Roundabouts versus traffic lights

I've been thinking about road safety since arriving in North America - driving on the other side of the street and looking the other way when crossing the road sharpens up the senses.
I've read in the press that one of the major causes of road deaths is drivers jumping red lights. This started me thinking - where are the roundabouts? Are roundabouts safer than traffic lights?
1. Scoot over to Drivers.com and check out this article and links to others.
2. They sharply reduce crashes, study finds.
Extract from an Insurance Institute of Highway Safety report:
"Roundabouts may be an unfamiliar type of intersection in the United States, but they’re becoming more familiar as evidence of their benefits grows. Improved traffic flow, aesthetics, and cost savings make roundabouts a good idea, and the safety gains are compelling. An Institute study shows far fewer crashes occur at intersections with roundabouts than at intersections with signals or stop signs. This is especially true of crashes resulting in occupant injuries. Researchers at Ryerson Polytechnic University [in Toronto], the Institute, and the University of Maine studied crashes and injuries at 24 intersections before and after construction of roundabouts.
The study found a 39 percent overall decrease in crashes and a 76 percent decrease in injury-producing crashes. Collisions involving fatal or incapacitating injuries fell as much as 90 percent."
In many instances it would appear that the roundabouts have it - lower approach speeds, always turning right, reduced accidents when drivers turn right on red, greatly reduced accidents overall. Why isn't this approach catching on? - well it is to an extent but couldn't it make a far more significant contribution to saving lives across North America and all the costs both human and financial that go with it.