Traffic Signs Manual Chapter 4 Warning Signs
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| 1.9 Siting
1.9.1. In general, the greater the speed of approach, the further in advance of the hazard the sign needs to be placed. This is to ensure that drivers have the necessary time to respond to the warning. Appendix A sets out recommendations for the distance from the hazard at which a sign should be sited. If it is impracticable to place a sign within about 10% of the recommended distance, it should be sited further upstream of the hazard at the nearest practicable point. It may be appropriate to supplement it with a distance plate (see section 17 ). A sign should not normally be sited more than 10% closer than the recommended distance, as this would be unlikely to provide sufficient warning. Where this is unavoidable, a distance plate should always be used, indicating the distance to the hazard to the nearest 10 yards. INTRODUCTION 10 1.9.2. Warning signs should normally be placed on the left hand side of the road, unless stated otherwise in the text (e.g. hazard markers to diagram 560, S2‑6‑2). However, site conditions sometimes make this impracticable. A warning sign might be placed on the right hand side on a left hand bend if it would otherwise be hidden from view, or if there would be no room for it on the left. If a sign is placed on the right hand side of the road, care must be taken to ensure that a driver would not be misled at night or in fog as to which side to pass. It might sometimes be appropriate to duplicate warning signs by providing them on each side of the road, as is recommended at the end of a dual carriageway, or on the approach to a roundabout on a high‑ speed road. 1.9.3. It is essential that drivers have an unobstructed view of traffic signs. The distance which should be kept clear of obstructions to the sight line, whether caused by foliage, other signs or street furniture, is known as the clear visibility distance. The higher the prevailing traffic speeds, the greater this distance needs to be. It is important therefore that sight lines are properly maintained so that the intended warning is not compromised. Care in siting can minimise future problems of obscuration. Sight lines should not cross private land as it will be difficult to control the growth of vegetation or the placement of other obstructions. It is equally important that warning signs should not be placed where they will obstruct the view of other signs e.g. advance direction signs. Such problems might be avoided by siting the sign further from the hazard, or on the right hand side of the road. tải về 2.25 Mb. Chia sẻ với bạn bè của bạn:
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