Paragraph 13 I1

A reflectorised stop line of the size and type shown in Diagram 1001 in the Regulations shall be provided across the left-hand side of carriageway on each approach to the crossing approximately 1 metre before the left-hand side traffic signal. Where this is not achievable due to crossing skew, the stop line shall be positioned in line with or in front of the duplicate traffic light signal. A stop line shall not be located behind a road traffic light signal in any circumstances.