Carmel's success with roundabouts on local roads could transform major state routes, starting with the expansion of U.S. 31 into a six-lane interstate-style highway.

Engineers on the U.S. 31 project have recommended the use of the European-bred traffic devices at two interchanges and are considering them on at least three more by 2018.

As many as 100,000 drivers daily use U.S. 31, the main north-south route from Indianapolis to South Bend. That total could rise to 120,000 or 140,000 by 2035, experts estimate.

The Indiana Department of Transportation will decide whether to use roundabouts on U.S. 31 this summer, after a public hearing Thursday. INDOT built its first traditional roundabout last year in Northwest Indiana, but the U.S. 31 project would be the state's first use of roundabouts at highway interchanges.

More roundabouts on state-controlled routes could soon follow.

"Roundabout interchanges have increasingly come into fashion," said Will Wingfield, a spokesman for the department.

Roundabouts have safety advantages, including as much as a 90 percent reduction in fatal crashes, notes the Insurance Institute for Highway Safety, a national group that has studied the safety of the traffic devices. Roundabouts also can save fuel by reducing idling at traffic lights.

At a roundabout interchange, cars exit a major roadway and enter a ramp to a roundabout instead of a traffic light or stop sign. The roundabout also carries traffic on the cross-street.

Carmel Mayor Jim Brainard led the city's charge to install 35 roundabouts, and 15 more are planned in the next two years.

The prevalence of roundabouts there and increasingly in other Hamilton County communities helped spur INDOT's designs for U.S. 31.

"You're supposed to look at how interchanges fit into the context of their surroundings," said Steve Fleming, the project's manager with RW Armstrong. "The surrounding communities have roundabouts in them. Signals don't seem to fit."

Carmel is building similar roundabouts on the stretch of Keystone Avenue within city limits. Carmel took control of the roadway from the state in October. Keystone parallels U.S. 31 through Carmel, then merges with it just north of the city. In 2004, Keystone was used by up to 47,000 drivers a day in its southern two blocks, INDOT reports.

Richard Retting, an engineer with the insurance institute, said he knows of no other U.S. city, including much larger ones, that has been as ambitious with building roundabouts as Carmel.

"If I were handing out an award, it would go to Carmel," Retting said. "Carmel is to America what France is to the world."

Carmel received such an award, the city announced Friday. Brainard took first-place honors in the second annual Mayors' Climate Protection Awards Program, sponsored by the U.S. Conference of Mayors and Wal-Mart Stores. In the small-cities category, Brainard was honored for making the case to install roundabouts by promoting their environmental friendliness, safety benefits, cost savings and ability to smooth traffic flow.

Safety and comfort concerns

In Carmel, city officials have calculated a 78 percent reduction in accidents with injuries at 24 intersections where roundabouts have been installed since 2001.

But roundabout advocates acknowledge there are downsides to using the traffic device for a highway interchange.

Roundabouts built on exit ramps of highways in other parts of the country have had to be modified because they couldn't accommodate heavy traffic volume and have led to a lot of fender benders.

"There's more going on (in roundabout interchanges) than with a low-volume residential street, where you can get away with any sort of circle and it will work," said Mark Johnson of Wisconsin-based MTJ Engineering, which has designed several U.S. roundabouts.

Also, many drivers on state highways may not be accustomed to roundabouts.

That's evident in Valparaiso, where the first INDOT roundabout opened in September on Ind. 130 at the intersections with LaPorte Avenue and North Sturdy Road.

Although city leaders say the device has reduced the number of accidents at the busy intersection, it remains unpopular among some drivers.

"I try to avoid it because I don't like driving it," said Liz Gerometta, 17, who occasionally visits Valparaiso University from her home in Chesterton, about 15 miles away. "It's hazardous. It's too crowded in that area."

More to come?

Still, roundabout interchanges are gaining traction not only in Indiana, but across the U.S.

