O4.6LIGHTING OF SIGNS
O4.6.1 The visibility of signs during the hours of darkness is extremely important and the reflectivity should be at least equal to that of permanent signs. All parts of the sign face, except those parts coloured black, must be reflectorised.
O4.6.2 Most traffic signs used at road works must be reflectorised and/or directly illuminated as required by the Regulations (Schedule 17). The exceptions are signs to diagrams 7007.1, 7008, 7016, 7017, 7018, 7018.1 and 7404.
O4.6.3 All signs that are required to be reflectorised and used at works on motorways and dual carriageway roads shall be reflectorised by the application of Class RA2 retroreflective material as detailed in BS EN 12899-1:2007 "Fixed, vertical road traffic signs". Note that this is the same as Class 1 in BS873-6: 1983 which has been superseded by BS EN 12899-1:2007. Alternatively, a suitable microprismatic sheeting may be used. Signs for use in connection with works on other roads, where these are unlit, may be Class RA1 or Class RA2 material as detailed in BS EN 12899-1:2007. On lit roads, signs to Class RA2 or a suitable microprismatic material should always be used where the Regulations do not require them to be directly illuminated (see paragraph O4.6.5).
O4.6.4 Note that Class RA1 and Class RA2 refer to the photometric properties of the sign. The weathering resistance requirement for temporary signs is specified in BS 8442, which provides two classes, T2 which requires three years natural weathering as in BS EN 12899-1, and T1 which requires only two years.
O4.6.5 All road works signs used on a lit road which are required to be lit must be illuminated directly either when the street lighting is illuminated, or throughout the hours of darkness, unless the road is subject to a permanent speed limit of 40 mph or less; see regulation 18 and Schedule 17 to the Regulations. On roads with a speed limit over 40 mph it will not be sufficient to rely on street lighting for the illumination of signs. Whenever temporary road lighting is installed on such roads, signs must be directly lit in accordance with the Regulations.
O4.6.6 Special attention should be given to the orientation of the lighting units to ensure that drivers are not dazzled.
O4.6.7 Where lighting is required, the standard of illumination required for temporary traffic management signing shall be a minimum mean illuminance on the sign of 100 lux.
O4.6.8 All lamps should be kept clean and in good working order.
O4.6.9 Illumination of signs shall only be by lamps that are electrically powered.
O4.7WARNING LIGHTS (ROAD DANGER LAMPS)
O4.7.1 The outer boundary of the works site, temporary fences, barriers etc. should always be marked by the addition of warning lights during the hours of darkness; refer to Part 1: Design, Section D3.12. The full width and length of the obstruction shall be clearly indicated by lights. It is important that the lights are placed correctly on top of the cones with the lens facing the oncoming traffic. On a dual carriageway, if distraction of drivers on the other carriageway is likely to be a problem then uni-directional warning lights, and not bidirectional or omni-directional, should be used.
O4.7.2 The spacing of lights on longitudinal coning and cone tapers is given in Table A1.3 (Appendix 1).
O4.7.3 Where barriers are used to delineate the works area, a warning light showing a steady light shall be placed at each corner of the obstruction and at 3 m intervals along each side which is accessible to pedestrians.
52
