An existing sign which extends over the right-of-way of any street or avenue may be maintained, and a permit may be issued for the erection, remodeling, or replacement of a sign which so extends only if the sign meets, or after remodeling or replacement will meet, all of the following requirements, as determined by the City Planner:
(A) The sign is attached only to, and supported only by, a building that is situated on a lot or tract of land concerning which there exists no restrictive building setback line of record, and that also abuts, at the point of attachment of the sign, the right-of-way line of the street or avenue;
(B) The sign is situated not less than ten feet above the surface of the sidewalk, or sidewalk area, and no part of the sign projects beyond a point which is perpendicularly above a point that is less than three feet distant from the rear line of the curb or, if there is no curb, from an extension of the rear line of the nearest curb; and
(C) The sign is or, as the case may be, will be safe and secure, and will not constitute a hazard to persons or vehicles on the street, avenue, sidewalk, or sidewalk area.