Minnesota Statutes Transportation (Ch. 160-174A) § 173.15. Prohibited advertising devices

(1) which purports to be or resembles an official traffic-control device, sign, or signal, or railroad sign or signal; or which hides from view or interferes in any material degree with the effectiveness of any traffic-control device, sign, or signal, or railroad sign or signal, or which obstructs or interferes with the driver's view of approaching, merging, or intersecting traffic for a distance not to exceed 500 feet;

(2) which prominently displays the word “stop” or “danger”;

(3) which contains statements, words, or pictures of an obscene, indecent, or immoral character, or such as would offend public morals or decency;

(4) on any right-of-way of the interstate system of highways, except as otherwise provided by law or allowed by the commissioner;

(5) on private land without the consent of the owner or occupant thereof;

(6) on trees, shrubs, or which are painted or drawn upon rocks or natural features, or on public utility poles;

(7) which has distracting flashing or moving lights so designed or lighted as to be a traffic hazard;

(8) to which access can be obtained only from an interstate main-traveled way but excluding frontage roads adjacent thereto;

(9) which are structurally unsafe, are in disrepair, or are abandoned.