Section 17C-3-2 - Placing and maintaining traffic-control devices and signs on state highways(a) The state road commission shall place and maintain such traffic-control devices, conforming to its manual and specifications, upon all state highways as it shall deem necessary to indicate and to carry out the provisions of this chapter or to regulate, warn, or guide traffic.(b) No local authority shall place or maintain any traffic- control device upon any highway under the jurisdiction of the state road commission except by the latter's permission.