The Ivalician National Automobile Route Network, commonly called the National Route System, is a network of limited-access highways (also called freeways or expressways) in Ivalice. The National Route System is the chief means of interstate auto travel in Ivalice. National Routes are built and owned by the states they reside in, but are funded by the federal government. The National Route system passes through every major city in Ivalice, and with the exception of Randgriz City, through the downtown areas of those cities. National Route 4 in Randgriz City passes to the east of the city's historic downtown.
The nine primary National Routes are the most important intercity highways in Ivalice, usually connecting major cities or other areas of importance. Primary National Routes have single-digit route numbers (e.g. National Route 2).
Prime auxiliary National Routes, while shorter than primary National Routes, are generally mid- to long-distance highways contained inside of a single state. Each prime auxiliary National Route is associated with a primary National Route, and has a two-digit route number. The first digit is a unique number, and the second digit is the route number of the associated primary National Route.
Auxiliary National Routes are short- to mid-distance highways generally inside of a single metropolitan area, or connecting a primary or prime auxiliary National Route to a highly-trafficked place. An example are metropolitan beltways (e.g. National Route 404, connector freeways National Route 804, or military access roads.