§47-15-105.

§47-15-105.
   
   (a) The Department of Highways shall place and maintain such
   traffic-control devices, conforming to its manual and specifications,
   upon all state and federal highways as it shall deem necessary to
   indicate and to carry out the provisions of this act 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 Department of
   Highways except by the latter's permission.