# The Traffic Signs (Temporary Obstructions) Regulations 1997, Paragraph 2


The triangle shall be equilateral. The area marked A in the diagram shall be coloured red, and shall be reflectorised to Class 1 of British Standard BS 873 Part 6 or an equivalent standard which has been approved by a recognised standardising body in an EEA State.

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Source: https://www.legislation.gov.uk/uksi/1997/3053/schedule/1/paragraph/2 (the official version)
Page: https://openlegislation.uk/traffic-signs-temporary-obstructions-regulations-1997/schedule-1/paragraph-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.