herbage. If this risk cannot be avoided by siting, the growth must be regularly cut and we refer to this in paragraph 289. Where the target value of a sign is impaired by the background against which it is viewed, it should be provided with a surround which effectively draws attention to it.
272. Reflectorised signs should be so mounted in relation to the carriageway that they can be seen easily in dipped headlights. For, with the increasing volume of vehicles on our roads it will become more and more necessary for drivers to travel with their headlights dipped after dark so as not to endanger oncoming traffic. This also makes it more important for signs at junctions on unlit roads to have independent illumination. We have recommended this at major junctions on Primary routes but it may also be desirable at major junctions elsewhere.
273. All signs which are placed so as to face along, rather than across the carriageway should be turned 5° away from oncoming traffic on straight roads, with suitable adjustments on left hand bends. This will prevent the legends on signs being made less legible by specular reflection from headlights. In the case of advance direction signs this is particularly important. We have recommended elsewhere that waiting restriction signs should be set at right angles to the carriageway so as to be more visible to traffic approaching from either direction. They should be mounted on top of their posts, but any supplementary plates should be set parallel to the carriageway and thus at right angles to the signs.
274. No entry signs (figure 15) should be aligned so as to face drivers who might attempt to enter the street to which the signs refer.
275. As far as possible smaller signs, particularly waiting restriction signs, should be fixed to existing posts or walls, in order to avoid adding to obstacles on the pavement. But care should be taken to see that the background is such as to make the signs conspicuous. We do not think that wall-mounting is satisfactory where the footpath is more than 6 feet wide. Where posts need to be provided for smaller signs they should continue to be round so that the positioning of the signs is easily adjustable after the posts are in position. Posts should if possible have the same diameter throughout their visible length, but if enlargement is necessary to contain equipment it should be at the base. The supporting post should not show above the sign. Where possible signs should be mounted together rather than on separate posts.
276. Where a sign has a plate below it there should be a sufficient distance. between the sign and the plate to ensure that the outline of the sign is not impaired (see Appendix VIII).
277. In densely trafficked urban areas where roadside signs and markings on the carriageway are liable to be hidden from the view of drivers by other vehicles, it may be necessary for direction signs to be mounted overhead. This
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