The Crash Performance of Strong-Post W-Beam Guardrail with Missing Posts

Guidelines for testing the crash performance of the modified steel strong-post w-beam guardrail are described in the National Cooperative Highway Research Program (NCHRP) Report 350. However, these tests are always performed on new guardrail installations. The performance of guardrail with missing posts due to damage or deterioration has never been quantitatively evaluated. Because of this, the decision on when to repair guardrail has been based on best judgment and can vary greatly from state to state. In this study, the effect of missing posts on the guardrail crash performance was quantitatively evaluated using finite element models of crash tests using a 2000 kg (4409 lb) pickup truck. These finite element models were validated against crash tests of two different systems: an undamaged guardrail and a long span guardrail. Simulations in which one, two, or three posts were removed from the guardrail were conducted with varying points of impact to evaluate the effect of missing posts. The finite element model results demonstrated that guardrail missing even one post can show markedly decreased vehicle performance due to wheel snagging. The guardrail performance was similarly degraded. Both maximum deflection and maximum rail tension greatly increased as more posts were removed from the guardrail. These results have important implications for roadside hardware maintenance. Even a single missing post in a guardrail may negatively affect the crash performance of the system and should have a high repair priority.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; Photos; References; Tables;
  • Pagination: 15p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01152200
  • Record Type: Publication
  • Report/Paper Numbers: 10-1589
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 10:42AM