Is the prohibition expressed by this sign valid from the point of its location to the nearest crossroads?

The visible square sign with a red border is the BT-1 tram sign "speed limit". According to regulations, the restriction expressed by this sign applies until the nearest intersection, track switch, or BT-2 "end of speed limit" sign. Therefore, the restriction may be cancelled earlier by a switch (track split), so it does not always apply until a road intersection.