During the next three years, the Highways Agency (HA) is planning to install gantries with variable message signs (VMS) on the busiest UK motorways, to improve their safety and traffic flow. This article examines how VMS technology for these and other signs has evolved, and explains how light-emitting diodes (LEDs) are overtaking the more traditional optical fibre technology. VMS using optical fibres can accurately represent all symbols and characters, and are widely used on the European Continent. The optical fibre system also produces the brightest and most directional light, and has no colour restrictions. It is the only proven system which yet produces the correct rendering of red, green, and white light to meet the HA light standard, but it is also costly to make. For text-only signs, LEDs have generally found favour, and LED technology for illuminating VMS has been developed by several electronic component manufacturers. The LEDs are normally arranged in pixels, each of which can be lit by a chosen combination of red, green, and blue light. Most text messages are lit by amber light, to which the human eye is most sensitive. The HA's telematics group has investigated four different types of VMS, including those using LEDs. The HA recently placed a large order for gantry VMS all using LEDs.

  • Availability:
  • Corporate Authors:

    Hemming Group, Limited

    32 Vauxhall Bridge Road
    London,   United Kingdom  SW1V 2SS
  • Authors:
    • Bennett, D
  • Publication Date: 1999-4-15


  • English

Media Info

  • Pagination: p. 16-8
  • Serial:
    • Volume: 186
    • Issue Number: 5528
    • Publisher: Hemming Group, Limited
    • ISSN: 0039-6303

Subject/Index Terms

Filing Info

  • Accession Number: 00769881
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Oct 7 1999 12:00AM