Are you allowed in this situation to make a U-turn at this intersection?

The signal on the S-3 directional traffic light in the form of a green arrow pointing down permits a U-turn from the current lane. According to § 97 para. 1 of the Regulation on road signs and signals, this signal means that travel in the indicated direction is allowed and there is no conflict with other road users. Therefore, in this situation, the U-turn manoeuvre is perfectly legal.