Round and round they go
Couple things that you seem to have missed in
30% of accidents occur in intersections with signals just *might* have something to do with signals being used on the most busy intersections, right?
Emergency vehicles approaching a traffic signal use a strobe light to "trigger" a green light, making traffic all flow in the direction of the emergency vehicle. Approaching the same traffic circle, most of the traffic will have to "slow and flow" through before the ambulance can get through (and to your house, where minutes count).
Large emergency vehicles such as fire trucks and large delivery trucks have problems working their way through the intersection, in particular those useful bits of concrete that direct regular sized cars in the right direction. And while the large statue or landscaping feature in the center blocks vision, here comes a car around the circle and right into the back of the slow moving truck picking its way through the obstacle course. Europe uses a lot more smaller trucks, and has less of a problem.
A lot of these city officials have fallen in love with the idea of traffic circles, despite the downsides, simply because of the construction/upkeep costs (lights take power, and maintenance). The main problem is that with circles, *everybody* get inconvenienced. And a lot of us just don't like that, and much prefer a light that is smart enough to see us coming and change, so we can just drive, instead of having to slalom our way down the street.
Labels: roundabout traffic circle