Increased Capacity, Strong-Post Guardrail System with Reduced Offset

This paper describes the development and testing of an improved strong post guardrail system. Several features are significant in the development of this guardrail system. The W-beam rail is mounted at a height of 31 in. to provide improved interaction and stability for impacts with high center-of-gravity vehicles. The rail splices are placed at mid-span between posts to change the state of stress on the splice and effectively increase the strength of the W-beam and enable it to contain and redirect heavier vehicles. The use of a new guardrail mounting bolt facilitates release of the post from the rail and enables the rail to maintain its height during vehicle engagement and redirection. Use of a new Steel Yielding Line Post (SYLP) in combination with the new guardrail mounting bolt mitigates the severity of the snagging contact between an impacting vehicle and the post without changing the deflection characteristics of the guardrail system. Further, the use of the modified post and connection facilitates removal of the offset block from the guardrail system, which provides benefits in terms of space and cost savings. Modified NCHRP Report 350 tests 3-10 and 3-11 were performed on the new guardrail system to demonstrate its ability to contain both heavy, high center-of-gravity light trucks and light passenger cars. The vehicles used in these two tests were both heavier than those previously used in NCHRP Report 350 testing, and conform to the specifications being recommended for use in the update of NCHRP Report 350. Additionally, the standard NCHRP Report 350 test 3-10 was performed on the new strong-post W beam guardrail system to verify its crashworthiness when impacted by small passenger cars. The new W-beam guardrail performed acceptably in all tests.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 23p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044975
  • Record Type: Publication
  • Report/Paper Numbers: 07-3124
  • Files: BTRIS, TRIS, TRB
  • Created Date: Feb 8 2007 7:49PM