BICYCLE LIGHTS LAW REQUIRMENTS IN North Carolina
In US the bike lights die required by Law if you reading in low light conditions, The light can be attached to either the bike or to the cyclist but must be visible at least 500 feet to the front of the bicyde, so be careful how you position the light. Additional lighting must be consistent with the law specifying required lights and reflectors, so a rear light must be red.
2014 North Carolina General Statutes
Chapter 20 - Motor Vehicles.
Article 3 - Motor Vehicle Act of 1937.
§ 20-129 - Required lighting equipment of vehicles.
(e) Lamps on Bicycles. – Every bicycle shall be equipped with a reflex mirror on the rear and both of the following when operated at night on any public street, public vehicular area, or public greenway:
(1) A lighted lamp on the front thereof, visible under normal atmospheric conditions from a distance of at least 300 feet in front of such bicycle.
(2) A lamp on the rear, exhibiting a red light visible under like conditions from a distance of at least 300 feet to the rear of such bicycle, or the operator must wear clothing or a vest that is bright and visible from a distance of at least
300 feet to the rear of the bicycle.