(1) A stop lamp on the rear which shall emit a red or yellow light and which shall be actuated upon application of the service (foot) brake and which may but need not be incorporated with a tail lamp.
(2) A lamp or lamps or mechanical signal device capable of clearly indicating any intention to turn either to the right or to the left and which shall be visible both from the front and rear.
(b) A stop lamp shall be plainly visible and understandable from a distance of one hundred feet to the rear both during normal sunlight and at nighttime and a signal lamp or lamps indicating intention to turn shall be visible and understandable during daytime and nighttime from a distance of one hundred feet both to the front and rear. When a vehicle is equipped with a stop lamp or other signal lamps, such lamp or lamps shall at all times be maintained in good working condition. No stop lamp or signal lamp shall project a glaring or dazzling light.
(c) All mechanical signal devices shall be self-illuminated when in use at the times mentioned in section two of this article.