Sunday, July 21, 2024

A roundabout might be coming to a CT intersection near you

The intersection of Routes 82 and 85 in Salem, sometimes called the Four Corners, used to have a lot of crashes, many of them serious.

Now it doesn’t.

The reason for the welcome decline is deceptively simple: the state changed the geometry of the crossroads. In 2012, the Connecticut Department of Transportation installed a modern roundabout in the center of the intersection.

The numbers make the point: From 2003 through 2008, the junction saw an average of 22 crashes, nine of them injury-related, each year. However, from 2018 to 2022, the average was down to 10 crashes, one injury-related, each year — a 55% decline in crashes and a 90% drop in injury-related crashes.

“I think it has saved lives,” said Salem First Selectman Ed Chmielewski.

A retired New London police sergeant, Chmielewski said that before the roundabout was built, the intersection was “deadly, with numerous accidents.” Now, he said, “we get some fender-benders, but we’re not seeing serious injures and fatalities. Life Star isn’t landing to take people away.”

The data from Salem is reflected around the state and the country. According to the Federal Highway Administration, roundabouts have 78% fewer injury and fatal crashes than signal-controlled intersections and 82% fewer than two-way stop (sign) controlled intersections.

The need for safer roads is clear; 2022 was the deadliest on record for fatal car crashes in Connecticut, taking an estimated 368 lives.

The message is not lost. The state Department of Transportation and a good number of towns are moving briskly to build more roundabouts, among other safety measures, so there could be one coming to an intersection near you.

Yield on entry

Though they may appear similar, modern roundabouts are decidedly not the same as traditional rotaries, or traffic circles. The latter have dotted the country’s roadscape since at least 1905, when Manhattan’s Columbus Circle opened. The older circles or rotaries are typically larger than modern roundabouts, so drivers don’t necessarily have to slow down to enter them, especially since cars in the circle were supposed to yield to cars entering the circle. Well, some do and some don’t, often causing delays, confusion and crashes.

Hartford’s Pulaski Circle is a prominent example. The circle is at the end of the Whitehead Highway connector to I-91 and brings cars from the interstate to the Capitol area. There is room for two lanes, but they aren’t marked, creating something of a free-for-all at busy times.

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According to a traffic analysis conducted as a part of the Greater Hartford Mobility Study, there were 109 crashes at Pulaski Circle from 2018 to 2022.

A view up Elm St. from Pulaski Circle to the Connecticut State Capitol from 525 Main St. on Tuesday, March 7, 2023. (Aaron Flaum/Hartford Courant)
A view up Elm St. from Pulaski Circle to the Connecticut State Capitol from 525 Main St. File. (Aaron Flaum/Hartford Courant)

CDOT has eliminated some older traffic circles and turned a couple into modern roundabouts. That could well happen to Pulaski Circle. The department is in the “early concept design phase” of a redo of the intersection, said a CTDOT spokesperson.

The modern roundabout, invented in Britain in the 1960s, is a radical rethinking of the traffic circle. In the old rotary model, cars already in the circle were supposed to yield to cars entering the circle. But Old Blighty flipped the switch and required cars entering the roundabout to yield to those already in the circle, a concept known as “yield on entry.”

Roundabouts have raised center islands and raised medians or “splitter islands” in each leg of the intersection, which channels incoming cars off to the right in a counterclockwise direction around the circle, from which they can exit with a right turn onto an outgoing split lane. So, all traffic is going in the same direction, virtually eliminating head-on or right-angle collisions. About a quarter of fatal crashes, and half of injury-related crashes, happen in or around traditional intersections, according to the Federal Highway Administration.

Vehicles approaching the roundabout have to slow down, to find an opening to merge into the circle and then to follow the tight turning radius. Slowing is good; speed is a factor in most crashes and in about a third of fatal crashes. “Drivers Can’t Run Roundabouts” read a bumper sticker created some years ago to support a roundabout in eastern Connecticut.

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Roundabouts can be built with multiple lanes, but virtually all in Connecticut are single-lane, considered the safest model. There are also mini or compact roundabouts, sometimes used at tight urban intersections.

“Our goal is speeds of 15 to 25 mph in roundabouts,” said Scott Bushee, principal engineer in the DOT’s highway design division and designer of several of the state’s roundabouts.

The slower speeds and split lanes make life easier for pedestrians and bicyclists. Pedestrians don’t cross the roundabout, crosswalks are typically two car lengths away on the split lanes. Since traffic in the splits is going one way, and hopefully slowly, the pedestrian only has to look in one direction.

“A pedestrian who is hit by a car going 20 mph has a nine in 10 chance of survival. If hit by a car going 40 mph, the chance of survival is one in 10,” said Bushee. He said the slowed speeds also make it easier for a cyclist to ride through the roundabout.

But do note: Fewer crashes doesn’t mean no crashes. Drivers make mistakes. The most common cause of roundabout crashes, according to a guide published by the FHWA, is failure to yield on entering the roundabout, followed by driving off the circulatory roadway. But the crashes that do happen are overwhelmingly those that send business to the body shop rather than the emergency room.

Go with the flow

Another major benefit of roundabouts is that they keep traffic moving. When a somewhat chaotic five-leg interchange in Ellington was replaced with a roundabout, the average delay went from four minutes to none, Bushee reported.

Good traffic flow means less lost time, less fuel burned and less air pollution. The transportation sector generates 28% of greenhouse gas emissions, per the U.S. Department of Environmental Protection, which is more than electricity production, industry or any other economic sector.

