§ 150.103 STRUCTURES.
   (A)   Materials. Mailboxes shall be of light sheet metal, fiberglass or plastic construction and conform to the requirements of the U.S. Postal Service. Newspaper delivery boxes shall be of light sheet metal or plastic construction and of minimum dimensions suitable for holding a newspaper.
   (B)   Support.
      (1)   Number of boxes. No more than 2 mailboxes shall be mounted on a support structure unless the support structure and mailbox arrangement have been shown to be safe by crash testing as conducted by the Federal Highway Administration or the Arizona Department of Transportation. Lightweight newspaper delivery boxes may be mounted below the mailbox on the side of the mailbox support.
      (2)   Concrete foundation. Mailbox supports shall be placed in native soil or in crushed aggregate base materials whenever these materials provide adequate support. Mailbox supports shall not be placed in concrete unless necessary for support. Mailbox supports shall not be set in concrete placed at depth any greater than 12 inches.
      (3)   Post. A single 4 inch by 4-1/2 inch diameter wooden post or metal post with a strength no greater than 2 inch diameter standard strength steel pipe, and embedded no more than 24 inches into the ground shall be acceptable as a mailbox support. A metal post shall not be fitted with an anchor plate, but it may have an anti-twist device that extends no greater than 10 inches below the ground surface.
      (4)   Attachment. The post-to-mailbox attachment details shall be of sufficient strength to prevent the mailbox from separating from the post top if the installation is struck by a vehicle. The minimum spacing between the centers of the support posts shall be 3/4 of the height of the post above the ground line.
(2001 Code, § 7-13-4)