Rising Number of Roundabouts Bring Safety Benefits, Skepticism

Almost every night, after he helps put his kid to bed, Joshua Blanton drives across his hometown of Ashland, Kentucky, to look at a roundabout.

Five were installed along one of its main commercial stretches this year, replacing five stoplights and reducing four traffic lanes to two. The project is part of a larger downtown revitalization effort to boost walkability and safety in the city of 20,000 people. But for Blanton, it’s become much more than that. “It’s habit,” he said of his frequent drives. “We were so involved in it, it’s just hard to break away.”

Shortly after Election Day, Blanton ...