STUDY ON MEDIAN STRUCTURE
IN JAPAN TRUCKS FORM A HIGHER PERCENTAGE OF TAFFIC VOLUME THAN IN OTHER COUNTRIES: E.G., 41.4% ON THE TOMEI EXPRESSWAY. ACCORDINGLY, MEDIAN BARRIERS HAVE TO BE DESIGNED FOR HEAVY VEHICLES AS WELL AS AUTOMOBILES. COLLISION TESTS WITH THREE TYPES OF BARRIERS WERE RUN WITH TRUCKS AT 46 KM/HR AND AN ANGLE OF 20 DEG, AND WITH CANS AT 80 KM/HR AND 20 DEG. THE BLOCKED-OUT MEDIAN GUARDRAIL, DEVELOPED IN GERMANY, WAS ADAPTED TO JAPANESE REQUIREMENTS BY USING A MORE RIGID STRUCTURE WITH POSTS NOT OF THE WEAK TYPE. THE POSTS AND OFFSET BRACKETS WERE FIRMLY CONNECTED WITH BOLTS. THE BOX-BEAM GUARDRAIL, DEVELOPED IN THE UNITED STATES, WAS STRENGTHENED TO REDUCE DEFORMATION. THE CABLE MEDIAN BARRIERS THAT WERE TESTED ALSO WERE ADAPTED TO INCLUDE STRONG POSTS AND BRACKETS. THE BLOCKED-OUT MEDIAN GRUARDRAIL PROVED CONSISTENTLY TO HAVE THE BEST PERFORMANCE OF THE THREE. THE BOX-BEAM GUARDRAIL, WHILE INHERENTLY INFERIOR, IS THOUGHT TO BE SUITABLE FOR BARRIERS ON NARROW MEDIANS, SINCE THE BLOCKED-OUT TYPE REQUIRES A LARGE INSTALLATION AREA. THE CABLE BARRIER GAVE ABOUT THE SAME PERFORMANCE AS THE BOX GQUARDRAIL. CERTAIN PROBLEMS AROSE IN TESTS WITH THE LAST TWO TYPES THAT SUGGEST THAT FURTHER RESEARCH IS IN ORDER.
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Authors:
- Yoshioka, T
- Publication Date: 1971
Media Info
- Features: Figures; Photos; Tables;
- Pagination: p. 64-72
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Serial:
- Japan Road Association Annual Report of Roads
- Publisher: Japan Road Association
Subject/Index Terms
- TRT Terms: Automobiles; Box beams; Cables; Crash tests; Crashes; Guardrails; Median barriers; Structural design; Testing; Trucks
- Old TRIS Terms: Blocked out guardrails
- Subject Areas: Design; Highways; Motor Carriers; Research;
Filing Info
- Accession Number: 00203679
- Record Type: Publication
- Files: TRIS
- Created Date: Feb 3 1973 12:00AM