An experienced traffic engineer’s studying a whole new way of “getting around” in Iowa. The specialty this veteran transportation planner’s working on is called a “roundabout,” an old term in Great Britain and one that’s catching on here. Hillary Isebrands is working on a doctoral degree in civil engineering at Iowa State University. That’s her background, too, as she already worked as a highway engineer for 6 years before returning to get her degree. She worked for a private engineering firm but her clients were the D-O-T, cities and counties, in Wisconsin.
Isebrands says there are nearly a dozen in Iowa. All so far have been built by local governments, including Coralville, Clive, Urbandale, Des Moines, West Des Moines and Bettendorf. But she says a dozen more are in the planning stages in municipalities around Iowa. A roundabout handles busy or sparse traffic by letting all drivers enter a big one-way road, that goes around a center island.
A modern roundabout, she says, is “a circular intersection.” Traffic goes counterclockwise and there’s a “Yield” sign on every approach. When traffic’s light, a vehicle that comes to the intersection can just drive right through it, with no traffic signal or stop signs. Europe and the east Coast have built a lot of roundabouts, and the Midwest is building more for safety, convenience and esthetic reasons. She says traffic at a roundabout never comes to a complete stop like it does at a four-way traffic light.
And all going the same way, she says it increases safety. The type of crashes changes in a roundabout, with no more head-on or right-angle “T-bone” crashes, which typically are the most severe. In a roundabout, if there’s an accident it’s likely to be a rear-end or sideswipe crash, which tend to be much less severe. The engineer says severe crashes and fatalities are reduced by fifty to 80-percent at roundabouts. The first one in Iowa planned for a public highway will be in Ottumwa, at the junction of U.S. 34 and US 63, just south of the river.
