spurs and loops that have three digital numbers. An example is 540, which is a loop off of Interstate 40, which goes around Raleigh. 

Advanced: A “spur” is an interstate route which a has three digital with an odd first digit. A spur is an offshoot or a short route branches off from the interstate. A “loop” has an even first digit and either passes through a city or bypasses a city then reconnects to the interstate.

Interstates are federally funded but are state-maintained. 

Interstate signs are in the shape of a shield with a red bar on the top with the word “INTERSTATE” and a dark blue bottom with white numbers. Loops and spur signs are in the shape of a shield with a solid green background with “BUSINESS LOOP” or “BUSINESS SPUR” at the top and the number at the bottom.

Road Numbers Activity

Pittsboro and Nearby Cities map This map displays the towns, cities, and roads from Pittsboro to these towns and cities. This map focuses on towns and cities near Pittsboro, which is in the middle area of the state.

NC Carolina Highways map This more complex map displays the major cities in NC and the major roads between the cities (mostly intersections with more details for cities closer to Pittsboro). Note: This map does not include every highway in North Carolina. This map is more complex and can be modified for young users, if needed. Remember, you can make a custom map of your state or use this NC map. If you make a map of another state, please share it with us! This map focuses more on the communities closer to Pittsboro, John’s home town.

Want to learn more about the roads near you? Research a highway!




By Diane Brauner