D3.11.2 Unless traffic is to be confined to a single lane delineated by cones on each side, it is important that existing road markings, reflecting road studs and raised rib lines are appropriately masked or removed when they might give misleading information to drivers or be hazardous in themselves.
D3.11.3 Drivers shall be given a clear indication of the path they should take. Temporary delineation in the form of traffic cones, cylinders and barriers etc. should be used for this purpose, augmented where practicable by temporary carriageway markings or temporary reflecting road studs to indicate the edge of the route to be followed.
D3.11.4 The performance of road studs is specified in European Standard BS EN 1463 Parts 1 and 2. The Traffic Signs General Directions 2002 (direction 57) specify which performance classes in the European Standard must be met. It is unlawful to use a stud that is not certified to at least these minimum classes.
D3.11.5 Temporary studs are not recommended for use for periods much longer than three months and they must not be utilised for more than one application.
D3.11.6 The following factors in particular should be considered by the designer when designing a temporary traffic management system which incorporates temporary road markings:
- time of year the work will be executed and thus the likely weather and climatic conditions throughout the duration of the works;
- the nature of the existing and proposed road surface – locations of road surfaces which may require special treatment both for the application of temporary markings and the removal of existing ones should be identified; and
- suitable methods for removal or covering of existing road markings – some methods can be time consuming and the possibility of an advance works phase prior to contract commencement may need to be considered.
D3.11.7 At sites with temporary layouts consideration should be given to the use of temporary road studs in place of road markings, where road studs are an alternative option, (e.g. Detail J, see Table A1.5 (Appendix 1)), to facilitate the installation of the layout in poor weather.
D3.11.8 The edge of a carriageway without raised kerbs should be indicated by a 100 mm-wide continuous reflectorised white line to diagram 1012.1 with its near side edge placed approximately 200 mm from the actual edge of the carriageway. Where flush kerbs are provided, the edge line should be superimposed on the kerb.
D3.12WARNING LIGHTS (ROAD DANGER LAMPS)
D3.12.1 Warning lights must conform to the National Annex to BS EN 12352:2006. In addition, the external surface of the light body visible to road users shall be coloured lemon, colour reference no. 335, or golden yellow, colour reference no. 356 of BS 381C2:1996. The lights should be placed at regular intervals along the line of an obstruction. The spacing of warning lights on tapers is specified in Table A1.3 (Appendix 1), also refer to Part 2: Operations, Section O4.7. High intensity warning lights (beacons) are defined as warning light types WL5 and WL6 in the National Annex to BS EN 12352:2006.
D3.12.2 Consideration shall be given to the use of backlit sequentially flashing warning lights to highlight taper coning in both daylight and darkness. Research has shown that use of these lights can help drivers to identify and make the necessary change of lane much earlier than with conventional lights, thereby reducing the risk of taper strikes. The use of these lights shall be restricted to lead-in and intermediate stepped tapers involving a lane drop and shall not be used when a lane or lanes are narrowed, at a changeover, or a crossover. Where these lights are in use, high intensity flashing lights shall not be used on barriers to diagram 7105
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