Testing of State Roadside Safety Systems Volume VII: Appendix F - Crash Testing and Evaluation of the Minnesota Swing-Away Mailbox Support (FHWA-RD-98-042)

The purpose of this study is to crash test and evaluate new or modified roadside safety hardware and, where necessary, redesign the devices to improve their impact performance. The three major areas addressed in this study are the impact performance of bridge railings, transitions from guardrails to bridge railings, and end treatments for guardrails and median barriers.|This report presents the results of four crash tests conducted on a swing-away mailbox support design by the Minnesota Department of Transportation in accordance with guidelines set forth in the 1985 American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Structural Supports for Highway Signs, Luminaries and Traffic Signals and National Cooperative Highway Research Program (NCHRP) Report 350. The first two tests corresponded to NCHRP Report 350 test designation 3-60 and 3-61, involving an 820-kg passenger car impacting the vertical mailbox support head-on at speeds of 35 km/h and 100 km/h, respectively. The mailbox support was aligned with the right front quarter point of the vehicle so that the interaction between the cantilevered arm and the mailbox assembly with the windshield of the vehicle can be evaluated. The third and fourth tests involved an 820-kg passenger car impacting the mailbox assembly head-on at a nominal speed of 100 km/h and zero (0) degree with the centerline of the mailbox assembly aligned with the centerline of the vehicle. These two tests are not required in NCHRP Report 350, but are included because of the cantilever design of the mailbox support. The Minnesota swing-away mailbox support was judged to have successfully met all evaluation criteria for a single mailbox assembly, but not for a triple mailbox assembly.|This volume is the seventh in a series of 14 volumes for the final report. The other volumes in the series are: Volume I - Technical Report; Volume II, Appendix A - Crash Testing and Evaluation of a Michigan Thrie-Beam Transition Design; Volume III, Appendix B - Crash Testing and Evaluation of a Guardrail System for Low-Fill Culvert; Volume IV, Appendix C - Crash Testing and Evaluation of a Pennsylvania Transition Design; Volume V, Appendix D - Crash Testing and Evaluation of a Washington, DC, PL-1 Bridge Rail; Volume VI, Appendix E - Crash Testing and Evaluation of a Modified Breakaway Cable Terminal (BCT) Design; Volume VIII, Appendix G - Crash Testing and Evaluation of the Single Slope Bridge Rail; Volume IX, Appendix H - Crash Testing and Evaluation of the NETC PL-2 Bridge Rail Design; Volume X, Appendix I Crash Testing and Evaluation of a Mini-MELT for a W-Beam, Weak-Post (G2) Guardrail System; Volume XI, Appendix J Crash Testing and Evaluation of Existing Guardrail Systems; Volume XII, Appendix K - Crash Testing and Evaluation of the MELT; Volume XIII, Appendix L - Crash Testing and Evaluation of the Modified MELT; and Volume XIV, Appendix M Laboratory and Pendulum Testing of Modified Breakaway Wooden Posts.