Hi Colin,
1. There are very few places now (to my knowledge) where those joining a roundabout have priority. The main one that springs to mind is the one that circles the Arc de Triomphe in Paris. If you think about it, if those on the roundabout had priority, with that volume of traffic I reckon it would be v difficulty/impossible to join it.. Once you understand the system in use today - ie, those joining have priority, it does manage to work. Plus it slows traffic on it right down - which is probably no bad thing.
2. My wife once explained the logic of this to me.. Given that the first instinct of a Frenchman in a car is to put his foot on the gas (!), this priority to traffic emerging from the right serves to slow down traffic on the main road - because if you hit a car joining from the right, you were clearly travelling too fast.
It makes you wonder why they didn't just put a Stop sign on the secondary road.. I can't help you with that. Sometimes what seems straightforward and logical to us isn't to them. (I think our brains must be wired up differently!)
I talked about the pleasure of driving on French D roads above.. Be aware that the speed limits are enforced and when entering a village, the moment you pass the sign with the name of the village on it, the speed limit is automatically
50km/h (30mph).. unless there's another sign to the contrary.
Priority to traffic on the right.. Here's a
translation of the French rules for you. The sign with the X on it means that traffic emerging from the right has priority.. You'll see this from time to time on French D roads - if you treat it as a
slow down sign you won't go far wrong - plus you do have to give way to traffic joining from the right.
The yellow diamond means that the road you're on has priority - and you can relax (& put away that pump action shotgun!)
The sign in the middle (from the above link) means that you're on a priority road (I think - I'll have to ask Madame)
Finally, old habits die hard and I've often wondered if learner drivers in France are taught how to drive on a roundabout.. There are those who will drive around in the outside lane (ie, on the extreme right) without indicating and they'll do a 270 before turning off without a signal.. Or they have their indicator flashing right all the way around. There are also those who treat roundabouts as a place to overtake (either on the left or the right). Someone once said if you see a Frenchman indicating on a roundabout, you're looking at a Frenchman who can't understand why his wipers aren't working! For the most part, they are good drivers - but there's always a few who can spoil your day.
Hope I haven't confused you.
Just stay calm and think happy thoughts!