When you exercise caution, are you allowed to enter a railway crossing if the barrier has just started to lower?

The question is about entering a level crossing at the moment when the half-barriers have only just started to come down. Even if you pay increased attention, you are not entitled to enter the level crossing. The answer is: no.

The Road Traffic Act prohibits a driver from driving around lowered barriers or half-barriers and from entering a level crossing if they have started to come down or have not finished going up. So the moment when the arm starts to come down is legally the same as a closed level crossing - it does not matter that you could still drive under it or that you "will pay attention". The reason: the half-barriers come down because the train is already close and will pass the level crossing in a dozen or so seconds; by entering now, you risk stopping on the tracks behind the lowered arm or in a traffic jam on the other side. You stop before the signal or the stop line, even if this means braking harder, and wait until the barriers have gone up completely and the red lights have gone out - only then may you move off, after making sure that another train is not coming on the other track.

Legal basis: Art. 28 para. 3 point 1 and para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)