# The Road Vehicles Lighting Regulations 1989, Paragraph 12

Extent: E+W+S

Other requirements–
(a) Every indicator (other than a semaphore arm, that is an indicator in the form of an illuminated sign which when in operation temporarily alters the outline of the vehicle to the extent of at least 150 mm measured horizontally and is visible from both the front and rear of the vehicle) shall when in operation show a light which flashes constantly at the rate of not less than 60 nor more than 120 flashes per minute. However, in the event of a failure, other than a short-circuit of an indicator, any other indicator on the same side of the vehicle or combination of vehicles may continue to flash, but the rate may be less than 60 or more than 120 flashes per minute. Every indicator shall when in operation perform efficiently regardless of the speed of the vehicle.
(b) Where two front or rear direction indicators are fitted to a motor vehicle first used on or after 1st April 1986, and two rear direction indicators are fitted to a trailer manufactured on or after 1st October 1985, in each case they shall be fitted so as to form a pair.
(c) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

---
Source: https://www.legislation.gov.uk/uksi/1989/1796/schedule/7/part/I/paragraph/12 (the official version)
Page: https://openlegislation.uk/road-vehicles-lighting-regulations-1989/schedule-7/part-I/paragraph-12
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.