Clark County Engineer’s Office
4075 Laybourne Road
Springfield, Ohio 45505-3613
(937) 521-1800 (937) 328-2473 fax
www.clarkcountyohio.gov/engineer
March 13, 2014
Standards for Rural Mailboxes
Foreword
It is the duty of the County Engineer to provide the safest possible highway system for the
traveling public of
Clark County. Section 5547 of the Ohio Revised Code provides for the removal of obstructions
within the county highway system rights-of-way. The Federal Highway Administration has
adopted the following standards for rural mailboxes. Mailboxes not in compliance with these
standards are a safety hazard and an obstruction to the safe use of the highway and should be
removed.
Requirements for the Installation of Mailboxes
All mailbox units, attachments, decals, supports and installation thereof are to be in strict
accordance with
United States Postal regulations and in compliance with the following specifications and
standard drawings.
1. The mailbox unit shall be constructed entirely of plastic and/or lightweight galvanized
steel attached to the support unit with sufficient strength to prevent the box from
separating from the post top if struck by a vehicle.
2. The support structure (post) shall be either a wooden post (no larger than 4 inch x 4 inch
square or 4 inch diameter round) or a metal post with a strength no greater than a 2 inch
diameter standard strength steel pipe (with a weight not in excess or 2.6 lbs. per foot). No
support structure shall be embedded more than 24 inches into the ground. A metal post
shall not be fitted with an anchor plate, but it may have an anti-twist device that extends
no more than 10 inches below the ground surface. Mailbox supports shall not be set in
concrete.
3. The unit shall be placed at an offset from the edge of the pavement so that the road-side
face of the mailbox is no closer than 3 feet from the edge of the pavement. When a
mailbox is installed in the vicinity of an existing guardrail, it shall be placed immediately
behind the guardrail unless otherwise approved by the County Engineer.
4. Multiple mailbox units of more than two boxes shall not be mounted on one support.
However, lightweight newspaper boxes may be mounted below the mailbox on the side
of the mailbox support. Multiple posts shall be placed no less than 3 feet apart.
5. Designs not described in this brochure will be acceptable only if written approval is
granted by the Clark County Engineer's Office.
6. The owner shall assume responsibility for and shall hold Clark County harmless and
defend any and all claims for personal injury and property damages that might be brought
as a result of this work.