O4.10.8 When selecting the height of the flat traffic delineator to be used, refer to Table A1.3 (Appendix 1).
O4.10.9 Rotating reflector delineators are mechanisms which enable one or more amber reflectors, complying with diagram 560 or 561, to be shown intermittently during the dynamic mode and constantly in the static mode. They do not constitute warning lights to BS EN 12352:2006. When used, they must always be mounted on top of traffic cones to diagram 7101.1.
O4.10.10 Rotating reflector delineators shall not be used in lead-in tapers. Elsewhere, if rotating reflector delineators are used, they may be mounted on the top of existing traffic cones provided they do not mask any of the retroreflective material, obscure the cone or affect its stability. Where they are used on cones on the nearside of traffic, the spacing of the warning lights may be increased by up to 100% with rotating reflectors at the midpoint between consecutive warning lights. In other situations, the spacing of the warning lights may be increased by up to 50% with rotating reflectors placed at the third points or midpoint between consecutive warning lights.
O4.10.11 Timber baulks, and other similar non-approved proprietary systems, shall not be used as a means of delineation of works areas on high-speed roads because their ability to control a fast-moving vehicle on impact is totally unpredictable. Subject to local Highway Authority approval, their use on roads with a permanent speed limit of 30 mph with street lighting is likely to be acceptable provided that:
- they are securely fastened together and that each one is securely fastened to the ground; and
- they are painted in alternate red and white bands, each approximately 600 mm wide.
O4.11USE OF BARRIERS
O4.11.1 Obstructions and excavations should be adequately guarded at all times for the protection of all persons who use the highway. There are four basic types of barrier:
- pedestrian barriers;
- traffic barriers for guiding vehicles and indicating that a traffic lane or part of a traffic lane is closed;
- lightweight barriers for delineating the inner edge of safety zones; and
- vehicle safety restraint barriers.
O4.11.2 Barriers, other than vehicle restraint barriers, adjacent to running traffic lanes should be guarded by a line of traffic cones, augmented by warning lights at night.
O4.11.3 Barriers should be stable under adverse weather conditions and be or appear to be substantial depending on the usage. They should not, however, cause excessive damage to a vehicle should they be struck. Mounds of soil are not acceptable as a barrier. Care should be taken to ensure that horizontal barriers do not project towards oncoming traffic. Wooden or tubular steel poles shall not be used as horizontal barriers as they constitute a serious hazard should a vehicle collide with them.
O4.11.4 In order to avoid a haphazard appearance, different kinds of barriers should not be mixed.
O4.11.5 Barriers should be marked so that they stand out conspicuously in contrast to the works behind them and are visible by day and night. See also Section O4.7 and paragraphs O4.11.12 and O4.11.13.
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