Maximum Mounting Height for Midwest Guardrail System (MGS)

Guardrail heights play a crucial role in the way that errant vehicles interact with roadside barriers. Low rail heights increase the propensity of vehicle rollover and override, while excessively-tall rails promote underride. Further, rail mounting heights and post embedment depths may be altered by variations in roadside terrain. An increased guardrail height may be desirable to accommodate construction tolerances, soil erosion, frost heave, and future roadway overlays. The acceptable range of rail mounting heights should be known to ensure containment and safe vehicle redirection during impact events. A research investigation was performed to evaluate the safety performance of increased mounting heights for the standard 31-in. tall, Midwest Guardrail System (MGS) through crash testing and computer simulation. Two full-scale crash tests with 1100C small passenger cars were performed on the MGS but with top-rail mounting heights of 34 in. and 36 in. Both system heights satisfied the Manual for Assessing Safety Hardware (MASH) Test Level 3 (TL-3) evaluation criteria for test designation no. 3-10. Test results were then used to calibrate computer simulation models. A mounting height of 36 in. was determined to be the maximum guardrail height that would safety contain and redirect 1100C vehicles and not allow underride or excessive vehicle snag on support posts. Recommendations were also provided regarding the safety performance of the increased-height MGS.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AFB20 Standing Committee on Roadside Safety Design.
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Julin, Ramen D
    • Pajouh, Mojdeh Asadollahi
    • Stolle, Cody S
    • Reid, John D
    • Faller, Ronald K
  • Conference:
  • Date: 2017

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 18p
  • Monograph Title: TRB 96th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01630170
  • Record Type: Publication
  • Report/Paper Numbers: 17-03364
  • Files: TRIS, TRB, ATRI
  • Created Date: Mar 27 2017 9:32AM