A LUMINANCE APPROACH TO HIGHWAY SIGN LIGHTING

OUTDOOR LIGHTING PRACTICE ALMOST INVARIABLY IS BASED UPON THE FOOTCANDLE, IN TERMS OF LEVEL AND UNIFORMITY. THAT VISION IS ACHIEVED THROUGH LUMINANCE AND LUMINANCE CONTRAST NORMALLY IS NOT TAKEN INTO ACCOUNT BECAUSE OF THE DIFFICULTIES ASSOCIATED WITH LUMINANCE DESIGN. THE AVERAGE LEVEL OF LUMINANCE IS CONSIDERED IN RELATION TO AMBIENT LIGHT LEVELS, AND THE EFFECTS OF NONUNIFORMITY ARE DISCUSSED IN THIS PAPER. THE DESCRIPTION OF A TECHNIQUE FOR ANALYZING THE REFLECTIVE CHARACTERISTICS OF SIGN-FACE MATERIALS IS DESCRIBED, AND THE APPLICATION OF SUCH DATA IS CONSIDERED. THE RESULTS SHOW THE VARIATION OF THE REFLECTANCE OF A TYPICAL RETROREFLECTIVE MATERIAL FROM THE BOTTOM TO THE TOP OF A SIGN. CONSIDERABLE VARIATION IS INDICATED, WHICH CAN PRODUCE POOR LUMINANCE UNIFORMITY, ALTHOUGH THE INCIDENT FOOTCANDLES MAY HAVE ADEQUATE UNIFORMITY. A PRINCIPLE OF LUMINAIRE DESIGN BASED UPON THE REFLECTANCE CHARACTERISTICS OF THE MATERIAL TO BE LIGHTED IS PRESENTED. /ARTICLE/

• Authors:
  • Lewin, I
• Publication Date: 1973-6

Media Info

• Pagination: p. 23
• Serial:
  • Lighting Design and Application
  • Volume: 3
  • Issue Number: 6
  • Publisher: Illuminating Engineering Society

Subject/Index Terms

• TRT Terms: Brightness; Design; Luminaires; Reflective signs; Reflectivity; Standardization; Traffic signs; Visibility
• Subject Areas: Design; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00222234
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 8 1973 12:00AM