One thing many drivers and riders don't understand is how does one define or determine who gets in to a circle or four stop first? Put another way, if I get to a four way or circle only a half second before the person to my right, do I have right of way? No. I always understood the rule to be if neither party stopped and would collide that equals same time. If I am fully stopped but the person on the right has not, I am first and can go. Traffic circles of course have no stop bar and you don't need to stop unless there's a pedestrian.
Part of this is because the application of the rules in Europe would differ from the North American treatment of a four way. In Europe, on the right hand drive roads, if everyone arrives at the same time you give way to the left. This makes sense because if I don't give way to the dude on the left, he is further into the circle by the time we collide. In North America, because of the four way rules, it is the right which means that I am further into the circle when we collide. It's counter-intuitive to the system.