[1] Its plannings began in the early 1950s, when the communities of Oker, Bündheim, and Bad Harzburg struggled with increasing traffic on their two-lane streets B 4 and B 6.

A first draft from a planning office in Brunswick in April 1953 proposed the recent pathway from Vienenburg east of the Radau river through the city.

Between 1982 and 1987, the four-lane Bundesstraße 6 was constructed between Goslar and the A 395, leading to the Bad Harzburg intersection being added to the highway.

After German Peaceful Revolution and reunification of Germany around 1990, the eastern part of the Bundesstraße 6 was constructed from Vienenburg to Bernburg (Saale) between 1997 and 2011.

In the context of the anticipated upgrade of the eastern part of the Bundesstraße 6 to Bundesautobahn 36 since 2017, the major of Bad Harzburg (Ralf Abrahms) as well as the Lower Saxon Minister for Environment, Energy, Building, and Climate Protection Olaf Lies requested the upgrade of the downgraded part of the A 395 as well, now under the old numbering of A 369.