Washington D.C.

Motorcycle:

“any motor vehicle that has a seat or saddle for the use of the operator and has two (2) or three (3) wheels in contact with the ground. The term ‘motorcycle’ does not include a tractor, a motor driven cycle or motorized bicycle unless operated at speeds in excess of thirty miles per hour (30 mph), or a three (3)-wheeled motor vehicle with a cab and windshield.”

Motor-Driven Cycle:

“a motor vehicle that has: (a) A seat or saddle for the use of the operator and has: (b) Two (2) or three (3) wheels in contact with the ground; (c) A gas, electric, or hybrid motor with a maximum piston or rotor displacement of fifty cubic centimeters (50 cc), or its equivalent, which will propel the device unassisted at a maximum speed no greater than thirty miles per hour (30 mph).”

Motorized Bicycle:

“a two or three wheeled vehicle with all of the following characteristics: (a) A post mounted seat or saddle for each person that the device is designed and equipped to carry; ‘(b) A vehicle with two (2) or three (3) wheels in contact with the ground, which are at least sixteen inches (16 in.) in diameter; ‘(c) Fully operative pedals for human propulsion; and ‘(d) A motor incapable of propelling the device at a speed of more than twenty miles per hour (20 mph) on level ground.’”