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Public Works

Phone: 913-715-8300

1800 W. Old Highway 56, Olathe, KS 66061

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Mailbox Guidelines

U.S. Postal Service Guidelines

For details on U.S. Postal Service requirements on mailboxes refer to their Domestic Mail Manual (DMM), specifically 508 Recipient Services:


County Guidelines on Mailboxes

This section provides County guidelines for mailboxes and newspaper delivery boxes on public right-of-ways.


No mailbox or newspaper delivery box, hereinafter referred to as mailbox, will be allowed to exist on County right of way if it interferes with the safety of the traveling public or the function, maintenance or operation of the road system. A mailbox installation not conforming to the provisions of this regulation is an unauthorized encroachment under Kansas State Statute Section 68-545.

Mailboxes supported by structures such as masonry columns, railroad rails and ties, tractor wheels, plow blades, and concrete-filled barrels, are roadside hazards that will need to be removed at the postal patron's expense.

The location and construction of mailboxes shall conform to the rules and regulations of the U.S. Postal Service as well as to standards established by the County. A mailbox installation that conforms to the following criteria will be considered acceptable unless, in the judgment of the County Engineer, the installation interferes with the safety of the traveling public or the function, maintenance, or operation of the road system.


No mailbox will be permitted where access is obtained from a freeway or where access is otherwise prohibited by law or regulation. Mailboxes shall be located on the right-hand side of the roadway in the carrier's direction of travel route except on one-way streets, where they may be placed on the left-hand side. The bottom of the box shall be set at a height established by the U.S. Postal Service, usually between 39 in. and 48 in. above the roadway surface. The roadside face of the box shall be offset from the edge of the traveled way a distance no less than the greater of the following:

  • 8ft (where no paved shoulder exists and shoulder cross slope is 13 percent or flatter), or
  • the width of the all-weather shoulder present plus 8 in. to 12 in., or
  • the width of an all-weather turnout specified by the County plus 8 in. to 12 in..

Exceptions to these placement criteria will exist on residential streets and certain designated rural roads where the County deems it in the public interest to permit lesser clearances or to require greater clearances. On curbed streets, the roadside face of the mailbox shall be set back from the face of the curb at a distance of between 6 in. and 12 in. On residential streets without curbs or all-weather shoulders that carry low traffic volumes operating at low speeds, the roadside face of the mailbox shall be offset between 8 in. and 12 in. behind the edge of the pavement. On very low-volume rural roads with low operating speeds, the County may find it acceptable to offset mailboxes a minimum of 6 ft. from the traveled way and under some low volume low-speed conditions may accept clearances as low as 32 in..


Design and/or location criteria for the mailbox support structure should consist of the following:

  • Where a mailbox is located at a driveway entrance, it shall be placed on the far side of the driveway in the carrier's direction of travel.
  • Where a mailbox is located at an intersecting road, it shall be located a minimum of 100 ft. beyond the center of the intersection road in the carrier's direction of travel. This distance shall be increased to 200ft when the average daily traffic on the intersection road exceeds 400 vehicles per day.
  • Mailboxes shall be of light sheet metal or plastic construction conforming to the requirements of the U.S. Postal Service. Newspaper delivery boxes shall be of light metal or plastic construction of minimum dimensions suitable for holding a newspaper.
  • No more than two mailboxes may be mounted on a support structure unless crash tests have shown the support structure and mailbox arrangement to be safe. However, light-weight newspaper boxes may be mounted below the mailbox on the side of the mailbox support.
  • Mailbox supports shall not be set in concrete unless crash tests have shown the support design to be safe.
  • A single 4-in.-by-4-in. square or 4-in. diameter wooden post; or metal post, Schedule 40, 2 in. (normal size IPS (external diameter 2⅜ in.]) (wall thickness 0.154 in. or smaller), embedded no more 24 in. 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 more than 10 in. below the ground surface.
  • The post-to-box attachment details should be of sufficient strength to prevent the box from separating from the post top if the installation is struck by a vehicle. The exact support hardware dimension and design may vary such as having a two-piece platform bracket or alternative slot-and-bole locations. The product must result in a satisfactory attachment of the mailbox to the post, and all components must fit together properly.
  • The minimum spacing between the centers of support posts shall be the height of the posts above the ground line. Mailbox support designs not described in this regulation are acceptable if approved by the County Engineer.
  • Where snow plowing operations cause damage to fixed mailbox installations, swing-away designs may be used.

Shoulder and Parking Area Construction

It shall be the responsibility of the postal patron to inform the County of any new or existing mailbox installations where shoulder construction is inadequate to permit all-weather vehicular access to the mailbox.

Removal of Nonconforming or Unsafe Mailboxes

Any mailbox that is found to violate the intent of these guidelines shall be removed by the postal patron upon notification by the County. At the discretion of the County, based on an assessment of hazard to the public, the patron shall be granted not less than 24 hours and no more than 30 days to remove an unacceptable mailbox. After the specified period has expired, the unacceptable mailbox will be removed by the County at the postal patron's expense.