It is declared to be the policy of the state that no signs which are visible from the main traveled way of the interstate system, primary system, or scenic system shall be erected or maintained except the following types:
(1) Directional or other official signs or notices that are required or authorized by law including signs with the Crime Stoppers name, logo, and telephone number;
(2) Signs advertising the sale or lease of the property upon which they are located;
(3) Signs advertising activities conducted on the property on which they are located;
(4) Signs, not inconsistent with the policy of this chapter and the national policy set forth in section 131 of title 23, United States Code as codified and enacted by Public Law 85-767 and amended only by section 106, Public Law 86-342, and the national standards promulgated thereunder by the secretary of commerce or the secretary of transportation, advertising activities being conducted at a location within twelve miles of the point at which such signs are located: PROVIDED, That no sign lawfully erected pursuant to this subsection adjacent to the interstate system and outside commercial and industrial areas shall be maintained by any person after three years from May 10, 1971;
(5) Signs, not inconsistent with the policy of this chapter and the national policy set forth in section 131 of title 23, United States Code as codified and enacted by Public Law 85-767 and amended only by section 106, Public Law 86-342, and the regulations promulgated thereunder by the secretary of commerce or the secretary of transportation, designed to give information in the specific interest of the traveling public: PROVIDED, That no sign lawfully erected pursuant to this subsection adjacent to the interstate system and outside commercial and industrial areas shall be maintained by any person after three years from May 10, 1971;
(6) Signs lawfully in existence on October 22, 1965, determined by the commission, subject to the approval of the United States secretary of transportation, to be landmark signs, including signs on farm structures or natural surfaces, of historic or artistic significance the preservation of which would be consistent with the purposes of chapter
47.42 RCW;
(7) Public service signs, located on school bus stop shelters, which:
(a) Identify the donor, sponsor, or contributor of said shelters;
(b) Contain safety slogans or messages which occupy not less than sixty percent of the area of the sign;
(c) Contain no other message;
(d) Are located on school bus shelters which are authorized or approved by city, county, or state law, regulation, or ordinance, and at places approved by the city, county, or state agency controlling the highway involved; and
(e) Do not exceed thirty-two square feet in area. Not more than one sign on each shelter may face in any one direction.
Subsection (7) of this section notwithstanding, the department of transportation shall adopt regulations relating to the appearance of school bus shelters, the placement, size, and public service content of public service signs located thereon, and the prominence of the identification of the donors, sponsors, or contributors of the shelters;
(8) Temporary agricultural directional signs, with the following restrictions:
(a) Signs shall be posted only during the period of time the seasonal agricultural product is being sold;
(b) Signs shall not be placed adjacent to the interstate highway system unless the sign qualifies as an on-premise [on-premises] sign;
(c) Signs shall not be placed within an incorporated city or town;
(d) Premises on which the seasonal agricultural products are sold must be within fifteen miles of the state highway, and necessary supplemental signing on local roads must be provided before the installation of the signs on the state highway;
(e) Signs must be located so as not to restrict sight distances on approaches to intersections;
(f) The department shall establish a permit system and fee schedule and rules for the manufacturing, installation, and maintenance of these signs in accordance with the policy of this chapter;
(g) Signs in violation of these provisions shall be removed in accordance with the procedures in RCW
47.42.080;
Only signs of types 1, 2, 3, 7, and 8 may be erected or maintained within view of the scenic system. Signs of types 7 and 8 may also be erected or maintained within view of the federal aid primary system.