D.C. Mun. Regs. tit. 18, r. 18-713
Any motor vehicle may be equipped, and when required by this chapter shall be equipped, with a stop lamp or lamps on the rear of the vehicle which shall display a red or amber light, or any shade of color between red and amber, visible from a distance of not less than one hundred feet (100 ft.) to the rear in normal sunlight, and which shall be actuated upon application of the service (foot) brake and which may (but need not be) incorporated with one (1) or more other rear lamps.
Stop lamps on motor-driven cycles and motorized bicycles may be actuated upon application of the left handlebar brake.
Any motor vehicle may be equipped; and when required, shall be equipped; with lamps showing to the front and rear for the purpose of indicating an intention to turn either to the right or left.
When lamps are used for turn indicators, the lamps showing to the front shall be located on the same level and as widely spaced laterally as practicable, and when in use shall display a white or amber light, or any shade of color between white and amber, visible from a distance of not less than one hundred feet (100 ft.) to the front in normal sunlight. The lamps showing to the rear shall be located at the same level and as widely spaced laterally as practicable, and when in use shall display a red or amber light, or any shade of color between red and amber, visible from a distance of' not less than one hundred feet (100 ft.) to the rear in normal sunlight.
When actuated, turn indicator lamps shall indicate the direction of the intended turn by flashing the light showing to the front and rear on the side toward which the turn is going to be made.
No stop lamp or signal lamp shall project a glaring light.
D.C. Mun. Regs. tit. 18, r. 18-713