As many as 100 people die each year in collisions with rural mailboxes. Some boxholders construct mailboxes with supports that are nearly indestructible. In a collision with such structures, a motor vehicle can be severely damaged and its occupants severely injured.

Mail boxes have been a link to the outside world for rural Americans since Rural Free Delivery began in 1896. For a hundred years, rural folks have decorated their front yards and expressed their individuality with their mailbox. Mailboxes have become a nostalgic subject for magazine articles and books, as well as a place to showcase one’s lifestyle or advertise a business interest. The creativity and uniqueness shown in these mail box designs can, however, hide unrecognized safety risks for motorists.

According to “A Guide for Erecting Mailboxes on Highways” published by the American Association of State Highway and Transportation Officials (AASHTO), there are aspects of individual and group mailboxes that can “turn a single mailbox installation into a lethal roadside obstacle”, obstacles that have “impaled or decapitated motorists”. “Possibly 70 to 100 people die annually in the United States in vehicles striking mailboxes where the design of the mailbox, and especially its support, can be shown to have contributed to the severity of the accident,” says AASHTO.

First, consider the location of the box itself, positioned right at the edge of the roadway, probably closer to passersby than any other object, and at car-window height. Even a couple of feet too close to the normal lane of traffic may clip someone’s rearview mirror or cause a mailbox to become a projectile.

If the box is heavier than the standard sheet metal or plastic box approved by the Postmaster, it may continue on through the windshield at 55 mph after an auto has clipped its post.

Similarly, a group mailbox installation on the typical horizontal plank or timber at windshield height may sail through the passenger compartment during a collision.

Second, motorists die or are more severely injured when the energy of a collision is absorbed all at once in a collision with a heavy, well-anchored object rather than something more forgiving. A collision with mailbox mountings constructed to withstand vandalism, road maintainers, snow plows, and wide machinery could leave the mailbox in better condition than a motor vehicle and its passengers.

Ask your Postmaster about the “Domestic Mail Manual” and consult the AASHTO guidelines to put up an attractive, safe mailbox.

Tips for Rural Mailbox Installations

  • Use only Postmaster-approved mailboxes made of light sheet metal or plastic.
  • Locate the mailbox away from traffic so that the mail delivery vehicle can stop completely out of the flow of traffic.
  • Use a support only strong enough to hold the mailbox. An ordinary 4″ x 4″ wood post or 1-1/2″ to 2″ metal pipe anchored in the ground no more than two feet is recommend.
  • Mailbox-to-post attachments should prevent the box from coming loose from the post if struck by a motor vehicle.
  • Multiple mailbox mountings should use individual mounting posts rather than a heavy, horizontal support member.
  • Never mark mailboxes with reflective materials that can mislead or confuse road users. It could be illegal in your state to mark your mailbox with a slow-moving vehicle (SMV) emblem.
  • Contact your Postmaster for specific installation details.


This article has been prepared by members of the Traffic and Transportation Committee of the National Institute for Farm Safety, Inc. (NIFS) in the interest of safety on rural roads. Approved for distribution 26 October 1997.