R.I. Gen. Laws § 31-24-14: Specifications for stop or signal lamps.

A stop lamp shall be plainly visible and understandable from a distance of one hundred feet (100′) 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 (100′) both to the front and rear. When a vehicle is equipped with a stop lamp or other signal lamps, the 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. Violations of this section are subject to fines enumerated in § 31-41.1-4.