I read the article written by Chris Morgan about the use of cell phones in vehicles and the Chattanooga Roundabouts.
Cell phone use in vehicles especially in crisis intersection situations is extremely dangerous.
I also agree with his assessment about the roundabouts. One problem I see with roundabouts is that on the two-lane roundabouts where they are coming in from a from four-lane highway, many of the drivers will come in from the right lane and then cut over to the left lane so as to maintain their speed and make this more of an oval-about than a roundabout.
I have advocated to traffic engineering that on each roundabout there should be the slow-down rumble strips to warn motorist to reduce their speed as they approach into the roundabouts. I also think yellow caution lights above each roundabout would remind motorist of the dangers that can happen in them.