When approaching a level crossing in this situation, are you obliged to stop the vehicle before the STOP sign?

In the photo you are driving on a road outside a town and approaching a level crossing marked with St Andrew's crosses; on the right, still a long way before the tracks, there is sign B-20 "STOP". You are not obliged to stop the vehicle right at the sign - you stop before the level crossing, at a place from which you can see the tracks. The answer is: no.

The Regulation on road signs and signals states that sign B-20 means a ban on entering without stopping and an obligation to give way, and you should stop at the place designated for this purpose, and if there is none - where the driver can make sure that they will not obstruct traffic; these rules apply accordingly to sign B-20 placed before the tracks of rail vehicles. The sign stands several dozen metres before the level crossing. You stop before line P-12, and when there is none, before the level crossing at a place from which you can look along the tracks in both directions. The Road Traffic Act also requires you to exercise particular caution when approaching a level crossing and, before driving onto the tracks, to make sure that no rail vehicle is approaching; if the level crossing has traffic lights, when the red light is on you wait until it goes out.

Legal basis: § 21 para. 1, 2 and 4 and § 98 para. 5 of the Regulation on road signs and signals; Art. 28 para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)