K6 originally started off by operating as part of the Capital Transit Company "New Hampshire Avenue" Bus Line during the year of 1964, between the White Oak Shopping Center in White Oak, MD & Metro Center in Downtown Washington D.C., via Columbia Pike (U.S. Route 29), Stewart Lane, Old Columbia Pike, Lockwood Drive, New Hampshire Avenue (MD 650), Mahan Road, the White Oak FDA/FRC Building (formerly known as the "Naval Ordinance Laboratory", New Hampshire Avenue (MD 650), Northampton Drive/Southampton Drive, New Hampshire Avenue (MD 650)/New Hampshire Avenue NE, North Capitol Street NW, New Hampshire Avenue NW, Monroe Street NW (to White Oak), Park Road NW (to Metro Center), 11th Street NW, F Street NW, 12th Street NW, G Street NW, & 11th Street NW.