A state highway, state road, or state route (and the equivalent provincial highway, provincial road, or provincial route) is usually a road that is either numbered or maintained by a sub-national state or province. A road numbered by a state or province falls below numbered national highways (Canada being a notable exception to this rule) in the hierarchy (route numbers are used to aid navigation, and may or may not indicate ownership or maintenance).
Roads maintained by a state or province include both nationally numbered highways and un-numbered state highways. Depending on the state, "state highway" may be used for one meaning and "state road" or "state route" for the other.
In some countries such as New Zealand, the word "state" is used in its sense of a sovereign state or country. By this meaning a state highway is a road maintained and numbered by the national government rather than local authorities.