Low-Profile Barrier with TL-3 Modification

The Low-Profile Barrier (LPB) is only 20 inches high with predictably improved visibility of intersecting and/or surrounding traffic compared to the 32-inch standard safety shape. The initial LPB was developed by Texas Transportation Institute (TTI) and Texas Department of Transportation (TxDOT) in 1995 and approved by the Federal Highway Administration (FHWA) for Test Level 2 (TL-2) (45 mph) in 1997 and 1998. Since that time, it has become a standard in Texas in construction zones and also has been applied to permanent installations. Florida engineers have developed their own single-sided LPB using TTI?s profile. A new advantage has been discovered that should have a significant influence on permanent installations. Design consultants have reported spectacular potential savings in soil/rock earth work in mountainous terrain if a 20-inch LPB can be used instead of the common 32 inch safety shape. This is due to the American Association of State Highway Transportation Officials (AASHTO) requirement for sight distance around horizontal curves. These applications often require TL-3 performance. TL-3 performance was achieved by using the existing LPB as the base and developing a stabilizing rail that attaches to the top of the LPB at connection points. A retrofit of the current LPB was tested for both visibility, and for pickup rollover stability, the flaw in LPB TL-2 performance. NCHRP Report 350 test 3-11 was performed on two designs to evaluate the modified barrier in containing and redirecting a pickup. This report includes details of the LPB 3 testing.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; References; Tables;
  • Pagination: 19p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01150953
  • Record Type: Publication
  • Report/Paper Numbers: 10-2303
  • Files: PRP, TRIS, TRB
  • Created Date: Jan 25 2010 11:04AM