On a road, once you go past this sign, can you make a U-turn?

In the photo you are driving along a small cobbled street in an estate of detached houses, and on the right there is sign D-4a "no through road" - a blue board with a red crossbar. On the road beyond this sign you can make a U-turn. The answer is: yes.

The Regulation on road signs and signals states that sign D-4a marks the beginning of a no through road, that is, a dead end that you cannot leave except by going back. The Road Traffic Act prohibits U-turns only in selected places: in a tunnel, on a bridge, on a flyover, on a one-way road, on a motorway, on an expressway except at a junction, and where this could endanger safety or obstruct traffic. A dead-end street in a housing estate is not one of these places, and a U-turn is actually necessary here. You make the U-turn at a place with good visibility, watching for pedestrians coming out from behind fences.

Legal basis: § 45 para. 1 of the Regulation on road signs and signals; Art. 22 para. 6 of the Road Traffic Act (Prawo o ruchu drogowym)