EVALUATION OF FLOATING GLASS BEADS FOR TRAFFIC STRIPES

THE RESULTS ARE PRESENTED OF A 2-YEAR FIELD STUDY TO DETERMINE THE POSSIBILITY FOR IMPROVING THE PERFORMANCE OF NEW JERSEY TRAFFIC LINES BY REFLECTORIZING THESE MARKINGS WITH A NEW TYPE OF SMALL, ESSENTIALLY SINGLE-SIZE GLASS BEAD HAVING A UNIQUE FLOTATION PROPERTY. THE PERFORMANCE OF THE BEADS WAS DETERMINED IN TESTS OF BOTH TRANSVERSE LINES AND ACTUAL LANE LINES ON BOTH CONCRETE AND BITUMINOUS PAVEMENT. THE BEADS STUDIED WERE OF FOUR GENERAL TYPES: STANDARD WELL-GRADED BEADS, UNIFORM GRADED BEADS WITH AND WITHOUT A FLOATION FEATURE, AND A SPECIAL "RAIN" BEAD. THE "RAIN" BEADS WERE WELL-GRADED, HIGH REFRACTIVE INDEX, FLOATING BEADS WHICH WERE DESIGNED TO PROVIDE GOOD NIGHT VISIBILITY IN RAINY WEATHER. THE NEW JERSEY STANDARD WELL-GRADED BEADS WERE FOUND TO EXHIBIT THE POOREST OVERALL VISIBILITY PERFORMANCE OF ANY OF THE BEADS CONSIDERED. THE POOR INITIAL BRIGHTNESS WAS OBSERVED TO BE CAUSED BY BEAD EXPOSURE BEING LIMITED TO ONLY THE LARGER SIZE BEADS, A FRACTION OF THE TOTAL NUMBER OF BEADS PRESENT IN TRAFFIC LINES. LOW VISIBILITY IN THE LATER STAGES OF SERVICE WAS FOUND TO RESULT FROM RELATIVELY EARLY BEAD DISLODGMENT. THE HIGHEST LEVEL OF NIGHT VISIBILITY AND MOST CONSISTENT BRIGHTNESS ADVANTAGE WAS PROVIDED BY LINES REFLECTORIZED WITH UNIFORMLY GRADED, FLOATING BEADS. THE OPTIMUM RATES OF APPLICATION OF THE FLOATING BEADS WERE FOUND TO BE 4 POUND PER GALLON FOR BITUMINOUS PAVEMENTS AND 6 POUNDS PER GALLON FOR CONCRETE PAVEMENTS. MIXED VISIBILITY RESULTS WERE OBTAINED FOR THE UNIFORMLY GRADED BEADS WITHOUT THE FLOTATION PROPERTY. PAVEMENT TYPE AND TRAFFIC VOLUME APPEARED TO HAVE AN EFFECT ON THE SPECIFIC PERFORMANCE LEVEL ACHIEVED. THE VISIBILITY CHARACTERISTICS OF THE "RAIN" BEADS UNDER CLEAR WEATHER CONDITIONS DIFFERED WITH PAVEMENT TYPE. ON CONCRETE PAVEMENT, THE RAIN BEAD STRIPES AFFORDED THE SAME HIGH BRIGHTNESS LEVELS AS THE LINES REFLECTORIZED WITH UNIFORMLY GRADED, FLOATING BEADS. ON BITUMINOUS PAVEMENT THE RAIN BEADS PROVIDED EVEN POORER VISIBILITY THAN THE STANDARD BEADS. UNDER RAINY CONDITIONS, THE RAIN BEADS INITIALLY SHOWED A DEFINITE BRIGHTNESS ADVANTAGE OVER THE OTHER BEADS. HOWEVER, IN SUBSEQUENT EVALUATIONS NO ADVANTAGE WAS DETECTED. /FHWA/

• Corporate Authors:

  New Jersey Department of Transportation

  1035 Parkway Avenue
  Trenton, NJ  United States  08625

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Croteau, J R
• Publication Date: 1971-10

Media Info

• Pagination: 151 p.

Subject/Index Terms

• TRT Terms: Bituminous pavements; Brightness; Concrete pavements; Floating structures; Glass beads; Moisture content; Night visibility; Reflectorized materials
• Uncontrolled Terms: Wet conditions
• Subject Areas: Bridges and other structures; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00215969
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: Study No. 7730
• Files: TRIS, USDOT, STATEDOT
• Created Date: Feb 15 1972 12:00AM