Display of unauthorized devices, signs, etc.; such devices, etc., declared nuisance and subject to removal

(a) No local authority or person shall place, maintain, or display upon or in view of any highway any unauthorized traffic- control device or traffic-control signal, or any unauthorized sign, signal, marking, or device which purports to be or is an imitation of or resembles an official traffic-control device or railroad sign or signal, or which attempts to direct the movement of traffic, or which hides from view or interferes with the effectiveness of any official traffic-control device or any railroad sign or signal, and no person shall place or maintain nor shall any public authority permit upon any highway any traffic-control device bearing thereon any commercial advertising. This shall not be deemed to prohibit the erection upon private property adjacent to highway of signs giving useful directional information and of a type that cannot be mistaken for official signs. (b) Every such prohibited device, signal, sign or marking is hereby declared to be a public nuisance and the state road commissioner or other authority having jurisdiction over the highway is hereby empowered to remove the same or cause it to be removed without notice.