required, need to be procured from the Highways Agency in England, the Welsh Assembly Government in Wales, the Department for Regional Development in Northern Ireland and the Transport Scotland in Scotland.
D4.2.5 A number of road works signs, although prescribed by the Regulations, require temporary traffic orders. These can be identified by the inclusion of direction 7 under item 2 in the table accompanying each diagram in the Schedules to the Regulations. The traffic authority should be consulted in good time if such signs are required.
D4.2.6 Vehicle width limits should be specified in imperial units (e.g. 6’-6"). Although it is not a mandatory requirement, the use of a dual-unit sign to diagram 629A is strongly recommended. If the dual-unit sign is incorporated into a road works sign (see diagram 7283.1) note that its diameter is increased from 750 to 900mm in order to maintain legibility. Smaller sizes are not prescribed. Similar rules apply to height limits, if the dual-unit sign to diagram 7284.1 is used, the diameter must be 900mm.
D4.2.7 The number of temporary diversion signs may be extensive and the location of each sign will need to be specified. It is important to ensure that temporary signs are consistent with permanent signs. As in all signing design, the choice of location should take account of existing services and sight lines, and should accord with actual site conditions.
D4.2.8 The following diversion signs may be used on all roads other than motorways: signs to diagrams 2703, 2705 or 2706 should be located on the approach to a junction, whilst flag signs to diagrams 2704 or 2707 should be located at the junction exit. Unless a roundabout is very large or complex, it is not necessary to provide signs to diagram 2704 or 2707 to guide traffic around the roundabout. However, it is necessary to provide left-pointing flag signs at exits from roundabouts.
D4.2.9 Driver information signs may be required by the traffic authority to explain to road users the reason for the works and for any delays. The Specification for Highway Works, clause 117.21, provides further advice on the siting and design of driver information signs. Variable message signs on the approaches to the site may be of particular use in informing drivers about exceptional delays, e.g. due to an accident.
D4.2.10 Access to and exit from the works area requires signing both for the purpose of directing works traffic, and to alert other road users of the likelihood of works vehicles making unexpected manoeuvres. Care needs to be taken to ensure that these signs do not obstruct sight lines and neither obstruct the view of, nor are obstructed by other signs.
D4.2.11 Working drawings which give details of the design of the signs shown in the plans and other prescribed signs are available for download free of charge on the Department for Transport website: www.dft.gov.uk.
D4.2.12 Unless otherwise stated, the speed limits referred to are the permanent mandatory speed limit that would apply to the carriageway without road works.
D4.3TEMPORARY TRAFFIC REGULATION ORDERS
D4.3.1 Temporary traffic regulation orders will be required to impose road and carriageway closures, traffic restrictions such as lane width and speed limits. For further information, see Section D3.39 and paragraph D4.2.5.
D4.4SIZE AND SITING OF SIGNS
D4.4.1 Signs should be placed where they will be clearly seen and cause minimum inconvenience to drivers, cyclists, pedestrians and other road users alike, and where there is minimum risk of their being hit or knocked over by traffic. Where there is a grass verge the signs should normally be placed there. If no verge is present,
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