Development of MASH TL-3 Deflection Reduction Guidance for 31-inch Guardrail

With the design and installation of guardrail systems, there routinely exist needs to provide a stiffening mechanism to reduce the lateral deflection distance behind these systems, for example when concrete bridge piers are located near roadway shoulders. Various means of providing reduced deflections have been made with past systems that have included nesting of guardrail and the reduction of guardrail post spacing. With the recent adoption of the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH), there is currently little to no guidance on the use of MASH compliant guardrail installations that reduce these types of deflections within Midwest Guardrail Systems (MGS) and their necessary transitions. Thus, a need exists to provide guidance for the use of MASH compliant guardrail installations that provide a safe transition to a stiffening mechanism which will reduce the deflection distances behind guardrail while maintaining the integrity and safety performance of the MGS. This research will continue the development of guidance for the design and installation of reduced deflection guardrail systems that are MASH compliant. The objective of this research is to develop guidance for the use of MASH TL-3 compliant guardrail installations that provide a safe transition to a stiffening mechanism that will reduce the deflection distances behind guardrail while maintaining the integrity and safety performance of the MGS. The proposed scope of this project is to: (1) determine potential stiffening mechanisms to reduce barrier deflection to desired levels; (2) perform an analysis of those mechanisms to determine their performance and safety; (3) perform full-scale testing of the proposed reduced deflection designs; (4) determine the need for providing a transition to the mechanism within the guardrail system; (5) provide a design of the transition; and (6) evaluate the transition through MASH TL-3 full-scale crash testing.

• Record URL:
  http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=4584
• Supplemental Notes:
  • Contract to a Performing Organization has not yet been awarded.

Language

• English

Project

• Status: Proposed
• Funding: $500000
• Contract Numbers:

  Project 22-38

• Sponsor Organizations:

  National Cooperative Highway Research Program

  Transportation Research Board
  500 Fifth Street, NW
  Washington, DC  United States  20001

  American Association of State Highway and Transportation Officials (AASHTO)

  444 North Capitol Street, NW
  Washington, DC  United States  20001

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Project Managers:

  Bush, Mark

• Start Date: 20180619
• Expected Completion Date: 0
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Deflection; Design; Guardrails; Guidelines; Impact tests; Installation; Stiffness
• Identifier Terms: AASHTO Manual for Assessing Safety Hardware
• Subject Areas: Design; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01672563
• Record Type: Research project
• Source Agency: Transportation Research Board
• Contract Numbers: Project 22-38
• Files: TRB, RiP
• Created Date: Jun 18 2018 3:03PM