Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/85

SIGNING PRINCIPLES signs can only be moved closer to the works. On signs where the numerals indicating distance may be varied, the equivalent imperial dimension shall be displayed in accordance with the appropriate item in Schedule 16 of TSRGD 2002.

The x-heights of letters displayed on signs must be within the ranges prescribed by the Regulations, and be appropriate to the speed of traffic and the quantity of information on the sign. In general, longer messages take longer to read and require larger x-heights. However, advice on recommended x-heights can be found in Table A1.2 (Appendix 1).

Guidance on advance warning signs is as follows:


 * on dual carriageway roads on which the national speed limit applies, advance warning signs should be provided at 2 miles and 1 mile. Further signs should be added at 3 miles (or more, as necessary, in 1 mile increments) if queuing is anticipated;
 * on dual carriageway roads with a permanent speed limit of 60mph, advance warning should be given at 1 mile and also at 2 miles if queuing is expected or, if the speed limit is 50mph, at 800m and also at 1 mile if queuing is expected,
 * on single carriageway roads on which the national speed limit applies, warning should be given at between 275 and 450 m,
 * the distance is less for roads with a permanent speed limit of 40mph or less — see Table A1.1 (A1|Appendix 1); and
 * in certain situations additional signs may be required further in advance of the works. At works for which relaxations apply fewer signs may be required.

Advance warning signs in accordance with paragraph D4.5.1 above are not required where the work is carried out off-carriageway and the conditions described in Section D3.20 are satisfied. The recommended signing when the conditions are not satisfied should be as for a road works situation as shown on plans in Sections D5 and D6.

The "lane closed ahead" sign to diagram 7202 should not be used if there is only a narrowing of the carriageway space and no reduction in the number of lanes available to traffic.

Drivers will be confused and hazards may be created if the information on existing signs or road markings cease to be applicable because of road works. This problem may be overcome by altering, covering or replacing signs or road markings to suit the circumstances, with the approval of the Highway Authority. It is essential to ensure that at all times the signing represents the prevailing conditions accurately. Any covers used must be durable, opaque and secured. Spraying with masking material should be done neatly. Small signs should be completely obliterated or removed. Temporary signs must not be allowed to obscure existing permanent signs which still apply.

Where a pedestrian or cycle crossing will become unusable or where the studs and marking are to be substantially removed or obliterated the crossing must be taken out of service. Any beacons must be covered, preferably with an opaque black or white bag. For signalised crossings, the signals must be switched off and a traffic sign to diagram 7019 "Light signals not in use" must be displayed. Barriers should be placed 84