The Age Of The Roundabout

Interlochen Public Radio | By Linda Stephan

Published February 16, 2011 at 12:00 AM EST

An image from a preliminary bayfront design for downtown Traverse City.

<a href="mailto:novshinsky@wdetfm.org">By Noah Ovshinsky, WDET</a> In the U.S., the traffic light has long been the preferred method for controlling the flow of cars and trucks. But that is changing. An increasing number of intersections are shedding this symbol of American mobility. Traverse City may one day have some major downtown intersections that look more circular than square and in other parts of the state, it seems the age of the "roundabout" is upon us. Confusing... At First First, a disclosure. I'm not so big on change. So when I drove through my first roundabout in Ann Arbor about a year ago, I was more than a bit confused. Sure I had seen them in Europe. But in Washtenaw County? Little did I know that this relatively new traffic control design is spreading faster than a rumor in high school. It also turns out I'm not alone in my confusion. "I think it improves flow," says Stacey Zaborny. I caught her at a strip mall right next to a busy roundabout at the corner. "It makes things run faster, however, I think people are little crazy in them and sometimes it can make it a little more difficult." Fellow shopper Anita Flanigan also thinks they're great, which this caveat: "A lot of people that don't live in this area don't understand them," she says. "They stop and they change lanes when they shouldn't and cause a lot of fender benders." Lester Burkow is also a fan. He points to the roundabout and says before it was built he had to wait for two or three lights to change before he could get through the intersection. Now Burkow says he wastes very little time. But he says that doesn't mean there isn't a downside for some drivers. "You have to merge with traffic and you have to just know how to do it," he says. "I've heard from elderly people that they don't know how to do it. It was a problem for them." Data Confirms These conflicting experiences are echoed in the considerable body of research that has been conducted on roundabouts. "It's essentially bi-polar. People are really strongly in favor or strongly against," says Assistant Professor Peter Savolainen with Wayne State University's Transportation Research Group. He, along with colleagues at the College of Engineering, have been studying roundabouts in the field and taking a hard look at the crash data. He says there seems to be a learning curve when it comes to roundabouts. "There's major issues with entering traffic," he says. "People, at least when they're first introduced, don't have a good recognition of who is supposed to yield and when. "We saw people stopping in the roundabout, which they should never do. And then, a lot of people just entering as they should for the circulating traffic...that kind of thing." In Michigan Savolainen says there seems to be one issue in particular that seems to vex drivers. "In the multi-lane roundabouts, drivers are supposed to select their lane before entering. But you see a lot of lane-change behaviors, and that, when you see a lot of those side-swipe collisions and such." Fewer Major Collisions The results vary on a case-by-case basis, but generally speaking, after an initial up-tick the number of accidents drops in the long term as drivers get better acquainted with a specific roundabout. Also on the positive side, Savolainen says these accidents rarely end in serious injury. He says that fact is partly responsible for the roundabouts' meteoritic rise in this country. Studies show that they virtually eliminate three of the most common factors behind serious crashes at intersections: red light running, excessive speed, and left-turn head-on collisions. Traditional intersections have 32 of what traffic engineers call "conflict points." Roundabouts only have eight. These are all the places that two automobiles can collide. Bad Reputation With all this upside, it's hard to imagine why this country was so slow in adopting roundabouts...especially when compared with Europe. France has 30,000. The U.S. has around 2,500. Craig Bryson, of the Oakland County Road Commission, says a previous incarnation gave the modern roundabout a bad name among the engineering community and the public at large. "For many years, especially out east, there was another circular form of intersection known as the traffic circle or rotary. There are a lot of them around the Boston area, for example, Washington D.C. "And though they are circular that is the only similarity to a roundabout," he says. "They are much larger, much faster, and much more dangerous, much less efficient. People have had negative perception of, or memories of, rotaries or traffic circles. And understandably so." Earliest Adapters Oakland County has 23 roundabouts, the highest concentration in the state. It was among the earliest adopters in Michigan. Bryson says the decision-making process has changed when the county looks at improving a specific intersection. "In the past that almost always would have been adding left turn lanes, right turn lanes, widening the signalized intersections," he says. "Today part of that process is to always determine whether or not a roundabout would help improve the intersection. And in many cases we find, by doing modeling and projections, that it would." Oakland County is so impressed with the roundabout, Bryson says the commission has a lot more on the drawing board. Move over France, here comes Michigan. Now all we need is a decent baguette.