In the presented situation, is the prohibition expressed by this sign binding from the place of its erection?

In the photo on the right there is sign B-33 "speed limit" with the number 30, and further on you can see roadworks and guide boards. The ban on exceeding 30 km/h starts to apply at the place where the sign stands, not only at the roadworks. The answer is: yes.

The Regulation on road signs and signals sets a general rule for all prohibition signs: the prohibition applies from the place where the sign is put up, unless a specific provision states otherwise. If the prohibition were to start further on, there would be plate T-21 with a distance under the sign. There is no such plate here, so you slow down to 30 km/h already at the sign - at roadworks the limit protects the workers standing right next to the roadway.

Legal basis: § 15 para. 2 and para. 5 point 2 and § 27 para. 1 of the Regulation on road signs and signals