I wanted to correct some misinformation here about navigating roundabouts. I’m from New England, the home of the “rotary,” which is basically just the New England word for roundabout. Yes, there are technical differences, but the general rules are the same.
#1. Yield to left. Traffic entering should yield to ALL lanes in the rotary, and should never pull in alongside a car in the inside lane. Traffic in the outside lane of the rotary should yield to traffic on the inside lane signalling to exit.
#2. The outside lane is for going halfway around or less (straight ahead or right, if the island weren’t there). Anything beyond that (going left) and you should use the inside lane(s). The inside lane(s) may be allowed to exit along-side the outside lane at the 12 o’clock exit, if the lane configurations will allow for it. It creates no conflicts if everyone chose their lane correctly ahead of time.
A picture is worth a thousand words, so check out this graphic that shows how you should use the lanes as a general rule.
http://www.dmv.ny.gov/olderDriver/images/multi-lane.png
Those are the general rules – the rules you follow if there are no signs or markings dictating otherwise. Obviously signs and markings take priority over the general rule.
A note on lane usage: you shouldn’t do any lane changes on entering the circle. If you need the inside lane, turn directly into it, don’t turn into the right-hand lane and then make a potentially unsafe lane change to the left.
Signalling is also a good idea. You should put on your right blinker as you pass the exit prior to the one you want. For example: If you’re taking the second exit, put your blinker on as you pass the first. If you’re taking the first exit, put your blinker on as you approach the rotary. If you need to change lanes to exit, use the same procedure as you would for any lane change.
All of these rules, but the number one unwritten rule of the rotary is this, don’t expect any other drivers to follow them. They’re not covered all that well in drivers ed courses, and many people just point their nose where they want to go and gun it, paying no attention to yield signs or lane-usage rules.