Page:The Traffic Signs Regulations and General Directions 1975 (UKSI 1975-1536).pdf/33

Rh (v) There shall be displayed in association with that lens, a device having an area of not less than 50 square centimetres and fitted with amber reflectors or amber reflecting material.

(vi) Where a lamp is used which shows a steady light, then the luminous intensity of that light shall not be less than 0.5 candela measured within 5 degrees above and below and 10 degrees left and right of the principal axis if the light so shown is emitted from the lamp in only one, two or three directions, and measured within 5 degrees above and below the horizontal plane around the vertical axis of symmetry if the said light is so emitted in every direction.

(vii) Where a lamp which shows an intermittent light is used, then that lamp shall be of such a size and type that the rate of flashing shall be not less than 900 flashes per minute and the peak luminous intensity measured in accordance with the last preceding sub-paragraph not less than I candela; except that where such a lamp is erected within 50 metres of a street lamp lit by electricity on a road subject to a speed limit of 40 miles per hour or less, that lamp may, as an alternative to the size and type last mentioned, be of such a size and type that the said rate shall be not less than 120 nor more than 150 flashes per minute and the said intensity so measured shall be not less than 1.5 candela.

(3) Until 1st January 1976, a lamp used to indicate to traffic the limits of a temporary obstruction of a road shall be treated as if prescribed by paragraph (1) notwithstanding that it is not in every respect of the size, colour and type prescribed by paragraph (2) if that lamp so used emits a steady red light of any intensity and has a lens or lenses of such a shape and size that the area of light projected horizontally thereby on to any vertical plane shall be capable of lying wholly inside a square having sides of 150 millimetres in length and wholly outside a square having sides of 40 millimetres in length, and if the said lamp and its lens or lenses comply with the provisions of sub-paragraphs (iii) and (iv) of paragraph (2)