What term is used for a designated route in the United States identified by numbers?

The term used for a designated route in the United States identified by numbers is "U.S. Route." These routes are part of a national network of highways that were established to facilitate travel across the country. Each U.S. Route is assigned a unique number that helps in navigation and is recognized by drivers nationwide.

U.S. Routes often connect major cities and regions, providing essential links for interstate travel. They are marked by distinctive signage that includes the shield symbol with the route number, making it easy for motorists to identify their path.

The other route types mentioned serve different purposes. Federal Routes typically refer to highways funded or maintained by the federal government, while State Routes are managed by state governments and may vary significantly in terms of maintenance and usage compared to U.S. Routes. Local Routes are those maintained by city or county governments, catering mainly to local traffic rather than long-distance travel. Thus, the distinction lies in the scope and identification of these routes, reinforcing why "U.S. Route" accurately captures the essence of the designated numbered routes in the United States.