Ark. Code Ann. § 27-52-105: Devices on state highways

(a) The State Highway Commission shall place and maintain 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 commission, except by the latter's permission.