Important cities that the B1 passes through in a north–south direction include Oshikango, Ondangwa, Tsumeb, Otavi, Otjiwarongo, Okahandja, Windhoek, Rehoboth, Mariental, Keetmanshoop and Noordoewer.

It heads north to Grünau, where it meets the B3 from Karasburg (and Upington from continuing on South Africa's N10 national route) and the Nakop-Windhoek railway line.

From Okahandja, the B1 resumes and heads north for approximately 175 kilometres (109 mi) to Otjiwarongo; this section is considered one of the deadliest roads in Namibia with a high crash fatality rate.

[3] From Otjiwarongo, the B1 heads in a more north-easterly direction to avoid the Etosha National Park, passing through Otavi (where the B8 provides a route to the Caprivi Strip and the border with Zambia) before reaching Tsumeb.

At Tsumeb, the route makes a hard turn to the north-west at the intersection with the B15 and skirts the Etosha Pan to reach Oshivelo and thence Ondangwa, from where it resumes a northerly path and heads to Oshikango.