The B1 is one of the most important roads in Namibia, passing through the centre of the country in a north-south direction. It connects Noordoewer on the South African border with Oshikango in the north on the Angolan border. Important cities it passes through in a North-South direction include Oshikango, Ondangwa, Tsumeb, Otavi, Otjiwarongo, Okahandja, Windhoek, Rehoboth, Mariental, Keetmanshoop and Noordoewer.
In 2007 the B1 lent its name to the B1 Butcher, a serial killer who professionally dismembered his victims and deposited body parts of at least five women near the road. The murderer has never been identified.