drive at a speed which does not exceed 30 miles per hour shall consist of 2 beacons showing light signals of the following size, colour and type, that is to say—
(1) 2 lamps each showing an intermittent amber light shall be used;
(2) the lamps shall be arranged vertically so that there is 5 distance of not less than 825 millimetres not more than 1 metre between the centres or the lenses or the lamps;
(3) each lamp shall be separately illuminated and the effective diameter of the lens thereof shall be not less 115 nor more than 175 millimetres;
(4) each lamp shall show the said light at a rate or flashing or not less than 60 nor more than 90 flashes per minute, and in such is manner that the light or one lamp is always shown at a time when the light of the other lamp is not shown.
39.—(1) Subject to the provisions or these Regulations, a traffic sign for conveying to vehicular traffic on motorways a warning or information of the description specified in or under a diagram in Part I of Schedule 6 shall be of the size, colour and type shown in the diagram relating to that warning or that information.
In this paragraph, the reference to vehicular traffic, where the traffic sign is erected beside the carriageway, is a reference to all vehicular traffic facing that sign and proceeding along the carriageway beside which the sign is so erected,and where the traffic sign is erected over the carriageway so as to operate in relation to vehicular traffic facing that sign and proceeding in the traffic lane (as defined by Regulation 36(1)) situated beneath it, is a reference only to such traffic so facing and proceeding in that lane.
(2) Each of the signs shown in any diagram in Part I of Schedule 6 shall, when displaying the pattern of circles indicated by the diagram relative to that sign, be illuminated by internal white or off-white lights so arranged as to form the said pattern and may be accompanied by four lamps each showing an intermittent amber light as provided in the next following paragraph.
(3) where the said four lamps accompany any of the signs mentioned in the last preceding paragraph, those lamps shall be or the size, colour and type prescribed by this paragraph, that is to say—
(a) the lamps shall, in relation to the said pattern of circles be so arranged as shown in diagram 6022 in Part II of Schedule 6 when erected beside the carriageway or as shown in diagram 6021 in the said Part II when erected over the carriageway;
(b) each lamp shall show an intermittent amber light and, subject to the provisions of sub—paragraph (f) or this paragraph be separately illuminated; and the effective diameter of the lens thereof shall be not less than 120 nor more than 130 millimetres;
(c) the lamps shall be so fitted as to enclose a rectangular area bounded by the one pair or sides extending horizontally in relation to the ground and terminating as to each side in the centres or each pair of lenses (in these Regulations called "the horizontal pairs") and by the other pair of side extending vertically in relation to the ground and terminating as to catch side in the centres of each pair of lenses (in these Regulations called "the vertical pairs");
