# The Road Vehicles Lighting Regulations 1989, Paragraph 10

Extent: E+W+S

Electrical connections–
(a) All indicators on one side of a vehicle together with all indicators on that side of any trailer drawn by the vehicle, while so drawn, shall be operated by one switch.
(b) All indicators on one side of a vehicle or combination of vehicles showing a flashing light shall flash in phase, except that in the case of a solo motor bicycle, a motor bicycle combination and a pedal cycle, the front and rear direction indicators on one side of the vehicle may flash alternately.

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Source: https://www.legislation.gov.uk/uksi/1989/1796/schedule/7/part/I/paragraph/10 (the official version)
Page: https://openlegislation.uk/road-vehicles-lighting-regulations-1989/schedule-7/part-I/paragraph-10
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.