Department of Civil, Construction, and Environmental Engineering

Roundabouts in Rural America

Hillary Isebrands, doctoral student in transportation engineering and CTRE research assistant, is studying whether modern roundabouts on rural Midwest highways can reduce crash severity.

She is also negotiating grants with the Iowa Department of Transportation, the Federal Highway Administration, the Minnesota Department of Transportation, and Minnesota’s Local Road Research Board to help develop guidelines for considering and building roundabouts.

She’s working with Shauna Hallmark, associate professor of transportation engineering and CTRE transportation engineer, to assess whether roundabouts can reduce vehicle emissions by decreasing idling time and creating fewer stops at intersections.

Roundabouts in Iowa

John Abrams, an engineer for the rural design section of the Iowa Department of Transportation, said the department will build its first highway roundabout this summer. That roundabout will be at the south intersection of U.S. highways 63 and 34 in Ottumwa.

The roundabout should improve a three-way “spaghetti jumble” at the intersection, he said. Coralville has built two roundabouts since 2002, has one under construction and another in the planning stage. Scott Larson, Coralville’s assistant city engineer, said the city built the first two roundabouts as alternatives to adding turn lanes and traffic signals.

He said drivers seem to like them and there have been few negative comments. And Isebrands thinks there’s room in Iowa for roundabouts and their safety features.

“I think there’s a place for them,” she said. “Roundabouts are a proven safety alternative for reducing crash severity at intersections and this puts Iowa one step closer to reducing the number of Iowans who die every year in crashes.”

For More Information

Contact Hillary Isebrands for more information about her research: hillaryiiastate.edu or 515-294-7188.