D.C. Mun. Regs. tit. 18, r. 18-2211
The driver of a vehicle shall not overtake and pass upon the left nor drive upon the left side of any streetcar proceeding in the same direction, whether the streetcar is actually in motion or temporarily at rest, except in the following instances:
The driver of any vehicle when permitted to overtake and pass to the left of a streetcar which has stopped for the purpose of receiving or discharging any passenger shall reduce speed, shall yield the right-of-way to pedestrians in accordance with this subtitle, and may proceed only upon exercising due caution for pedestrians.
The driver of any vehicle proceeding upon any streetcar tracks in front of a streetcar on a street, shall remove the vehicle from the track as soon as practicable after signal from the operator of the streetcar.
The driver of a vehicle overtaking on the right of any streetcar stopped or about to stop for the purpose of receiving or discharging any passenger shall stop the vehicle at least five feet (5 ft.) to the rear of the door of the streetcar and remain standing until all passengers have boarded the car or, upon a lighting, have reached a place of safety.
Notwithstanding the requirements of § 2211.4, where a safety zone has been established, a vehicle need not be brought to a stop before passing any such safety zone, whether occupied by a streetcar or not, but must proceed at a speed no greater than is reasonable and proper and with due caution for the safety of pedestrians.
No vehicle shall at any time be driven through or within a safety zone.
It shall be unlawful for the directing officer or operator of any railroad train or streetcar to direct the operation of or to operate the train or streetcar in such a manner as to prevent the use of any street for purposes of travel for a period of longer than five (5) minutes; Provided, that this subsection shall not apply to trains or cars in motion, other than those engaged in switching.
It shall be unlawful for any streetcar to stop within an intersection or a crosswalk for the purpose of receiving or discharging passengers.
D.C. Mun. Regs. tit. 18, r. 18-2211