However, raised rib and other lane markings may be left in situ where they match with the temporary lane markings. There should be no need to remove or cover the lane markings at a changeover position when only one lane is being switched.
O4.3SIGN CONDITION
O4.3.1 All temporary traffic management equipment shall be clean and fit for its intended purpose on initial deployment and shall be regularly maintained in such condition until completion of the work (refer to Section O3.7). Temporary traffic signs/cones should be cleaned by personnel in a place of safety. See Section O3.2 for safety clearance requirements.
O4.3.2 Guidance on assessing the condition and acceptability of temporary traffic management equipment can be found in Appendix A4.3.
O4.3.3 When temporary sign face patches are fixed to permanent signing e.g. for temporary diversions, they shall be capable of being removed completely without damage to the sign face. Temporary patches shall be removed at the end of the works.
O4.3.4 It is inadequate and unacceptable to spray masking paint over the numerals on speed limit signs; if this method is used, the entire sign face including the red border must be completely obscured in order to prevent the numerals being visible in daylight or in silhouette against the retroreflective background at night.
O4.4STABILITY OF SIGNS
O4.4.1 Suitable and sufficient measures should be taken to ensure that traffic signs, cones, cylinders etc. are sufficiently robust to prevent them from being displaced during any windy conditions likely to be encountered on site or by buffeting from passing vehicles. BS 8442 "Miscellaneous road traffic signs and devices – Requirements and test methods" offers three classes of resistance to wind loads. Any system used to mount signs or to fix signs to safety fences must be capable of resisting the specified wind load. For details of the requirements for traffic cones and traffic cylinders see Part 1: Design, Section D4.9.
O4.4.2 Ballast used to stabilise traffic signs shall be in the form of fine, granular material contained in a sack so that, should the sack be hit, it would split and the contents be dispersed without causing further problems.
O4.4.3 Kerbstones, timber baulks, heavy weights, straw bales or other traffic management equipment shall not be used as ballast. Road pins shall not be used.
O4.4.4 Ballast should always be placed below car windscreen height to prevent serious injury in the event of a collision.
O4.5MOUNTING AND SITING OF SIGNS
O4.5.1 The signs must not be obscured in any way. The signs may be mounted on portable frames; see BS 8442 "Miscellaneous road traffic signs and devices – Requirements and test methods". Note however that, regardless of the size of the sign, the lower edge of the sign should be no less than 300 mm from ground level. For the minimum clearance of temporary signs to carriageways in use on motorways and dual carriageways, and for the positioning of signs using microprismatic material, see O3.2.17.
50
