Page:UK Traffic Signs Manual Chapter 1 (1982 amended to 2004).pdf/18



1.57 It is desirable to limit the number of posts in footways, especially in urban areas, because proliferation creates additional hazards for visually handicapped pedestrians and unnecessary obstructions for people with perambulators and wheelchairs. Where possible signs should be attached to adjacent walls, so that they are not more than 2 metres from the edge of the carriageway, or be grouped on posts in accordance with paragraphs 1.62–1.68. Certain signs with small letters, e.g. plates for waiting restrictions, must always be mounted close to the edge of the carriageway. When posts must be erected in narrow footways they should be positioned to cause the least possible obstruction and should not reduce the clear walkway width to less than 1.0 metre.

1.58 Sign posts should be designed to accommodate the total area of signs to be attached to them. The attachment of larger or additional signs, to existing posts, should only be done after checking the adequacy of the strength of the posts, taking account of any reduction in strength due to corrosion. When existing posts are inadequate for the total loading they should be replaced rather than use additional posts for new signs. Lighting columns are normally not designed to accommodate the wind loading from signs attached to them. Signs should therefore never be attached to lighting columns unless:

(a) The columns, with signs attached, have been specifically designed to BS 5649 and the relevant Departmental Standard.

or (b) The adequacy of the columns with signs attached have been checked in accordance with BS 5649 and the relevant Departmental Standard. For existing lighting columns the design check should take account of the structural condition of the column. Attachment of signs to lighting columns should be by external circumferential clamps which will not damage the column or its protective coating.

1.59 Purpose-made metal posts should preferably be tubular and of uniform diameter along their length; they should not project above the sign or lighting unit. Where possible the mounting should allow an angular movement for the adjustment of the sign before locking in its final position. Where enlargement of a post is needed to house control equipment it should be provided at the base of the post.

1.60 The very large signs used on high speed roads will require specially designed concrete or steel posts and the signs themselves will have to be strongly braced or framed. The mounting of the lighting units will also need special attention.

1.61 Posts for signs may be of any single colour; posts for Zebra pedestrian crossing beacons, hazard markers, and load gauges are black and white, whilst those for portable traffic signals must be yellow, (see Appendix I). Concrete supports retain their natural colour. The backs of signs and bracing must be grey or black as should the fixing clips where these are painted.

1.62 Generally, not more than two signs should be erected on any one post. Where a sign requires a supplementary plate, the combination of sign and plate may be regarded as one sign. Exceptionally, three signs may be mounted on one post provided none requires a supplementary plate.

1.63 A warning sign or signs should not be mounted on the same post as a Stop or Give Way or terminal speed limit sign. Sign combinations which may be mounted together should be placed in the following order from top to bottom:

(a) Stop or Give Way or any triangular warning sign or signs.

(b) Speed limit signs.

(c) Other circular signs.

(d) Rectangular signs.

1.64 Generally, no assembly should exceed 4 metres in overall height above ground level, but this may be exceeded to obtain visibility of the signs at particularly difficult sites.

1.65 All proposed assemblies should be critically examined to ensure that the intended messages are clear and that there is no ambiguity, particularly where a supplementary plate with the legend 'End' is used to indicate the termination of a prohibition or restriction.

1.66 Where a speed limit sign is erected on the same post as a clearway sign accompanied by an End plate, the plate should be butted directly up to the base of the clearway sign. The speed limit sign should be mounted at the top of the assembly with space equal to twice the width of the red border between the roundels to ensure that there is no ambiguity.

1.67 Where rectangular signs are mounted together or a supplementary plate is mounted below a triangular sign, the signs should be separated by a space not exceeding the x-height of the lettering on the lower sign. In all other cases signs may be butted together one above the other.

1.68 Where two or more warning signs are to be erected together the sign relating to the hazard first encountered should be placed upper-most.