Maryland Code, TRANSPORTATION 22-215
(b) (1) Every combination of farm tractor and towed farm equipment, at all times mentioned in § 22-201.1 of this subtitle, shall be equipped with lamps as provided in this subsection.
(2) The farm tractor element of the combination shall be equipped as required in subsection (a) of this section.
(3) The towed unit of farm equipment of the combination shall be equipped on the rear with two red lamps visible when lighted from a distance of not less than 1,000 feet to the rear, and two red reflectors visible to the rear from all distances within 600 feet to 100 feet to the rear when directly in front of lawful upper beams of headlamps.
(4) The combination also shall be equipped with a lamp displaying a white or amber light, or any shade of color between white and amber, visible when lighted from a distance of not less than 1,000 feet to the front. This lamp shall be so positioned to indicate, as nearly as practicable, the extreme left projection of the combination carrying it.
(c) The two red lamps and the two red reflectors required in this section on a self-propelled unit of farm equipment or combination of farm tractor and towed farm equipment shall be positioned to show from the rear as nearly as practicable the extreme width of the vehicle or combination carrying them.