Despite what the name might suggest, roundabouts don’t necessarily describe a perfect circle. They can be elliptical or even peanut-shaped, depending on the lay of the land, traffic patterns and other factors. New Haven opened a peanut-shaped roundabout earlier this year at the previously crash-prone intersection of Chapel Street and Yale Avenue in the city’s Westville neighborhood. Early reports are positive.

But not every intersection needs a roundabout.

“Often, a roundabout will significantly reduce the potential for a severe crash … but some sites may have not have had a severe crash problem to start with,” Bushee said in an email.

“It’s important to understand the problems we are trying to solve, to ensure the outcome will be successful and to be sure the roundabout is the right choice for that location. Not every location would gain the same measurable success in traffic operations and safety by installing a roundabout.”

Roundabouts can be more aesthetically pleasing, and less expensive to build and operate, than signalized intersections. And there is one more benefit few saw coming — they appear to help adjacent businesses. But some business owners had to see it to believe it.

Slow but steady

After the British created the modern roundabout, the new design spread to other drive-on-the-left countries such as Australia. Someone figured out that the inverse would work as well, and drive-on-the-right countries began adopting the yield-on-entry circular intersection, as travelers to France and other countries since the mid-1980s are doubtless aware.

The new design was slower to arrive in this country; the first modern roundabout was built in Summerlin, Nev., in 1990. Since that first one, the number has increased to about 9,000, according to data reported by the Washington Post. Florida has the most, with 749; Nebraska has the most per population, 166; and Maryland has the most per mile of road, 314.

South Dakota and Wyoming have 13 and 18, respectively. Connecticut, counting roundabouts build or assisted by CTDOT, has 17 completed, two under construction and seven in the design phase, according to a department spokesperson.

In 2013, the department won a national award for the conversion of a rotary in Killingworth to a modern roundabout, resulting in a 50% reduction in the number of crashes and a 86% reduction in injuries at the site.

Roundabouts are built by city as well as state governments. On the municipal level, no one can hold a headlight to Carmel, Ind. The well-heeled Indianapolis suburb has 142 roundabouts, at last count, and bills itself at the “City of Roundabouts” or “Roundabout Capital of America.”

Though they won’t compete for the national title anytime soon, Connecticut towns that have built roundabouts on town roads appear happy with them. For example, Glastonbury put two on two different sections on Hebron Avenue, one primarily to reduce crashes and the other, in the center of town, to improve traffic flow. “We think we succeeded in both cases,” said town engineer Dan Pennington. A third roundabout is in the works.

Roundabout revolution

The roundabout revolution in Connecticut, on state roads at least, can be dated to 2004, when CTDOT senior engineer William Britnell, having studied European models, urged the department to explore modern roundabouts. The department put it in gear.

Their first one, designed by Bushee, was built in West Haven in 2008. But Connecticut, being inclined to welcome change with closed arms, was not without local opposition. Opponents claimed the roundabout was confusing, unnecessary, difficult for buses and large trucks and would hurt businesses. It took several lengthy public meetings for the DOT to convince enough residents and town officials that this was a good thing.

But they did, and it was built, and, said Bushee, it was successful.

This was the pattern for the first few roundabouts: initial skepticism, if not outright opposition, then construction, then, as people got used to the roundabout, acceptance, even suggestions for more roundabouts.

“The tide has turned,” Bushee said. “People are recognizing the value (of roundabouts). They are getting good public acceptance.”

“The complaints have really died down; the feedback now is largely positive,” said Granby development director Abby Kenyon about the (tastefully landscaped) roundabout in her town on Route 202 and Notch Road that was completed in 2020.

Interestingly, a couple of coffee shops and other small businesses have opened near some roundabouts, suggesting they may actually enhance commerce — perhaps because traffic is slower and drivers can see the business and safely pull off.

Bushee said a business owner in West Haven who had initially opposed the roundabout came up to him later and said, “I just want to tell you I was wrong.”

More coming

Drivers would be well-advised to get used to roundabouts, because more are coming. CTDOT has a multidisciplinary roundabout committee that helps plan, design and build roundabouts on state roads and assists towns as well.

The department, along with other state DOTs and their federal counterpart, celebrate National Roundabout Week each year (it was Sept. 18-22, in case you missed it) to promote the concept.

More immediately, the Capitol Region Council of Governments, of CRCOG, is nearing completion of am extensive two-year “screening study” that will produce a list of existing intersections in the 38-town region “that are most likely to benefit from conversion to a single-lane modern roundabout.”

The study’s authors began by examining more than 8,000 intersections in the region, then they ranked the top 300, and then winnowed the list down to 100, based on number of crashes, available space, utilities, traffic volume, driveways and other factors, said Roger Krahn, CRCOG’s principal transportation engineer.

Perhaps not surprisingly, the municipalities with the most intersections tended to have the most potential roundabout locations: Hartford had 48, New Britain 10 and West Hartford 7, with others scattered in smaller towns.

The study team went back to the list of 300, so each town would have at least three potential targets for roundabout conversion. Krahn said the study can be a tool for towns to both identify potential sites for roundabouts and seek state and federal funding for their construction.

The roundabout revolution didn’t materialize out of thin air. Britnell and others brought the idea forward and made a case for it. One of the earliest and most persistent advocates for roundabouts in the state, going back at least to the 1980s, was Hartford planner Toni Gold. Asked about the new surge of roundabouts, she replied by email:

“Success! Hooray!”

Tom Condon writes about urban and regional issues for CT Mirror, including planning, transportation, land use, development and historic preservation. 


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