VEHICLE CRASH TEST AND EVALUATION OF MEDIAN BARRIERS FOR TEXAS HIGHWAYS

FULL-SCALE TESTS WERE CONDUCTED TO EVALUATE AND COMPARE THE PERFORMANCE OF THREE MEDIAN BARRIERS OF DIFFERENT CONFIGURATION AND LATERAL STIFFNESS. THE THREE BARIERS WERE :(A) THE METAL BEAM GUARD FENCE (MBGF) WHICH CONSISTS OF TWO BACK-TO-BACK STEEL W-BEAM GUARDRAILS ON WEAK BREAKAWAY STEEL POSTS; (B) THE E-3 WHICH CONSISTS OF TWO DIFFERENT SIZE STRONG ELLIPTICAL STEEL RAIL MEMBERS MOUNTED ON STRONG FABRICATED STEEL POSTS; AND (C) THE CONCRETE MEDIAN BARRIER (CMB) WITH SLOPING FACES. ALL THREE BARRIERS REMAINED INTACT IN RESTRAINING AND REDIRECTING A STANDARD SIZE 4,000 LB. PASSENGER VEHICLE UNDER THE SEVERE IMPACT CONDITIONS OF ABOUT 60 MPH AND 25 DEGREES. HOWEVER, SOME SNAGGING OCCURRED ON A POST OF THE E-3 BARRIER AS A RESULT OF THE VEHICLE MOUNTING THR LOWER RAIL MEMBER. THE TEST ALSO DEMONSTRATED THAT LUMINAIRE POLES AND FENCING CAN BE SAFELY MOUNTED ON THE TOP OF THE CMB BARRIER IN NARROW MEDIANS, BUT FLEXIBLE GUARDRAIL MAY BE UNSAFE IN NARROW MEDIANS. A COMPARATIVE STUDY OF THE THREE BARRIERS DEMONSTRATED THAT BARRIER DISPLACEMENTS WERE EFFECTIVE IN REDUCING VEHICLE DECELERATIONS, VEHICLE DAMAGE, AND THE PROBABILITY AND SEVERITY OF INJURIES TO UNRESTRAINED OCCUPANTS. AN INJURY PROBABILITY OF 46 PERCENT REPRESENTS THE APPARENT DIVISION BETWEEN MINOR AND MAJOR INJURIES. A GRAPH IS PRESENTED FROM WHICH AN ENGINEER CAN EXAMINE THE PROBABILITY AND SEVERITY OF INJURY ASSOCIATED WITH RIGID TRAFFIC BARRIERS UNDER VARIOUS COMBINATIONS OF IMPACT SPEED, IMPACT ANGLE, AND PASSENGER VEHICLE WEIGHT. THE RESULTS OF THIS AND OTHER STUDIES SHOW THAT THE PERFORMANCE OF THE CMB BARRIER WITH SLOPING FACES WOULD BE SIMILAR TO THAT OF A RIGID CONCRETE BARRIER WITH A VERTICAL WALL UNDER THOSE COMBINATIONS OF IMPACT SPEED AND ANGLE EXCEEDING AN AVERAGE LATERAL VEHICLE DECELERATION OF 2 G'S AND A PROBABILITY INJURY LEVEL OF 20 PERCENT. THIS STUDY ADDS SUPPORT TO THE BASIC KNOWLEDGE THAT MAINTENANCE REPAIR INCREASES AS BARRIER FLEXIBILITY INCREASES. THE FINDINGS OF THIS STUDY INDICATE THAT THE CMB BARRIER WOULD BEST SERVE THE PUBLIC IN NARROW MEDIANS OF ROADWAYS LOCATED IN URBAN DEVELOPMENTS AND CARRYING HIGH SPEED AND HIGH TRAFFIC VOLUME. INFORMATION IS PRESENTED ON THE SAFETY, ECONOMIC, AND AESTHETIC CONSIDERATIONS FOR EACH OF THE THREE BARRIERS INVESTIGATED.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 109 p.

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Filing Info

  • Accession Number: 00203689
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 2 1973 12:00AM