The remaining part from Koszalin to Bożepole Wielkie is under construction, which includes adding the second carriageway to the existing single-carriageway bypass of Słupsk.

Upon completion of the ongoing contracts, scheduled for late 2025 and 2026, A6/S6 will be open on its entire intended route from the German border to Gdańsk.

After World War I, the German HaFraBa association had already set up plans to build an Autobahn along the route from Berlin through the Polish Corridor, to the Free City of Danzig and East Prussia (today informally known as Berlinka).

The construction was pushed by the Nazi authorities after 1933 as an extraterritorial Reichsautobahn across the Polish Corridor of prewar Poland further south than the modern S6 freeway has been planned for, but the road was never completed.

The tenders for design-build contracts on the section between Goleniów and Koszalin were announced in August 2014, with expected completion around 2018.