LED TECHNOLOGY IN MESSAGE SIGNS AND TRAFFIC SIGNALS

The conservation of energy, reduction of operating costs, and high reliability are leading factors influencing the decision by transportation authorities to install both LED changeable message signs and LED traffic signals in their jurisdictions. Two high brightness LED semiconductor technologies are being used, the 640 nm red TS AlGaAs for traffic signals and the 590 nm amber AlInGaP for changeable message signs. Transportation engineers are concerned with the reliability and optical performance of LED devices compared to existing technologies. This paper discusses the technical aspects of both LED technologies including LED reliability and degradation, LED intensity and color, and gives brief descriptions of LED message signs and traffic signals.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 48-52

Subject/Index Terms

Filing Info

  • Accession Number: 00716569
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 1 1996 12:00AM