If you change lanes once you go past this sign, are you obliged to indicate your intention of making such a manoeuvre?

In the video we are driving in the right lane of a tree-lined street; lane-change arrows pointing to the left appear on the roadway, and sign D-14 "end of lane" stands at the right edge. Beyond this sign you are obliged to signal your intention to change lanes - the answer is YES.

Sign D-14 informs you that the far lane on the side shown on the sign is ending, and P-9 arrows require you to move into the adjacent lane. The Road Traffic Act requires you to signal your intention to change lanes with your indicator in good time and clearly - there is no exception here for a lane that is disappearing. When changing lanes, you give way to vehicles travelling in the lane you are moving into. When traffic is heavy and moving slowly, drivers in the adjacent lane must let you in directly before the point where your lane ends, on the zipper merge (jazda na suwak) principle. Before changing lanes you look in the mirror and over your shoulder, because a moped can easily hide in the blind spot.

Legal basis: Art. 22 para. 4, 4a and 5 of the Road Traffic Act (Prawo o ruchu drogowym); § 49 para. 5 and § 87 para. 3 of the Regulation on road signs and signals