Manual for Assessing Safety Hardware Crash Testing and Evaluation of Multiple Mailbox Supports for Use with Locking Architectural Mailboxes

Abstract

With increasing concern about mail-identity theft, there is a growing demand among homeowners and businesses for the use of locking mailboxes for theft deterrence and resistance to vandalism. Lockable mailbox products can be significantly larger and heavier than standard lightweight mailboxes. Therefore, the Texas Department of Transportation (TxDOT) requested evaluation of their crashworthiness before permitting their use on the state highway system. Under TxDOT Project 9-1002-12, crash tests were performed following the Manual for Assessing Safety Hardware (MASH) guidelines and procedures to assess the impact performance of lockable, secure mailboxes in both single and multiple mount configurations. Testing of the larger and heavier locking mailboxes on multiple-mount support posts was unsuccessful owing to vehicle windshield deformation and intrusion. This paper describes the efforts to develop and evaluate the crashworthiness of new proposed designs for multiple mailbox supports used with a combination of lockable and standard mailboxes. The crash tests were performed following MASH guidelines and the evaluation criteria. Two proposed designs were evaluated through full-scale crash testing. Both systems satisfied all required MASH evaluation criteria at low and high impact speeds using a passenger car, which was considered to be the critical design vehicle based on the mailbox mounting height.