Priorite a droit

On the way home I encountered that slightly crazy French road system priorité a droit. When the priorite a droit applies you must give way to vehicles entering from the right, even though you are driving on the main through road. The yellow diamond sign means you have priority over people from the right and is usually displayed when leaving a built-up area. If there is a black diagonal stripe through the sign is means 'give way to the right', or 'be on your toes'. I obviously wasn't quite on the ball today and driving down the main road I had to slam on the anchors to let someone out of a side street. At first glance the rule seems like an accident waiting to happen, but I have heard it argued that it adds to road safety because traffic in towns is more cautious. Another little idiosyncrasity.