The Road Traffic Regulation Act 1984 (RTRA) defies a traffic sign as: “any object or device (whether field or portable) for conveying to traffic on roads or any specified class of traffic, warnings, information, requirements, restrictions or prohibitions of any description…”. Lawful traffic signs must either be prescribed by regulations or authorised by the Secretary of State. The Traffic Signs Regulations and General Directions 2002 (TSRGD) define a variable message sign as: “a device capable of displaying, at different times, two or more aspects…”. These aspects may take the form of a sign prescribed by TSRGD, a legend in accordance with Schedule 15 to TSRGD, a non-prescribed temporary sign or a blank grey or blank black face. Thus, the expression “variable message sign” (VMS) encompasses all types of variable sign from simple flip-type field signs to complex light-emitting panels. This leaflet provides guidance to inform the use of light-emitting VMS capable of displaying text and/or pictograms. It does not apply to matrix signs as prescribed by regulation 46 of TSRGD and contained in Part I of Schedule 11 to the Regulations. On all-purpose roads, VMS will generally be located in the nearside verge. On motorways and wide all-purpose roads (especially those with a hard shoulder) mounting on gantries may be necessary to prevent obscuration by large vehicles in the nearside lane(s). The requirements in respect of siting, lateral clearance, etc. are the same as those set out in Chapter 1 of the Traffic Signs Manual3 for field signs. On roads where the 85th percentile approach speed of private cars, as determined in accordance with TA 22/81 4, is greater than 40 mph, it is recommended that two VMS displaying the same legend are provided where possible. This is especially important if the information to be displayed is likely to conflict with that on field directional signs, for example a VMS message indicating a mandatory or advised diversion. (Author/publisher)
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