Traffic Signs Manual Chapter 4 Warning Signs
Mounting more than one sign on a post
tải về 2.25 Mb. Chế độ xem pdf
|
| 1.11 Mounting more than one sign on a post
1.11.1. Research has shown that the greater the number of signs which drivers are presented with simultaneously, the greater the difficulty they are likely to have in assimilating the information. This problem in dealing with information overload increases with age, so that older drivers suffer disproportionately. Generally, therefore, not more than two signs should be mounted on one post. When a sign is accompanied by a supplementary plate, the combination of sign and plate should be regarded as one sign for this purpose. Exceptionally, three signs may be mounted on one post provided none requires a supplementary plate. INTRODUCTION 11 1.11.2. Warning signs should not be mounted on the same post as a STOP or GIVE WAY or terminal speed limit sign, nor mounted on a traffic signal post. When mounted with other types of sign, the triangular warning signs should always be mounted at the top. 1.11.3. Where two or more warning signs are erected together, the sign relating to the hazard first encountered should be placed uppermost. When a new sign is added to an existing post, a review of current signs should be carried out, and if all are still required it is important to ensure that the correct order is maintained, if necessary adjusting the position of the existing signs. 1.11.4. Generally no assembly should exceed a height of 4 m above ground level. All proposed assemblies should be critically examined to ensure that the intended warnings are clear. Account should always be taken of the potential environmental impact of tall and cluttered arrays of signs. 1.11.5. It should also be borne in mind that high‑mounted signs may receive little light from vehicle headlamps, particularly on dipped beam. Where such signs are not directly lit but rely on reflectorisation to be seen at night, they are likely to be less legible (see also tải về 2.25 Mb. Chia sẻ với bạn bè của bạn:
|