(1) Nonconforming signs may be maintained, except as provided in subsection (3) of this section, unless otherwise removed pursuant to chapter 47.42 RCW.

(2) A nonconforming sign may be sold or leased, or otherwise transferred without affecting its status, but its location may not be changed. A nonconforming sign removed as a result of a right of way taking or for any other reason may be relocated to a conforming location but cannot be reestablished at another nonconforming location.

(3) A nonconforming sign may not be maintained if:

(a) The sign face size is increased more than fifteen percent over the original sign face size as of May 10, 1971 (the effective date of the Scenic Vistas Act), or as of the effective date of Scenic Vistas Act control over a given route, whichever applies;

(b) There are substantial changes to the sign structure's original construction materials, such as upgrades from wooden to steel signposts; or

(c) It is abandoned, destroyed, discontinued, or relocated, except as provided under subsection (2) of this section.

(4) Nonconforming signs shall be considered for sign spacing requirements pursuant to WAC 468-66-050.

(5) Destroyed nonconforming signs may only be reerected, and only in kind, if destroyed due to vandalism or other criminal or tortious acts.