There have been several recent letters giving the impression that roundabouts speed up vehicular traffic. I believe the writers do not comprehend the difference between improving the flow of traffic and vehicle speed.
The improvement comes from the fact that four vehicles can navigate a roundabout at the same time while, at a typical four way stop, only one car at a time can use the intersection. In previous letters, I have posted information that confirms that roundabouts, in fact, slow traffic and dramatically improve safety both in the number and the severity of vehicular crashes.
It is also important to note the difference between roundabouts, rotaries and traffic circles. I am not a traffic engineer, but my investigations support a single-lane roundabout as the ideal solution for the issues with the intersection of Avenue of the Fountains and La Montana. Something similar could work at the Saguaro end of the Avenue. The one-lane/two-lane situation there would require professional study.
I have included the web address for the official website for the U.S. Department of Transportation, Federal Highway Administration which provides an excellent reference about roundabouts and related issues. I encourage every interested resident check it out: fhwa.dot.gov/intersection/innovative/roundabouts/.