Is passing permitted in this situation?

Explanation

In built-up areas sign 1.2 "Railway crossing without a barrier" is placed 50–100 m before the crossing, so an overtaking started at this sign would take place less than 100 m from it. Overtaking is prohibited on railway crossings and within 100 m before them, and the Rules make no exception for a bus moving slower than 30 km/h (Rules, point 77, subpoint 3; sign 1.2).