A 2005 report by Lee Rodegerdts, an Oregon-based traffic engineer and an author of a 2000 Federal Highway Administration guide on roundabouts, expected the nation would soon have more than 1,000.

Although traffic circles have long existed on roadways, particularly on the East Coast -- Dupont Circle in Washington and Monument Circle in Indianapolis are not roundabouts -- the first modern roundabout was built outside Las Vegas in 1990, Retting said. From that point forward, they began cropping up on local roadways and highway projects, with some state agencies embracing them as the default design option.

About 100 U.S. interchanges have been built with roundabouts since 1990, and at least a dozen states have roundabout programs, Rodegerdts said.

"Over the decades, more and more people are sort of getting on board with them," Johnson said.

"Slowly, the resistance sort of fades."

What's going on in the metro area

The current suggestions on U.S. 31 call for a large roundabout shaped like a dog bone at 131st Street and a series of four smaller roundabouts at 136th Street. Engineers also are considering them at 106th, 116th and 161st streets.

On U.S. 31 and elsewhere, rising bills for asphalt and fuel are forcing INDOT to think of different ways to do things, Wingfield said. Roundabouts could save operating and maintenance costs on thousands of stoplights. INDOT pays about $270 a year to power the stoplight from I-465 East to U.S. 31 (Meridian Street).

Noblesville, Fishers and Westfield have started building roundabouts. Outside Hamilton County, Avon opened one in November and has three more under design. Greenfield put in a roundabout two years ago and created a long-term plan for about five more.

"As more roundabouts are built around the Indy metro (area), that makes it easier for us to consider it a solution for other state highways," INDOT's Wingfield said. "This may increasingly become a play in the playbook that we look to as we consider design options."

Additional Facts
POTENTIAL TIME SAVINGS
Based on engineers' estimates, taking stoplights off U.S. 31 as part of the project to reconfigure the highway could cut the average commute time from I-465 in Indianapolis to 216th Street north of Westfield by 10 minutes.

That's based on a southbound commute time of 25 minutes and a northbound commute time of 24 minutes.

With a 55 mph limit along the 13-mile stretch, the new commute time would be 14 minutes when the road is stoplight-free.

Source: Jennifer Dzwonar, spokeswoman on the U.S. 31 project in Hamilton County

MORE ONLINE
Learn more about the U.S. 31 reconfiguration at www.us31hamiltoncounty.in.gov.

WHAT DRIVERS THINK
We talked to residents in Carmel and Valparaiso, where a roundabout was installed on a state-controlled highway. Here are some of their thoughts:

"It does make the intersection go faster. However, I think people got their driver's license before manuals taught you the rules of a roundabout. It's a good idea, as along as it's in an area where people are used to slowing down and stopping."
-- Laura Czerwionka, Carmel

"I take the roads with them if I know where they are. I will seek them out to get to and from Castleton."
-- Mike Levine, Carmel

"I think it's working just fine, if you drive through with caution."
-- Ruth Weeden, Valparaiso, on that city's roundabout on Ind. 130

"I think they're terrible. The first time I got in it, I kept going around in a circle. I couldn't figure out how to get off of it."
-- Mary Grace, Winamac, who drives to Valparaiso once a week for shopping

--- Francesca Jarosz

THE GOOD AND THE BAD

Pros
» Improves traffic safety: Fatal crashes have been reduced up to 90 percent, according to data from the Insurance Institute for Highway Safety.

» Helps the environment: Eliminates idling at stoplights, decreasing fuel emissions and saving gas.

Cons
» Driver confusion: For those who haven't driven on roundabouts, they can be confusing.

» Design complexity: They're harder to design than stoplight interchanges, leaving room for design flaws that could increase the number of fender benders.

Neutrals
» Cost: In some cases, they cost more; in others, less. It depends on the location and the amount and cost of land needed.

» Land use: As a general rule, they require more land at an interchange but less along a mainline road. The impact depends on the location of homes, businesses and other establishments in the area.

--- Francesca Jarosz

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