A 'Roundabout' sign alone gives no priority to traffic on the ring
Roundabouts: rules and sources
On a roundabout marked with sign 4.10 ('Roundabout'), traffic already on the ring has priority. The give-way-to-the-right rule does not apply on roundabouts.
Details
Para. 16.12 (since 2017): you give way to the right at junctions of equal roads 'except at junctions with circular traffic'; at uncontrolled junctions with circular traffic marked with sign 4.10, priority belongs to vehicles already on the ring. No separate give-way sign is needed for this — sign 4.10, which marks a roundabout, is enough. The tram's priority at uncontrolled junctions also does not apply on roundabouts. If the roundabout has traffic lights, follow the signals.
Traffic already on the ring has priority only where the entry carries sign A-7 'Give way' (an inverted triangle) together with sign C-12 'Roundabout'. With C-12 alone, the roundabout is an ordinary junction and give-way-to-the-right applies: whoever is entering has priority over traffic on the ring.
Details
Signs regulation § 36(1): sign C-12 on its own only tells you to drive round the island in the arrows' direction. § 36(2): priority for traffic on the ring comes from C-12 and A-7 together. Without A-7 the general rule of art. 25(1) applies — give way to the right. So look for both signs at every entry. Overtaking at an uncontrolled junction is banned; on a roundabout or a signal-controlled junction it is allowed (art. 24(7) item 3).