In this situation, are you allowed to perform a U-turn?

In the video, you are driving on a road through a forest outside town; the directions of traffic are separated by a double solid line, and a cyclist is riding by the right-hand edge. You are not allowed to make a U-turn here. The answer is: no.

The Regulation on road signs and signals states that road marking P-4 "double solid line" separates lanes for opposite directions of traffic and means that you must not cross this line or drive on it. A U-turn would require crossing this line to the opposite side of the roadway, so it is ruled out here - regardless of the fact that there is no sign B-23. The Road Traffic Act adds that a U-turn is prohibited in conditions where it could endanger road safety or impede traffic, and also, among other places, in a tunnel, on a bridge, on a flyover, on a one-way road, on a motorway and on an expressway. On a narrow road through a forest, with a cyclist at the edge and limited visibility, a U-turn would be dangerous even without the line. If you need to change direction, you drive on to a junction, a lay-by or a place where the double solid line ends and visibility in both directions lets you do the manoeuvre without forcing anyone to brake.

Legal basis: § 86 para. 5 of the Regulation on road signs and signals; Art. 22 para. 6 of the Road Traffic Act (Prawo o ruchu drogowym)