The DC Council has enacted several laws regarding bicycling. These include the creation of a city bicycle transportation and safety program, a bicycle advisory council, a requirement that children under 16 wear a helmet while bicycling, and both a helmet educational and financial assistance program. 

Such bicycling legislation can be found on the website for the District of Columbia Official Code . For instance, the bullet point named "Title 50. Motor and Non-Motor Vehicles and Traffic  " has an informational node called "Subtitle V. Non-Motorized Vehicles" that expands to reveal more detail.

Accessible from the Office of Documents website, are specific bicycle regulations . For example, bicycle-related legislation includes a 3-foot passing rule (18-2202.10 ). Another example is the residential building bicycle parking requirements . The list of moving  and non-moving
violations and associated fines  are also available.

Incidentally, the Washington Area Bicyclist Association publishes a Pocket Guide ^[PDF] to DC Bike Laws

Lastly, the DC Department of Motor Vehicles website has a chart ^[PDF] that clarifies the application of existing DC laws to motorized bicycles, Segways, and other two-wheeled vehicles.