Are you permitted, in this situation to enter the level crossing only after making sure that no rail vehicle is approaching?

In the photo you are approaching a level crossing over an electrified line in a town; the half-barriers on both sides are raised, the lights are not lit, and a white car is coming from the opposite direction. You are allowed to enter the crossing only after making sure that no rail vehicle is approaching. The answer is: yes.

The Road Traffic Act requires a driver approaching a level crossing to exercise particular caution, and before entering the tracks to make sure that no rail vehicle is approaching; it also requires you to drive at such a speed that you can stop the vehicle in a safe place when a train is approaching or a signal prohibits entry. Raised half-barriers and unlit lights mean that the automatic system has not detected a train, but the automatic system can fail - that is why the duty to check the tracks always rests with you, and not only at crossings without barriers. You slow down, turn the radio down, look left and right along the tracks, and drive on when you see that they are empty and that there is room beyond the crossing to get off the tracks.

Legal basis: Art. 28 para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)