A wise, previous poster on a previous thread about round-a-bouts put this in simple terms that I thought made it very clear. Just picture each round-a-bout as if you are coming to a stop sign.
If you plan to turn right, you must be in the right lane.
If you plan to go straight, you can be in either lane.
If you plan to turn left or make a u-turn, you must be in the left lane.
It really does follow a very well-known and common-sense traffic pattern.
Add that those coming into the roundabout must merge, and you have a smooth traffic flow. Just like a stop sign (or traffic light), it works well as long as drivers obey the rules.
Unfortunately, those who want to remain in the right lane when making a left turn (3rd exit) are basically cutting across traffic and creating a hazard. Thus, the sage advice - always look out!!!
