D.C. Mun. Regs. r. 18-2400
No person shall stand or park a vehicle in a roadway other than parallel with the edge of the roadway headed in the direction of lawful traffic movement.
A person shall stand or park a vehicle on a two-way street with the right-hand wheels of the vehicle within twelve inches (12 in.) of the right curb or edge of the roadway.
On a one-way street, a vehicle may be parked in the same manner as on a two-way street or may park with the left-hand wheels of the vehicle adjacent to and within twelve inches (12 in.) of the left-hand curb.
If a highway includes two (2) or more separate roadways and traffic is restricted to one direction upon any such roadway, no person shall stand or park a vehicle upon the left-hand side of such one-way roadway unless signs are erected to permit such standing or parking.
No person shall park a vehicle upon any roadway for the principal purpose of doing either of the following:
The provisions of this chapter prohibiting the stopping, standing, or parking of a vehicle shall apply at all times, or at those times herein specified, or as indicated on official signs and parking meters, except when it is necessary to stop a vehicle to avoid conflict with other traffic or when complying with the direction of a police officer or official traffic control device.
The provisions of this chapter imposing a time limit on parking shall not relieve any person from the duty to observe other and more restrictive provisions prohibiting or limiting the stopping, standing, or parking of vehicles in specified places or at specified times.
A person may park a motorcycle, motor-driven cycle, or motorized bicycle in a direction other than parallel with the edge of the roadway, including perpendicular with the curb, if the motorcycle, motor-driven cycle, or motorized bicycle does not obstruct the flow of traffic.
D.C. Mun. Regs. r. 18-2400