UK roundabouts are not the same as Modern Roundabouts. If you want to see the difference between a traffic circle, a rotary (UK roundabout) and a modern roundabout, search www.k-state.edu
to see pictures. The FHWA has a video about modern roundabouts that is mostly accurate ( http://www.youtube.com/watch...
Modern roundabouts are the safest form of intersection in the world. Search www.iihs.org
for FAQs and safety facts. The safety comes from the ‘slow and go’ operation instead of the ‘stop or go fast’ way a stop light works (or the ‘keep going fast’ large traffic circle fantasy). The smaller size of the modern roundabout is what makes them safer and keeps speeds in the 20 mph range. This makes it much easier to avoid a crash or stop for pedestrians. It also means that if a crash happens the likelihood of injury is very low. Safety is the #1 reason there are over 2,400 modern roundabouts in the US today and many more on the way.
Slow and go also means less delay than a stop light, especially the other 20 hours a day people aren’t driving to or from work. Average daily delay at a signal is around 12 seconds per car. At a modern roundabout average delay is less than five seconds. Signals take an hour of demand and restrict it to a half hour, at best only half the traffic gets to go at any one time. At a modern roundabout four drivers entering from four directions can all enter at the same time. Don’t try that with a signalized intersection.
Here’s a quote:
“By 2025, a quarter of all drivers in the United States will be over the age of 65. Intersections are the single most dangerous traffic environment for drivers of any age with left-hand turns being the single most dangerous traffic maneuver that any of us can make. Forty percent of all crashes that involve drivers over the age of 65 occur at intersections. This is nearly twice the rate of experienced younger drivers. AARP would like to see more roundabouts constructed because of the many safety benefits that they present for drivers of all ages.”- Jana Lynott, AARP Public Policy Institute