In United States the highways has been Splited into four different types of system

Interstate Highways

This interstate system is freeways for transportation. This system is backbone of the U.S. for the transportation with millions of Americans. This system is federally funded and administered. Americans are relaying on it for commutes, freight, highly and huge transport daily. The highway has been constructed in very standard, designed for maximum high-speed. This has been designed for safety and efficiency travel; it has also contained very auxiliary routes which are assigned as normally three digit route number. All this interstate highways are same as national highways system, the network of highways are essential to defense, economy and mobility of the country.

U.S. Highways

The older system is U.S. Highway system. Because of the prominence of the interstate system many roots of U.S. has been downgraded to state numbered routes over the year and the most famous being is the decommissioning of the well known U.S. route 66. This system is coordinated by the American association of state highway and transportation officials, and it has been maintained by state and local government.

State Highways

Every state has a state highway system. Few state highways are travelled so heavily that they are build to Interstate standard, others highways are travelled so lightly, rarely that the quality of road is minimal. So the state highways are of varying standards and quality.

County Highways

County routes are travelled vary widely. The routes are very expressways to direct us the roads into remote part of the country. The final administrative level in some state is the country-maintained country highway.

All designations are displayed along the route of highways. Each and every system carry there own and unique design that gives us an identification to know the system belongs to which route. All the highways are designed in unique pattern. Highways are designed and organized by indication like a route number or letter. All such indication helps us to move in a right direction.