Since Texas and many other states have literally thousands of turned down end guardrails installed on their highways, Texas Transportation Institute and Texas highway engineers have been seeking a relatively simple method of modifying the turned down end treatment which would eliminate or greatly minimize the probability of a vehicle ramping and rolling over. Recent tests conducted by the Texas Transportation Institute indicate that a relatively simple solution has been found. To modify the standard rail the 5/8 inch diameter bolts were removed from the first five (5) posts. With these bolts removed the rail will drop to the ground when the turned down terminal piece is struck by a vehicle. This action eliminates the undesirable vehicle ramp and roll over behavior. In order to hold the rail at the proper height (27 inches in Texas) before and during vehicle angle impact along the "length of need", "back-up plates" are bolted to the first five (5) posts. The test program includes the four (4) crash tests recommended by NCHRP 153 for longitudinal barrier terminals and two other additional tests. All tests have been successful and no vehicle roll over has resulted. /FHWA/

  • Supplemental Notes:
    • Sponsored by the Texas State Department of Highways and Public Transportation. Research performed in cooperation with the Department of Transportation, Federal Highway Administration. Study Title: Development of Effective Highway Safety Appurtenances.
  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  United States  76011
  • Authors:
    • Buth, C E
    • Hirsch, T J
  • Publication Date: 1977-5

Media Info

  • Pagination: 94 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00189361
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: FHWA-RD-79-S0806 Final Rpt., FCP 41G1-222
  • Contract Numbers: 2-10-76-189
  • Files: TRIS, USDOT
  • Created Date: Apr 12 1979 12:00AM