A county whose ordinances or regulations are otherwise in full compliance with Section 5412, is not in violation of that section if the county elects to require the removal without compensation of any display which meets all the following requirements:

1. (a) The display is located within an unincorporated area shown as agricultural on a local general plan as of either the date an ordinance or regulation is enacted or becomes applicable to the area which incorporates the provisions of this section.
2. (b) The display is located within an area zoned for agricultural use either on the date on which the removal requirement is adopted or becomes applicable to the area.
3. (c) The display is not located within 660 feet from the edge of the right-of-way of an interstate or primary highway with its copy visible from the highway, nor is placed or maintained beyond 660 feet from the edge of the right-of-way of an interstate or primary highway with the purpose of its message being read from the main traveled way.
4. (d) The display is not required to be removed because of an overlay zone, combining zone, or any other special zoning district whose primary purpose is the removal or control of signs.

5. (e) The display is allowed to remain in existence for the period of time set forth below after the adoption or amendment after January 1, 1983, of any ordinance or regulation necessary to bring the entity requiring removal into compliance with Section 5412, and after giving notice of the removal requirement:

   Fair Market Value on Date of Notice	Minimum Years
   of Removal Requirement	Allowed
   Under $1,999	3.0
   $2,000 to $3,999	4.5
   $4,000 to $5,999	6.0
   $6,000 to $7,999	7.5
   $8,000 to $9,999	9.0
   $10,000 and over	10.5

   The amounts provided in this section shall be adjusted each January 1 after January 1, 1983, in accordance with the changes in building costs, as indicated in the United States Department of Commerce Composite Cost Index for Construction Costs.