Md. Code, Transp. § 22-216
Every vehicle, including animal-drawn vehicles and vehicles referred to in § 22-101(e) of this title, not specifically required by the provisions of this subtitle to be equipped with lamps or other lighting devices, at all times specified in § 22-201.1 of this subtitle, shall be equipped with at least one lamp displaying a white light visible from a distance of not less than 1,000 feet to the front of the vehicle, and also shall be equipped with two lamps displaying red lights visible from a distance of not less than 1,000 feet to the rear of the vehicle or, as an alternative, one lamp displaying a red light visible from a distance of not less than 1,000 feet to the rear and two red reflectors visible from all distances of 600 to 100 feet to the rear when illuminated by the upper beams of headlamps.
Md. Code, TR § 22-216