Dr. Joshua S. Steelman
Date of this Version
Quintero-Paez, R.A., "INVESTIGATION AND MODIFICATION OF SINGLE-POST ALUMINUM SIGN SUPPORTS FOR MASH CRASHWORTHINESS" , University of Nebraska, Lincoln, Nebraska, July, 2023
Traffic signs are used to display information to drivers and are one of the most commonly encountered roadside structures. Although they are a vital traffic control device, signs can pose a significant safety risk to errant drivers due to their extensive placement and proximity to the roadway. Therefore, traffic signs and their supports must be designed with crashworthiness in mind to reduce the likelihood of injury in the event of a vehicle impact. Prior to 2009, these systems were evaluated using the crash testing criteria found in the National Cooperative Highway Research Program (NCHRP) Report No. 350 . Currently, they are evaluated using AASHTO’s Manual for Assessing Safety Hardware (MASH) , which introduced pickup truck testing for traffic signs and modified the failure criteria for crash tests. The roof crush is limited to 4.0 in., the windshield cannot experience any tear of the plastic liner and the maximum deformation is limited to 3 in. There is no shattering of windows allowed because of direct contact with the system.
The objective of this research effort was to develop a cost-effective modification to the existing FDOT single-post sign system design that would meet MASH TL-3 crash testing criteria. In particular, the objective was to reduce vehicle roof deformation and windshield shattering caused by the sign impacting the vehicle following slip base detachment.
The outcome of the simulation analysis resulted in a viable option for the Florida Department of Transportation that met MASH criteria when full-scale-crash tested. Following the successful crash tests, an additional design concept was determined that showed sufficient promise and recommended for further investigation in the next phase of the research.
Advisor: Joshua S. Steelman