Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/169

DUAL CARRIAGEWAY ROADS Where controlled or managed motorway signal systems are used to provide advance signing and lane control in preference to static signs, physical protection of workers must be provided by mobile lane or carriageway closure techniques. See paragraphs D6.13.2 to D6.13.6 for the use of gantry signing.

The following sections cover the principles and plans which guide the design of temporary traffic management arrangements. The design is divided into five zones, these are as follows:
 * The approach zone starts at the first sign and continues to 100m upstream of the first sign requiring a lane-change decision.
 * The lane-change zone starts 100m upstream of the first sign requiring a lane-change decision, and continues to the point at which all lane changes should have been completed.
 * The lead-in zone starts at the point at which all lane changes, if required, should have been completed and continues to the beginning of the longitudinal safety zone.
 * The works zone starts at the beginning of the longitudinal safety zone and continues to the end of the works area.
 * The end-of-works zone starts at the end of the works area and continues to the last sign.

The zones are illustrated in Figure 6.1.

Unless otherwise stated, the speed limits referred to in headings indicating road type are the permanent mandatory speed limit that would apply to the carriageway without road works.

A key to the areas shown in the plans in the following sections is provided in Table A1.4 (Appendix 1). Table A1.5 (Appendix 1) explains the meaning of Details A to K in the plans and includes details of cone and cylinder height and spacing where this varies according to the type of dual carriageway road or works type. Details of cone spacing are also specified in Table A1.3 (Appendix 1). 168