Page:UK Traffic Signs Manual - Chapter 4 - Warning Signs. 2013.pdf/13

JUNCTIONS crossroads Signs are required at junctions controlled by traffic signals only in the circumstances described in para 8.3. Exceptionally, warning signs may be provided in addition to advance direction signs where visibility is so poor that drivers are unable to obtain an adequate advance view of the junction or the directional signs associated with it.

Junction warning signs are not normally provided on very minor rural roads, nor in urban areas where it would be impracticable to sign every junction. They may of course be used where a specific need has been identified.

A sign to diagram 508.1 or 509.1 is used to give warning where two physically separated streams of traffic proceeding in the same direction join the same carriageway. These signs may be used only in situations where the traffic stream joining from a These signs may be used only in conjunction with diagram 7070 and may be used with diagram 572 slip road crosses a road marking to diagram 1010 (direction 17) and is required to concede priority to any through traffic. They are not intended for use at lane gain junctions where one or more traffic lanes are added to the main carriageway. Diagrams 868, 868.1 and 873 to 876 may be used in these circumstances.

The sign to diagram 508.1 is used to warn that there is traffic joining on the left hand side and should be sited on the left of the main carriageway. The sign to diagram 509.1 is used to warn drivers that they are about to join a main carriageway and may have to concede priority. Neither sign is reversible. The designs prescribed in the 1964, 1975 and 1981 Regulations (diagrams 508 and 509) where both arms of the symbol have equal weight, were required by the 1994 Regulations to be removed by 31 December 1998 and are now therefore unlawful.

Traffic merge warning signs should normally be used only in the following circumstances:

(i) where there is no other advance signing on a main carriageway indicating a junction ahead, e.g. where there is an access slip road, but no exit slip road preceding it to alert drivers to the likelihood of joining traffic, or

(ii) where there is a series of closely-spaced junctions which are a mixture of lane gain and lane merge (but see para 2.11), or

(iii) where it is not apparent to drivers that they are on a slip road (e.g. a former main road through a village joining a by-pass, or the main carriageway of a motorway joining another motorway).

Rectangular merge signs based on the lane gain signs referred to in para 2.8 are available on special authorisation (see para 1.5). These may be more appropriate in the circumstance described in para 2.10(ii). Further guidance on the use of these signs will be given in Chapter 2.

A plate to diagram 572 should be used when the distance between the sign and the merge point is different from that recommended in Appendix A (but see para 1.20).

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