A sign shown in diagram 7023 or 7024 may be placed on or near a road only where one-way working is necessary owing to a temporary closure to vehicular traffic of a part of the width of the carriageway of the road.

A sign shown in diagram 829.1, 829.2, 829.3, 829.4 or 1063 may be placed on or near a road only by a constable in uniform or a person acting under the instructions or authority of the chief officer of police.

A sign shown in diagram 554 (when varied to “Flood” or “No smoking”), 554.2 (when placed in conjunction with the plate shown in diagram 554.3), or 562 (when placed in combination with the plate shown in diagram 563 varied to “Accident”, “Census”, “Dust cloud”, “Fallen tree”, “Overhead cable repairs” or “Smoke”) may be retained only on or near a road for so long as the hazard indicated by the sign continues to exist or is expected to recur in the near future.

The sign shown in diagram 950 may be placed in combination with the plate shown in diagram 950.1 only while the training or testing of child cyclists is in progress.