U.S. Route 1 (US 1) is the easternmost and longest of the major north–south routes of the older 1920s era United States Numbered Highway System, running from Key West, Florida, to Fort Kent, Maine. In the U.S. state of Maryland, it runs 81 miles (130 km) from the Washington, D.C. line to the Pennsylvania state line near the town of Rising Sun.

The Baltimore–Washington Parkway is a controlled-access parkway in the U.S. state of Maryland, running southwest from Baltimore to Washington, D.C. The road begins at an interchange with U.S. Route 50 (US 50) near Cheverly in Prince George's County at the Washington, D.C. border, and continues northeast as a parkway maintained by the National Park Service (NPS) to MD 175 near Fort Meade, serving many federal institutions. This portion of the parkway is dedicated to Gladys Noon Spellman, a representative of Maryland's 5th congressional district, and has the unsigned Maryland Route 295 (MD 295) designation. Commercial vehicles, including trucks, are prohibited within this stretch. This section is administered by the NPS's Greenbelt Park unit. After leaving park service boundaries the highway is maintained by the state and signed with the MD 295 designation. This section of the parkway passes near Baltimore–Washington International Thurgood Marshall Airport.