Yes, DOT studies show that roundabouts reduce crashes. But readers say that some drivers haven't bought into the circular logic.
Instead of turning right and joining the counterclockwise flow, they're determined to turn left. This happens where roundabouts are new and the locals haven't figured it out, and where the roundabouts are just too small to make sense.
John Dagenhart sees problems with small roundabouts tucked into Durham's Trinity Park neighborhood:
While they work rather well most of the time, some people “just don’t get it” on how to turn left at one of these intersections. I’m not sure if the drivers don’t know the rules or just don’t care. Either way, it’s dangerous.
Quite often, I observe cars go clockwise (i.e., the short way) to make a left-hand turn. This is dangerous. Just last week, I almost had a head-on collision with someone doing just that. I was going the right way; they, the wrong way. If I had not been looking for this (I always peak around the corners to see who is coming) we certainly would have hit each other.
I agree that the larger roundabouts work well. You can’t help but go around them in the right direction. But the smaller ones are a problem.
Mike Fox points out that some shopping centers, such as Beaver Creek Commons in Apex, have dinky little circles that don't work at all. I've seen a similarly ill-conceived roundabout at University Mall in Chapel Hill.
In Wake Forest, some long tractor-trailer trucks have gotten hung up trying to squeeze into the roundabout at NC 98 and US 1A. There are plans for more roundabouts in the future. Holly E. Spring, an assistant town engineer, says Wake Forest is educating citizens in proper roundabout etiquette:
Slow down as you approach the roundabout.
Yield to pedestrians in the crosswalk.
Look left. Yield to traffic in the roundabout.
When there's a gap, enter the roundabout.
Travel counter-clockwise until you reach your exit.
Turn on your right-turn signal and exit the roundabout.

Bruce Siceloff reports on traffic and transportation. A News & Observer reporter, editor and blogger since 1976, he took over the