Maryland Code, Transportation § 22-226

(a) At all times specified in § 22-201.1 of this subtitle, at least two lighted lamps shall be displayed, one on each side, at the front of every motor vehicle other than a motorcycle, except when the vehicle is parked subject to the regulations governing lights on parked vehicles.

(b) Whenever a motor vehicle equipped with required headlamps also is equipped with any auxiliary lamps or a spot lamp or any other lamp on its front projecting a beam of intensity greater than 300 candlepower, not more than four of these lamps on the front of a vehicle may be lighted at any one time when on a highway.