This article explains why variable message signs (VMS) provide a critically important interface between Intelligent Transport Systems (ITS) and drivers. If a VMS has poor performance, is illegible, or is badly installed, it will damage the credibility of the ITS to which it belongs. In the system design and selection process, VMS require equal consideration as detection, data acquisition, monitoring, control, and communication systems. For the foreseeable future, collective driver information systems using VMS will be the primary method by which an ITS disseminates its information to drivers. The EU has done much to enhance the credibility of VMS messages in its DRIVE research programme. In the UK, the Highways Agency (HA), Scottish Executive, and Welsh Assembly have all been progressive in applying VMS. The US Department of Transportation (DOT) has formulated four criteria for applying VMS successfully: can the observer see the sign in its environment, read its message, understand its message, and rely on its message. Work on a European (CEN/EN) draft standard for VMS has progressed well. The article discusses fibre optic technology in VMS and lists its advantages and disadvantages, and a new range of light-emitting diodes (LEDs).


  • English

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Filing Info

  • Accession Number: 00790476
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Apr 11 2000 12:00AM