Testing and Evaluation of Molded Plastic Mailboxes (0-1792-6)

Under this project, researchers investigated the impact performance of molded plastic mailboxes through full-scale crash testing. TxDOT has been receiving an increasing number of requests to use these molded plastic mailboxes in lieu of the Department's standard mailbox support and mailbox connection hardware. These molded plastic mailboxes are available in a variety of styles and colors, which make them an aesthetic alternative to conventional mailbox installations. Crash tests were conducted to evaluate the performance of molded plastic mailboxes on three different types of support posts: 4x4 wood, 2 lb/ft U-channel, and 3-in. diameter schedule 40 pipe. In all three tests, the molded plastic mailbox units satisfied National Cooperative Highway Research Program (NCHRP) Report 350 evaluation criteria. However, some variations in performance associated with the different support posts were observed. From both a functional and impact performance standpoint, the 4x4 timber support post appears to be the best alternative from among the three support posts investigated. It is therefore recommended that these mailboxes be installed on a 4x4 wood support post per manufacturers' recommendations.