Regulation 17 Obligatory warning beaconsI1
England, Wales and Scotland
Subject to paragraph (2), no person shall use, or cause or permit to be used, on an unrestricted dual-carriageway road any motor vehicle with four or more wheels having a maximum speed not exceeding 25 mph unless it or any trailer drawn by it is fitted with at least one warning beacon which–
complies with Schedule 16, and
is showing an amber light.
Paragraph (1) shall not apply in relation to–
any motor vehicle first used before 1st January 1947; and
any motor vehicle, or any trailer being drawn by it, to which paragraph (1) would otherwise apply, when that vehicle or trailer is on any carriageway of an unrestricted dual-carriageway road for the purpose only of crossing that carriageway in the quickest manner practicable in the circumstances.