Europe has used them for 100 years, but to us, they’ve always been a confusing oddity--conjuring up a funny scene from the movie "European Vacation."
This fall, the roundabout is starting to make sense--on 62nd Avenue in Johnston.
“We grew about 100% between 2000 and 2010," says Johnston city administrator, Jim Sanders, "and so that road has seen a lot of traffic improvement.”
There are three major north/south corridors in Johnston, but the booming suburb has just two running east/west. Traffic on 62nd was already bad and more stop lights loomed. Someone suggested using roundabouts. City leaders winced.
“Very much," Sanders nods, "Americans typically don’t have much experience with roundabouts.”
“I was skeptical," says public works director, Dave Cubit, "I’d had a bad experience.”
It’s a normal reaction. Studies show most American shake their heads at them at first.
“Well, I think human nature is such that we all resist change a little bit," Cubit says, "and these are obviously much different than what people are used to traveling through in central Iowa.”
Traffic engineers will tell you there are several benefits, but one which really stands out.
“We keep the traffic moving for the entire day,” says Moly Long, whose firm, Foth Engineering, designed the Johnston roundabouts.
“You don’t have people stopping vehicles, idling here," Cubits adds, "that’s a cost savings to the motoring public for fuel economy and fuel usage, but also from their time perspective.”
Our time-lapse video seems to prove their point. The east-west traffic continues to flow. The occasional north-south car doesn’t stop it by triggering a red light, and by the way, traffic light structures cost about $250,000 apiece, so to improved safety and fuel economy, add cost savings to the list of roundabout benefits.
The trick to a roundabout is remembering the “Y” word.
“You yield to people in the roundabout," Sanders explains, "so once they get that down, it does keep things going…”
Approaching drivers yield to cars inside the circle. It takes a bit of getting used to, but there are four roundabouts between 86th and Merle Hay.
“So once they’ve been through the corridor a couple times, they’ve got it,” Long says.
And city leaders say those who’ve got them down like them a lot. There are more roundabouts being considered, some for much busier intersections, and it’s likely that other cities will follow Johnston’s lead in throwing our American prejudices for a loop.