According to the Iowa Department of Transportation, a modern roundabout is an unsignalized, circular intersection engineered to maximize safety and minimize traffic delay. Over the last few decades, tens of thousands of roundabouts have been installed in Europe, Australia and other parts of the world. Recently, they have gained support in the United States, including communities in Iowa. From 1999 to 2009, at least 33 modern roundabouts were constructed in Iowa.
The city of Johnston has a series of five roundabouts located on NW 62nd Avenue, the first series of its size in our state. There is also a plan to add roundabouts to NW 70th Avenue and NW 100th Street because of their safety record and efficiency in moving traffic.