That's not generally the problem. The problem is that city planners needlessly complicate them with lanes separated by concrete medians and traffic lights every 2oo feet.
I live in Minnesota where the traffic lights turn from green to a very long yellow and people know that and just speed up to go through the intersection. As far as the traffic circles go I love them. However, my daughter lives in Boston with very heavy traffic. When it's not rush hour they work great but during rush hour it's nasty.