Testing and Evaluation of Guardrail Posts Installed in Mow Strips

During an impact event with a W-beam guardrail system, post rotation through the surrounding soil accounts for the majority of the energy dissipation. When guardrail posts are installed in pavements or mow strips that restrict rotation, the amount of energy dissipation is reduced, and the rail is subjected to increased forces. This scenario negatively affects the safety performance of guardrail systems by increasing the risk of rail rupture and vehicle penetration. As a result, it is recommended that strong-post guardrail systems installed in mow strips utilize a blocked-out area or "leave-out" in the pavement around the base of the post. Recently, the Midwest Guardrail System (MGS) Bridge Rail was developed utilizing S3x5.7 posts instead of the standard W6x9 guardrail post. These weak posts were placed in rigid sockets attached to the bridge deck and provided energy dissipation through plastic bending instead of rotation through soil. The MGS Bridge Rail was successfully full-scale crash tested and showed promise as a weak-post design for other applications. The Midwest Roadside Safety Facility (MwRSF) has an existing project to adapt the MGS Bridge Rail for use in mow strips and other rigid pavements. That project has funding to evaluate design concepts through dynamic component testing and to conduct a full-scale crash test of the selected design. However, further research is needed to evaluate various mow strip configurations and their effects on system performance and damage when coupled with a weak-post guardrail system. Therefore this proposal seeks to supplement the concept development of installing weak posts in mow strip pavements through dynamic component testing.

Language

• English

Project

• Status: Completed
• Funding: $60000.00
• Contract Numbers:

  DTRT12-G-UTC07

• Sponsor Organizations:

  Research and Innovative Technology Administration

  University Transportation Centers Program
  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Performing Organizations:

  Mid-America Transportation Center

  University of Nebraska-Lincoln
  2200 Vine Street, PO Box 830851
  Lincoln, NE  United States  68583-0851
• Principal Investigators:

  Reid, John

  Faller, Ronald

  Lechtenberg, Karla

  Rosenbaugh, Scott

• Start Date: 20130701
• Expected Completion Date: 0
• Actual Completion Date: 20141231
• Source Data: RiP Project 34757

Subject/Index Terms

• TRT Terms: Bridge railings; Crash tests; Dissipation; Guardrails; Highway safety; Posts
• Identifier Terms: Midwest Guardrail System
• Uncontrolled Terms: Mow strips; W-beam guardrail
• Subject Areas: Highways; Maintenance and Preservation; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01487975
• Record Type: Research project
• Source Agency: Mid-America Transportation Center
• Contract Numbers: DTRT12-G-UTC07
• Files: UTC, RIP
• Created Date: Jul 24 2013 1:02AM