(1) Public highways of this state are classified as follows:
(a) commission-designated highway systems;
(b) state highways;
(c) county roads;
(d) city streets.
(2) All highways that are not designated, selected, or established by the commission or constructed or maintained by the department may be designated as county roads or city streets upon the acceptance of the county or city.
(3) County roads are those that are opened, established, constructed, maintained, changed, abandoned, or discontinued by a county in accordance with Title 7, chapter 14, or that have been the subject of a request under 7-14-2622 and for which a legal route has been recognized by a district court as provided in 7-14-2622.
(4) City streets are those public highways under the jurisdiction of municipal officials.