PC*MILER State + National Network routing favors using the U.S. Federally designated National Network (primary Interstates with reasonable entry/egress points up to 1 mile off the Interstate), combined with a preference to favor using the state-designated extensions to the Federal National Network (additional highways and supporting roads that can be any distance off the Interstate, as determined by the individual states).

In PC*MILER 37 and lower, State + National Network routing can be selected using the Road Network route option under Routing Preferences, either as part of a route profile or in the Route Options dialog for an individual route.

In PC*MILER 38 and higher, the State + National Network setting has been removed. If a vehicle's length is greater than 48 feet or if its width is greater than 96 inches, then Road Network will automatically be set to State + National Network. With a length of 48 feet or less or a width of 96 inches or less, the setting is automatically None.