Idaho Statutes Title 49. Motor Vehicles § 49-805. Display of unauthorized signs, signals or markings

(1) No person shall place, maintain or display upon or in view of any highway any unauthorized sign, signal, marking or device which purports to be, or is an imitation of, or resembles a 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 traffic-control device or any railroad sign or signal.

(2) No person shall place or maintain, nor shall any public authority permit upon any highway any traffic-control device bearing on it any commercial advertising, except for business signs included as a part of official roadside area information panels approved by the department.

(3) This section shall not be deemed to prohibit the erection upon private property adjacent to highways of signs giving useful directional information and of a type that cannot be mistaken for traffic-control signs.

(4) Every prohibited sign, signal or marking is declared to be a public nuisance and the authority having jurisdiction over the highway is empowered to remove the public nuisance or cause it to be removed without notice.