As an interesting side bar, Massachusetts and, I believe, New Hampshire (the "Live Free or Die" state) both had a traffic law for decades which stated that, upon entering an intersection, the car to the right had the right of way (usually meaning that the car to the right could proceed first).
Now....think about this with a Rotary; If one believes, as our faire Commonwealth's Law-Givers did, that Rotary traffic was sacrosanct and should not be messed with, then the "Right Hand Rule" as it was then known, must be dealt with, and swiftly. Therefore, they decreed that "traffic already within the Rotary has the right of way", meaning that those entering a Rotary (and they're always on the right, unless you're driving in England, Ireland, Austrailia, New Zealand or Japan, where things are a tiny bit different) must wait for an opening in the traffic before proceeding into the Rotary traffic stream (yes, it does seem like a bunch of Salmon swimming in a whirlpool).
This change in traffic laws would have probably worked seamlessly, were it not for one small thing (well, two, maybe): (1.) They left the "Right Hand Rule" in place for all other intersections, leaving no small amount of confusion in the minds of many, many motorists and (2.) all of the "youth-challenged" motorists who had grown up with the "Right Hand Rule" during the 1940's never had to take an updated driving test, so they totally ignore the sanctity of Rotary Traffic Flow and simply barge in, knowing that they have the right of way and those dimwits out there in the Rotary have to stop for them.
I certainly hope that this clears up proper driver etiquette in the traversing of "Rotaries", also know as "Roundabouts", "Traffic Circles" and "Rings of Hell".
gn