It can get complex for us here as well, one example is when the priority road doesn't go straight through the intersection, eg. L-shaped main road, and then the other two have a stop and a yield sing. A lot of people where I live wrongly think that the yield has priority over the stop sign, it's a widespread misconception (I'd say more people believe it than not). In reality the priority to the right rule applies between side roads and the only difference between yield & stop is that the stop sign requires you to actually stop the vehicle.
And then there are plenty of T intersections in smaller towns and villages where people assume the road going straight is the main road, even though there aren't signs and the priority to right would apply. I guess drivers mostly rely on habits and intuition.
