R.I. Gen. Laws § 31-24-17: Road lamps and fog lamps.

Any motor vehicle may be equipped with not more than two (2) road lamps or fog lamps which shall be rigidly affixed to the motor vehicle below the level of the head lamps, and shall be so aimed and used that no part of the high-intensity portion of the light beam shall rise more than eighteen inches (18") above the ground at a distance of seventy-five feet (75′) or more in front of the vehicle or be directed left of the prolongation of the extreme left side of the vehicle. Fog lamps and road lamps shall not be used in lieu of head lamps. Violations of this section are subject to fines enumerated in § 31-41.1-4.