(1) A nonconforming advertising device may be continued to be maintained at the same location at which the nonconforming advertising device was lawfully erected.

(2) The right to maintain any nonconforming advertising device shall be terminated by:

(a) Abandonment of the nonconforming advertising device;

(b) Increase of any dimension of the nonconforming advertising device;

(c) Change of any aspect of or in the character of the nonconforming device;

(d) Failure to comply with the provisions of this part 4, concerning permits for the maintenance of advertising devices;

(e) Damage to or destruction of the nonconforming advertising device from any cause whatsoever, except willful destruction, where the cost of repairing the damage or destruction exceeds fifty percent of the cost of such device on the date of damage or destruction, as determined by the department-approved schedule of compensation;

(f) Obsolescence of the nonconforming advertising device where the cost of repairing the device exceeds fifty percent of the replacement cost of such device on the date that the department determines said device is obsolete.

(3) Reasonable and customary repair and maintenance of the device, including a change of advertising message or design, is not a change that would violate subsection (2) of this section. However, such message or design change shall not be compensable under section 43-1-414.

(4) If the right to maintain any nonconforming advertising device is terminated under this section, the advertising device shall become illegal and shall be removed pursuant to section 43-1-412.