For use in this chapter, the following terms are defined
1. "Breakaway support" means a supporting post which shall be no larger than a 4-inch x 4-inch wood post or a metal post with a strength no greater than a 2-inch diameter schedule 40 steel pipe and which is buried no more than 24 inches deep. Such a support post shall not be set in concrete unless specifically designed as a breakaway support system as defined in A Guide for Erecting Mailboxes on Highways published by the American Association of State Highway and Transportation Officials, May 24, 1984 (ASHTO).
2. "Clear zone" means an unobstructed flat area adjacent to the traveled portion of a roadway that is used for the recovery of errant vehicles.
33. "Cluster-style mailbox" means a style whereby mailboxes, meeting the specifications of the United States Postal Service (USPS) with the inscription plainly legible "U.S. MAIL" and "APPROVED BY THE POSTMASTER GENERAL," are assembled and grouped together on a single area of land so that they are regarded as one unit. Cluster-style mailboxes must be manufactured cluster-style mailboxes approved by both the City and the USPS.
4. "Curbside mailbox" means a mailbox consisting of a lightweight sheet metal or plastic box meeting the specifications of the United States Postal Service (USPS) with the inscription plainly legible "U.S. MAIL" and "APPROVED BY THE POSTMASTER GENERAL," which is erected at the edge of a roadway or curbside of a street and is mounted on a breakaway support post, and is intended or used for the collection of mail and is to be served by a mail carrier from a vehicle.
5. "Custom-built mailbox" means a mailbox erected at the edge of a roadway or curbside of a street constructed using materials that do not meet the definition of a "curbside mailbox" and "breakaway support."