Does the sign in the situation presented, warn you of a narrowing on both sides of the road, which may pose an obstruction traffic?

In the video you are driving along a street in a city, past a school building on the left, and approaching a junction with a pedestrian crossing; on the right, in front of a tree, there is a yellow triangle with a symbol of a roadway narrowing on both sides - sign A-12a "road narrows on both sides". It warns of a narrowing of the roadway on both sides, which may cause traffic obstruction. The answer is: yes.

The Regulation on road signs and signals states that signs A-12a "road narrows on both sides", A-12b "road narrows on the right" and A-12c "road narrows on the left" warn of a narrowing of the roadway on the side shown on the sign, which may cause traffic obstruction. The symbol shows on which side the roadway narrows: on A-12a both edges come together towards the middle. A narrowing means that further on there may not be enough room for two wide vehicles to pass each other or to overtake a cyclist with a one-metre gap. Warning signs require you to exercise particular caution - you slow down, watch oncoming vehicles and, if necessary, stop to let a wider vehicle through; the Road Traffic Act requires you, when passing an oncoming vehicle, to keep a safe distance and, if necessary, to move over to the right, reduce speed or stop.

Legal basis: § 7 para. 3 and § 3 para. 1 of the Regulation on road signs and signals; Art. 23 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)