Iowa Code § 306B.2: Advertising prohibited — exceptions.

An advertising device shall not be erected or maintained within six hundred sixty feet of the edge of the right-of-way of the interstate system except in areas zoned and used for commercial or industrial purposes under authority of law, regulation, or ordinance of this state or a political subdivision of this state. For purposes of this section, “areas zoned and used for commercial or industrial purposes” means an area zoned for commercial or industrial purposes in accordance with chapter 414, in the case of city zoning, or in accordance with chapter 335, in the case of county zoning, in which one or more commercial or industrial activities, as defined under the city or county zoning ordinance, are located.