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Traffic engineers tout roundabouts for safety

WASHINGTON—To reduce traffic congestion and get vehicles through intersections faster and more safely, some traffic engineers are very excited about an old idea.

Take out the traffic lights, they suggest. Instead, move vehicles around a central circular island continuously at low speeds. Require drivers who are entering the circle to yield to those who already are in it.

They're called roundabouts these days, a Britishism that's meant to distinguish the updated concept from the primitive traffic circles or rotaries that your grandfather swore his way around. From Scandinavia to Sydney, Australia, the improved versions work like a charm, proponents say, and they could in the United States, too.

Like spinach and recent Democratic presidential candidates, however, roundabouts are easier to endorse than to like. So far, U.S. highway departments have built only about 500 new-style roundabouts, although advocates say that at least 26,000 major U.S. intersections would benefit from them.

Although they've been hooted down in some cities, roundabout backers remain unbowed, some noting that Americans for years disdained another European standby _bottled water.

A recent institute study by the Insurance Institute for Highway Safety, a research group for insurers, found that crashes typically drop by 40 percent or more when roundabouts replace traditional right-angle intersections governed by traffic lights.

The number of crash injuries at roundabouts drops even more dramatically because roundabouts eliminate right-angle collisions, which are the most dangerous after head-on collisions. In France, new roundabouts reduced crash injuries at intersections by 78 percent, according to a 2002 study. In Austria, they dropped 87 percent.

"There's nothing that we can do in traffic engineering that's anywhere near as significant as this," said Richard Retting, senior transportation engineer at the highway safety group, based in Arlington, Va.

Fuel consumption and air pollution also drop sharply, according to Retting, thanks to reductions in traffic delays of 40 percent or more when roundabouts replace conventional intersections. In a recent analysis of 10 busy signal-controlled intersections in nearby Washington suburbs, Retting projected that roundabouts would save 300,000 hours and 200,000 gallons of fuel a year.

"If I had to commit the remainder of my career to one safety factor, it would be this," said Retting, 45, a leader of the national roundabout campaign.

It could take that long. Transportation officials in some states, including California, New York, Florida and North Carolina, are buying into the new roundabout solution. New Jersey, South Carolina, Michigan, Minnesota, Ohio and Missouri are considering roundabouts as intersection options, while officials in many other states, including Texas, Georgia and Kentucky, are unimpressed or unfamiliar with them.

"Some part of our profession," said Phil Caruso, the deputy executive director of the Institute of Transportation Engineers in Washington, "lacks enough experience with roundabouts to get beyond the `Well, it's different and I don't like it' argument."

That's true in Texas, where a recent study of ways to reduce urban congestion didn't even consider roundabouts. "The reason they weren't on the list was because we don't have many of them," said Tim Lomas of the Texas Transportation Institute at Texas A&M University in College Station.

Except for being circular, modern roundabouts are unlike the traffic circles that first appeared in France in 1903. Drivers barreled into these multi-lane circles at full speed, as they still do into many of their American counterparts, dueled for the right of way, merged at high speeds then shot out at their chosen exits, if their timing was good.

Such traffic circles, the only kind that many Americans have known, are "confusing, inefficient and/or dangerous," said Eugene Russell, a transportation engineering professor at Kansas State University in Manhattan.

The modern roundabout dates from the 1960s, when the British adopted a "yield at entry" strategy. It gives the right of way to drivers who already are in the roundabout. It also employs narrow, curved lanes to slow entering traffic. The circle itself has a design speed of 20 mph or less, which is achieved mainly by shrinking the center island compared with the traditional traffic circle and reducing the number of lanes around it.

Slowing traffic increases a roundabout's capacity because it's easier for drivers who are entering to find slots for their vehicles in a lane of traffic that's moving slowly. "It's counterintuitive, but it's true," Retting said, and Caruso agreed.

The big problem with selling roundabouts is that they're counterintuitive.

Take safety. "Intuitively, the layperson thinks traffic lights are safe," said Per Garder, a traffic-engineering professor at the University of Maine in Orono. Drivers who run lights, fail to yield or rear-end other vehicles at lights may cause frequent accidents, Garder said, but collisions are still rare in the experience of individual drivers.

"A roundabout seems more dangerous," Garder continued, "because instead of being governed by a traffic light, you yourself are responsible for getting around it. You can't be drinking coffee while you're driving around the circle; it requires too much attention. And that's one reason roundabouts are safer: They absorb more driver attention."

Another key to modern roundabouts is drivers' willingness to yield the right of way. Garder, who grew up in Sweden and has studied roundabouts' acceptance in Europe, found that it varies by nationality. British drivers don't mind deferring, Garder concluded, because they value politeness. Germans, on the other hand, hate roundabouts because Germans are taught that priority must go to the driver on the right. Roundabouts seize up if you drive by that rule.

American drivers are sometimes polite, sometimes not, in Garder's view. But when it comes to traffic intersections, "Americans are the most conservative people in the world: They like it the way it's always been," he said. "And since Americans didn't invent roundabouts, they're reluctant to accept them."

Tell that to Russell, the transportation engineer, who chronicled the resistance to roundabouts in Manhattan, Kan., nicknamed the Little Apple.

When the city proposed a roundabout west of town in 2000, skeptics said it would back up Kansas State University football stadium traffic for 20 miles and cost the Wildcats much of their fan base. They said that freshmen, their parents and west Kansas farmers who'd never navigated roundabouts would crash in great numbers.

According to Edward Seaton, the editor and publisher of the daily Manhattan Mercury newspaper, the roundabout has eased congestion rather than added to it. As for a surge in crashes, Manhattan's had them every fall for years even before the roundabout, said Seaton, especially among new-to-town motorists from rural western Kansas.

"They catch on eventually," he said.


For more on roundabouts, go to the Insurance Institute for Highway Safety Web site, at, place your pointer on "Research and Statistics" and click on "Topical Index" and then on "Roundabouts."


Roundabouts can be hard for drivers to love. Here are some tips for getting around them:

_ Try not to stop.

_ Remember that traffic in the roundabout has the right of way.

_ Yield when a driver in front of you wants to move right to prepare to exit.

_ In a multiple-lane roundabout, get into the left lane and travel the inside of the circle until you see your exit. Then merge to the outside and slingshot out.

_ If you miss your exit, go around again.


(c) 2005, Knight Ridder/Tribune Information Services.

GRAPHIC (from KRT Graphics, 202-383-6064): 20051207 ROUNDABOUTS

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