LOW-PRESSURE SODIUM LAMPS LIGHT THE "CARRIAGEWAYS" OF JOHANNESBURG

Low-pressure sodium lamps are being used in Johannesburg, South Africa, to provide an efficient, economical way of lighting highways. Luminaires atop the lighting poles are mounted axially, or parallel to, the roadway, and the top portion of each lighting pole can be tilted so that the double arm poles follow the contour of the roadway. These design features results in a uniform road surface luminance combined with a flowing line of light which clearly shows the run of the road. Discomforting glare is minimized and roadway obstructions are easily visible. In addition, the design is aesthetically pleasing in daytime. A beam angle of 50 to 55 degrees is required to give the correct distribution of light with axial mounting. Color- corrected mercury lamps are used for the off-lamps. This dual scheme, resulting in dual colors, makes an oncoming off-ramp easily visible.

• Corporate Authors:

  Illuminating Engineering Society

  120 Wall Street, 17th Floor
  New York, NY  United States  10005-4001
• Publication Date: 1975-9

Media Info

• Pagination: p. 46
• Serial:
  • Lighting Design and Application
  • Volume: 5
  • Issue Number: 9
  • Publisher: Illuminating Engineering Society

Subject/Index Terms

• TRT Terms: Aesthetics; Design; Economic efficiency; Glare; Mercury vapor lamps; Off ramps; Pressure; Sodium vapor lamps; Street lighting; Visibility
• Uncontrolled Terms: Efficiency
• Old TRIS Terms: Low pressure; Mercury lamps; Sodium lamps
• Subject Areas: Design; Economics; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00127046
• Record Type: Publication
• Files: TRIS
• Created Date: Nov 18 1975 12:00AM