In the presented situation, before driving onto the rails, are you obliged to make sure that no rail vehicle is approaching?

Why?

Before driving onto the tracks, you must take particular care and check that no rail vehicle is approaching. The raised barriers shown in the video do not remove this duty. The B-20 STOP sign before the crossing also requires you to stop.

art. 28 ust. 1 Prawa o ruchu drogowym; znak B-20, § 21 ust. 1 i 4 rozporządzenia w sprawie znaków i sygnałów drogowych