SNOWPLOWS RIDE OVER THESE RAISED REFLECTIVE MARKERS

SNOWPLOWABLE RAISED, REFLECTIVE MARKERS HAVE BEEN PROVIDED FOR LANE DELINEATION ON THE SCHUYLKILL EXPRESSWAY IN SUBURBAN PHILADELPHIA. THE MARKERS ARE THE FIRST DESIGNED FOR USE ON ROADS SUBJECT TO SNOW REMOVAL. PRINCIPLES OF GUIDANCE ARE THE SAME AS THOSE ESTABLISHED USING RAISED REFLECTIVE MARKERS OF MOLDED PLASTIC IN CALIFORNIA. TO OVERCOME THE PROBLEMS CAUSED BY SNOW PLOWING, THE NEW MARKERS ARE HARDENED STEEL CASTINGS. THEY ARE SET INTO GROOVES CUT INTO THE PAVEMENT AND ARE HELD IN PLACE WITH AN EPOXY ADHESIVE. THE CASTINGS ARE TAPERED TO ALLOW SNOWPLOW BLADES TO RIDE UP AND OVER THE MARKERS WITHOUT DAMAGING THE BLADES OR THE REFLECTIVE PLASTIC ELEMENTS THAT ARE MOUNTED IN THE STEEL HOUSING. THE EXPRESSWAY INSTALLATION USES THE RAISED REFLECTIVE MARKERS IN CONJUNCTION WITH THERMOPLASTIC LINES. THE RAISED REFLECTIVE MARKER HAS SERRATED KEELS WHICH FIT INTO GROOVES CUT BY TWIN DIAMOND SAW BLADES AND ARE SEATED IN EPOXY. TWO REFLECTIVE ELEMENTS ARE USED IN EACH MARKER. ONE, FACING THE NORMAL FLOW OF TRAFFIC, RETURNS A CRYSTAL CLEAR SIGNAL. THE OTHER SHOWS A RED WARNING TO WRONGWAY DRIVERS. REFLECTIVE FACES ARE REPLACEABLE IF BROKEN. THEY ARE STRIPS OF PRECISION MOLDED, HIGH-STRENGTH ACRYLIC PLASTIC. THE RAISED MARKERS WERE INSTALLED ON THE EXPRESSWAY AFTER TWO YEARS OF IN-HIGHWAY TESTING. THE INSTALLATION PROCEDURE IS DESCRIBED WHICH INVOLVES A THREE- STAGE OPERATION: (1) TWO PARALLEL GROOVES ARE CUT INTO THE PAVEMENT TO RECEIVE THE KEELS ON THE BOTTOM OF THE CASTING, (2) THE EPOXY ADHESIVE IS APPLIED BY A SPECIAL MACHINE WHICH MIXES THE TWO EPOXY COMPONENTS AND EJECTS THE ADHESIVE INTO THE GROOVES THROUGH A SPECIAL NOZZLE, AND (3) THE CASTINGS ARE PLACED INTO THE GROOVES BY HAND. A CALIFORNIA STUDY HAS SHOWN THAT LANE CHANGING WAS REDUCED BY 40 PERCENT WHEN RAISED MARKERS WERE INSTALLED. THIS MAY REDUCE THE ACCIDENT RATE AND LANE CHANGING ON THE SCHUYLKILL EXPRESSWAY.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/1606878
• Supplemental Notes:
  • Vol 100, No 1, PP 90-92, 6 PHOT
• Publication Date: 1969-1

Media Info

• Serial:
  • Public Works
  • Publisher: Hanley Wood
  • ISSN: 0033-3840
  • Serial URL: http://www.pwmag.com

Subject/Index Terms

• TRT Terms: Crash rates; Epoxides; Highway delineators; Raised separators; Reflectivity; Road markings; Snow removal; Snowplows; Steel castings; Traffic lanes
• Old TRIS Terms: Delineators (Traffic); Epoxy; Lane separator; Traffic marking
• Subject Areas: Geotechnology; Highways; Maintenance and Preservation; Materials; Vehicles and Equipment;

Filing Info

• Accession Number: 00216801
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 21 1994 12:00AM