RAISED REFLECTIVE MARKERS FOR HIGHWAY LANE LINES

CALIFORNIA USES A BROKEN /9 FOOT PAINTED 15 FOOT UNPAINTED WHITE STRIPE TO DELINEATE TRAFFIC LINES. THE PAINTED PORTION IS BEADED FOR NIGHT VISIBILITY. DURING PERIODS OF INCLEMENT WEATHER AT NIGHT WATER TENDS TO ACCUMULATE ON THE PAVEMENT TO A DEPTH SUFFICIENT TO COVER AND OBSCURE THE BEADED PAINTED CENTERLINE TRAFFIC STRIPE. IN ORDER TO SELECT A MARKER WHICH IS VISIBLE IN BOTH CLEAR AND RAINY WEATHER DAY AND NIGHT, CALIFORNIA HAS RECENTLY USED A PARTIALLY BEADED MARKER. EXPERIMENTAL INSTALLATIONS OF A RAISED MARKER THAT IS WEDGE SHAPED AND REFLECTIVE AS THE REFLEX REFLECTORS USED ON GUIDE POSTS WERE STUDIED. THE FOLLOWING FACTS CONCERNING THE SUITABILITY OF WHITE PLASTIC MARKERS UNDER VARIOUS CONDITIONS WERE DETERMINED' /1/ THE FULLY REFLECTO- RIZED MARKERS /BEADED/ ARE INEFFECTIVE FOR DAYLIGHT DELINEATION IN CLEAR AND RAINY WEATHER, PARTICULARLY ON PORTLAND CEMENT CONCRETE, /2/ THE FULLY BEADED BUTTON MARKER IS MORE EFFECTIVE IN RAINY WEATHER AT NIGHT THAN IS THE WEDGE MARKER, /3/ ON ASPHALTIC CONCRETE PAVEMENTS, THE WEDGE MARKER IS MORE DURABLE THAN THE BUTTON TYPE, /4/ THE GLASS BEADS USED IN THE REFLECTIVE BUTTON OR WEDGE MARKERS SHOULD CONTAIN THE HIGH INDEX OF REFRACTION VARIETY /1.90 MINIMUM/ AND /5/ UNDER OVERHEAD LIGHTING OR IN THE DAYTIME THE NON- BEADED MARKERS ARE MORE EFFECTIVE THAN THE BEADED TYPE IN BOTH CLEAR AND RAINY WEATHER.

Media Info

  • Media Type: Print
  • Features: Figures; Tables;
  • Pagination: pp 1-7
  • Monograph Title: Traffic control: Devices and Delineation
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00224775
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 29 1994 12:00AM