You intend to go straight ahead through this junction. Do you have the right of way over a vehicle that may approach from the right?

In the video you are driving on a country road towards a junction marked with sign D-1 with plate T-6a, on which the priority road turns right and a thin line goes straight on. When going straight on, you do not have right of way over a vehicle that may approach from the right. The answer is: no.

The Regulation on road signs and signals states that sign D-1 marks the beginning or continuation of a priority road, and plate T-6a under it shows the actual route of this road through the junction. Since the thick line goes off to the right, the priority road turns right, and the section straight ahead is a minor road. So the vehicle from the right is driving on the priority road, and you, going straight on, are leaving it - that vehicle has right of way, and you give way. Sign D-1 on your road may itself be misleading: it does not mean that you have right of way in all directions, only that you are on a priority road whose route is shown by the plate. If you turned right, you would continue along the thick line and would keep right of way. When approaching the junction, you slow down and look to the right, ready to stop.

Legal basis: § 43 para. 1 and 2 of the Regulation on road signs and signals; Art. 25 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)