In this scenario, once you’ve confirmed that no train is approaching, are you permitted to drive around the lowered half-barrier and cross the railway tracks?

Why?

The photo shows lowered half-barriers and a red light, so you must not enter the crossing. Driving around lowered half-barriers is prohibited even if you cannot see an approaching train. The open part of the road does not give you permission to cross.

art. 28 ust. 3 pkt 1 Prawa o ruchu drogowym; § 98 ust. 5 rozporządzenia w sprawie znaków i sygnałów drogowych