Limitations to the application of the white light trade-off in street lighting

The designed illuminance for lighting in subsidiary streets in the UK is specified in BS EN 13201-2:2003 and BS5489-1:2003. These describe six lighting classes, the S-series, and how to choose the appropriate class according to traffic flow and crime rate. The second standard permits a reduction of illuminance of one S class when using lamps with a colour rendering index (CRI) of Ra greater than or equal to 60. Research on the validity of the single class reduction in light levels for residential streets when white light is used is reviewed. The research considered brightness and visual performance. A life-cycle cost analysis was also conducted to compare the installation and energy costs of high-pressure sodium (HPS) and metal halide (MH) lighting. It was concluded that the white lighting would appear equal in brightness to HPS lighting if the judgement of brightness is made immediately after exposure to the lighting, that there is a reduction in achromatic visual acuity and contrast detection threshold under MH lighting, and that MH lighting could yield savings in installation costs and energy consumption. (A)


  • English

Media Info

  • Pagination: 24-29
  • Serial:
    • Volume: 71
    • Issue Number: 6
    • ISSN: 0950-4559

Subject/Index Terms

Filing Info

  • Accession Number: 01043400
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Mar 6 2007 9:04AM