Page:The Traffic Signs Regulations and General Directions 1975 (UKSI 1975-1536).pdf/22

 so incorporated shall be not less than 250 nor more than 500 millimetres in length except that where an arrow is incorporated in the index part of a sign with a pointed end such arrow shall be not less than 100 nor more than 200 millimetres in length

(5) Every letter, numeral, arrow, chevron or symbol incorporated in a temporary sign shall be—

(a) black on a background of white, or yellow; or

(b) white on a blue background.

(6) There may be incorporated in, or attached to, a temporary sign the arms, badge or other device of a highway authority, police authority or the Royal Automobile Club, the Royal Scottish Automobile Club or the Automobile Association or words or letters indicating the highway authority or that the sign is a police sign.

(7) No sign shall by virtue of this Regulation convey to traffic any information, warning, requirement, restriction or prohibition of a description which can be so conveyed either by a sign shown in a diagram in Part I, Part II or Part IV of Schedule 1 or by a sign so shown used in combination with or in conjunction with another sign shown in such a diagram.

Flashing beacons and flags

28.—(1) Beacons showing an intermittent amber light for conveying the warning that drivers of vehicles should take special care may be used in combination with any of the signs specified in the last preceding Regulation or with any of the signs shown in diagrams 562 to 569 or 610 subject to the following conditions:—

(i) the light emitted by the lens or lenses of each such beacon shall be of peak intensity of not less than 100 candelas on the principal axis of the relevant lens;

(ii) the part of that beacon through which light is cmitted shall be of such a shape and size that the perimeter of the area projected horizontally thereby on to any vertical plane shall be capable of lying wholly inside a square having sides of 200 millimetres in length and wholly outside a square having sides of 100 millimetres in length:

(iii) the height of the centre of the lenses from the surface of the carriageway in the immediate vicinity shall be not less than 800 nor more than 1500 millimetres;

(iv) the rate of flashing shall be not less than 120 nor more than 150 flashes per minute and the period between flashes shall not exceed of a second; and

(v) the structure, if any, on which the said beacons are supported shall be coloured yellow.

(2) Beacons showing an intermittent blue light for conveying the warning that drivers of vehicles should take special care may be used by a constable, or a person acting under the instructions (whether general or specific) of the chief officer of police, in combination with any of the signs shown in diagrams 606, 609,610 and 633 to 635 subject to the same conditions specified in paragraph (1) (iii) and (iv) and to the condition that the structure, if any, on which such beacons are supported shall be coloured black and white in alternate sloping bands.

(3) Flags of an area of not less than 0.2 square metres and coloured red for conveying the warning that it would be dangerous for drivers to cause their vehicles to proceed may be used in an emergency at or in the vicinity of works being executed, or of an obstruction situated on or near a road.